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Ji Y, Luo W, Shi Q, Ma X, Wu Z, Zhang W, Gao Y, An T. Mechanisms of isomerization and hydration reactions of typical β-diketone at the air-droplet interface. J Environ Sci (China) 2024; 141:225-234. [PMID: 38408823 DOI: 10.1016/j.jes.2023.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 04/13/2023] [Accepted: 04/13/2023] [Indexed: 02/28/2024]
Abstract
Acetylacetone (AcAc) is a typical class of β-diketones with broad industrial applications due to the property of the keto-enol isomers, but its isomerization and chemical reactions at the air-droplet interface are still unclear. Hence, using combined molecular dynamics and quantum chemistry methods, the heterogeneous chemistry of AcAc at the air-droplet interface was investigated, including the attraction of AcAc isomers by the droplets, the distribution of isomers at the air-droplet interface, and the hydration reactions of isomers at the air-droplet interface. The results reveal that the preferential orientation of two AcAc isomers (keto- and enol-AcAc) to accumulate and accommodate at the acidic air-droplet interface. The isomerization of two AcAc isomers at the acidic air-droplet interface is more favorable than that at the neutral air-droplet interface because the "water bridge" structure is destroyed by H3O+, especially for the isomerization from keto-AcAc to enol-AcAc. At the acidic air-droplet interface, the carbonyl or hydroxyl O-atoms of two AcAc isomers display an energetical preference to hydration. Keto-diol is the dominant products to accumulate at the air-droplet interface, and excessive keto-diol can enter the droplet interior to engage in the oligomerization. The photooxidation reaction of AcAc will increase the acidity of the air-droplet interface, which indirectly facilitate the uptake and formation of more keto-diol. Our results provide an insight into the heterogeneous chemistry of β-diketones and their influence on the environment.
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Affiliation(s)
- Yuemeng Ji
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| | - Weiyong Luo
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Qiuju Shi
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xiaohui Ma
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Ziqi Wu
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Weina Zhang
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Yanpeng Gao
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Taicheng An
- Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Institute Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
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Futamata S, Onishi Y, Adachi S, Khuwijitjaru P, Watanabe Y, Tani F, Kobayashi T. Efficient synthesis of rare sugars from galactose in hot compressed water using eggshells as an environmentally friendly catalyst. Bioresour Technol 2024; 399:130642. [PMID: 38561154 DOI: 10.1016/j.biortech.2024.130642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 04/04/2024]
Abstract
Aqueous galactose solutions containing eggshell was heated at 120 °C to produce calcium supplements containing rare sugars. Galactose was isomerized to rare sugars with improving rare sugar yields compared to those without eggshell. Organic acids were also formed as byproducts during the reaction. These acids were neutralized by dissolving eggshells with increasing the calcium ion concentration in the solution. When eggshell components (calcium carbonate, magnesium carbonate, or calcium phosphate) were used for the treatment, rare sugars were also formed. Especially, addition of magnesium carbonate improved rare sugar yield, but byproduct formation became more pronounced. Eggshells used in the treatment were used for repeated treatments. When eggshells were used three times, rare sugar yield changed only slightly but the selectivity of rare sugars improved significantly. By these processes, we obtained an aqueous solution of rare sugars containing calcium ion at 295 mg/L, which has potential as ingredients for dietary supplements.
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Affiliation(s)
- Shin Futamata
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Yuichiro Onishi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Shuji Adachi
- Department of Agriculture and Food Technology, Faculty of Bioenvironmental Sciences, Kyoto University of Advanced Science, Kameoka, Kyoto 621-8555, Japan
| | - Pramote Khuwijitjaru
- Department of Food Technology, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, Thailand
| | - Yoshiyuki Watanabe
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Fumito Tani
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takashi Kobayashi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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Gupta S, Schöneich C, Rathore AS. Assessment of change in the basic variants composition of trastuzumab during dilution in saline for administration. Eur J Pharm Biopharm 2024:114295. [PMID: 38636881 DOI: 10.1016/j.ejpb.2024.114295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 04/01/2024] [Accepted: 04/15/2024] [Indexed: 04/20/2024]
Abstract
Postproduction handling of drug products during preparation or clinical use may affect the structure and efficacy of the drug and perhaps remain unnoticed. Since chemical modifications can impact the product's structure, stability, and biological activity, this study investigates the impact of elevated temperature and subtle shift in pH on the drug product post-dilution in saline. The mAb sample diluted in saline for administration was stressed at elevated temperature and slightly acidic pH condition. Extended stability studies were performed and monitored for size and charge heterogeneity. Size heterogeneity shows no significant changes, whereas charge heterogeneity shows an increase in basic variants and a reduction in main species. Further, basic variants were isolated and characterized to identify the type and site of chemical modification. Intact mass analysis and peptide mapping identify that the basic variants were attributed majorly to the isomerization of HC Asp102 into iso-Asp or its succinimide intermediate. Four basic variants were found to exhibit similar structural properties as the main and control samples. However, basic variants showed reduced binding affinity to HER2 receptor, while there was no significant difference in FcRn binding. The results indicate that modification in the HC Asp102, which is present in the CDR, affects antigen binding and thus can influence the potency of the drug product. Hence, with the conventional stability studies required to license the drug product, including in-use or extended stability studies to mimic the postproduction handling would be desirable.
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Affiliation(s)
- Surbhi Gupta
- Department of Chemical Engineering, Indian Institute of Technology Delhi,New Delhi 110016, India
| | | | - Anurag S Rathore
- Department of Chemical Engineering, Indian Institute of Technology Delhi,New Delhi 110016, India.
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Xu H, Chakraborty R, Adak AK, Das A, Yang B, Meier D, Riss A, Reichert J, Narasimhan S, Barth JV, Papageorgiou AC. On-Surface Isomerization of Indigo within 1D Coordination Polymers. Angew Chem Int Ed Engl 2024; 63:e202319162. [PMID: 38235942 DOI: 10.1002/anie.202319162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/10/2024] [Accepted: 01/17/2024] [Indexed: 01/19/2024]
Abstract
Natural products are attractive components to tailor environmentally friendly advanced new materials. We present surface-confined metallosupramolecular engineering of coordination polymers using natural dyes as molecular building blocks: indigo and the related Tyrian purple. Both building blocks yield identical, well-defined coordination polymers composed of (1 dehydroindigo : 1 Fe) repeat units on two different silver single crystal surfaces. These polymers are characterized atomically by submolecular resolution scanning tunnelling microscopy, bond-resolving atomic force microscopy and X-ray photoelectron spectroscopy. On Ag(100) and on Ag(111), the trans configuration of dehydroindigo results in N,O-chelation in the polymer chains. On the more inert Ag(111) surface, the molecules additionally undergo thermally induced isomerization from the trans to the cis configuration and afford N,N- plus O,O-chelation. Density functional theory calculations confirm that the coordination polymers of the cis-isomers on Ag(111) and of the trans-isomers on Ag(100) are energetically favoured. Our results demonstrate post-synthetic linker isomerization in interfacial metal-organic nanosystems.
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Affiliation(s)
- Hongxiang Xu
- Technical University of Munich, TUM School of Natural Sciences, Physics Department E20, James Franck Strasse 1, 85748, Garching, Germany
| | - Ritam Chakraborty
- Theoretical Sciences Unit & School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur, Bangalore, 560054, India
| | - Abhishek Kumar Adak
- Theoretical Sciences Unit & School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur, Bangalore, 560054, India
- Current address: The Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, 34151, Trieste, Italy
| | - Arpan Das
- Theoretical Sciences Unit & School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur, Bangalore, 560054, India
| | - Biao Yang
- Technical University of Munich, TUM School of Natural Sciences, Physics Department E20, James Franck Strasse 1, 85748, Garching, Germany
- Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou, 215123, P. R. China
| | - Dennis Meier
- Technical University of Munich, TUM School of Natural Sciences, Physics Department E20, James Franck Strasse 1, 85748, Garching, Germany
| | - Alexander Riss
- Technical University of Munich, TUM School of Natural Sciences, Physics Department E20, James Franck Strasse 1, 85748, Garching, Germany
| | - Joachim Reichert
- Technical University of Munich, TUM School of Natural Sciences, Physics Department E20, James Franck Strasse 1, 85748, Garching, Germany
| | - Shobhana Narasimhan
- Theoretical Sciences Unit & School of Advanced Materials, Jawaharlal Nehru Centre for Advanced Scientific Research Jakkur, Bangalore, 560054, India
| | - Johannes V Barth
- Technical University of Munich, TUM School of Natural Sciences, Physics Department E20, James Franck Strasse 1, 85748, Garching, Germany
| | - Anthoula C Papageorgiou
- Technical University of Munich, TUM School of Natural Sciences, Physics Department E20, James Franck Strasse 1, 85748, Garching, Germany
- Laboratory of Physical Chemistry, Department of Chemistry, National and Kapodistrian University of Athens Panepistimiopolis, 15771, Athens, Greece
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Onishi Y, Adachi S, Tani F, Kobayashi T. Effect of phosphate buffer concentration on the isomerization of galactose to rare sugars under subcritical water conditions. Food Chem 2024; 434:137432. [PMID: 37713753 DOI: 10.1016/j.foodchem.2023.137432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/21/2023] [Accepted: 09/07/2023] [Indexed: 09/17/2023]
Abstract
Galactose was treated in sodium phosphate buffer at various concentrations (0.1-500 mmol/L) under subcritical water conditions (140 °C), and the effects of the buffer concentration and reaction time (0-300 s) on the reaction behavior were evaluated. The reaction proceeded rapidly at higher buffer concentrations. Rare sugars (tagatose, talose, and sorbose) were formed from galactose by isomerization. The highest yield of the main product, tagatose, was approximately 14 % in 50 mmol/L buffer. However, the tagatose yield did not increase further with increasing buffer concentration. On the other hand, the formation of talose and sorbose was accelerated at higher buffer concentrations, with the highest yields of approximately 5 % and 12 %, respectively, in 500 mmol/L buffer. At the same time, the formation of byproducts (organic acids and colored substances) was also accelerated in high-concentration buffers. These results suggest that phosphate buffer promoted all reactions occurring under subcritical water conditions.
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Affiliation(s)
- Yuichiro Onishi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Shuji Adachi
- Department of Agriculture and Food Technology, Faculty of Bioenvironmental Sciences, Kyoto University of Advanced Science, Kameoka, Kyoto 621-8555, Japan
| | - Fumito Tani
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takashi Kobayashi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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Fujimoto K, Izawa S, Yamada K, Yagi S, Inuzuka T, Sanada K, Sakamoto M, Hiramoto M, Takahashi M. Wavily Curved Perylene Diimides: Synthesis, Characterization, and Photovoltaic Properties. Chempluschem 2024:e202300748. [PMID: 38329154 DOI: 10.1002/cplu.202300748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/31/2024] [Accepted: 02/08/2024] [Indexed: 02/09/2024]
Abstract
Solubility enhancement is a key issue for developing the perylene diimide-based functional materials. Introduction of curved structure proved an effective solubilizing method without employing steric repulsion. In this work, wavily curved perylene diimides were developed as a new family of highly soluble curved perylene diimides. Moreover, their conformational dynamics, aggregating properties, electronic properties, and photovoltaic performances were thoroughly examined in comparison to the previously reported isomer exhibiting an arched curvature. The waved isomer demonstrated heightened rigidity and a greater propensity for aggregation compared to the arched isomer, likely attributed to its more planar structure. Each benzoxepin unit played a role in cancelling out the curvature on the opposite side. While the difference in the molecular curvature did not cause significant alterations in the photophysical and electron-accepting properties, we identified that the modulation of the curved structure is effective in controlling the morphology of the photoelectric conversion layer.
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Affiliation(s)
- Keisuke Fujimoto
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan
| | - Seiichiro Izawa
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan
- Joining and Welding Research Institute, Osaka University, 11-1, Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Kazuki Yamada
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan
| | - Sota Yagi
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan
| | - Toshiyasu Inuzuka
- Division of Instrumental Analysis, Life Science Research Center, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Kazutaka Sanada
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Masami Sakamoto
- Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522, Japan
| | - Masahiro Hiramoto
- Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
| | - Masaki Takahashi
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, 432-8561, Japan
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Xu R, Wang Z, Yang Y, Gu C, Luan C, Wang S, Chen X, Yu K. Formation and Transformation of CdS Clusters during the Prenucleation Stage and in a Dilute Dispersion at Room Temperature. Nano Lett 2024; 24:1294-1302. [PMID: 38230964 DOI: 10.1021/acs.nanolett.3c04287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
The formation and transformation of colloidal semiconductor clusters remain poorly understood. With CdS as a model system, we show that, in the reaction of cadmium myristate (Cd(MA)2) and S powder in 1-octadecene (ODE), clusters form in the prenucleation stage of quantum dots (QDs). Called precursor compounds (PCs), the clusters can transform to magic-size clusters (MSCs) in reaction at a relatively high temperature (MSC-322 displaying optical absorption peaking at 322 nm) or in a dispersion at room temperature (MSC-360). When the reaction temperature is increased, PC-360 forms at 140 °C, while PC-322 and MSC-322 form at 180 °C. In a dispersion of cyclohexane and octylamine, MSC-322 transforms to MSC-360 via MSC-345. The MSC-345 to MSC-360 transformation displays continuous and discontinuous shifts in the optical absorption. The PCs and MSCs are a group of isomers. The present findings bring insight into the cluster formation and isomerization in the prenucleation stage of QDs and in a dispersion.
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Affiliation(s)
- Rongkuan Xu
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Zhe Wang
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Yusha Yang
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Cheng Gu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Chaoran Luan
- College of Biomedical Engineering, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Shanling Wang
- Analytical & Testing Center, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Xiaoqin Chen
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
| | - Kui Yu
- Engineering Research Center in Biomaterials, Sichuan University, Chengdu, Sichuan 610065, P. R. China
- Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, Sichuan 610065, P. R. China
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Vennard T, Meredith NA, Maria SD, Brink L, Shah N, Morrow AL, Simmons R, Gray MA, Phillips SC. A novel LC-MS/MS method to characterize the antimicrobial lipid glycerol monolaurate in global human milk. J Pharm Biomed Anal 2024; 238:115817. [PMID: 37939550 DOI: 10.1016/j.jpba.2023.115817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/16/2023] [Accepted: 10/25/2023] [Indexed: 11/10/2023]
Abstract
Glycerol monolaurate (GML), a monoglyceride found in human milk (HM), has antimicrobial properties against a broad spectrum of bacteria, viruses, and fungi. In this study, an LC-MS/MS method was developed and validated for quantifying GML in HM based on quantification of two distinct isomers, 1-monolaurin and 2-monolaurin. The method validation included assessments of selectivity (no interferences), linearity (r2 range of 0.9954- 0.9985 and 96 of 98 individual points having residual <15%), accuracy (average recovery of 96.4% across both isomers and a range of spiked levels), and precision (total GML repeatability 6.6% RSD and intermediate precision 9.7% RSD). This validated method was used to measure the concentration of GML in unpasteurized HM from 60 mothers and compared geographical locations (Cincinnati and Shanghai), lactation time (weeks 2 and 26), and self-reported maternal allergy status (yes or no). Our findings suggest GML concentration in unpasteurized HM is considerably lower than previously reported in a study characterizing pasteurized HM. The data reported here highlights a novel, validated method used to quantify GML in HM and identified no differences in total GML concentrations when comparing HM from different geographical locations, lactation times, and mother's allergy status.
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Affiliation(s)
- Thomas Vennard
- Reckitt/Mead Johnson Nutrition Institute, 2400 West Lloyd Expressway, Evansville, IN 47721, USA.
| | - Nathan A Meredith
- Reckitt/Mead Johnson Nutrition Institute, 2400 West Lloyd Expressway, Evansville, IN 47721, USA
| | - Sarah D Maria
- Reckitt/Mead Johnson Nutrition Institute, 2400 West Lloyd Expressway, Evansville, IN 47721, USA
| | - Lauren Brink
- Reckitt, 399 Interpace Parkway, Parsippany, NJ 07054-0225, USA
| | - Neil Shah
- Reckitt, Turner House, 103-105 Bath Road, Slough, Berkshire SL1 3UH, UK
| | - Ardythe L Morrow
- University of Cincinnati Medical Center, College of Medicine, Cincinnati, OH 45229, USA
| | - Ruth Simmons
- Reckitt, Turner House, 103-105 Bath Road, Slough, Berkshire SL1 3UH, UK
| | - Michael A Gray
- Reckitt/Mead Johnson Nutrition Institute, 2400 West Lloyd Expressway, Evansville, IN 47721, USA
| | - Shay C Phillips
- Reckitt/Mead Johnson Nutrition Institute, 2400 West Lloyd Expressway, Evansville, IN 47721, USA
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9
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Kuroda K, Ouchi M. Umpolung Isomerization in Radical Copolymerization of Benzyl Vinyl Ether with Pentafluorophenylacrylate Leading to Degradable AAB Periodic Copolymers. Angew Chem Int Ed Engl 2024; 63:e202316875. [PMID: 37971837 DOI: 10.1002/anie.202316875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 11/16/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023]
Abstract
This study revealed that benzyl vinyl ether (BnVE) shows a peculiar isomerization propagation in its radical copolymerization with an electron-deficient acrylate carrying a pentafluorophenyl group (PFA). The co-monomer pair inherently exhibits the cross-over propagation feature due to the large difference in the electron density. However, the radical species of PFA was found to undergo a backward isomerization to the penultimate BnVE pendant giving a benzyl radical species prior to propagation with BnVE. The isomerization brings a drastic change in the character of the growing radical species from electrophilic to nucleophilic, and thus the isomerized benzyl radial species propagates with PFA. Consequently, the two monomers were consumed in the order AAB (A: PFA; B: BnVE) and the unique periodic consumption was confirmed by the pseudo-reactivity ratios calculated by the penultimate model: r11 =0.174 and r21 =6600 for PFA (M1 ) with BnVE (M2 ). The pentafluorophenyl ester groups of the resulting copolymers are transformed into ester and amide groups by post-polymerization alcoholysis and aminolysis modifications. The unique isomerization in the AAB sequence allowed the periodic introduction of a benzyl ether structure in the backbone leading to efficient degradation under acid conditions.
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Affiliation(s)
- Keita Kuroda
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Makoto Ouchi
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
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10
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Hashimoto K, Niina T, Kobayashi T, Adachi S, Watanabe Y. Isomerization and epimerization of fructose in phosphate buffer under subcritical water conditions. Carbohydr Res 2024; 535:109003. [PMID: 38056027 DOI: 10.1016/j.carres.2023.109003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/10/2023] [Accepted: 11/29/2023] [Indexed: 12/08/2023]
Abstract
Isomerization and epimerization of fructose to glucose, mannose, allulose, and allose were executed using a subcritical phosphate buffer solution to effectively produce useful monosaccharides. The conversion of the substrate and the yield of products were dependent on the reaction temperature, initial pH, initial substrate concentration, and buffer concentration. A high yield of mannose was achieved under the optimal reaction conditions we identified. We subsequently performed the kinetic analysis based on the proposed reaction network, and evaluated the effects of temperature and pH on the reactions. We then estimated the apparent activation energy values for each reaction.
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Affiliation(s)
- Kenta Hashimoto
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Tsugumi Niina
- Department Applied Life Science, Graduate School of Life and Environmental Science, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan
| | - Takashi Kobayashi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Shuji Adachi
- Department of Agriculture and Food Technology, Faculty of Bioenvironmental Sciences, Kyoto University of Advanced Science, Kameoka, Kyoto, 621-8555, Japan
| | - Yoshiyuki Watanabe
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan.
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11
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Rashidiani M, Zahedi E, Zare K, Seif A. Theoretical investigation on the mechanism and kinetics of the OH •‒initiated atmospheric degradation of p-chloroaniline: Addition of ∑ g-3O 2 and isomerization of peroxy radicals. J Mol Graph Model 2024; 126:108651. [PMID: 37865033 DOI: 10.1016/j.jmgm.2023.108651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/10/2023] [Accepted: 10/11/2023] [Indexed: 10/23/2023]
Abstract
Atmospheric oxidation of the p-chloroaniline-OH• adduct [C6H4ClNH2-OH]• (AD-C2) by ∑g-3O2 and internal isomerization processes of peroxy radical [C6H4ClNH2-OH]•-O2 are theoretically investigated at the M06-2X/aug-cc-pVTZ and CBS-QB3//M06-2X/aug-cc-pVTZ level of theories. Potential energy surfaces (PESs) for the most efficient pathways indicated that the oxidation process begins via the complexation of individual reactants in syn mode forming PRCy-iOO-syn (y = 2,5) in an exothermic and endogenic step. The syn mode addition is favored over the anti one due to the formation of internal hydrogen bond between the hydroxyl and peroxy groups. Formation of new C5-OO bond in PRCy-iOO-syn complex is an unimolecular process which is exothermic and exoergic. This pathway is predominated over other internal conversions due to the presence of stronger intramolecular hydrogen bond. Cyclization of the produced [C6H4ClNH2-OH]•-O2 peroxy radical AD-C2-5OO-syn into the bicyclic peroxy radical AD-C2-5,6OO-syn is the last step which is strongly endothermic and endogenic. The rate coefficients are calculated by means of the RRKM theory over the temperature range 250-350 K and at a pressure range of 0.1 bar to the high-pressure limit. The RRKM rate coefficients at the M06-2X/aug-cc-pVTZ level for the first bimolecular and last unimolecular steps are in order of 10-16 cm3 molecule-1 s-1 and 10-7 s-1, respectively, while the obtained rate coefficients at the CBS-QB3//M06-2X/aug-cc-pVTZ are overestimated about two order of magnitude.
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Affiliation(s)
- Maryam Rashidiani
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Ehsan Zahedi
- Department of Chemistry, Herbal Medicines Raw Materials Research Center, Shahrood Branch, Islamic Azad University, Shahrood, Iran.
| | - Karim Zare
- Department of Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Ahmad Seif
- Department of Chemistry, Central Tehran Branch, Islamic Azad University, Tehran, Iran
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12
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Yang C, An Q, Jiang M, Ma X, Mahmood A, Zhang H, Zhao X, Zhi HF, Jee MH, Woo HY, Liao X, Deng D, Wei Z, Wang JL. Optimized Crystal Framework by Asymmetric Core Isomerization in Selenium-Substituted Acceptor for Efficient Binary Organic Solar Cells. Angew Chem Int Ed Engl 2023; 62:e202313016. [PMID: 37823882 DOI: 10.1002/anie.202313016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2023] [Revised: 10/04/2023] [Accepted: 10/10/2023] [Indexed: 10/13/2023]
Abstract
Both the regional isomerization and selenium-substitution of the small molecular acceptors (SMAs) play significant roles in developing efficient organic solar cells (OSCs), while their synergistic effects remain elusive. Herein, we developed three isomeric SMAs (S-CSeF, A-ISeF, and A-OSeF) via subtly manipulating the mono-selenium substituted position (central, inner, or outer) and type of heteroaromatic ring on the central core by synergistic strategies for efficient OSCs, respectively. Crystallography of asymmetric A-OSeF presents a closer intermolecular π-π stacking and more ordered 3-dimensional network packing and efficient charge-hopping pathways. With the successive out-shift of the mono-selenium substituted position, the neat films give a slightly wider band gap and gradually higher crystallinity and electron mobility. The PM1 : A-OSeF afford favourable fibrous phase separation morphology with more ordered molecular packing and efficient charge transportation compared to the other two counterparts. Consequently, the A-OSeF-based devices achieve a champion efficiency of 18.5 %, which represents the record value for the reported selenium-containing SMAs in binary OSCs. Our developed precise molecular engineering of the position and type of selenium-based heteroaromatic ring of SMAs provides a promising synergistic approach to optimizing crystal stacking and boosting top-ranked selenium-containing SMAs-based OSCs.
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Affiliation(s)
- Can Yang
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Qiaoshi An
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Mengyun Jiang
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Xiaoming Ma
- National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Asif Mahmood
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Heng Zhang
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Xin Zhao
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Hong-Fu Zhi
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Min Hun Jee
- Department of Chemistry, Korea University, Seoul, 136-713, Republic of Korea
| | - Han Young Woo
- Department of Chemistry, Korea University, Seoul, 136-713, Republic of Korea
| | - Xilin Liao
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Dan Deng
- National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Zhixiang Wei
- National Center for Nanoscience and Technology, Beijing, 100190, China
| | - Jin-Liang Wang
- Key Laboratory of Cluster Science of Ministry of Education, Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
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13
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Karpenko MY, Abronina PI, Zinin AI, Chizhov AO, Kononov LO. TIPS group-assisted isomerization of benzyl protected d-manno- and d-glucopyranose to d-fructofuranose derivatives. Carbohydr Res 2023; 534:108942. [PMID: 37769375 DOI: 10.1016/j.carres.2023.108942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 09/30/2023]
Abstract
Base-promoted (MeONa in MeOH or imidazole in DMF) isomerization of a series of 3,4,6-tri-O-benzyl-d-gluco- and d-mannopyranose derivatives with triisopropylsilyl (TIPS) substituents was studied. The presence of a bulky TIPS group at O-1 or O-2 was shown to be favorable for the isomerization of benzyl protected d-gluco- and d-mannopyranose derivatives to d-fructofuranose derivatives, in which the bulky silyl group occupies less sterically hindered primary position. The highest yield (33%) of the fructofuranose derivative was achieved when 3,4,6-tri-O-benzyl-2-O-triisopropylsilyl-d-mannopyranose was treated with MeONa in MeON at 50 °C.
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Affiliation(s)
- Maxim Y Karpenko
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp. 47, 119991, Moscow, Russian Federation
| | - Polina I Abronina
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp. 47, 119991, Moscow, Russian Federation.
| | - Alexander I Zinin
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp. 47, 119991, Moscow, Russian Federation
| | - Alexander O Chizhov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp. 47, 119991, Moscow, Russian Federation
| | - Leonid O Kononov
- N. D. Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Leninsky Prosp. 47, 119991, Moscow, Russian Federation.
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14
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De Clercq E. The magic of a methyl group: Biochemistry at the service of medicine. Biochem Pharmacol 2023; 216:115786. [PMID: 37660830 DOI: 10.1016/j.bcp.2023.115786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/30/2023] [Accepted: 08/31/2023] [Indexed: 09/05/2023]
Abstract
A carbon-carbon linkage is created when a methyl group is implanted on dUMP, thus resulting in the formation of dTMP by thymidylate synthase. The methyl group is deleted by aromatase when androgens are converted to estrogens. The methyl group is rearranged with the help of vitamin B12 in the isomerization of methylmalonyl-CoA to succinyl-CoA. S-adenosylmethionine (SAM) serves as the universal methyl donor involved in the biosynthesis of adrenaline and creatine(phosphate). It also interferes with the 5'-mRNA capping and the degradation of catecholamines (i.e. adrenaline, noradrenaline). Cholesterol could be viewed as a conglomeration of methyl groups. Finally, as part of valine, two methyl functions participate in the origin of one of the most frequent hereditary diseases on earth, sickle cell anemia.
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Affiliation(s)
- Erik De Clercq
- Emeritus Professor at the KU Leuven (Belgium), Visiting Professor at the Jihočeská University of South Bohemia, České Budějovice, Czech Republic
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15
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Feng Z, Li Y, Zhang P, Wang J, Xu Y, Feng Y, Zhai X, Yang X, Wan X, Yin J. Formation and isomerization of (Z)-methyl epijasmonate, the key contributor of the orchid-like aroma, during tea processing. Food Res Int 2023; 172:113186. [PMID: 37689937 DOI: 10.1016/j.foodres.2023.113186] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/19/2023] [Accepted: 06/27/2023] [Indexed: 09/11/2023]
Abstract
The elegant orchid-like fragrance of tea has always been tea processors and consumers' top priority. Controlling the production process is very important for tea aroma formation. This study aims to investigate the synthesis of (Z)-methyl epijasmonate (epi-MeJA), a key contributor to orchid-like aroma properties in tea, during tea processing. The changes in content of epi-MeJA were analysed during the processing of two tea varieties (Anxi Tieguanyin and Taiping Houkui) with typical orchid-like fragrance. It was found to be mainly synthesized and accumulated during tea processing, as fresh tea leaves contained little or even no epi-MeJA. Its content was positively correlated with the processing time in the enzyme active stages (before fixation). During the fixation stages, isomerization occurred due to high temperatures, with a degree of epimerization to the much less odor active isomer (Z)-methyl jasmonate. Isomerization could also occurred during the drying process, which is dominated by the drying temperature.
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Affiliation(s)
- Zhihui Feng
- Tea Research Institute Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Yifan Li
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui, China
| | - Ping Zhang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui, China
| | - Jieqiong Wang
- Tea Research Institute Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Yongquan Xu
- Tea Research Institute Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Yingying Feng
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui, China
| | - Xiaoting Zhai
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui, China
| | - Xiaogen Yang
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui, China.
| | - Xiaochun Wan
- State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, Hefei, Anhui, China.
| | - Junfeng Yin
- Tea Research Institute Chinese Academy of Agricultural Sciences, Hangzhou, Zhejiang, China.
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16
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Chen C, Guo W, Qiao D, Zhu S. Synthesis of Enantioenriched 1,2-cis Disubstituted Cycloalkanes by Convergent NiH Catalysis. Angew Chem Int Ed Engl 2023; 62:e202308320. [PMID: 37470299 DOI: 10.1002/anie.202308320] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/12/2023] [Accepted: 07/19/2023] [Indexed: 07/21/2023]
Abstract
Enantioenriched multi-substituted cycloalkanes constitute an essential class of compounds in pharmaceuticals, natural products and agrochemicals. Here we report an NiH-catalyzed asymmetric migratory hydroalkylation process for the efficient and selective construction of such compounds. Through a dynamic kinetic asymmetric transformation (DYKAT), easily accessible racemic and isomeric mixtures of cycloalkenes could be directly utilized as starting materials, convergently producing thermo-dynamically disfavored chiral 1,2-cis disubstituted cycloalkanes bearing vicinal stereocenters with high levels of regio-, diastereo- and enantioselectivity. In addition, prochiral cyclic alkenes can be also employed, and deliver chiral 1,2-cis disubstituted cycloalkanes through desymmetrization process.
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Affiliation(s)
- Changpeng Chen
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, 210093, Nanjing, China
| | - Wenqing Guo
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, 210093, Nanjing, China
| | - Deyong Qiao
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, 210093, Nanjing, China
| | - Shaolin Zhu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, 210093, Nanjing, China
- School of Chemistry and Chemical Engineering, Henan Normal University, 453007, Xinxiang, China
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Shanghai Jiao Tong University, 200240, Shanghai, China
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17
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Marotta A, Fang H, Adams CE, Sun Marcus K, Daniliuc CG, Molloy JJ. Direct Light-Enabled Access to α-Boryl Radicals: Application in the Stereodivergent Synthesis of Allyl Boronic Esters. Angew Chem Int Ed Engl 2023; 62:e202307540. [PMID: 37326432 DOI: 10.1002/anie.202307540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/15/2023] [Accepted: 06/15/2023] [Indexed: 06/17/2023]
Abstract
Operationally simple strategies to assemble boron containing organic frameworks are highly enabling in organic synthesis. While conventional retrosynthetic logic has engendered many platforms focusing on the direct formation of C-B bonds, α-boryl radicals have recently reemerged as versatile open-shell alternatives to access organoborons via adjacent C-C bond formation. Direct light-enabled α-activation is currently contingent on photo- or transition metal-catalysis activation to efficiently generate radical species. Here, we disclose a facile activation of α-halo boronic esters using only visible light and a simple Lewis base to enable homolytic scission. Intermolecular addition to styrenes facilitates the rapid construction of highly versatile E-allylic boronic esters. The simplicity of activation permits the strategic merger of this construct with selective energy transfer catalysis to enable the complimentary stereodivergent synthesis of Z-allylic boronic esters.
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Affiliation(s)
- Alessandro Marotta
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
| | - Hao Fang
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
| | - Callum E Adams
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Kailey Sun Marcus
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
| | - Constantin G Daniliuc
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149, Münster, Germany
| | - John J Molloy
- Department of Biomolecular Systems, Max-Planck-Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476, Potsdam, Germany
- Department of Chemistry and Biochemistry, Freie Universität Berlin, Arnimallee 22, 14195, Berlin, Germany
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18
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Yang J, Gui Z, He Y, Zhu S. Functionalization of Olefinic C-H Bonds by an Aryl-to-Vinyl 1,4-Nickel Migration/Reductive Coupling Sequence. Angew Chem Int Ed Engl 2023:e202304713. [PMID: 37147743 DOI: 10.1002/anie.202304713] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/07/2023]
Abstract
An attractive approach to selective functionalization of remote C-H bonds is a metal/hydride shift/cross-coupling reaction sequence. Complimentary to the heavily exploited 1,2-nickel/hydride shift along an sp3 chain, a chain-walking process, the 1,4-nickel/hydride shift along an sp2 chain is more complex. Here we report an unprecedented aryl-to-vinyl 1,4-nickel/hydride shift reaction, in which the migratory alkenylnickel species generated in situ is selectively trapped by one of various coupling partners, such as isocyanates, alkyl bromides, aryl chlorides or alkynyl bromides, allowing regio- and stereoselective access to trisubstituted alkenes. In contrast to the well-reported ipso-aryl coupling reactions, this strategy provides remote alkenyl C-H functionalized products with good yield and with excellent chemo-, regio- and E/Z-selectivity.
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Affiliation(s)
- Jingjie Yang
- Nanjing University, Chemistry, 210046, Nanjing, CHINA
| | - Zhuofan Gui
- Nanjing University, Chemistry, Nanjing, CHINA
| | - Yuli He
- China Pharmaceutical University School of Pharmacy, Medicinal Chemistry, Nanjing, CHINA
| | - Shaolin Zhu
- Nanjing University, Chemistry, No 22 Hankou Road, 210093, Nanjing, CHINA
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19
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Wang D, Wang Y, Zhang Z, Qiu S, Yuan Y, Song G, Li L, Yuan T, Gong J. Degradation, isomerization and stabilization of three dicaffeoylquinic acids under ultrasonic treatment at different pH. Ultrason Sonochem 2023; 95:106401. [PMID: 37060713 PMCID: PMC10130687 DOI: 10.1016/j.ultsonch.2023.106401] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/23/2023] [Accepted: 04/06/2023] [Indexed: 06/19/2023]
Abstract
Dicaffeoylquinic acids (diCQAs) are found in a variety of edible and medicinal plants with various biological activities. An important issue is the low stability of diCQAs during extraction and food processing, resulting in the degradation and transformation. This work used 3,5-diCQA as a representative to study the influence of different parameters in ultrasonic treatment on the stability of diCQAs, including solvent, temperature, treatment time, ultrasonic power, duty cycle, and probe immersion depth. The generation of free radicals and its influence were investigated during the treatment. The stability of three diCQAs (3,5-diCQA, 4,5-diCQA and 3,4-diCQA) under the certain ultrasonic condition at different pH conditions was evaluated and found to decrease with the increase of pH, further weakened by ultrasonic treatment. Ultrasound was found to accelerate the degradation and isomerization of diCQAs. Different diCQAs showed different pattern of degradation and isomerization. The stability of diCQAs could be improved by adding epigallocatechin gallate and vitamin C.
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Affiliation(s)
- Danli Wang
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Yushi Wang
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Zhenlei Zhang
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Shaoping Qiu
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Yawen Yuan
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Gongshuai Song
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Ling Li
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Tinglan Yuan
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Jinyan Gong
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China.
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20
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Pagacz-Kostrzewa M, Szaniawska W, Wierzejewska M. NIR and UV induced transformations of indazole-3-carboxylic acid isolated in low temperature matrices. Spectrochim Acta A Mol Biomol Spectrosc 2023; 290:122283. [PMID: 36586171 DOI: 10.1016/j.saa.2022.122283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
The molecular structure and NIR and UV induced phototransformations of indazole-3-carboxylic acid were studied in low temperature argon and nitrogen matrices by FTIR spectroscopy and B3LYP/6-311++G(2d,2p) calculations. Eleven minima of IC were located on the S0 potential energy surface. The three most stable structures were detected experimentally in both matrices after deposition. Upon NIR irradiation a dominant process was rotamerization within the carboxylic group leading to changes in the population of the trans 1HIC1 and cis 1HIC2 forms. In turn, at UV irradiation at λ = 260 nm two new tautomers (2HIC2 and 2HIC3) were generated indicating that the hydrogen atom transfer in pyrazole ring took place. Based on the obtained kinetic curves, differences in the phototransformation rates in different matrices were indicated.
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Affiliation(s)
- M Pagacz-Kostrzewa
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
| | - W Szaniawska
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - M Wierzejewska
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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21
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Tonoli A, Wagner K, Bacchin A, Reiter T, Bergantino E, Robescu MS, Hall M. Stereodivergent Biocatalytic Formal Reduction of α-Angelica Lactone to (R)- and (S)-γ-Valerolactone in a One-Pot Cascade. Chembiochem 2023; 24:e202300146. [PMID: 36940139 DOI: 10.1002/cbic.202300146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 03/21/2023]
Abstract
The formal asymmetric and stereodivergent enzymatic reduction of α-angelica lactone to both enantiomers of γ-valerolactone was achieved in a one-pot cascade by uniting the promiscuous stereoselective isomerization activity of Old Yellow Enzymes with their native reductase activity. In addition to running the cascade with one enzyme for each catalytic step, a bifunctional isomerase-reductase biocatalyst was designed by fusing two Old Yellow Enzymes, thereby generating an unprecedented case of an artificial enzyme catalyzing the reduction of nonactivated C=C bonds to access (R)-valerolactone in overall 41% conversion and up to 91% ee. The enzyme BfOYE4 could be used as single biocatalyst for both steps and delivered (S)-valerolactone in up to 84% ee and 41% overall conversion. The reducing equivalents were provided by a nicotinamide recycling system based on formate and formate dehydrogenase, added in a second step. This enzymatic system provides an alternative asymmetric approach to generate valuable chiral building blocks from an abundant bio-based chemical.
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Affiliation(s)
- Alessia Tonoli
- Karl-Franzens-Universitat Graz, Chemistry, UNITED KINGDOM
| | - Karla Wagner
- University of Bielefeld: Universitat Bielefeld, Chemistry, GERMANY
| | - Arianna Bacchin
- University of Graz: Karl-Franzens-Universitat Graz, Chemistry, AUSTRIA
| | - Tamara Reiter
- University of Graz: Karl-Franzens-Universitat Graz, Chemistry, AUSTRIA
| | | | - Marina S Robescu
- University of Pavia: Universita degli Studi di Pavia, Drug sciences, ITALY
| | - Mélanie Hall
- University of Graz: Karl-Franzens-Universitat Graz, Department of Chemistry, Heinrichstrasse 28, 8010, Graz, AUSTRIA
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22
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Nougué R, Takahashi S, Baceiredo A, Saffon-Merceron N, Branchadell V, Kato T. Reversible Isomerization Between Silacyclopropyl Cation and Cyclic (Alkyl)(Amino)Silylene. Angew Chem Int Ed Engl 2023; 62:e202215394. [PMID: 36445806 PMCID: PMC10108311 DOI: 10.1002/anie.202215394] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 11/30/2022]
Abstract
A phosphine-stabilized silacyclopropyl cation 2 has been synthesized and fully characterized. Of particular interest, 2 reversibly isomerizes into the corresponding seven-membered cyclic (alkyl)(amino)silylene 3 at room temperature via a formal migratory ethylene insertion into the Si-P bond. Although silylene 3 has not been spectroscopically detected, its transient formation has been evidenced by the isolation of the corresponding disilene dimer 5 as well as by trapping reactions.
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Affiliation(s)
- Raphaël Nougué
- Université de Toulouse, UPS, CNRS, LHFA UMR 5069, 31062, Toulouse, France
| | - Shintaro Takahashi
- Université de Toulouse, UPS, CNRS, LHFA UMR 5069, 31062, Toulouse, France
| | - Antoine Baceiredo
- Université de Toulouse, UPS, CNRS, LHFA UMR 5069, 31062, Toulouse, France
| | | | - Vicenç Branchadell
- Departament de Química, Universitat Autònoma de Barcelona, 08193, Bellaterra, Spain
| | - Tsuyoshi Kato
- Université de Toulouse, UPS, CNRS, LHFA UMR 5069, 31062, Toulouse, France
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23
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Dantignana V, Pérez-Segura MC, Besalú-Sala P, Delgado-Pinar E, Martínez-Camarena Á, Serrano-Plana J, Álvarez-Núñez A, Castillo CE, García-España E, Luis JM, Basallote MG, Costas M, Company A. Characterization of a Ferryl Flip in Electronically Tuned Nonheme Complexes. Consequences in Hydrogen Atom Transfer Reactivity. Angew Chem Int Ed Engl 2023; 62:e202211361. [PMID: 36305539 PMCID: PMC10107328 DOI: 10.1002/anie.202211361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Indexed: 12/04/2022]
Abstract
Two oxoiron(IV) isomers (R 2a and R 2b) of general formula [FeIV (O)(R PyNMe3 )(CH3 CN)]2+ are obtained by reaction of their iron(II) precursor with NBu4 IO4 . The two isomers differ in the position of the oxo ligand, cis and trans to the pyridine donor. The mechanism of isomerization between R 2a and R 2b has been determined by kinetic and computational analyses uncovering an unprecedented path for interconversion of geometrical oxoiron(IV) isomers. The activity of the two oxoiron(IV) isomers in hydrogen atom transfer (HAT) reactions shows that R 2a reacts one order of magnitude faster than R 2b, which is explained by a repulsive noncovalent interaction between the ligand and the substrate in R 2b. Interestingly, the electronic properties of the R substituent in the ligand pyridine ring do not have a significant effect on reaction rates. Overall, the intrinsic structural aspects of each isomer define their relative HAT reactivity, overcoming changes in electronic properties of the ligand.
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Affiliation(s)
- Valeria Dantignana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - M Carmen Pérez-Segura
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Pau Besalú-Sala
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Estefanía Delgado-Pinar
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Álvaro Martínez-Camarena
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Joan Serrano-Plana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Andrea Álvarez-Núñez
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Carmen E Castillo
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Enrique García-España
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Josep M Luis
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Manuel G Basallote
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
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24
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Hugenbusch D, Lehr M, von Glasenapp JS, McConnell AJ, Herges R. Light-Controlled Destruction and Assembly: Switching between Two Differently Composed Cage-Type Complexes. Angew Chem Int Ed Engl 2023; 62:e202212571. [PMID: 36215411 PMCID: PMC10099457 DOI: 10.1002/anie.202212571] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Indexed: 12/30/2022]
Abstract
We report on two regioisomeric, diazocine ligands 1 and 2 that can both be photoswitched between the E- and Z-configurations with violet and green light. The self-assembly of the four species (1-Z, 1-E, 2-Z, 2-E) with CoII ions was investigated upon changing the coordination vectors as a function of the ligand configuration (E vs Z) and regioisomer (1 vs 2). With 1-Z, Co2 (1-Z)3 was self-assembled, while a mixture of ill-defined species (oligomers) was observed with 2-Z. Upon photoswitching with 385 nm to the E configurations, the opposite was observed with 1-E forming oligomers and 2-E forming Co2 (2-E)3 . Light-controlled dis/assembly was demonstrated in a ligand competition experiment with sub-stoichiometric amounts of CoII ions; alternating irradiation with violet and green light resulted in the reversible transformation between Co2 (1-Z)3 and Co2 (2-E)3 over multiple cycles without significant fatigue by photoswitching.
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Affiliation(s)
- Daniel Hugenbusch
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Marc Lehr
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Jan-Simon von Glasenapp
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Anna J McConnell
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
| | - Rainer Herges
- Otto-Diels-Institute of Organic Chemistry, Christian-Albrechts-Universität zu Kiel, Otto-Hahn-Platz 4, 24118, Kiel, Germany
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25
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Stieglitz L, Lenz TM, Saurwein A, Rieger B. Perfectly Isotactic Polypropylene upon In Situ Activation of Ultrarigid meso Hafnocenes. Angew Chem Int Ed Engl 2022; 61:e202210797. [PMID: 36125844 PMCID: PMC9828379 DOI: 10.1002/anie.202210797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Indexed: 01/12/2023]
Abstract
For more than 40 years, the synthesis of C2 -symmetric indenyl-based racemic metallocenes for the isoselective polymerization of propylene relied on a tedious separation of the produced rac and meso isomers. Status quo, latter are considered wasteful as they produce atactic polypropylene (aPP) rather than isotactic polypropylene (iPP) if activated with methylaluminoxane (MAO). Unexpectedly, the in situ activation of meso hafnocene I yielded perfectly isotactic polypropylene. We verified an isomerization of the meso compound to the corresponding racemic one upon triisobutylaluminum (TIBA) addition via nuclear magnetic resonance (NMR) spectroscopy and established an easy and convenient polymerization protocol, enabling productivities comparable to pure rac-I if applied to pure meso-I or a mixture of both isomers. With this established isomerization protocol, the potential yield of iPP was enhanced by more than 400 %. This protocol was also shown to be applicable to other meso hafnocenes and some initial mechanistic insights were received.
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Affiliation(s)
- Lucas Stieglitz
- Wacker-Lehrstuhl für Makromolekulare ChemieCatalysis Research CenterTechnische Universität MünchenLichtenbergstraße 485748Garching bei MünchenGermany
| | - Tim M. Lenz
- Wacker-Lehrstuhl für Makromolekulare ChemieCatalysis Research CenterTechnische Universität MünchenLichtenbergstraße 485748Garching bei MünchenGermany
| | - Andreas Saurwein
- Wacker-Lehrstuhl für Makromolekulare ChemieCatalysis Research CenterTechnische Universität MünchenLichtenbergstraße 485748Garching bei MünchenGermany
| | - Bernhard Rieger
- Wacker-Lehrstuhl für Makromolekulare ChemieCatalysis Research CenterTechnische Universität MünchenLichtenbergstraße 485748Garching bei MünchenGermany
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26
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Kouyama T, Ihara K. Existence of two substates in the O intermediate of the bacteriorhodopsin photocycle. Biochim Biophys Acta Biomembr 2022; 1864:183998. [PMID: 35753392 DOI: 10.1016/j.bbamem.2022.183998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 04/12/2022] [Accepted: 06/18/2022] [Indexed: 06/15/2023]
Abstract
The proton pumping cycle of bacteriorhodopsin (bR) is initiated when the retinal chromophore with the 13-trans configuration is photo-isomerized into the 13-cis configuration. To understand the recovery processes of the initial retinal configuration that occur in the late stage of the photocycle, we have performed a comprehensive analysis of absorption kinetics data collected at various pH levels and at different salt concentrations. The result of analysis revealed the following features of the late stages of the trans photocycle. i) Two substates occur in the O intermediate. ii) The visible absorption band of the first substate (O1) appears at a much shorter wavelength than that of the late substate (O2). iii) O1 is in rapid equilibrium with the preceding state (N), but O1 becomes less stable than N when an ionizable residue (X1) with a pKa value of 6.5 (in 2 M KCl) is deprotonated. iv) At a low pH and at a low salt concentration, the decay time constant of O2 is longer than those of the preceding states, but the relationship between these time constants is altered when the medium pH or the salt concentration is increased. On the basis of the present observations and previous studies on the structure of the chromophore in O, we suspect that the retinal chromophore in O1 takes on a distorted 13-cis configuration and the O1-to-O2 transition is accompanied by cis-to-trans isomerization about C13C14 bond.
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Affiliation(s)
- Tsutomu Kouyama
- Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan
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27
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Zhu X, Chen Z, Ai H. Mechanistic insight into the tautomerization of histidine initiated by water-catalyzed N-H and C-H cleavages. J Mol Model 2022; 28:325. [PMID: 36136156 DOI: 10.1007/s00894-022-05222-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 07/12/2022] [Indexed: 10/14/2022]
Abstract
The N-H and C-H activation is of great significance in organic chemistry and chemical industry fields, especially, in the utilization of petroleum raw materials. High NδH (tautomer of natural histidine) content would increase Alzheimer's disease risk. To inhibit this and improve the activation of N-H and C-H bonds, the isomerization mechanism from NδH to NεH of histidine-containing dipeptide catalyzed by water cluster was explored. The results discovered that water cluster assists this reaction by reducing the activation energies from 68.20 to 9.60 kcal mol-1, and its size not only affects the reaction rate but also determines the reaction pathway in a degree. Moreover, water cluster, taken as a potential green catalyst, is more effective on the reactions involving N-H and C-H bond cleavages than reported common toxic organometallic compounds and has different catalytic mechanisms. This work also provides some theoretical guidance for the modulation of Alzheimer's disease induced by histidine isomerization.
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Affiliation(s)
- Xueying Zhu
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, People's Republic of China.
| | - Zijiao Chen
- Institute of Science and Technology, Xinjiang University, Aksu, 843100, People's Republic of China
| | - Hongqi Ai
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, People's Republic of China.
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28
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Zhang J, Xie Z. N-Ligand-Enabled Aromatic Nucleophilic Amination of 1,2-Diaryl-o-Carboranes with (R 2 N) 2 Mg for Selective Synthesis of 4-R 2 N-o-Carboranes and 2-R 2 N-m-Carboranes. Angew Chem Int Ed Engl 2022; 61:e202202675. [PMID: 35579912 DOI: 10.1002/anie.202202675] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Indexed: 11/08/2022]
Abstract
The nucleophilic aromatic BH substitution reaction of carboranes is uncommon, compared to the electrophilic one. This work reported a pyridine-enabled transition-metal-free regioselective nucleophilic aromatic cage B(4)-H amination of 1,2-diaryl-o-carboranes with magnesium bisamides, giving a series of B(4)-aminated o-carboranes. DFT calculations showcased a stepwise B-N formation/B-H cleavage process, in which Mg-H formation/cage closure is the rate-determining step. Unprecedentedly, in the presence of 4,4'-di-tert-butyl-2,2'-dipyridyl (dtbpy), a tandem B(4)-amination/cage isomerization reaction of o-carboranes was discovered for the facile preparation of B(2)-aminated m-carboranes. Control experiments indicated that magnesium complex, bidentate ligand (dtbpy) and reaction temperature were crucial in the cage isomerization process. This direct nucleophilic aromatic cage B-H amination reaction offers an alternative strategy for selective amination of o- and m-carboranes.
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Affiliation(s)
- Jie Zhang
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Zuowei Xie
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
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29
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Lin SY, Chou SL, Tseng CM, Wu YJ. IR absorption spectra of aniline cation, anilino radical, and phenylnitrene isolated in solid argon. Spectrochim Acta A Mol Biomol Spectrosc 2022; 276:121233. [PMID: 35405375 DOI: 10.1016/j.saa.2022.121233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 03/29/2022] [Accepted: 04/02/2022] [Indexed: 06/14/2023]
Abstract
Electron bombardment of aniline (PhNH2) in an Ar matrix mainly generated the aniline cation (PhNH2+), anilino (PhNH) and phenyl (Ph) radicals, and phenylnitrene (PhN). Further irradiation of the electron-bombarded matrix sample at 365 nm depleted PhNH2+ and PhN, and resulted in the formation of PhNH2, PhNH, and Ph. In separate experiments, irradiation of the PhNH2/Ar matrix samples at 265 or 160 nm mainly generated PhNH and Ph radicals, but without the formation of PhNH2+ and PhN. According to the observed photochemical behaviors, quantum-chemically predicted harmonic vibrational wavenumbers of each species, and the information reported in previous photodissociation studies, we unambiguously characterized the IR features of the aromatic species. The information of the vibrational fundamentals of PhNH is new and the formation mechanism is discussed.
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Affiliation(s)
- Shu-Yu Lin
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
| | - Sheng-Lung Chou
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan
| | - Chien-Ming Tseng
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
| | - Yu-Jong Wu
- Department of Applied Chemistry and Institute of Molecular Science, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan; National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu Science Park, Hsinchu 30076, Taiwan.
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30
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Yan L, Yang H, Liu N, Meng F, Zhang S. A photochromic salicylaldehyde hydrazone derivative based on CN isomerization and ESIPT mechanisms and its detection of Al 3+ in aqueous solution. Spectrochim Acta A Mol Biomol Spectrosc 2022; 275:121116. [PMID: 35316626 DOI: 10.1016/j.saa.2022.121116] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 03/01/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
A simple photochromic Schiff base was successfully prepared by the condensation of salicylaldehyde and benzoyl hydrazine. This compound has reversible photochromic properties based on isomerization and ESIPT mechanisms. In organic solvents, after irradiation with 365 nm UV light for 2 min, the absorption peak at 367 nm of the compound showed a significant decrease, while a double absorption peak appeared at 418 nm and 438 nm, accompanied by a significant change of the solution color from colorless to yellow. The compound can also complex with Al3+ at the molar ratio of 2:1 in the water solution (acetonitrile/water, v/v, 1:99), resulting in significantly enhanced fluorescence of the compound, so as to achieve fluorescence detection of Al3+ in living cells and water samples.
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Affiliation(s)
- Liqiang Yan
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541006, PR China.
| | - Hong Yang
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541006, PR China
| | - Nan Liu
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541006, PR China
| | - Fengjuan Meng
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541006, PR China
| | - Shiqing Zhang
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, Guangxi 541006, PR China
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31
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Kouyama T, Ihara K. Two substates in the O intermediate of the light-driven proton pump archaerhodopsin-2. Biochim Biophys Acta Biomembr 2022; 1864:183919. [PMID: 35304864 DOI: 10.1016/j.bbamem.2022.183919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 02/16/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
The proton pumping cycle of archaerhodopsin-2 (aR2) was investigated over a wide pH range and at different salt concentrations. We have found that two substates, which are spectroscopically and kinetically distinguishable, occur in the O intermediate. The first O-intermediate (O1) absorbs maximumly at ~580 nm, whereas the late O-intermediate (O2) absorbs maximumly at 605 nm. At neutral pH, O1 is in rapid equilibrium with the N intermediate. When the medium pH is increased, O1 becomes less stable than N and, in proportion to the amount of O1 in the dynamic equilibrium between N and O1, the formation rate of O2 decreases. By contrast, the decay rate of O2 increases ~100 folds when the pH of a low-salt membrane suspension is increased from 5.5 to 7.5 or when the salt concentration is increased to 2 M KCl. Together with our recent study on two substates in the O intermediate of bacteriorhodopsin (bR), the present study suggests that the thermally activated re-isomerization of the retinylidene chromophore into the initial all-trans configuration takes place in the O1-to-O2 transition; that is, O1 contains a distorted 13-cis chromophore. It is also found that the pKa value of the key ionizable residue (Asp101aR2, Asp96bR) in the proton uptake channel is elevated in the O1 state of aR2 as compared to the O1 state of bR. This implies that the structural property of O1 in the aR2 photocycle can be investigated over a wide pH range.
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Affiliation(s)
- Tsutomu Kouyama
- Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan
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32
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Ushakou D, Wróblewski T. Scutellarein in organic solvents: changes in spectroscopic properties caused by solute-solvent interactions. Spectrochim Acta A Mol Biomol Spectrosc 2022; 273:121027. [PMID: 35182824 DOI: 10.1016/j.saa.2022.121027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
In this work, the spectroscopic properties of scutellarein (6-hydroxyapigenin) were studied in three organic solvents (methanol, acetonitrile and N,N-dimethylformamide) taking into account possible ionization and isomerization (tautomerization) processes. Significant visible colour changes were reported in the case of scutellarein in N,N-dimethylformamide. It was shown that isomerization processes can be one of the reasons for the observed changes in absorption spectrum, because some scutellarein isomers have an absorption band at about 623 nm while other forms of scutellarein show no absorption in this region. Moreover, spectroscopic properties were studied for cases of scutellarein in acetonitrile and methanol. The molar extinction coefficient has been found in the case of methanol solution which could be used to determine scutellarein concentration in this solvent using spectroscopic methods in future studies. The quantum-chemical calculations were performed for neutral and anionic forms and for two types of possible isomers of scutellarein in each solvent. The results help explain the experimentally observed rising absorption in the 500-750 nm wavelength range. Another important result of the quantum-chemical calculations is a prediction of excited state intramolecular proton transfer (ESIPT) in scutellarein. This result has been obtained for free molecule in vacuum and in the cases of methanol, acetonitrile and N,N-dimethylformamide solution. It was found that the excited state energy of the normal molecular form is higher than the excited state energy of the tautomer form of scutellarein.
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Affiliation(s)
- Dzmitryi Ushakou
- Pomeranian University in Słupsk, str. Arciszewskiego 22b, 76-200 Słupsk, Poland.
| | - Tomasz Wróblewski
- Pomeranian University in Słupsk, str. Arciszewskiego 22b, 76-200 Słupsk, Poland
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Hirao Y, Hamamoto Y, Kubo T. Tunable Solid-State Thermochromism: Alkyl Chain Length-Dependent Conformational Isomerization of Bianthrones. Chem Asian J 2022; 17:e202200121. [PMID: 35388961 DOI: 10.1002/asia.202200121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/05/2022] [Indexed: 11/12/2022]
Abstract
The introduction of linear alkoxy chains into bianthrone promoted the aggregation of the minor twisted conformer and made it compete with the major folded conformer in the solid-state. Rapid evaporation approach to the methoxy- and n -butoxy-substituted derivatives provided powder mixtures of folded and twisted conformers as metastable solids. Upon heating the powders, different lengths of alkyl chains converged to different conformers via solid-state thermal reaction with an apparent color change. Monitoring by FT-IR spectroscopy and powder XRD ensured that these thermal reactions involve only conformational isomerization without pyrolysis. In addition, single crystal X-ray structure analysis revealed that twisted conformers with longer alkyl chains are stabilized in the solid-state by the synergistic effect of their inter-chain hydrophobic interactions and π-π stacking interactions.
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Affiliation(s)
- Yasukazu Hirao
- Osaka University: Osaka Daigaku, Department of Chemistry, Graduate School of Science, 1-1 Machikaneyama, 560-0043, Toyonaka, Osaka, JAPAN
| | - Yosuke Hamamoto
- Osaka University: Osaka Daigaku, Department of Chemistry, Graduate School of Science, 1-1 Machikaneyama, 5600043, Toyonaka, JAPAN
| | - Takashi Kubo
- Osaka University: Osaka Daigaku, Department of Chemistry, Graduate School of Science, 1-1 Machikaneyama, 5600043, Toyonaka, JAPAN
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Takashima Y, Saga Y. Isomerization kinetics of bacteriochlorophyll b and bacteriopheophytin b under acidic conditions. Photochem Photobiol Sci 2022; 21:1193-1199. [PMID: 35349123 DOI: 10.1007/s43630-022-00207-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/10/2022] [Indexed: 11/27/2022]
Abstract
Bacteriochlorophyll (BChl) b has a unique π-conjugation system, in which the bacteriochlorin macrocycle is conjugated with the C8-ethylidene group. This π-system is converted easily to the chlorin macrocycle. However, the effects of the central magnesium in BChl b on this conversion are unclear. In this study, the isomerization kinetics of BChl b and its demetalated pigment, bacteriopheophytin (BPhe) b, was analyzed under weakly acidic conditions. BChl b exhibited faster acid-induced isomerization than BPhe b. These results were attributed to the stabilization of a cationic intermediate, whose C8-ethylidene group is protonated, during the isomerization of BChl b compared to BPhe b because of a difference in the electron densities of the π-conjugation systems between BChl b and BPhe b. High-performance liquid chromatography analyses indicated that BChl b was primarily isomerized to 3-acetyl Chl a, followed by demetalation. The reaction order was due to the slower demetalation kinetics of metallobacteriochlorins than metallochlorins. These results will be helpful for handling unstable BChl b and BPhe b. The reaction properties of BChl b and BPhe b demonstrated here will be helpful for understanding the in vivo formation of BPhe b, which acts as the primary electron acceptor in photosynthetic reaction center complexes in BChl b-containing purple photosynthetic bacteria.
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Affiliation(s)
- Yusuke Takashima
- Department of Chemistry, Faculty of Science and Engineering, Kindai University, Higashi-Osaka, Osaka, 577-8502, Japan
| | - Yoshitaka Saga
- Department of Chemistry, Faculty of Science and Engineering, Kindai University, Higashi-Osaka, Osaka, 577-8502, Japan.
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35
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Zhu J, Guo T, Wang Z, Zhao Y. Triggered azobenzene-based prodrugs and drug delivery systems. J Control Release 2022; 345:475-493. [PMID: 35339578 DOI: 10.1016/j.jconrel.2022.03.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/18/2022] [Accepted: 03/20/2022] [Indexed: 12/18/2022]
Abstract
Azobenzene-based molecules show unique trans-cis isomerization upon ultraviolet light irradiation, which induce the change of polarity, crystallinity, stability, and binding affinity with pharmacological target. Moreover, azobenzene is the substrate of azoreductase that is often overexpressed in many pathological sites, e.g. hypoxic solid tumor. Therefore, azobenzene can be a multifunctional molecule in material science, pharmaceutical science and biomedicine because of its sensitivity to light, hypoxia and certain enzymes, hence showing potential application in site-specific smart therapy. Herein we focus on the employment of azobenzene and its derivatives for engineering triggered prodrug and drug delivery systems, and provide an overview of photoswitchable azo-based prodrugs, the associated problems regarding ultraviolet light and reversible isomerization, as well as the potential solutions. We also present the advance of azo-bearing delivery vehicles wherein azobenzene act as the linker, capping agent, and building block, and discuss the corresponding mechanisms for controlled cargo release, endocytosis enhancement and sensitization of free radical cancer therapy.
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Affiliation(s)
- Jundong Zhu
- School of Pharmaceutical Science & Technology, Tianjin Key Laboratory for Modern Drug Delivery & High Efficiency, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China
| | - Tao Guo
- Tianjin Academy of Traditional Chinese Medicine Affiliated Hospital, Tianjin 300120, China
| | - Zheng Wang
- School of Pharmaceutical Science & Technology, Tianjin Key Laboratory for Modern Drug Delivery & High Efficiency, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China.
| | - Yanjun Zhao
- School of Pharmaceutical Science & Technology, Tianjin Key Laboratory for Modern Drug Delivery & High Efficiency, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, China.
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Kumar N, Murli C, Varma M, Poswal HK, Thomas S, Kshirsagar RJ. High pressure Raman investigation on trans-urocanic acid. Spectrochim Acta A Mol Biomol Spectrosc 2022; 266:120438. [PMID: 34627016 DOI: 10.1016/j.saa.2021.120438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/27/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Trans-urocanic acid (t-UCA) is an important epidermal UV protector predominantly found in human skin. Exposure of UV radiation triggers photoisomerization of t-UCA into its other conformer, cis-urocanic acid (cis-UCA), which has been shown to be a mediator of UV-induced immune-suppression leading to skin cancer. In this report, we present the investigation of molecular changes of t-UCA under high pressures by in-situ high pressure Raman spectroscopy. The study indicates onset of ring opening polymerization of t-UCA at pressure above 1.4 GPa. At pressures beyond 5 GPa, a well discernible characteristic vibrational mode (CC stretch) accompanied by several other spectral features such as δ CO2- and δ NH modes of cis-UCA point towards the isomerization of residual t-UCA monomers into cis-UCA. The content of cis-UCA gradually increased with increase in pressure. On release to ambient conditions, the spectrum of the quenched sample showed Raman modes of polymer and cis-UCA indicating that the changes are irreversible.
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Affiliation(s)
- Naveen Kumar
- Infrared Laser Spectroscopy Section, Bhabha Atomic Research Centre, Trombay, Mumbai 85, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 94, India.
| | - C Murli
- High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 85, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 94, India
| | - Meera Varma
- High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 85, India
| | - H K Poswal
- High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 85, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 94, India
| | - S Thomas
- High Pressure & Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 85, India.
| | - R J Kshirsagar
- Infrared Laser Spectroscopy Section, Bhabha Atomic Research Centre, Trombay, Mumbai 85, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 94, India
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Wang D, Wang J, Sun J, Qiu S, Chu B, Fang R, Li L, Gong J, Zheng F. Degradation kinetics and isomerization of 5- O-caffeoylquinic acid under ultrasound: Influence of epigallocatechin gallate and vitamin C. Food Chem X 2021; 12:100147. [PMID: 34761202 DOI: 10.1016/j.fochx.2021.100147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 09/27/2021] [Accepted: 10/25/2021] [Indexed: 11/23/2022] Open
Abstract
The increase of pH accelerated the degradation of 5-CQA. The isomerization of 5-CQA was found at neutral and alkaline conditions. Ultrasound boosted the degradation and isomerization of 5-CQA. EGCG and VC slowed down the degradation of 5-CQA induced by ultrasound.
5-O-Caffeoylquinic acid (5-CQA), also known as chlorogenic acid, exhibits various biological activities. Hence the interest in its property change during processing and extraction has increased. The present work studied the influence of ultrasound on the stability of 5-CQA at different pH (pH 4.69, 7.09, 7.69 and 9.22) in water and 50% methanol-water system. Different parameters including solvent, ultrasonic power, time, temperature, duty cycle, and liquid height were investigated during the treatment. Results indicate that ultrasound accelerated the degradation of 5-CQA. Based on Weibull model, the degradation kinetics were described. The rate constant (k) of the degradation increased with the increasing pH, demonstrating the alkali sensitivity of 5-CQA. The isomerization of 5-CQA to 3- and 4-O-caffeoylquinic acid was found at neutral and alkaline conditions, which was further boosted by ultrasound. The stability of 5-CQA was improved by adding epigallocatechin gallate (EGCG) and vitamin C (VC) respectively.
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Pagacz-Kostrzewa M, Mucha K, Gul W, Wierzejewska M. FTIR spectroscopic evidence for new isomers of 3-aminopyrazine-2-carboxylic acid formed in argon matrices upon UV irradiations. Spectrochim Acta A Mol Biomol Spectrosc 2021; 263:120158. [PMID: 34274637 DOI: 10.1016/j.saa.2021.120158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/28/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
The UV-induced photochemistry and molecular structure of 3-aminopyrazine-2-carboxylic acid were studied in argon matrices by Fourier-transform infrared spectroscopy and B3LYP/6-311++G(2d,2p) calculations. Out of seventeen possible isomers of this molecule located on the singlet potential energy surface the most stable one, APA1 comprising intramolecular O-H···N and N-H···O hydrogen bonds, was detected experimentally in the matrix after deposition. Two new conformers APA2 and APA3 were generated upon irradiation with λ = 280 nm by trans/cis-COOH isomerization and at λ = 360 nm by COOH group rotamerization, respectively, whereas an amino-imino tautomerization leading to IPA1 and IPA2 structures occurred at λ = 305 nm. The reverse reactions were also observed upon irradiation of the matrices at 265, 230 and 400 nm. Simultaneously with the photoisomerizations, a cleavage of the pyrazine ring along with CO2 elimination was observed leading to the formation of carbodiimide and cyanamide derivatives.
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Affiliation(s)
- M Pagacz-Kostrzewa
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland.
| | - K Mucha
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - W Gul
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
| | - M Wierzejewska
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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Dai H, Lee C, Liu W, Yang T, Claret J, Zou X, Dauenhauer PJ, Li X, Rimer JD. Enhanced Selectivity and Stability of Finned Ferrierite Catalysts in Butene Isomerization. Angew Chem Int Ed Engl 2021; 61:e202113077. [PMID: 34877748 DOI: 10.1002/anie.202113077] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Indexed: 11/09/2022]
Abstract
Designing zeolite catalysts with improved mass transport properties is crucial for restrictive networks of either one- or two-dimensional pore topologies. Here, we demonstrate the synthesis of finned ferrierite (FER), a commercial zeolite with two-dimensional pores, where protrusions on crystal surfaces behave as pseudo nanoparticles. Catalytic tests of 1-butene isomerization reveal a 3-fold enhancement of catalyst lifetime and an increase of 12 % selectivity to isobutene for finned samples compared to corresponding seeds. Electron tomography was used to confirm the identical crystallographic registry of fins and seeds. Time-resolved titration of Brønsted acid sites confirmed the improved mass transport properties of finned ferrierite compared to conventional analogues. These findings highlight the advantages of introducing fins through facile and tunable post-synthesis modification to impart material properties that are otherwise unattainable by conventional synthesis methods.
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Affiliation(s)
- Heng Dai
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204, USA
| | - Choongsze Lee
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Wen Liu
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Dalian, 116023, China
| | - Taimin Yang
- Department of Materials and Environmental Chemistry, Stockholm University, 10691, Stockholm, Sweden
| | - Jakob Claret
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204, USA
| | - Xiaodong Zou
- Department of Materials and Environmental Chemistry, Stockholm University, 10691, Stockholm, Sweden
| | - Paul J Dauenhauer
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Xiujie Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Dalian, 116023, China
| | - Jeffrey D Rimer
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204, USA
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Wang D, Liu J, Qiu S, Wang J, Song G, Chu B, Li L, Xiao G, Gong J, Zheng F. Ultrasonic degradation kinetics and isomerization of 3- and 4-O-caffeoylquinic acid at various pH: The protective effects of ascorbic acid and epigallocatechin gallate on their stability. Ultrason Sonochem 2021; 80:105812. [PMID: 34736117 PMCID: PMC8569701 DOI: 10.1016/j.ultsonch.2021.105812] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 10/23/2021] [Accepted: 10/27/2021] [Indexed: 06/13/2023]
Abstract
Caffeoylquinic acids are existed in many plant species with various biological and pharmacological activities. 3-O-caffeoylquinic acid and 4-O-caffeoylquinic acid are two isomers of caffeoylquinic acids, which may be degraded and transformed to their isomers in processing. The present paper found that the stability of 3- and 4-O-caffeoylquinic acid had decreased with the increasing solution alkalinity. 3-O-caffeoylquinic acid was more stable than 4-O-caffeoylquinic acid at the same condition. During degradation, 3- and 4-O-caffeoylquinic acid were partially converted to their isomers. Additionally, ultrasonic effects on the degradation and isomerization of 3- and 4-O-caffeoylquinic acid at different pH were studied. Ultrasound facilitated the degradation and isomerization of these compounds. The degradation kinetics were described by the Weibull equation. The protective effect of ascorbic acid and epigallocatechin gallate were also explored. Ascorbic acid and epigallocatechin gallate could alleviate the degradation of 3- and 4-O-caffeoylquinic acid under certain conditions.
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Affiliation(s)
- Danli Wang
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Jiayuan Liu
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Shaoping Qiu
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Jingjing Wang
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Gongshuai Song
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Bingquan Chu
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Ling Li
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Gongnian Xiao
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China
| | - Jinyan Gong
- Zhejiang Provincial Key Lab for Biological and Chemical Processing Technologies of Farm Product, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China; Beijing Laboratory of Food Quality and Safety, Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100048, China.
| | - Fuping Zheng
- Beijing Laboratory of Food Quality and Safety, Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100048, China.
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Sang-Aroon W, Phatchana R, Tontapha S, Ruangpornvisuti V. A DFT calculation on nonenzymatic degradation of isoaspartic residue. J Mol Model 2021; 27:300. [PMID: 34570254 DOI: 10.1007/s00894-021-04920-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/16/2021] [Indexed: 11/30/2022]
Abstract
βAsp is an isomer of Asp that can be formed by either deamidation of Asn or isomerization of Asp and known as biological clock. The presence of βAsp affects the proteolytic stability of the protein. Formation of the isomerized Asp plays a diverse and crucial role in aging, cancer, autoimmune, neurodegenerative, and other diseases. A number of methods have been developed to detect βAsp, and they are usually used in conjunction. Because of identical mass, differentiation of βAsp and Asp residues is challenged. Degradation of βAsp is still unclear and needed to be explored. The energetics and mechanism of five possible pathways for cleavages at βAsp in peptide model have been investigated by DFT/B3LYP/6-311 + + G(d,p) level of the theory. The calculations show that peptide bond cleavage at α-chain (amino side) due to αOC → αCN ring closure is the most favorable reaction. The result is in agreement with experiment utilizing PSD/CRF method. The second most favorable pathway is due to αOC → βC ring closure results in β-chain cleavage. The cleavage products βAsp and Asp fragments can be used to signify an abundance of βAsp residue in nonenzymatic condition. Other three cyclizations initiated by either α- or β-amino nitrogen result in various cleavages, isomerization to Asp, and reconversion to original βAsp. These three cyclization pathways are obstructed because they require mostly high activation barriers and their intermediates are quite less thermodynamically stable. Thus, computational results also confirm that βAsp → Asp is prohibited in case of nonenzymatic condition which means that protein L-isoaspartyl O-methyl transferase (PIMT) is needed for this modification.
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Affiliation(s)
- Wichien Sang-Aroon
- Department of Chemistry, Faculty of Engineering, Rajamangala University of Technology Isan, KhonKaen Campus, Khon Kaen, 40000, Thailand.
| | - Ratchanee Phatchana
- Department of Chemistry, Faculty of Engineering, Rajamangala University of Technology Isan, KhonKaen Campus, Khon Kaen, 40000, Thailand
| | - Sarawut Tontapha
- Post Doctoral Research Fellow, Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, KhonKaen University, Khon Kaen, 40001, Thailand
| | - Vithaya Ruangpornvisuti
- Supramolecular Chemistry Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, 10320, Thailand
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Dedes G, Karnaouri A, Marianou AA, Kalogiannis KG, Michailof CM, Lappas AA, Topakas E. Conversion of organosolv pretreated hardwood biomass into 5-hydroxymethylfurfural (HMF) by combining enzymatic hydrolysis and isomerization with homogeneous catalysis. Biotechnol Biofuels 2021; 14:172. [PMID: 34454576 PMCID: PMC8403452 DOI: 10.1186/s13068-021-02022-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Over the last few years, valorization of lignocellulosic biomass has been expanded beyond the production of second-generation biofuels to the synthesis of numerous platform chemicals to be used instead of their fossil-based counterparts. One such well-researched example is 5-hydroxymethylfurfural (HMF), which is preferably produced by the dehydration of fructose. Fructose is obtained by the isomerization of glucose, which in turn is derived by the hydrolysis of cellulose. However, to avoid harsh reaction conditions with high environmental impact, an isomerization step towards fructose is necessary, as fructose can be directly dehydrated to HMF under mild conditions. This work presents an optimized process to produce fructose from beechwood biomass hydrolysate and subsequently convert it to HMF by employing homogeneous catalysis. RESULTS The optimal saccharification conditions were identified at 10% wt. solids loading and 15 mg enzyme/gsolids, as determined from preliminary trials on pure cellulose (Avicel® PH-101). Furthermore, since high rate glucose isomerization to fructose requires the addition of sodium tetraborate, the optimum borate to glucose molar ratio was determined to 0.28 and was used in all experiments. Among 20 beechwood solid pulps obtained from different organosolv pretreatment conditions tested, the highest fructose production was obtained with acetone (160 °C, 120 min), reaching 56.8 g/100 g pretreated biomass. A scale-up hydrolysis in high solids (25% wt.) was then conducted. The hydrolysate was subjected to isomerization eventually leading to a high-fructose solution (104.5 g/L). Dehydration of fructose to HMF was tested with 5 different catalysts (HCl, H3PO4, formic acid, maleic acid and H-mordenite). Formic acid was found to be the best one displaying 79.9% sugars conversion with an HMF yield and selectivity of 44.6% and 55.8%, respectively. CONCLUSIONS Overall, this work shows the feasibility of coupling bio- and chemo-catalytic processes to produce HMF from lignocellulose in an environmentally friendly manner. Further work for the deployment of biocatalysts for the oxidation of HMF to its derivatives could pave the way for the emergence of an integrated process to effectively produce biobased monomers from lignocellulose.
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Affiliation(s)
- Grigorios Dedes
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 9 Iroon Polytechniou Str, 15780, Athens, Greece
| | - Anthi Karnaouri
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 9 Iroon Polytechniou Str, 15780, Athens, Greece.
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187, Luleå, Sweden.
| | - Asimina A Marianou
- Center for Research and Technology Hellas, Chemical Process and Energy Resources Institute, 57001, Thessaloniki, Greece
| | - Konstantinos G Kalogiannis
- Center for Research and Technology Hellas, Chemical Process and Energy Resources Institute, 57001, Thessaloniki, Greece
| | - Chrysoula M Michailof
- Center for Research and Technology Hellas, Chemical Process and Energy Resources Institute, 57001, Thessaloniki, Greece
| | - Angelos A Lappas
- Center for Research and Technology Hellas, Chemical Process and Energy Resources Institute, 57001, Thessaloniki, Greece
| | - Evangelos Topakas
- Industrial Biotechnology & Biocatalysis Group, School of Chemical Engineering, National Technical University of Athens, Zografou Campus, 9 Iroon Polytechniou Str, 15780, Athens, Greece.
- Biochemical Process Engineering, Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187, Luleå, Sweden.
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Goossen LJ, Koley D, De S, Sivendran N. Isomerization of Functionalized Olefins Using the Dinuclear Catalyst [PdI(μ-Br)(PtBu3)]2: A Mechanistic Study. Chemistry 2021; 27:15226-15238. [PMID: 34387372 PMCID: PMC8596456 DOI: 10.1002/chem.202102554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Indexed: 11/13/2022]
Abstract
In a combined experimental and computational study, the isomerization activity of the dinuclear palladium(I) complex [PdI(μ‐Br)(PtBu3)]2 towards allyl arenes, esters, amides, ethers, and alcohols has been investigated. The calculated energy profiles for catalyst activation for two alternative dinuclear and mononuclear catalytic cycles, and for catalyst deactivation are in good agreement with the experimental results. Comparison of experimentally observed E/Z ratios at incomplete conversion with calculated kinetic selectivities revealed that a substantial amount of product must form via the dinuclear pathway, in which the isomerization is promoted cooperatively by two palladium centers. The dissociation barrier towards mononuclear Pd species is relatively high, and once the catalyst enters the energetically more favorable mononuclear pathway, only a low barrier has to be overcome towards irreversible deactivation.
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Affiliation(s)
- Lukas J Goossen
- Ruhr-Universität Bochum, Organische Chemie I, Universitätsstraße 150, ZEMOS 2/27, 44801, 44801 Bochum, GERMANY
| | - Debasis Koley
- IISER-K: Indian Institute of Science Education and Research Kolkata, Chemical Sciences, Campus Rd, 741 246, Mohanpur, Nadia, INDIA
| | - Sriman De
- IISER-K: Indian Institute of Science Education and Research Kolkata, Chemical Sciences, Campus Rd, 741 246, Mohanpur, Nadia, INDIA
| | - Nardana Sivendran
- Ruhr-Universität Bochum: Ruhr-Universitat Bochum, Chemistry and Biochemistry, Universitätsstr. 150, ZEMOS, 44795, Bochum, GERMANY
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Kimura M, Ito T, Sato H, Higashi M. Theoretical study on isomerization of α-acids: A DFT calculation. Food Chem 2021; 364:130418. [PMID: 34192634 DOI: 10.1016/j.foodchem.2021.130418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 05/24/2021] [Accepted: 06/17/2021] [Indexed: 11/17/2022]
Abstract
The α-acids contained in hops are one of the ingredients of beer. The isomerization of α-acids produces iso-α-acids, the main source of bitterness in beer. In this study, the isomerization mechanism of the α-acid, cohumulone, was elucidated by using density functional theory in conjunction with the polarizable continuum model or 3D-RISM integral equation theory of liquids. The calculated reaction diagram is consistent with experimental results; the activation free energy difference between the cis and trans isomers is in good agreement with the experimental estimate. The activation energy difference results from solvation energy. Additionally, a calculation of NMR chemical shifts showed that the proton position of isocohumulone is different from that proposed previously. The effect of Mg2+ cation on the isomerization was also investigated. Both the activation and reaction free energy are stabilized by the presence of Mg2+, which is consistent with experimental results. Water solvation reduces the activation free energy.
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Affiliation(s)
- Minami Kimura
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Tadashi Ito
- Department of Chemistry, Biology and Marine Science, University of the Ryukyus, 1 Senbaru, Nishihara, Okinawa 903-0213, Japan
| | - Hirofumi Sato
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan; Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Kyoto 615-8520, Japan; Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Masahiro Higashi
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan; Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Kyoto 615-8520, Japan.
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Alrazi IMD, Sadakane K, Maruta S. Novel photochromic inhibitor for mitotic kinesin Eg5 which forms multiple isomerization states. J Biochem 2021; 170:229-237. [PMID: 33752234 DOI: 10.1093/jb/mvab035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 03/15/2021] [Indexed: 11/14/2022] Open
Abstract
The mitotic kinesin Eg5 is a plus-end directed homotetrameric molecular motor essential for the formation of bipolar spindles during cell division. Kinesin Eg5 is overexpressed in cancer cells and hence considered a target for cancer therapy; the inhibitors specific for Eg5 have been developed as anti-cancer drugs. In this study, we synthesized a novel functional photoresponsive inhibitor composed of spiropyran and azobenzene derivatives to control Eg5 function with multi-stage inhibitory activity accompanied by the formation of different isomerization states. The photochromic inhibitor spiropyran-sulfo-azobenzene (SPSAB) exhibited three isomerization states: Spiro (SP)-trans, Merocyanine (MC)-cis, and MC-trans, upon exposure to visible light (VIS), ultraviolet (UV), and in the dark, respectively. SPSAB induced reversible changes in the inhibitory activity of ATPase and motor activities correlating with photo-isomerization among the three states. Among the three isomerization states of SPSAB, the SP-trans isomer showed potent inhibitory activity at an IC50 value of 30 µM in the basal ATPase assay. MC-trans and MC-cis exhibited less inhibitory activity at IC50 values of 38 µM and 86 µM, respectively. The results demonstrated that the novel photochromic inhibitor enabled precise control of Eg5 function at three different levels using light irradiation.
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Affiliation(s)
- Islam M D Alrazi
- Department of Biosciences, Graduate School of Science and Engineering Soka University, Hachioji, Tokyo, 192-8577, Japan
| | - Kei Sadakane
- Department of Biosciences, Graduate School of Science and Engineering Soka University, Hachioji, Tokyo, 192-8577, Japan
| | - Shinsaku Maruta
- Department of Biosciences, Graduate School of Science and Engineering Soka University, Hachioji, Tokyo, 192-8577, Japan
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Jauregi P, Guo Y, Adeloye JB. Whey proteins-polyphenols interactions can be exploited to reduce astringency or increase solubility and stability of bioactives in foods. Food Res Int 2021; 141:110019. [PMID: 33641953 DOI: 10.1016/j.foodres.2020.110019] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 12/05/2020] [Accepted: 12/09/2020] [Indexed: 11/21/2022]
Abstract
Whey proteins have very interesting properties including, high solubility in water, strong interactions with polyphenols, aggregation properties and are classified as GRAS. Here the application of whey proteins to improve food formulations is evaluated. In particular, the reduction of astringency in wine by whey proteins and peptides was assessed applying an analytical method based on determination of tannins. As shown previously for β-lactoglobulin (β-Lg) and β-Lg-Caseinomacropeptides fractions, here it was shown that hydrolysates interacted with polymeric polyphenols such as tannins which, led to their complexation and precipitation effectively reducing astringency. In addition, nanoparticles of β-Lg and sweet whey were produced by applying a method developed previously in our group based on heat induced denaturation which could consistently produce nanoparticles of 200-300 nm with high colloidal stability. Here further characterisation of β-Lg nanoparticles showed that addition of ethanol up to 28% led to nanoparticles destabilisation mainly due to a reduction in β-Lg overall charge. The application of centrifugal force above 863g led to the disruption of colloidal stability and β-Lg sedimentation. However, nanoparticles were stable to freeze drying conditions. Furthermore, it was shown that sweet whey could be used instead of β-Lg to produce nanoparticles of similar characteristics. These β-Lg nanoparticles formed nanocomplexes with resveratrol which, resulted in improved solubility and increased antioxidant activity under pasteurisation conditions. The isomerization from trans to cis and a protective effect of nanoparticles against some chemical changes that result in reduced activity could explain these results. Thus, whey proteins show promise in their application for improved formulations of food/beverages with bioactive ingredients.
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Honda M, Kageyama H, Hibino T, Osawa Y, Kawashima Y, Hirasawa K, Kuroda I. Evaluation and improvement of storage stability of astaxanthin isomers in oils and fats. Food Chem 2021; 352:129371. [PMID: 33706139 DOI: 10.1016/j.foodchem.2021.129371] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/11/2020] [Accepted: 02/12/2021] [Indexed: 11/26/2022]
Abstract
Astaxanthin Z-isomers potentially have greater bioavailability and biological activity than (all-E)-astaxanthin. However, the stability of the Z-isomers is lower than the all-E-isomer, which is a serious problem affecting its practical use. In this study, we investigated the impacts of different suspension media (oils and fats) and additives on astaxanthin isomer stability and identified suitable ones for astaxanthin stabilization. The evaluations showed that several vegetable oils and antioxidants significantly improved astaxanthin isomer stability, e.g., when soybean and sunflower oils were used as the suspension medium, astaxanthin isomers were hardly degraded; however the total Z-isomer ratio decreased from ~80% to ~50% during 6-week storage at 30 °C. Moreover, it was revealed that (9Z)-astaxanthin showed higher stability than the 13Z- and 15Z-isomers. Hence, to maintain astaxanthin concentration and the Z-isomer ratio over long periods, it is important to use suitable suspension mediums and antioxidants, and select a Z-isomerization method that increases (9Z)-astaxanthin ratio.
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Affiliation(s)
- Masaki Honda
- Faculty of Science & Technology, Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan.
| | - Hakuto Kageyama
- Faculty of Science & Technology, Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan; Graduate School of Environmental and Human Sciences, Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan
| | - Takashi Hibino
- Faculty of Science & Technology, Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan; Graduate School of Environmental and Human Sciences, Meijo University, Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan
| | - Yukiko Osawa
- Biotechnology R&D Group, ENEOS Corporation, Chidoricho, Naka-ku, Yokohama 231-0815, Japan.
| | - Yuki Kawashima
- Biotechnology R&D Group, ENEOS Corporation, Chidoricho, Naka-ku, Yokohama 231-0815, Japan
| | - Kazuaki Hirasawa
- Biotechnology R&D Group, ENEOS Corporation, Chidoricho, Naka-ku, Yokohama 231-0815, Japan
| | - Ikuo Kuroda
- Biotechnology R&D Group, ENEOS Corporation, Chidoricho, Naka-ku, Yokohama 231-0815, Japan
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Urlaub J, Kaiser RP, Scherf-Clavel O, Bolm C, Holzgrabe U. Investigation of isomerization of dexibuprofen in a ball mill using chiral capillary electrophoresis. Electrophoresis 2021; 42:1790-1799. [PMID: 33502037 DOI: 10.1002/elps.202000307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/23/2020] [Accepted: 12/28/2020] [Indexed: 02/02/2023]
Abstract
Besides the racemate, the S-enantiomer of ibuprofen (Ibu) is used for the treatment of inflammation and pain. Since the configurational stability of S-Ibu in solid state is of interest, it was studied by means of ball milling experiments. For the evaluation of the enantiomeric composition, a chiral CE method was developed and validated according to the ICH guideline Q2(R1). The addition of Mg2+ , Ca2+ , or Zn2+ ions to the background electrolyte (BGE) was found to improve Ibu enantioresolution. Chiral separation of Ibu enantiomers was achieved on a 60.2 cm (50.0 cm effective length) x 75 μm fused-silica capillary using a background electrolyte (BGE) composed of 50 mM sodium acetate, 10 mM magnesium acetate tetrahydrate, and 35 mM heptakis-(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CD) as chiral selector. The quantification of R-Ibu in the mixture was performed using the normalization procedure. Linearity was evaluated in the range of 0.68-5.49% R-Ibu (R2 = 0.999), recovery was found to range between 97 and 103%, the RSD of intra- and interday precision below 2.5%, and the limit of quantification for R- in S-Ibu was calculated to be 0.21% (extrapolated) and 0.15% (dilution of racemic ibuprofen), respectively. Isomerization of S-Ibu was observed under basic conditions by applying long milling times and high milling frequencies.
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Affiliation(s)
- Jonas Urlaub
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Würzburg, Germany
| | - Reinhard P Kaiser
- Institute for Organic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Oliver Scherf-Clavel
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Würzburg, Germany
| | - Carsten Bolm
- Institute for Organic Chemistry, RWTH Aachen University, Aachen, Germany
| | - Ulrike Holzgrabe
- Institute for Pharmacy and Food Chemistry, University of Würzburg, Würzburg, Germany
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Agarkar H, Dave D, Das D. Transition metal complexes incorporated with photoswitchable azo-based benzimidazole ligands: Photochromic and solvatochromic studies. Spectrochim Acta A Mol Biomol Spectrosc 2020; 242:118735. [PMID: 32731148 DOI: 10.1016/j.saa.2020.118735] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 07/03/2020] [Accepted: 07/04/2020] [Indexed: 06/11/2023]
Abstract
Photochromic compounds are well-known for their promising applications in many areas. It attracts remarkable attention because of their potential ability for optical memory media and optical switching devices. Herein, we have synthesized azo-based benzimidazole ligand and their transition metal complexes for photochromic applications in the liquid state. The azo-based benzimidazole ligand exhibits trans-to-cis photoisomerization with highly tunable and excellent π-π* and n-π* band separation of ligand, whereas complexes show light-induced photo-dissociation as well as trans-to-cis photoisomerization of the ligand part. The reverse cis-to-trans isomerization can be driven by without using light or any external stimuli at room temperature by keeping the system in the dark condition.
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Affiliation(s)
- Harshawardhan Agarkar
- Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400019, India
| | - Dhwanit Dave
- Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400019, India
| | - Dipanwita Das
- Department of Chemistry, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
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Qin N, Lu X, Liu Y, Qiao Y, Qu W, Feng F, Sun H. Recent research progress of Uncaria spp. based on alkaloids: phytochemistry, pharmacology and structural chemistry. Eur J Med Chem 2020; 210:112960. [PMID: 33148492 DOI: 10.1016/j.ejmech.2020.112960] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 10/16/2020] [Accepted: 10/18/2020] [Indexed: 02/06/2023]
Abstract
Medicinal plants are well-known in affording clinically useful agents, with rich medicinal values by combining with disease targets through various mechanisms. Plant secondary metabolites as lead compounds lay the foundation for the discovery and development of new drugs in disease treatment. Genus Uncaria from Rubiaceae family is a significant plant source of active alkaloids, with anti-hypertensive, sedative, anti-Alzheimer's disease, anti-drug addiction and anti-inflammatory effects. This review summarizes and discuss the research progress of Uncaria based on alkaloids in the past 15 years, mainly in the past 5 years, including biosynthesis, phytochemistry, pharmacology and structural chemistry. Among, focusing on representative compounds rhynchophylline and isorhynchophylline, the pharmacological activities surrounding the central nervous system and cardiovascular system are described in detail. On the basis of case studies, this article provides a brief overview of the synthesis and analogues of representative compounds types. In summary, this review provides an early basis for further searching for new targets and activities, discussing the mechanisms of pharmacological activity and studying the structure-activity relationships of active molecules.
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Affiliation(s)
- Nan Qin
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, 211198, People's Republic of China
| | - Xin Lu
- School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, People's Republic of China
| | - Yijun Liu
- School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, People's Republic of China
| | - Yuting Qiao
- School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, People's Republic of China
| | - Wei Qu
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, 211198, People's Republic of China
| | - Feng Feng
- Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing, 211198, People's Republic of China; Jiangsu Food and Pharmaceutical Science College, Huaian, 223003, People's Republic of China.
| | - Haopeng Sun
- School of Pharmacy, China Pharmaceutical University, Nanjing, 211198, People's Republic of China; Jiangsu Food and Pharmaceutical Science College, Huaian, 223003, People's Republic of China.
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