151
|
Lai CK, Tang WK, Siu CK, Chu IK. Evidence for the Prerequisite Formation of Phenoxyl Radicals in Radical-Mediated Peptide Tyrosine Nitration In Vacuo. Chemistry 2020; 26:331-335. [PMID: 31657861 DOI: 10.1002/chem.201904484] [Citation(s) in RCA: 4] [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: 10/03/2019] [Indexed: 12/30/2022]
Abstract
The elementary mechanism of radical-mediated peptide tyrosine nitration, which is a hallmark of post-translational modification of proteins under nitrative stress in vivo, has been elucidated in detail by using an integrated approach that combines the gas-phase synthesis of prototypical molecular tyrosine-containing peptide radical cations, ion-molecule reactions, and isotopic labeling experiments with DFT calculations. This reaction first involves the radical recombination of . NO2 towards the prerequisite phenoxyl radical tautomer of a tyrosine residue, followed by proton rearrangements, finally yielding the stable and regioselective 3-nitrotyrosyl residue product. In contrast, nitration with the π-phenolic radical cation tautomer is inefficient. This first direct experimental evidence for the elementary steps of the radical-mediated tyrosine nitration mechanism in the gas phase provides a fundamental insight into the regioselectivity of biological tyrosine ortho-nitration.
Collapse
Affiliation(s)
- Cheuk Kuen Lai
- Department of Chemistry, University of Hong Kong, Pokfulam, Hong Kong, S.A.R. China
| | - Wai Kit Tang
- Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong, S.A.R. China
| | - Chi-Kit Siu
- Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong, S.A.R. China
| | - Ivan K Chu
- Department of Chemistry, University of Hong Kong, Pokfulam, Hong Kong, S.A.R. China
| |
Collapse
|
152
|
Akatsuka K, Abe R, Takase T, Oyama D. Coordination Chemistry of Ru(II) Complexes of an Asymmetric Bipyridine Analogue: Synergistic Effects of Supporting Ligand and Coordination Geometry on Reactivities. Molecules 2019; 25:E27. [PMID: 31861731 DOI: 10.3390/molecules25010027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [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: 11/29/2019] [Revised: 12/17/2019] [Accepted: 12/17/2019] [Indexed: 01/09/2023] Open
Abstract
The reactivities of transition metal coordination compounds are often controlled by the environment around the coordination sphere. For ruthenium(II) complexes, differences in polypyridyl supporting ligands affect some types of reactivity despite identical coordination geometries. To evaluate the synergistic effects of (i) the supporting ligands, and (ii) the coordination geometry, a series of dicarbonyl-ruthenium(II) complexes that contain both asymmetric and symmetric bidentate polypyridyl ligands were synthesized. Molecular structures of the complexes were determined by X-ray crystallography to distinguish their steric configuration. Structural, computational, and electrochemical analysis revealed some differences between the isomers. Photo- and thermal reactions indicated that the reactivities of the complexes were significantly affected by both their structures and the ligands involved.
Collapse
|
153
|
Cinà V, Carbonell E, Fusaro L, García H, Gruttadauria M, Giacalone F, Aprile C. Tuneable Emission of Polyhedral Oligomeric Silsesquioxane Based Nanostructures that Self-Assemble in the Presence of Europium(III) Ions: Reversible trans-to-cis Isomerization. Chempluschem 2019; 85:391-398. [PMID: 32118361 DOI: 10.1002/cplu.201900575] [Citation(s) in RCA: 5] [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: 09/22/2019] [Revised: 11/11/2019] [Indexed: 11/10/2022]
Abstract
Hybrid nanostructures with switchable and reversible "blue-red-green" emission were efficiently synthesized. These nanostructures comprise polyhedral oligomeric silsesquioxanes (POSS) that behave as a nanocage that can be functionalized with terpyridine-based organic ligands, which can be easily complexed with europium (III) ions. The complexes were characterized by UV-Vis and fluorescence spectroscopy and their stoichiometry was also confirmed by 1 H NMR spectroscopy. In the presence of the Eu(III) ions, the octafunctionalized nanocages self-assemble to form 3D architectures that display an intense red-emission, especially in the solid state. The presence of an alkenyl group bridging the inorganic core to the organic moiety was employed to tune the emission properties by trans-cis isomerization of the double bond. In the case of the octafunctionalized nanocages (O-POSS), this isomerization was monitored in the presence of Eu(III) cations and was accompanied by an evident colour change from blue (trans-O-POSS) to red (Eu@trans-O-POSS) and finally to green (cis-O-POSS) as consequence of the release of the metal cations. This behaviour, together with the easy dispersion of the dry powder and the possibility of coating as a film in presence of small amounts of solvent, makes the emissive solid promising for applications in materials science.
Collapse
Affiliation(s)
- Valerio Cinà
- Laboratory of Applied Material Chemistry (CMA), University of Namur, 61 rue de Bruxelles, 5000, Namur, Belgium.,Department of Biological Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Ed. 17, 90128, Palermo, Italy
| | - Esther Carbonell
- Laboratory of Applied Material Chemistry (CMA), University of Namur, 61 rue de Bruxelles, 5000, Namur, Belgium
| | - Luca Fusaro
- Laboratory of Applied Material Chemistry (CMA), University of Namur, 61 rue de Bruxelles, 5000, Namur, Belgium
| | - Hermenegildo García
- Department of Chemistry, Instituto de Tecnología Química CSIC-UPV, Universitat Politècnica de València, Av. de los Naranjos s/n, 46022, Valencia, Spain
| | - Michelangelo Gruttadauria
- Department of Biological Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Ed. 17, 90128, Palermo, Italy
| | - Francesco Giacalone
- Department of Biological Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Ed. 17, 90128, Palermo, Italy
| | - Carmela Aprile
- Laboratory of Applied Material Chemistry (CMA), University of Namur, 61 rue de Bruxelles, 5000, Namur, Belgium
| |
Collapse
|
154
|
Wan ZQ, Ren WM, Yang S, Li MR, Gu GG, Lu XB. Reversible Transformation between Amorphous and Crystalline States of Unsaturated Polyesters by Cis-Trans Isomerization. Angew Chem Int Ed Engl 2019; 58:17636-17640. [PMID: 31595601 DOI: 10.1002/anie.201910369] [Citation(s) in RCA: 20] [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: 08/14/2019] [Revised: 10/07/2019] [Indexed: 11/08/2022]
Abstract
An aliphatic polyester has been prepared from ethylene oxide and maleic anhydride that undergoes reversible transformation between amorphous (Tg =18 °C) and crystalline (Tm =124 °C) states through cis-trans isomerization of the C=C bonds in the polymer backbone without any change in either the molecular weight or dispersity of the polymer. A similar transformation was also observed in chiral unsaturated polyesters formed from enantiopure terminal epoxides, such as epichlorohydrin, phenyl glycidyl ether, and (2,3-epoxypropyl)benzene. These unsaturated polyesters with 100 % E-configuration in the crystalline state were prepared by quantitative isomerization of their Z-configuration analogues in the presence of a catalytic amount of diethylamine, while in the presence of benzophenone, irradiation with 365 nm UV light resulted in the transformation of about 30 % trans-alkene to cis-maleate form, thereby affording amorphous polyesters.
Collapse
Affiliation(s)
- Zhao-Qian Wan
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Wei-Min Ren
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Shuai Yang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Ming-Ran Li
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Ge-Ge Gu
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China
| | - Xiao-Bing Lu
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 116024, P. R. China
| |
Collapse
|
155
|
Wheeler R, Yu X, Hou C, Mitra P, Chen JM, Herkules F, Ivanov DN, Tsodikov OV, Rohr J. Discovery of a Cryptic Intermediate in Late Steps of Mithramycin Biosynthesis. Angew Chem Int Ed Engl 2019; 59:826-832. [PMID: 31702856 DOI: 10.1002/anie.201910241] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 08/11/2019] [Revised: 10/14/2019] [Indexed: 12/23/2022]
Abstract
MtmOIV and MtmW catalyze the final two reactions in the mithramycin (MTM) biosynthetic pathway, the Baeyer-Villiger opening of the fourth ring of premithramycin B (PMB), creating the C3 pentyl side chain, strictly followed by reduction of the distal keto group on the new side chain. Unexpectedly this results in a C2 stereoisomer of mithramycin, iso-mithramycin (iso-MTM). Iso-MTM undergoes a non-enzymatic isomerization to MTM catalyzed by Mg2+ ions. Crystal structures of MtmW and its complexes with co-substrate NADPH and PEG, suggest a catalytic mechanism of MtmW. The structures also show that a tetrameric assembly of this enzyme strikingly resembles the ring-shaped β subunit of a vertebrate ion channel. We show that MtmW and MtmOIV form a complex in the presence of PMB and NADPH, presumably to hand over the unstable MtmOIV product to MtmW, yielding iso-MTM, as a potential self-resistance mechanism against MTM toxicity.
Collapse
Affiliation(s)
- Ryan Wheeler
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Xia Yu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA.,Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, 410013, P. R. China
| | - Caixia Hou
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Prithiba Mitra
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Jhong-Min Chen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Frank Herkules
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Dmitri N Ivanov
- Department of Biochemistry, University of Texas Health Science Center, San Antonio, TX, 78229, USA
| | - Oleg V Tsodikov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| | - Jürgen Rohr
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, 789 South Limestone Street, Lexington, KY, 40536-0596, USA
| |
Collapse
|
156
|
Pünner F, Schmidt A, Hilt G. Corrigendum: Up the Hill: Selective Double-Bond Isomerization of Terminal 1,3-Dienes towards Z-1,3-Dienes or 2Z,4E-Dienes. Angew Chem Int Ed Engl 2019; 58:17103. [PMID: 31736259 DOI: 10.1002/anie.201902504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
157
|
Vargas KM, San KA, Shon YS. Isolated Effects of Surface Ligand Density on the Catalytic Activity and Selectivity of Palladium Nanoparticles. ACS Appl Nano Mater 2019; 2:7188-7196. [PMID: 34085029 PMCID: PMC8171273 DOI: 10.1021/acsanm.9b01696] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Alkanethiolate-capped palladium nanoparticles (PdNPs) have previously been synthesized by using a modified Brust-Schiffrin synthesis (using alkanethiosulfate instead of alkanethiol), in which the nanoparticle core size is established during alkanethiosulfate ligand passivation of the nanoparticle nucleation-growth initiated by borohydride reduction. Because of the dependence of core size on the amount of ligand present, surface ligand density decreases with increasing core size. Herein we present a method in which the core size is established independent of ligand addition, allowing the formation of PdNPs with similar core sizes yet different surface ligand densities. In this method, the core size is established during the temporary passivation of growing nanoparticles by borohydride and tetra-N-octylammonium bromide (TOAB), allowing nucleation to reach completion. Various molar equivalents of alkyl thiosulfate are then added, prompting the replacement of borohydride and TOAB and the formation of alkanethiolate-capped PdNPs. The resulting PdNPs were characterized by using 1H NMR, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). The overall enhanced catalytic activity of hydrogenation/isomerization of alkenes and dienes was observed for PdNPs with a lower ligand density, proving the isolated effect of surface ligand density from other variations such as core size and shape. Surface ligand density is also shown to influence the hydrogenation/isomerization product selectivity of the catalytic reactions by regulating the formation of certain Pd-substrate intermediates and the kinetic diffusion of surface hydrogen/substrates.
Collapse
Affiliation(s)
- Kevin M. Vargas
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840, United States
- Keck Energy Materials Program, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840, United States
| | - Khin Aye San
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840, United States
| | - Young-Seok Shon
- Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840, United States
- Keck Energy Materials Program, California State University Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840, United States
- Corresponding Author:. Phone: 562-985-4466. Fax: 562-985-8547
| |
Collapse
|
158
|
Matsusaki M, Okuda A, Matsuo K, Gekko K, Masuda T, Naruo Y, Hirose A, Kono K, Tsuchi Y, Urade R. Regulation of plant ER oxidoreductin 1 (ERO1) activity for efficient oxidative protein folding. J Biol Chem 2019; 294:18820-18835. [PMID: 31685660 DOI: 10.1074/jbc.ra119.010917] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 09/04/2019] [Revised: 10/27/2019] [Indexed: 12/14/2022] Open
Abstract
In the endoplasmic reticulum (ER), ER oxidoreductin 1 (ERO1) catalyzes intramolecular disulfide-bond formation within its substrates in coordination with protein-disulfide isomerase (PDI) and related enzymes. However, the molecular mechanisms that regulate the ERO1-PDI system in plants are unknown. Reduction of the regulatory disulfide bonds of the ERO1 from soybean, GmERO1a, is catalyzed by enzymes in five classes of PDI family proteins. Here, using recombinant proteins, vacuum-ultraviolet circular dichroism spectroscopy, biochemical and protein refolding assays, and quantitative immunoblotting, we found that GmERO1a activity is regulated by reduction of intramolecular disulfide bonds involving Cys-121 and Cys-146, which are located in a disordered region, similarly to their locations in human ERO1. Moreover, a GmERO1a variant in which Cys-121 and Cys-146 were replaced with Ala residues exhibited hyperactive oxidation. Soybean PDI family proteins differed in their ability to regulate GmERO1a. Unlike yeast and human ERO1s, for which PDI is the preferred substrate, GmERO1a directly transferred disulfide bonds to the specific active center of members of five classes of PDI family proteins. Of these proteins, GmPDIS-1, GmPDIS-2, GmPDIM, and GmPDIL7 (which are group II PDI family proteins) failed to catalyze effective oxidative folding of substrate RNase A when there was an unregulated supply of disulfide bonds from the C121A/C146A hyperactive mutant GmERO1a, because of its low disulfide-bond isomerization activity. We conclude that regulation of plant ERO1 activity is particularly important for effective oxidative protein folding by group II PDI family proteins.
Collapse
Affiliation(s)
- Motonori Matsusaki
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Aya Okuda
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Koichi Matsuo
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Kagamiyama, Higashi-hiroshima, Hiroshima 739-0046, Japan
| | - Kunihiko Gekko
- Hiroshima Synchrotron Radiation Center, Hiroshima University, Kagamiyama, Higashi-hiroshima, Hiroshima 739-0046, Japan
| | - Taro Masuda
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yurika Naruo
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Akiho Hirose
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Keiichi Kono
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yuichiro Tsuchi
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Reiko Urade
- Division of Agronomy and Horticultural Science, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
| |
Collapse
|
159
|
Abstract
Donor-acceptor cyclopropanes not only participate in a broad range of ring openings with nucleophiles, electrophiles, radical and red-ox agents, but also are excellent substrates for various (3+n)-cycloaddition and (3+n)-annulation processes. Moreover, under treatment with Lewis acid donor-acceptor cyclopropanes can produce new ring systems via isomerization or cyclodimerization. Authors' contribution to the synthesis of diverse carbocycles from donor-acceptor cyclopropanes is summarized in this account.
Collapse
Affiliation(s)
- Olga A Ivanova
- Department of Chemistry, M.V. Lomonosov Moscow State University, Leninskie Gory 1-3, Moscow, 119991, Russian Federation.,N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky pr. 47, Moscow, 119991, Russian Federation
| | - Igor V Trushkov
- N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky pr. 47, Moscow, 119991, Russian Federation.,Dmitry Rogachev National Research Center of Pediatric Hematology, Oncology and Immunology, Samory Mashela, 1, Moscow, 117997, Russian Federation
| |
Collapse
|
160
|
Tong F, Chen S, Li Z, Liu M, Al-Kaysi RO, Mohideen U, Yin Y, Bardeen CJ. Crystal-to-Gel Transformation Stimulated by a Solid-State E→Z Photo isomerization. Angew Chem Int Ed Engl 2019; 58:15429-15434. [PMID: 31397530 DOI: 10.1002/anie.201907454] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [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: 06/14/2019] [Revised: 08/07/2019] [Indexed: 01/03/2023]
Abstract
The molecule (E)-(5-(3-anthracen-9-yl-allylidene)-2,2-dimethyl-[1,3] dioxane-4,6-dione) (E-AYAD) undergoes E→Z photoisomerization. In the solid state, this photoisomerization process can initiate a physical transformation of the crystal that is accompanied by a large volume expansion (ca. 10 times), loss of crystallinity, and growth of large pores. This physical change requires approximately 10 % conversion of the E isomer to the Z isomer and results in a gel-like solid with decreased stiffness that still retains its mechanical integrity. The induced porosity allows the expanding gel to engulf superparamagnetic nanoparticles from the surrounding liquid. The trapped superparamagnetic nanoparticles impart a magnetic susceptibility to the gel, allowing it to be moved by a magnetic field. The photoinduced phase transition, starting with a compact crystalline solid instead of a dilute solution, provides a new route for in situ production of functional porous materials.
Collapse
Affiliation(s)
- Fei Tong
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Shaolong Chen
- Department of Physics & Astronomy, University of California, Riverside, 900 University Ave, Riverside, CA, 92521, USA
| | - Zhiwei Li
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Mingyue Liu
- Department of Physics & Astronomy, University of California, Riverside, 900 University Ave, Riverside, CA, 92521, USA
| | - Rabih O Al-Kaysi
- College of Science and Health Professions-3124, King Saud bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, Ministry of National Guard Health Affairs, Riyadh, 11426, Kingdom of Saudi Arabia
| | - Umar Mohideen
- Department of Physics & Astronomy, University of California, Riverside, 900 University Ave, Riverside, CA, 92521, USA
| | - Yadong Yin
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA
| | - Christopher J Bardeen
- Department of Chemistry, University of California, Riverside, 501 Big Springs Road, Riverside, CA, 92521, USA
| |
Collapse
|
161
|
Gadais C, Van Holsbeeck K, Moors SLC, Buyst D, Fehér K, Van Hecke K, Tourwé D, Brigaud T, Martin C, De Proft F, Pytkowicz J, Martins JC, Chaume G, Ballet S. Trifluoromethylated Proline Surrogates as Part of "Pro-Pro" Turn-Inducing Templates. Chembiochem 2019; 20:2513-2518. [PMID: 31062451 DOI: 10.1002/cbic.201900294] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 05/03/2019] [Indexed: 12/27/2022]
Abstract
Proline is often found as a turn inducer in peptide or protein domains. Exploitation of its restricted conformational freedom led to the development of the d-Pro-l-Pro (corresponding to (R)-Pro-(S)-Pro) segment as a "templating" unit, frequently used in the design of β-hairpin peptidomimetics, in which conformational stability is, however, inherently linked to the cis-trans isomerization of the prolyl amide bonds. In this context, the stereoelectronic properties of the CF3 group can aid in conformational control. Herein, the impact of α-trifluoromethylated proline analogues is examined for the design of enhanced β-turn inducers. A theoretical conformational study permitted the dipeptide (R)-Pro-(R)-TfmOxa (TfmOxa: 2-trifluoromethyloxazolidine-2-carboxylic acid) to be selected as a template with an increased trans-cis rotational energy barrier. NMR spectroscopic analysis of the Ac-(R)-Pro-(R)-TfmOxa-(S)-Val-OtBu β-turn model, obtained through an original synthetic pathway, validated the prevalence of a major trans-trans conformer and indicated the presence of an internal hydrogen bond. Altogether, it was shown that the (R)-Pro-(R)-TfmOxa template fulfilled all crucial β-turn-inducer criteria.
Collapse
Affiliation(s)
- Charlène Gadais
- Research Group of Organic Chemistry, Departments of Bioengineering Sciences and Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Kevin Van Holsbeeck
- Research Group of Organic Chemistry, Departments of Bioengineering Sciences and Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.,NMR and Structure Analysis Unit, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281, 9000, Gent, Belgium
| | - Samuel L C Moors
- Eenheid Algemene Chemie (ALGC), Department of Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Dieter Buyst
- NMR and Structure Analysis Unit, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281, 9000, Gent, Belgium
| | - Krisztina Fehér
- NMR and Structure Analysis Unit, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281, 9000, Gent, Belgium
| | - Kristof Van Hecke
- XStruct Bio-Inorganic Group, Department of Chemistry, Ghent University, Krijgslaan 281, 9000, Gent, Belgium
| | - Dirk Tourwé
- Research Group of Organic Chemistry, Departments of Bioengineering Sciences and Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Thierry Brigaud
- Laboratoire de Chimie Biologique, Université de Cergy-Pontoise, 5 Mail Gay-Lussac, 95031, Cergy-Pontoise cedex, France
| | - Charlotte Martin
- Research Group of Organic Chemistry, Departments of Bioengineering Sciences and Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Frank De Proft
- Eenheid Algemene Chemie (ALGC), Department of Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| | - Julien Pytkowicz
- Laboratoire de Chimie Biologique, Université de Cergy-Pontoise, 5 Mail Gay-Lussac, 95031, Cergy-Pontoise cedex, France
| | - José C Martins
- NMR and Structure Analysis Unit, Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281, 9000, Gent, Belgium
| | - Grégory Chaume
- Laboratoire de Chimie Biologique, Université de Cergy-Pontoise, 5 Mail Gay-Lussac, 95031, Cergy-Pontoise cedex, France
| | - Steven Ballet
- Research Group of Organic Chemistry, Departments of Bioengineering Sciences and Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium
| |
Collapse
|
162
|
Li J, Bisoyi HK, Lin S, Guo J, Li Q. 1,2-Dithienyldicyanoethene-Based, Visible-Light-Driven, Chiral Fluorescent Molecular Switch: Rewritable Multimodal Photonic Devices. Angew Chem Int Ed Engl 2019; 58:16052-16056. [PMID: 31487106 DOI: 10.1002/anie.201908832] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [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: 07/15/2019] [Indexed: 12/20/2022]
Abstract
Reported here is the first example of a 1,2-dithienyldicyanoethene-based visible-light-driven chiral fluorescent molecular switch that exhibits reversible trans to cis photoisomerization. The trans form in solution almost completely transforms into the cis form, accompanied by a 10-fold decrease in its fluorescence intensity within 60 seconds when exposed to green light (520 nm). The reverse isomerization proceeds upon irradiation with blue light (405 nm). When doped into commercially available achiral liquid crystal hosts, this molecular switch efficiently induces luminescent helical superstructures, that is, a cholesteric phase. The intensity of the circularly polarized fluorescence as well as the selective reflection wavelength of the induced cholesteric phases can be reversibly tuned using visible light of two different wavelengths. Optically rewritable photonic devices using cholesteric films containing this molecular switch are described.
Collapse
Affiliation(s)
- Juntao Li
- Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Hari Krishna Bisoyi
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
| | - Siyang Lin
- Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Jinbao Guo
- Key Laboratory of Carbon Fibers and Functional Polymers, Ministry of Education, and College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Quan Li
- Advanced Materials and Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
| |
Collapse
|
163
|
Klemmer L, Kaiser Y, Huch V, Zimmer M, Scheschkewitz D. Persistent Digermenes with Acyl and α-Chlorosilyl Functionalities. Chemistry 2019; 25:12187-12195. [PMID: 31306508 PMCID: PMC6852044 DOI: 10.1002/chem.201902553] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 06/04/2019] [Revised: 07/12/2019] [Indexed: 11/25/2022]
Abstract
We report the preparation of α‐chlorosilyl‐ and acyl‐substituted digermenes. Unlike the corresponding transient disilenes, these species with a Ge=Ge double bond show an unexpectedly low tendency for cyclization, but in turn are prone to thermal Ge=Ge bond cleavage. Triphenylsilyldigermene has been isolated as a crystalline model compound, and is the first fully characterized example of a neutral digermene with an A2GeGeAB substitution pattern. Spectroscopic and computational evidence prove the constitution of 1‐adamantoyldigermene as a first persistent species with a heavy double bond conjugated with a carbonyl moiety.
Collapse
Affiliation(s)
- Lukas Klemmer
- Krupp Chair of General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Yvonne Kaiser
- Krupp Chair of General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Volker Huch
- Krupp Chair of General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Michael Zimmer
- Krupp Chair of General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - David Scheschkewitz
- Krupp Chair of General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| |
Collapse
|
164
|
Baláž M, Kudličková Z, Vilková M, Imrich J, Balážová Ľ, Daneu N. Mechanochemical Synthesis and Isomerization of N-Substituted Indole-3-carboxaldehyde Oximes †. Molecules 2019; 24:molecules24183347. [PMID: 31540034 PMCID: PMC6766794 DOI: 10.3390/molecules24183347] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 07/29/2019] [Accepted: 09/11/2019] [Indexed: 11/16/2022] Open
Abstract
Performing solution-phase oximation reactions with hydroxylamine hydrochloride (NH2OH·HCl) carries significant risk, especially in aqueous solutions. In the present study, four N-substituted indole-3-carboxaldehyde oximes were prepared from the corresponding aldehydes by solvent-free reaction with NH2OH·HCl and a base (NaOH or Na2CO3) using a mechanochemical approach, thus minimizing the possible risk. In all cases, the conversion to oximes was almost complete. The focus of this work is on 1-methoxyindole-3-carboxaldehyde oxime, a key intermediate in the production of indole phytoalexins with useful antimicrobial properties. Under optimized conditions, it was possible to reach almost 95% yield after 20 min of milling. Moreover, for the products containing electron-donating substituents (-CH3, -OCH3), the isomerization from the oxime anti to syn isomer under acidic conditions was discovered. For the 1-methoxy analog, the acidic isomerization of pure isomers in solution resulted in the formation of anti isomer, whereas the prevalence of syn isomer was observed in solid state. From NMR data the syn and anti structures of produced oximes were elucidated. This work shows an interesting and possibly scalable alternative to classical synthesis and underlines environmentally friendly and sustainable character of mechanochemistry.
Collapse
Affiliation(s)
- Matej Baláž
- Department of Mechanochemistry, Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, 04001 Košice, Slovakia.
| | - Zuzana Kudličková
- Department of Chemistry, Biochemistry and Biophysics, University of Veterinary Medicine and Pharmacy, Komenského 73, 04181 Košice, Slovakia.
| | - Mária Vilková
- NMR Laboratory, Faculty of Science, P. J. Šafárik University, Moyzesova 11, 04001 Košice, Slovakia.
| | - Ján Imrich
- NMR Laboratory, Faculty of Science, P. J. Šafárik University, Moyzesova 11, 04001 Košice, Slovakia.
| | - Ľudmila Balážová
- Department of Pharmacognosy and Botany, University of Veterinary Medicine and Pharmacy, Komenského 73, 04181 Košice, Slovakia.
| | - Nina Daneu
- Advanced Materials Department, Jožef Stefan Institute, Jamova cesta 39, 1000 Ljubljana, Slovenia.
| |
Collapse
|
165
|
Abstract
The breast cancer type-1 susceptibility protein (BRCA1) contributes to genome integrity through homologous recombinational DNA repair and by protecting stalled replication forks from nucleolytic degradation. We recently discovered that fork protection requires a conformational change of BRCA1 unimportant to homologous recombination repair, indicating separate roles for BRCA1 in these pathways.
Collapse
Affiliation(s)
- Manuel Daza-Martin
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, UK
| | - Ruth M. Densham
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, UK
| | - Joanna R. Morris
- Birmingham Centre for Genome Biology and Institute of Cancer and Genomics Sciences, University of Birmingham, Birmingham, UK
| |
Collapse
|
166
|
Xue S, Kuzuhara D, Aratani N, Yamada H. Control of Aromaticity and cis-/trans-Isomeric Structure of Non-Planar Hexaphyrin(2.1.2.1.2.1) and Metal Complexes. Angew Chem Int Ed Engl 2019; 58:12524-12528. [PMID: 31287217 DOI: 10.1002/anie.201906946] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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: 06/04/2019] [Indexed: 11/10/2022]
Abstract
Vinylene-bridged hexaphyrin(2.1.2.1.2.1) was synthesized from dipyrrolyl diphenylethenes by acid-catalyzed condensation reactions. Freebase hexaphyrin(2.1.2.1.2.1) forms a distorted structure with non-aromatic characteristics. The aromaticity and molecular configuration of non-planar hexaphyrin(2.1.2.1.2.1) can be controlled by insertion of metal ions. Freebase and zinc complexes show a distorted structure without macrocyclic aromaticity, whereas copper complexes show a figure-of-eight structure with macrocyclic aromaticity. It is the first example of aromaticity conversion of a distorted expanded porphyrin involving vinylene bridges.
Collapse
Affiliation(s)
- Songlin Xue
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan
| | - Daiki Kuzuhara
- Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Iwate, 020-8551, Japan
| | - Naoki Aratani
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan
| | - Hiroko Yamada
- Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikoma, Nara, 630-0192, Japan
| |
Collapse
|
167
|
Zhou K, Cao X, Bautista J, Chen Z, Hershey N, Ludwig R, Tao L, Zeng M, Das TK. Structure-Function Assessment and High-Throughput Quantification of Site-Specific Aspartate Isomerization in Monoclonal Antibody Using a Novel Analytical Tool Kit. J Pharm Sci 2019; 109:422-428. [PMID: 31469998 DOI: 10.1016/j.xphs.2019.08.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [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: 05/10/2019] [Revised: 08/14/2019] [Accepted: 08/21/2019] [Indexed: 12/13/2022]
Abstract
Isomerization of surface-exposed aspartic acid (Asp) in the complementarity-determining regions of therapeutic proteins could potentially impact their target binding affinity because of the sensitive location, and often requires complex analytical tactics to understand its effect on structure-function and stability. Inaccurate quantitation of Asp-isomerized variants, especially the succinimide intermediate, presents major challenge in understanding Asp degradation kinetics, its stability, and consequently establishing a robust control strategy. As a practical solution to this problem, a comprehensive analytical tool kit has been developed, which provides a solution to fully characterize and accurately quantify the Asp-related product variants. The toolkit offers a combination of 2 steps, an ion-exchange chromatography method to separate and enrich the isomerized variants in the folded structure for structure-function evaluation and a novel focused peptide mapping method to quantify the individual complementarity-determining region isomerization components including the unmodified Asp, succinimide, and isoaspartate. This novel procedure allowed an accurate quantification of each Asp-related variant and a comprehensive assessment of the functional impact of Asp isomerization, which ultimately helped to establish an appropriate control strategy for this critical quality attribute.
Collapse
Affiliation(s)
- Kaimeng Zhou
- Drug Product Science and Technology, Bristol-Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08901
| | - Xiang Cao
- Analytical Development, BioTherapeutics Development, Janssen Research & Development, LLC, 200 Great Valley Pkwy, Malvern, Pennsylvania 19355
| | - James Bautista
- Drug Product Science and Technology, Bristol-Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08901
| | - Zhi Chen
- Drug Product Science and Technology, Bristol-Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08901
| | - Neil Hershey
- Analytical Development, BioTherapeutics Development, Janssen Research & Development, LLC, 200 Great Valley Pkwy, Malvern, Pennsylvania 19355
| | - Richard Ludwig
- Biophysical and Chemical Characterization Center of Excellence, Bristol-Myers Squibb, 311 Pennington Rocky Hill Rd, Pennington, New Jersey 08534
| | - Li Tao
- Biophysical and Chemical Characterization Center of Excellence, Bristol-Myers Squibb, 311 Pennington Rocky Hill Rd, Pennington, New Jersey 08534
| | - Ming Zeng
- Drug Product Science and Technology, Bristol-Myers Squibb, 1 Squibb Drive, New Brunswick, New Jersey 08901.
| | - Tapan K Das
- Biophysical and Chemical Characterization Center of Excellence, Bristol-Myers Squibb, 311 Pennington Rocky Hill Rd, Pennington, New Jersey 08534
| |
Collapse
|
168
|
Larocca AV, Toniolo G, Tortorella S, Krokidis MG, Menounou G, Di Bella G, Chatgilialoglu C, Ferreri C. The Entrapment of Somatostatin in a Lipid Formulation: Retarded Release and Free Radical Reactivity. Molecules 2019; 24:E3085. [PMID: 31450691 DOI: 10.3390/molecules24173085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 08/10/2019] [Revised: 08/19/2019] [Accepted: 08/22/2019] [Indexed: 11/25/2022] Open
Abstract
The natural peptide somatostatin has hormonal and cytostatic effects exerted by the binding to specific receptors in various tissues. Therapeutic uses are strongly prevented by its very short biological half-life of 1–2 min due to enzymatic hydrolysis, therefore encapsulation methodologies are explored to overcome the need for continuous infusion regimes. Multilamellar liposomes made of natural phosphatidylcholine were used for the incorporation of a mixture of somatostatin and sorbitol dissolved in citrate buffer at pH = 5. Lyophilization and reconstitution of the suspension were carried out, showing the flexibility of this preparation. Full characterization of this suspension was obtained as particle size, encapsulation efficiency and retarded release properties in aqueous medium and human plasma. Liposomal somatostatin incubated at 37 °C in the presence of Fe(II) and (III) salts were used as a biomimetic model of drug-cell membrane interaction, evidencing the free radical processes of peroxidation and isomerization that transform the unsaturated fatty acid moieties of the lipid vesicles. This study offers new insights into a liposomal delivery system and highlights molecular reactivity of sulfur-containing drugs with its carrier or biological membranes for pharmacological applications.
Collapse
|
169
|
Getter T, Gulati S, Zimmerman R, Chen Y, Vinberg F, Palczewski K. Stereospecific modulation of dimeric rhodopsin. FASEB J 2019; 33:9526-9539. [PMID: 31121099 PMCID: PMC6662988 DOI: 10.1096/fj.201900443rr] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 04/23/2019] [Indexed: 11/11/2022]
Abstract
The classic concept that GPCRs function as monomers has been challenged by the emerging evidence of GPCR dimerization and oligomerization. Rhodopsin (Rh) is the only GPCR whose native oligomeric arrangement was revealed by atomic force microscopy demonstrating that Rh exists as a dimer. However, the role of Rh dimerization in retinal physiology is currently unknown. In this study, we identified econazole and sulconazole, two small molecules that disrupt Rh dimer contacts, by implementing a cell-based high-throughput screening assay. Racemic mixtures of identified lead compounds were separated and tested for their stereospecific binding to Rh using UV-visible spectroscopy and intrinsic fluorescence of tryptophan (Trp) 265 after illumination. By following the changes in UV-visible spectra and Trp265 fluorescence in vitro, we found that binding of R-econazole modulates the formation of Meta III and quenches the intrinsic fluorescence of Trp265. In addition, electrophysiological ex vivo recording revealed that R-econazole slows photoresponse kinetics, whereas S-econazole decreased the sensitivity of rods without effecting the kinetics. Thus, this study contributes new methodology to identify compounds that disrupt the dimerization of GPCRs in general and validates the first active compounds that disrupt the Rh dimer specifically.-Getter, T., Gulati, S., Zimmerman, R., Chen, Y., Vinberg, F., Palczewski, K. Stereospecific modulation of dimeric rhodopsin.
Collapse
Affiliation(s)
- Tamar Getter
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California–Irvine, California, USA
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA
| | - Sahil Gulati
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California–Irvine, California, USA
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Physiology and Biophysics, University of California–Irvine, Irvine, California, USA
| | - Remy Zimmerman
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California–Irvine, California, USA
| | - Yuanyuan Chen
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Frans Vinberg
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA
| | - Krzysztof Palczewski
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California–Irvine, California, USA
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Physiology and Biophysics, University of California–Irvine, Irvine, California, USA
| |
Collapse
|
170
|
Zhang Y, Han B, Zhu S. Rapid Access to Highly Functionalized Alkyl Boronates by NiH-Catalyzed Remote Hydroarylation of Boron-Containing Alkenes. Angew Chem Int Ed Engl 2019; 58:13860-13864. [PMID: 31287597 DOI: 10.1002/anie.201907185] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [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: 06/09/2019] [Indexed: 02/05/2023]
Abstract
The direct and selective functionalization of relatively simple and readily accessible precursors to produce highly functionalized alkyl boronates is a synthetically useful process. Herein we report a NiH-catalyzed remote hydroarylation process that can, through a synergistic combination of chain walking and subsequent cross-coupling, introduce an aryl group at the adjacent carbon atom of alkyl boronates under mild conditions. By means of a preliminary experiment with moderate enantioselectivity, it was shown that an asymmetric version could also be realized.
Collapse
Affiliation(s)
- Yao Zhang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Bo Han
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Shaolin Zhu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| |
Collapse
|
171
|
Dajnowicz S, Langan PS, Weiss KL, Ivanov IN, Kovalevsky A. Room-temperature photo-induced martensitic transformation in a protein crystal. IUCrJ 2019; 6:619-629. [PMID: 31316806 PMCID: PMC6608640 DOI: 10.1107/s2052252519005761] [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] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 04/26/2019] [Indexed: 06/10/2023]
Abstract
Martensitic transformations are the first-order crystal-to-crystal phase transitions that occur mostly in materials such as steel, alloys and ceramics, thus having many technological applications. These phase transitions are rarely observed in molecular crystals and have not been detected in protein crystals. Reversibly switchable fluorescent proteins are widely used in biotechnology, including super-resolution molecular imaging, and hold promise as candidate biomaterials for future high-tech applications. Here, we report on a reversibly switchable fluorescent protein, Tetdron, whose crystals undergo a photo-induced martensitic transformation at room temperature. Room-temperature X-ray crystallography demonstrates that at equilibrium Tetdron chromophores are all in the trans configuration, with an ∼1:1 mixture of their protonated and deprotonated forms. Irradiation of a Tetdron crystal with 400 nm light induces a martensitic transformation, which results in Tetdron tetramerization at room temperature revealed by X-ray photocrystallography. Crystal and solution spectroscopic measurements provide evidence that the photo-induced martensitic phase transition is coupled with the chromophore deprotonation, but no trans-cis isomerization is detected in the structure of an irradiated crystal. It is hypothesized that protein dynamics assists in the light-induced proton transfer from the chromophore to the bulk solvent and in the ensuing martensitic phase transition. The unique properties of Tetdron may be useful in developing novel biomaterials for optogenetics, data storage and nanotechnology.
Collapse
Affiliation(s)
- Steven Dajnowicz
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Patricia S. Langan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Ilia N. Ivanov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| |
Collapse
|
172
|
Dajnowicz S, Langan PS, Weiss KL, Ivanov IN, Kovalevsky A. Room-temperature photo-induced martensitic transformation in a protein crystal. Corrigendum. IUCrJ 2019; 6:781. [PMID: 31318360 PMCID: PMC6608638 DOI: 10.1107/s2052252519007851] [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: 06/10/2023]
Abstract
[This retracts the article DOI: 10.1107/S2052252519005761.].
Collapse
Affiliation(s)
- Steven Dajnowicz
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, USA
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Patricia S. Langan
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Ilia N. Ivanov
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| |
Collapse
|
173
|
Abstract
Heating and cooling can induce reversible solid-to-liquid transitions of matter. In contrast, athermal photochemical processes can induce reversible solid-to-liquid transitions of some newly developed azobenzene compounds. Azobenzene is photoswitchable. UV light induces trans-to-cis isomerization; visible light or heat induces cis-to-trans isomerization. Trans and cis isomers usually have different melting points (Tm ) or glass transition temperatures (Tg ). If Tm or Tg of an azobenzene compound in trans and cis forms are above and below room temperature, respectively, light may induce reversible solid-to-liquid transitions. In this Review, we introduce azobenzene compounds that exhibit photoinduced reversible solid-to-liquid transitions, discuss the mechanisms and design principles, and show their potential applications in healable coatings, adhesives, transfer printing, lithography, actuators, fuels, and gas separation. Finally, we discuss remaining challenges in this field.
Collapse
Affiliation(s)
- Wen-Cong Xu
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Jinzhai Road 96, Hefei, 230026, China
| | - Shaodong Sun
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Jinzhai Road 96, Hefei, 230026, China
| | - Si Wu
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Jinzhai Road 96, Hefei, 230026, China
| |
Collapse
|
174
|
Spiegelberg B, Dell'Acqua A, Xia T, Spannenberg A, Tin S, Hinze S, de Vries JG. Additive-Free Isomerization of Allylic Alcohols to Ketones with a Cobalt PNP Pincer Catalyst. Chemistry 2019; 25:7820-7825. [PMID: 30973658 DOI: 10.1002/chem.201901148] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 03/11/2019] [Indexed: 11/06/2022]
Abstract
Catalytic isomerization of allylic alcohols in ethanol as a green solvent was achieved by using air and moisture stable cobalt (II) complexes in the absence of any additives. Under mild conditions, the cobalt PNP pincer complex substituted with phenyl groups on the phosphorus atoms appeared to be the most active. High rates were obtained at 120 °C, even though the addition of one equivalent of base increases the speed of the reaction drastically. Although some evidence was obtained supporting a dehydrogenation-hydrogenation mechanism, it was proven that this is not the major mechanism. Instead, the cobalt hydride complex formed by dehydrogenation of ethanol is capable of double-bond isomerization through alkene insertion-elimination.
Collapse
Affiliation(s)
- Brian Spiegelberg
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Strasse 29a, 18059, Rostock, Germany
| | - Andrea Dell'Acqua
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Strasse 29a, 18059, Rostock, Germany
| | - Tian Xia
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Strasse 29a, 18059, Rostock, Germany
| | - Anke Spannenberg
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Strasse 29a, 18059, Rostock, Germany
| | - Sergey Tin
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Strasse 29a, 18059, Rostock, Germany
| | - Sandra Hinze
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Strasse 29a, 18059, Rostock, Germany
| | - Johannes G de Vries
- Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Strasse 29a, 18059, Rostock, Germany
| |
Collapse
|
175
|
Tam DY, Zhuang X, Wong SW, Lo PK. Photoresponsive Self-Assembled DNA Nanomaterials: Design, Working Principles, and Applications. Small 2019; 15:e1805481. [PMID: 30861628 DOI: 10.1002/smll.201805481] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [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: 12/24/2018] [Revised: 01/30/2019] [Indexed: 05/23/2023]
Abstract
Photoresponsive DNA nanomaterials represent a new class of remarkable functional materials. By adjusting the irradiation wavelength, light intensity, and exposure time, various photocontrolled DNA-based systems can be reversibly or irreversibly regulated in respect of their size, shape, conformation, movement, and dissociation/association. This Review introduces the most updated progress in the development of photoresponsive DNA-based system and emphasizes their advantages over other stimuli-responsive systems. Their design and mechanisms to trigger the photoresponses are shown and discussed. The potential application of these photon-responsive DNA nanomaterials in biology, biomedicine, materials science, nanophotonic and nanoelectronic are also covered and described. The challenges faced and further directions of the development of photocontrolled DNA-based systems are also highlighted.
Collapse
Affiliation(s)
- Dick Yan Tam
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China
| | - Xinyu Zhuang
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China
| | - Sze Wing Wong
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China
| | - Pik Kwan Lo
- Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR, China
- Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong, Shenzhen, 518057, China
| |
Collapse
|
176
|
Abstract
Gold is currently one of the most used metals in organometallic catalysis. The ability of gold to activate unsaturated groups in different modes, together with its tolerance to a wide range of functional groups and reaction conditions, turns gold-based complexes into efficient and highly sought after catalysts. Natural products and relevant compounds with biological and pharmaceutical activity are often characterized by complex molecular structures. (Cyclo)isomerization reactions are often a useful strategy for the generation of this molecular complexity from synthetically accessible reactants. In this review, we collect the most recent contributions in which gold(I)- and/or gold(III)-catalysts mediate intramolecular (cyclo)isomerization transformations of unsaturated species, which commonly feature allene or alkyne motifs, and organize them depending on the substrate and the reaction type.
Collapse
Affiliation(s)
- Marta Marín-Luna
- Departamento de Química Orgánica, Universidade de Vigo, Vigo, Spain
| | | | | |
Collapse
|
177
|
Abstract
Azo dyes that combine electron-withdrawing thiazole/benzothiazole heterocycles and electron-donating amino groups within the very same covalent skeleton exhibit relaxation times for their thermal isomerization kinetics within milli- and microsecond timescales at room temperature. Notably, the thermal back reaction of the corresponding benzothiazolium and thiazolium salts occurred much faster, within the picosecond temporal domain. In fact, these new light-sensitive platforms are the first molecular azo derivatives capable of reversible switching between their trans and cis isomers in a subnanosecond timescale under ambient conditions. In addition, theoretical calculations revealed very low activation energies for the isomerization process, in accordance with the fast subnanosecond kinetics that were observed experimentally.
Collapse
Affiliation(s)
- Jaume Garcia-Amorós
- Grup de Materials Orgànics, Institut de Nanociència i Nanotecnologia (IN2UB), Departament de Química Inorgànica i Orgànica, (Secció de Química Orgànica), Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
| | - Benjamin Maerz
- Chair for BioMolecular Optics, Department of Physics, Ludwigs-Maximilians-University, Oettingenstrasse 67, 80538, Munich, Germany
| | - Marta Reig
- Grup de Materials Orgànics, Institut de Nanociència i Nanotecnologia (IN2UB), Departament de Química Inorgànica i Orgànica, (Secció de Química Orgànica), Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
| | - Alba Cuadrado
- Grup de Materials Orgànics, Institut de Nanociència i Nanotecnologia (IN2UB), Departament de Química Inorgànica i Orgànica, (Secció de Química Orgànica), Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
| | - Lluís Blancafort
- Institut de Química Computacional i Catàlisi and Departament de Química, Universitat de Girona, Campus de Montilivi, 17003, Girona, Spain
| | - Elena Samoylova
- Chair for BioMolecular Optics, Department of Physics, Ludwigs-Maximilians-University, Oettingenstrasse 67, 80538, Munich, Germany
| | - Dolores Velasco
- Grup de Materials Orgànics, Institut de Nanociència i Nanotecnologia (IN2UB), Departament de Química Inorgànica i Orgànica, (Secció de Química Orgànica), Universitat de Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
| |
Collapse
|
178
|
Sun W, Liu C, Duan H, Niu C, Wang J, Zheng F, Li Y, Li Q. Isomerization of Gibberellic Acid During the Brewing Process. J Food Sci 2019; 84:1353-1361. [PMID: 31066915 DOI: 10.1111/1750-3841.14620] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 12/26/2018] [Revised: 03/16/2019] [Accepted: 03/19/2019] [Indexed: 12/17/2022]
Abstract
Gibberellic acid (GA3) was added to three types of beer barley, and the chemical changes to GA3 during the beer brewing process were studied using HPLC. The results demonstrated that the GA3 concentration decreased throughout the malting, mashing, and boiling processes and that no GA3 was detected in the congress wort. A new substance, herein called Substance A, was detected by HPLC analysis using a C18 column; this substance exhibited retention characteristics different from GA3. The concentration of Substance A increased throughout the malting, mashing, and boiling processes. Mass spectrometry revealed that Substance A has the same molecular weight as GA3 and nuclear magnetic resonance studies determined that Substance A is a structural isomer of GA3. PRACTICAL APPLICATION: This study developed a new idea to understand GA3 behavior during the brewing, which provided a practical reference for food safety in beer and other fields using GA3 as a food additive.
Collapse
Affiliation(s)
- Weikang Sun
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China.,Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China
| | - Chunfeng Liu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China.,Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China
| | - Hongxu Duan
- School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China
| | - Chengtuo Niu
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China.,Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China
| | - Jinjing Wang
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China.,Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China
| | - Feiyun Zheng
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China.,Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China
| | - Yongxian Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China.,Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China
| | - Qi Li
- Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China.,Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan Univ., Wuxi, 214122, China
| |
Collapse
|
179
|
He ZC, Mellerup SK, Liu L, Wang X, Dao C, Wang S. Reversible Photo isomerization from Borepin to Boratanorcaradiene and Double Aryl Migration from Boron to Carbon. Angew Chem Int Ed Engl 2019; 58:6683-6687. [PMID: 30912238 DOI: 10.1002/anie.201902231] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [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: 02/19/2019] [Indexed: 01/29/2023]
Abstract
B(npy)Ar2 (npy=2-(naphthalen-1-yl)pyridine) compounds bearing various nonbulky aryl groups undergo a clean and sequential two-step photoisomerization in which two aryl substituents on boron migrate to a carbon atom of the naphthyl moiety. The second isomerization step is the first example of a reversible photoisoermization between a borepin and a borirane. Both steric and electronic factors have been found to have a great impact on this photoreactivity. Furthermore, the borirane isomer reacts with oxygen, forming a rare oxaborepin dimer.
Collapse
Affiliation(s)
- Zhe-Chang He
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Soren K Mellerup
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Lijie Liu
- Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing, P. R. China
| | - Xiang Wang
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Caitlin Dao
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada
| | - Suning Wang
- Department of Chemistry, Queen's University, 90 Bader Lane, Kingston, Ontario, K7L 3N6, Canada.,Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, 5 South Zhongguancun Street, Beijing, P. R. China
| |
Collapse
|
180
|
Wang L, Zhang Y, Zhan C, You Y, Zhang H, Ma J, Xiong Z, Liu X, Wei R. Synthesis and Photoinduced Anisotropy of Polymers Containing Nunchaku-Like Unit with an Azobenzene and a Mesogen. Polymers (Basel) 2019; 11:E600. [PMID: 30960583 DOI: 10.3390/polym11040600] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 03/14/2019] [Revised: 03/25/2019] [Accepted: 03/25/2019] [Indexed: 02/06/2023] Open
Abstract
A series of polymers containing nunchaku-like unit with an azo chromophore and a mesogen group was successfully prepared and photoinduced anisotropy of the obtained polymers was minutely investigated. Firstly, monomers containing nunchaku-like unit with an azo chromophore and a mesogen group linked by flexible group were synthesized. The structure of the monomers was confirmed via NMR COSY spectra. Subsequently, the obtained monomers were polymerized into corresponding polymers through RAFT polymerization. The prepared polymer samples were characterized through NMR, FTIR, gel permeation chromatography (GPC), and UV-vis testing while the thermal properties of the samples were investigated through differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) measurements. The photoinduced isomerization of the polymers, which was researched in situ via measuring UV-vis spectra of the polymer solutions and spin-coated films under irradiation with 450 nm light or putting in darkness, demonstrated the rapid trans-cis-trans isomerization of the polymers. When irradiated with a linearly polarized light, significant photoinduced birefringence and dichroism were observed, suggesting photoinduced isomerization of azobenzene can drive orientation of mesogen in the system. This study blazes a way to design the optical materials with light-controllable birefringence and dichroism.
Collapse
|
181
|
Tang Y, Fields C. A UHPLC-UV Method Development and Validation for Determining Kavalactones and Flavokavains in Piper methysticum (Kava). Molecules 2019; 24:E1245. [PMID: 30934989 PMCID: PMC6479543 DOI: 10.3390/molecules24071245] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 03/21/2019] [Accepted: 03/27/2019] [Indexed: 12/14/2022] Open
Abstract
An ultra-high-performance liquid chromatographic (UHPLC) separation was developed for six kava pyrones (methysticin, dihydromethysticin (DHM), kavain, dihydrokavain (DHK), desmethoxyyangonin (DMY), and yangonin), two unidentified components, and three Flavokavains (Flavokavain A, B, and C) in Piper methysticum (kava). The six major kavalactones and three flavokavains are completely separated (Rs > 1.5) within 15 min using a HSS T3 column and a mobile phase at 60 °C. All the peaks in the LC chromatogram of kava extract or standard solutions were structurally confirmed by LC-UV-MS/MS. The degradations of yangonin and flavokavains were observed among the method development. The degradation products were identified as cis-isomerization by MS/MS spectra. The isomerization was prevented or limited by sample preparation in a non-alcoholic solvent or with no water. The method uses the six kava pyrones and three flavokavains as external standards. The quantitative calibration curves are linear, covering a range of 0.5⁻75 μg/mL for the six kava pyrones and 0.05⁻7.5 μg/mL for the three flavokavains. The quantitation limits for methysticin, DHM, kavain, DHK, DMY, and yangonin are approximately 0.454, 0.480, 0.277, 0.686, 0.189, and 0.422 μg/mL. The limit of quantification (LOQs) of the three flavokavains are about 0.270, 0.062, and 0.303 μg/mL for flavokavain C (FKC), flavokavain A (FKA), and flavokavain B (FKB). The average recoveries at three different levels are 99.0⁻102.3% for kavalactones (KLs) and 98.1⁻102.9% for flavokavains (FKs). This study demonstrates that the method of analysis offers convenience and adequate sensitivity for determining methysticin, DHM, kavain, DHK, yangonin, DMY, FKA, FKB, and FKC in kava raw materials (root and CO₂ extract) and finished products (dry-filled capsule and tablet).
Collapse
Affiliation(s)
- Yijin Tang
- Applied Food Sciences, Inc., 2500 Crosspark Road, Coralville, IA 52241, USA.
| | - Christine Fields
- Applied Food Sciences, Inc., 2500 Crosspark Road, Coralville, IA 52241, USA.
| |
Collapse
|
182
|
Luo Z, Liu T, Chen Z, Xiao Y, Zhang G, Huo L, Zhong C, Lu X, Yan H, Sun Y, Yang C. Isomerization of Perylene Diimide Based Acceptors Enabling High-Performance Nonfullerene Organic Solar Cells with Excellent Fill Factor. Adv Sci (Weinh) 2019; 6:1802065. [PMID: 30937273 PMCID: PMC6425449 DOI: 10.1002/advs.201802065] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/18/2018] [Indexed: 05/06/2023]
Abstract
A strategy that employs the central-core regiochemistry to develop two isomeric perylene diimide (PDI)-based small molecular acceptors (SMAs), BPT-Se and BPT-Se1, is introduced, and the effect of the central-core regiochemistry on the optical, electronic, charge-transport, photovoltaic, and morphological properties of the molecules and their devices is investigated. The PDBT-T1:BPT-Se1-based device delivers a power conversion efficiency (PCE) of 9.54% with an excellent fill factor (FF) of 73.2%, while the BPT-Se-based device yields a PCE of 7.78%. The large improvement of PCE upon isomerization of BPT-Se should be ascribed to the concurrent enhancement of FF, short circuit current ( J SC), and open circuit voltage (V OC) of the PDBT-T1:BPT-Se1 devices. The higher FF of the organic solar cells (OSCs) based on PDBT-T1:BPT-Se1 can be attributed to the higher charge dissociation and charge collection efficiency, less bimolecular combination, more balanced µ h/µ e, better molecular packing and a more favorable morphology. It is worth mentioning that the FF of 73.2% is the highest value for PDI-based SMAs OSCs to date. The result shows that regiochemistry of the central core in PDI-based SMAs greatly affects the physicochemical properties and photovoltaic performance. The success of the isomerization strategy offers exciting prospects for the molecular design of PDI-based SMAs.
Collapse
Affiliation(s)
- Zhenghui Luo
- Hubei Key Lab on Organic and Polymeric Optoelectronic MaterialsDepartment of ChemistryWuhan UniversityWuhan430072P. R. China
- Shenzhen Key Laboratory of Polymer Science and TechnologyCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Tao Liu
- School of ChemistryBeihang UniversityBeijing100191P. R. China
- Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & ReconstructionHong Kong University of Science and Technology (HKUST)Clear Water BayKowloonHong Kong999077P. R. China
| | - Zhanxiang Chen
- Hubei Key Lab on Organic and Polymeric Optoelectronic MaterialsDepartment of ChemistryWuhan UniversityWuhan430072P. R. China
| | - Yiqun Xiao
- Department of PhysicsChinese University of Hong KongNew TerritoriesHong Kong999077P. R. China
| | - Guangye Zhang
- Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & ReconstructionHong Kong University of Science and Technology (HKUST)Clear Water BayKowloonHong Kong999077P. R. China
| | - Lijun Huo
- School of ChemistryBeihang UniversityBeijing100191P. R. China
| | - Cheng Zhong
- Hubei Key Lab on Organic and Polymeric Optoelectronic MaterialsDepartment of ChemistryWuhan UniversityWuhan430072P. R. China
| | - Xinhui Lu
- Department of PhysicsChinese University of Hong KongNew TerritoriesHong Kong999077P. R. China
| | - He Yan
- Department of Chemistry and Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration & ReconstructionHong Kong University of Science and Technology (HKUST)Clear Water BayKowloonHong Kong999077P. R. China
| | - Yanming Sun
- School of ChemistryBeihang UniversityBeijing100191P. R. China
| | - Chuluo Yang
- Hubei Key Lab on Organic and Polymeric Optoelectronic MaterialsDepartment of ChemistryWuhan UniversityWuhan430072P. R. China
- Shenzhen Key Laboratory of Polymer Science and TechnologyCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
| |
Collapse
|
183
|
Zhang JQ, Zhang DS, Chen QJ, Xu HB, Kurmoo M, Zeng MH. Thermally Induced trans-to-cis Isomerization and Its Photoinduced Reversal Monitored using Absorption and Luminescence: Cooperative Effect of Metal Coordination and Steric Substituent. Chemistry 2019; 25:5177-5185. [PMID: 30740800 DOI: 10.1002/chem.201900204] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [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: 01/14/2019] [Indexed: 11/07/2022]
Abstract
For ethene derivatives with large groups the cis-isomer is often quite unstable and unavailable. Herein, we report an exception of two stable coordination complexes, (cis-L)ZnCl2 , starting from trans-1,2-bis(1-R-benzo[d]imidazol-2-yl)ethene (R=H, L1; R=CH3 , L2) ligands under solvothermal condition (T ≥140 °C). Using the intensity of the absorption and luminescence spectra as probes we proposed its progressive cis-to-trans reversal upon irradiation with UV light, which was confirmed by powder X-ray diffraction (PXRD). Similar results observed in the series of (cis-L2)MII Cl2 [M=Fe (4), Co (5), Ni (6)] demonstrate the universal strategy. The results of PXRD, NMR spectroscopy, ESI-MS and DFT calculations support the above conclusion. NMR spectroscopy indicates that irradiation of 1 converts an optimized 71 % of the cis-isomer to trans, whereas the free trans-L1 ligand transforms to only 15 % cis-isomer under similar conditions.
Collapse
Affiliation(s)
- Jun-Quan Zhang
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, P. R. China
| | - De-Shan Zhang
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, P. R. China
| | - Qiu-Jie Chen
- Key Laboratory for the Synthesis and Application of, Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan, 430062, P. R. China
| | - Hai-Bing Xu
- Key Laboratory for the Synthesis and Application of, Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan, 430062, P. R. China
| | - Mohamedally Kurmoo
- Université de Strasbourg, Institut de Chimie de Strasbourg, CNRS-UMR7177, 4 rue Blaise Pascal, Strasbourg Cedex, 67070, France
| | - Ming-Hua Zeng
- Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, 541004, P. R. China.,Key Laboratory for the Synthesis and Application of, Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan, 430062, P. R. China
| |
Collapse
|
184
|
Adhikari B, Aratsu K, Davis J, Yagai S. Photoresponsive Circular Supramolecular Polymers: A Topological Trap and Photoinduced Ring-Opening Elongation. Angew Chem Int Ed Engl 2019; 58:3764-3768. [PMID: 30632667 DOI: 10.1002/anie.201811237] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [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: 09/30/2018] [Indexed: 02/05/2023]
Abstract
Topological features of one-dimensional macromolecular chains govern the properties and functionality of natural and synthetic polymers. To address this issue in supramolecular polymers, we synthesized two topologically distinct supramolecular polymers with intrinsic curvature, circular and helically folded nanofibers, from azobenzene-functionalized supramolecular rosettes. When a mixture of circular and helically folded nanofibers was exposed to UV light, selective unfolding of the latter open-ended supramolecular polymers was observed as a result of the curvature-impairing internal force produced by the trans-to-cis photoisomerization of the azobenzene. This distinct sensitivity suggests that the topological features of supramolecular polymers define their mechanical stability. Furthermore, the exposure of circular supramolecular polymers in more polar media to UV irradiation resulted in ring opening followed by chain elongation, thus demonstrating that the circular supramolecular polymer can function as a topological kinetic trap.
Collapse
Affiliation(s)
- Bimalendu Adhikari
- Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.,Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Keisuke Aratsu
- Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Joyal Davis
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Knowledge City, Sector 81, S. A. S. Nagar, Manauli PO, Punjab, 140306, India
| | - Shiki Yagai
- Graduate School of Engineering, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.,Institute for Global Prominent Research (IGPR), Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| |
Collapse
|
185
|
Zhou F, Zhang Y, Xu X, Zhu S. NiH-Catalyzed Remote Asymmetric Hydroalkylation of Alkenes with Racemic α-Bromo Amides. Angew Chem Int Ed Engl 2019; 58:1754-1758. [PMID: 30548518 DOI: 10.1002/anie.201813222] [Citation(s) in RCA: 129] [Impact Index Per Article: 25.8] [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: 11/19/2018] [Indexed: 12/12/2022]
Abstract
Reported here is a terminal-selective, remote asymmetric hydroalkylation of olefins with racemic α-bromo amides. The reaction proceeds by NiH-catalyzed alkene isomerization and subsequent alkylation reaction, and can enantioconvergently introduce an unsymmetrical secondary alkyl group from a racemic α-bromo amide onto a terminal C(sp3 )-H position along the hydrocarbon chain of the alkene. This mild process affords a range of structurally diverse chiral α-alkylalkanoic amides in excellent yields, and high regio- and enantioselectivities. In addition, the synthetic utility of this protocol is further highlighted by the regioconvergent conversion of industrial raw materials of isomeric olefin mixtures into enantioriched α-alkylalkanoic amides on large scale.
Collapse
Affiliation(s)
- Fang Zhou
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Yao Zhang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Xianfeng Xu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| | - Shaolin Zhu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, China
| |
Collapse
|
186
|
Muraoka T, Shima T, Kajitani T, Hoshino N, Morvan E, Grélard A, Dufourc EJ, Fukushima T, Akutagawa T, Nabeya K, Kinbara K. Heat-Triggered Crystallization of Liquid Crystalline Macrocycles Allowing for Conductance Switching through Hysteretic Thermal Phase Transitions. Chem Asian J 2019; 14:141-148. [PMID: 30371022 DOI: 10.1002/asia.201801372] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 09/12/2018] [Indexed: 11/11/2022]
Abstract
A polymesomorphic thermal phase-transition of a macrocyclic amphiphile consisting of aromatic groups and oligoethylene glycol (OEG) chains is reported. The macrocyclic amphiphile exists in a highly-ordered liquid crystal (LC) phase at room temperature. Upon heating, this macrocycle shows phase-transition from columnar-lamellar to nematic LC phases followed by crystallization before melting. Spectroscopic studies suggest that the thermally induced crystallization is triggered by a conformational change at the OEG chains. Interestingly, while the macrocycle returns to the columnar-lamellar phase after cooling from the isotropic liquid, it retains the crystallinity after cooling from the thermally-induced crystal. Thanks to this bistability, conductance switching was successfully demonstrated. A different macrocyclic amphiphile also shows an analogous phase-transition behavior, suggesting that this molecular design is universal for developing switchable and memorizable materials, by means of hysteretic phase-transition processes.
Collapse
Affiliation(s)
- Takahiro Muraoka
- Department of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.,PRESTO, Japan Science and Technology Agency, 4-1-8, Honcho, Kawaguchi, Saitama, 332-0012, Japan
| | - Tatsuya Shima
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Takashi Kajitani
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.,RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo, Hyogo, 679-5148, Japan
| | - Norihisa Hoshino
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Estelle Morvan
- European Institute of Chemistry and Biology, University of Bordeaux, UMS 3033, CNRS, INSERM, 2 rue Robert Escarpit, 33607, Pessac, France
| | - Axelle Grélard
- Institute of Chemistry and Biology of Membranes and Nano-objects, University of Bordeaux, UMR 5248, CNRS, Bordeaux INP, allée Geoffroy Saint Hilaire, 33600, Pessac, France
| | - Erick J Dufourc
- Institute of Chemistry and Biology of Membranes and Nano-objects, University of Bordeaux, UMR 5248, CNRS, Bordeaux INP, allée Geoffroy Saint Hilaire, 33600, Pessac, France
| | - Takanori Fukushima
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan
| | - Tomoyuki Akutagawa
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Kota Nabeya
- Department of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan
| | - Kazushi Kinbara
- Department of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.,Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai, 980-8577, Japan
| |
Collapse
|
187
|
Schultze C, Schmidt B. Ring-closing-metathesis-based synthesis of annellated coumarins from 8-allylcoumarins. Beilstein J Org Chem 2018; 14:2991-2998. [PMID: 30591822 PMCID: PMC6296409 DOI: 10.3762/bjoc.14.278] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [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: 09/13/2018] [Accepted: 11/22/2018] [Indexed: 11/23/2022] Open
Abstract
8-Allylcoumarins are conveniently accessible through a microwave-promoted tandem Claisen rearrangement/Wittig olefination/cyclization sequence. They serve as a versatile platform for the annellation of five- to seven-membered rings using ring-closing olefin metathesis (RCM). Furano-, pyrano-, oxepino- and azepinocoumarins were synthesized from the same set of precursors using Ru-catalyzed double bond isomerizations and RCM in a defined order. One class of products, pyrano[2,3-f]chromene-2,8-diones, were inaccessible through direct RCM of an acrylate, but became available from the analogous allyl ether via an assisted tandem catalytic RCM/allylic oxidation sequence.
Collapse
Affiliation(s)
- Christiane Schultze
- Universität Potsdam, Institut fuer Chemie, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam-Golm, Germany
| | - Bernd Schmidt
- Universität Potsdam, Institut fuer Chemie, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam-Golm, Germany
| |
Collapse
|
188
|
Zhou QQ, Zou YQ, Lu LQ, Xiao WJ. Visible-Light-Induced Organic Photochemical Reactions through Energy-Transfer Pathways. Angew Chem Int Ed Engl 2018; 58:1586-1604. [PMID: 29774651 DOI: 10.1002/anie.201803102] [Citation(s) in RCA: 552] [Impact Index Per Article: 92.0] [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: 03/14/2018] [Revised: 05/17/2018] [Indexed: 12/25/2022]
Abstract
Visible-light photocatalysis is a rapidly developing and powerful strategy to initiate organic transformations, as it closely adheres to the tenants of green and sustainable chemistry. Generally, most visible-light-induced photochemical reactions occur through single-electron transfer (SET) pathways. Recently, visible-light-induced energy-transfer (EnT) reactions have received considerable attentions from the synthetic community as this strategy provides a distinct reaction pathway, and remarkable achievements have been made in this field. In this Review, we highlight the most recent advances in visible-light-induced EnT reactions.
Collapse
Affiliation(s)
- Quan-Quan Zhou
- CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University (CCNU), 152 Luoyu Road, Wuhan, Hubei, 430079, China
| | - You-Quan Zou
- CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University (CCNU), 152 Luoyu Road, Wuhan, Hubei, 430079, China
| | - Liang-Qiu Lu
- CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University (CCNU), 152 Luoyu Road, Wuhan, Hubei, 430079, China
| | - Wen-Jing Xiao
- CCNU-uOttawa Joint Research Centre, Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University (CCNU), 152 Luoyu Road, Wuhan, Hubei, 430079, China
| |
Collapse
|
189
|
Abstract
Cell cycle progression is tightly controlled by many cell cycle-regulatory proteins that are in turn regulated by a family of cyclin-dependent kinases (CDKs) through protein phosphorylation. The peptidyl-prolyl cis/trans isomerase PIN1 provides a further post-phosphorylation modification and functional regulation of these CDK-phosphorylated proteins. PIN1 specifically binds the phosphorylated serine or threonine residue preceding a proline (pSer/Thr-Pro) motif of its target proteins and catalyzes the cis/trans isomerization on the pSer/Thr-Pro peptide bonds. Through this phosphorylation-dependent prolyl isomerization, PIN1 fine-tunes the functions of various cell cycle-regulatory proteins including retinoblastoma protein (Rb), cyclin D1, cyclin E, p27, Cdc25C, and Wee1. In this review, we discussed the essential roles of PIN1 in regulating cell cycle progression through modulating the functions of these cell cycle-regulatory proteins. Furthermore, the mechanisms underlying PIN1 overexpression in cancers were also explored. Finally, we examined and summarized the therapeutic potential of PIN1 inhibitors in cancer therapy.
Collapse
Affiliation(s)
- Chi-Wai Cheng
- Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Eric Tse
- Department of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| |
Collapse
|
190
|
Dudek M, Deiana M, Pokladek Z, Pawlik K, Matczyszyn K. Reversible Photocontrol of DNA Melting by Visible-Light-Responsive F4-Coordinated Azobenzene Compounds. Chemistry 2018; 24:18963-18970. [PMID: 30198626 DOI: 10.1002/chem.201803529] [Citation(s) in RCA: 9] [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: 07/10/2018] [Indexed: 12/23/2022]
Abstract
Spatiotemporal control over the regulation of intra- and intermolecular motions in naturally occurring systems is systematically studied to expand the toolbox of mechanical operations in multicomponent nanoarchitectures. DNA is ideally suited for programming light-powered processes that are based on a minimalist molecular design. Here, the noncovalent incorporation of bistable photoswitches into B-like DNA moieties is shown to trigger the thermal transition midpoint of the duplexes by converting visible light into directed mechanical work by orchestrating the collective actions of the photoresponsive chromophores and the host DNA nanostructures. Besides its practical applications, the resulting hybrid nanosystem bears unique features of modulability, biocompatibility, reversibility, and addressability, which are key components for developing molecular photon-controlled programmed materials.
Collapse
Affiliation(s)
- Marta Dudek
- Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370, Wroclaw, Poland
| | - Marco Deiana
- Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370, Wroclaw, Poland
| | - Ziemowit Pokladek
- Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370, Wroclaw, Poland
| | - Krzysztof Pawlik
- Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Rudolfa Weigla 12, 53-114, Wroclaw, Poland
| | - Katarzyna Matczyszyn
- Advanced Materials Engineering and Modelling Group, Faculty of Chemistry, Wroclaw University of Science and Technology, Wyb. Wyspianskiego 27, 50-370, Wroclaw, Poland
| |
Collapse
|
191
|
Schmidt D, Rodat T, Heintze L, Weber J, Horbert R, Girreser U, Raeker T, Bußmann L, Kriegs M, Hartke B, Peifer C. Axitinib: A Photoswitchable Approved Tyrosine Kinase Inhibitor. ChemMedChem 2018; 13:2415-2426. [PMID: 30199151 DOI: 10.1002/cmdc.201800531] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [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: 08/07/2018] [Indexed: 12/20/2022]
Abstract
The goal of photopharmacology is to develop photoswitchable enzyme modulators as tunable (pro-)drugs that can be spatially and temporally controlled by light. In this context, the tyrosine kinase inhibitor axitinib, which contains a photosensitive stilbene-like moiety that allows for E/Z isomerization, is of interest. Axitinib is an approved drug that targets the vascular endothelial growth factor receptor 2 (VEGFR2) and is licensed for second-line therapy of renal cell carcinoma. The photoinduced E/Z isomerization of axitinib has been investigated to explore if its inhibitory effect can be turned "on" and "off", as triggered by light. Under controlled light conditions, (Z)-axitinib is 43 times less active than that of the E isomer in an VEGFR2 assay. Furthermore, it was proven that kinase activity in human umbilical vein cells (HUVECs) was decreased by (E)-axitinib, but only weakly affected by (Z)-axitinib. By irradiating (Z)-axitinib in vitro with UV light (λ=385 nm), it is possible to switch it almost quantitatively into the E isomer and to completely restore the biological activity of (E)-axitinib. However, switching the biological activity off from (E)- to (Z)-axitinib was not possible in aqueous solution due to a competing irreversible [2+2]-photocycloaddition, which yielded a biologically inactive axitinib dimer.
Collapse
Affiliation(s)
- Dorian Schmidt
- Institute of Pharmacy, Christian Albrechts University of Kiel, Gutenbergstraße 76, 24116, Kiel, Germany
| | - Theo Rodat
- Institute of Pharmacy, Christian Albrechts University of Kiel, Gutenbergstraße 76, 24116, Kiel, Germany
| | - Linda Heintze
- Institute of Pharmacy, Christian Albrechts University of Kiel, Gutenbergstraße 76, 24116, Kiel, Germany
| | - Jantje Weber
- Institute of Pharmacy, Christian Albrechts University of Kiel, Gutenbergstraße 76, 24116, Kiel, Germany
| | - Rebecca Horbert
- Institute of Pharmacy, Christian Albrechts University of Kiel, Gutenbergstraße 76, 24116, Kiel, Germany
| | - Ulrich Girreser
- Institute of Pharmacy, Christian Albrechts University of Kiel, Gutenbergstraße 76, 24116, Kiel, Germany
| | - Tim Raeker
- Institute for Physical Chemistry, Christian Albrechts University of Kiel, Max-Eyth-Strasse 1, 24118, Kiel, Germany
| | - Lara Bußmann
- University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, Department of Otorhinolaryngology and Head and Neck Surgery, Martinistrasse 52, 20246, Hamburg, Germany.,Laboratory of Radiobiology & Experimental Radiooncology and UCCH Kinomics Core Facility, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Malte Kriegs
- Laboratory of Radiobiology & Experimental Radiooncology and UCCH Kinomics Core Facility, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Bernd Hartke
- Institute for Physical Chemistry, Christian Albrechts University of Kiel, Max-Eyth-Strasse 1, 24118, Kiel, Germany
| | - Christian Peifer
- Institute of Pharmacy, Christian Albrechts University of Kiel, Gutenbergstraße 76, 24116, Kiel, Germany
| |
Collapse
|
192
|
Liu L, Xu K, Li J, Maia M, Mathieu M, Elliott R, Yang J, Nijem I, Kaur S. Optimizing hybrid LC-MS/MS binding conditions is critical: impact of biotransformation on quantification of trastuzumab. Bioanalysis 2018; 10:1819-31. [PMID: 30325201 DOI: 10.4155/bio-2018-0196] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Background: Hybrid ligand-binding (LB) LC-MS/MS protein quantitative assays involve a LB step for analyte enrichment that has less stringent requirements than the conventional LB assays. Results: Herceptin™(trastuzumab) binding to HER2 extracellular domain was evaluated using on-bead and off-bead capture formats. The two formats yielded significantly different trastuzumab concentrations in human and monkey serum pharmacokinetic samples. Biotransformations, including deamidation of asparagine and isomerization of aspartic acid near the complementarity-determining regions of trastuzumab, had a profound impact on the LB step for analyte enrichment and trastuzumab quantification. Conclusion: Quantitative measurements were profoundly impacted by LB conditions in a hybrid LB LC-MS/MS protein assay due to biotransformations. Therefore, similar to conventional LB assays, binding conditions should be carefully evaluated during assay development.
Collapse
|
193
|
Amatov T, Jangra H, Pohl R, Cisařová I, Zipse H, Jahn U. Unique Stereoselective Homolytic C-O Bond Activation in Diketopiperazine-Derived Alkoxyamines by Adjacent Amide Pyramidalization. Chemistry 2018; 24:15336-15345. [PMID: 30092124 DOI: 10.1002/chem.201803284] [Citation(s) in RCA: 6] [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: 06/28/2018] [Revised: 08/02/2018] [Indexed: 12/12/2022]
Abstract
Simple monocyclic diketopiperazine (DKP)-derived alkoxyamines exhibit unprecedented activation of a remote C-O bond for homolysis by amide distortion. The combination of strain-release-driven amide planarization and the persistent radical effect (PRE) enables a unique, irreversible, and quantitative trans→cis isomerization under much milder conditions than typically observed for such homolysis-limited reactions. This isomerization is shown to be general and independent of the steric and electronic nature of both the amino acid side chains and the substituents at the DKP nitrogen atoms. Homolysis rate constants are determined, and they significantly differ for both the labile trans diastereomers and the stable cis diastereomers. To reveal the factors influencing this unusual process, structural features of the kinetic trans diastereomers and thermodynamic cis diastereomers are investigated in the solid state and in solution. X-ray crystallographic analysis and computational studies indicate substantial distortion of the amide bond from planarity in the trans-alkoxyamines, and this is believed to be the cause for the facile and quantitative isomerization. Thus, these amino-acid-derived alkoxyamines are the first examples that exhibit a large thermodynamic preference for one diastereomer over the other upon thermal homolysis, and this allows controlled switching of configurations and configurational cycling.
Collapse
Affiliation(s)
- Tynchtyk Amatov
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 16610, Prague, Czech Republic.,Ludwig Maximilian University, Department of Chemistry, Butenandstrasse 5-13, 81377, München, Germany
| | - Harish Jangra
- Ludwig Maximilian University, Department of Chemistry, Butenandstrasse 5-13, 81377, München, Germany
| | - Radek Pohl
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 16610, Prague, Czech Republic
| | - Ivana Cisařová
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 12843, Prague, Czech Republic
| | - Hendrik Zipse
- Ludwig Maximilian University, Department of Chemistry, Butenandstrasse 5-13, 81377, München, Germany
| | - Ullrich Jahn
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 16610, Prague, Czech Republic
| |
Collapse
|
194
|
Abstract
Metal migration through a carbon chain is a versatile method for achieving remote functionalization. However, almost all known examples involve the overall net migration of alkylmetal species. Here, we report that allylrhodium species obtained from hydrorhodation of 1,3-dienes undergo chain walking toward esters, amides, or (hetero)arenes over distances of up to eight methylene units. The final, more highly conjugated allylrhodium species undergo nucleophilic allylation with aldehydes and with an imine to give Z-homoallylic alcohols and amines, respectively.
Collapse
Affiliation(s)
- Alistair Groves
- The GlaxoSmithKline Carbon Neutral Laboratories for Sustainable, Chemistry, University of Nottingham, Jubilee Campus, Triumph Road, Nottingham, NG7 2TU, UK.,School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Jose I Martínez
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Joshua J Smith
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Hon Wai Lam
- The GlaxoSmithKline Carbon Neutral Laboratories for Sustainable, Chemistry, University of Nottingham, Jubilee Campus, Triumph Road, Nottingham, NG7 2TU, UK.,School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| |
Collapse
|
195
|
Checco JW, Zhang G, Yuan WD, Le ZW, Jing J, Sweedler JV. Aplysia allatotropin-related peptide and its newly identified d-amino acid-containing epimer both activate a receptor and a neuronal target. J Biol Chem 2018; 293:16862-16873. [PMID: 30194283 DOI: 10.1074/jbc.ra118.004367] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [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: 06/08/2018] [Revised: 09/04/2018] [Indexed: 12/13/2022] Open
Abstract
l- to d-residue isomerization is a post-translational modification (PTM) present in neuropeptides, peptide hormones, and peptide toxins from several animals. In most cases, the d-residue is critical for the biological function of the resulting d-amino acid-containing peptide (DAACP). Here, we provide an example in native neuropeptides in which the DAACP and its all-l-amino acid epimer are both active at their newly identified receptor in vitro and at a neuronal target associated with feeding behavior. On the basis of sequence similarity to a known DAACP from cone snail venom, we hypothesized that allatotropin-related peptide (ATRP), a neuropeptide from the neuroscience model organism Aplysia californica, may form multiple diastereomers in the Aplysia central nervous system. We determined that ATRP exists as a d-amino acid-containing peptide (d2-ATRP) and identified a specific G protein-coupled receptor as an ATRP receptor. Interestingly, unlike many previously reported DAACPs and their all-l-residue analogs, both l-ATRP and d2-ATRP were potent agonists of this receptor and active in electrophysiological experiments. Finally, d2-ATRP was much more stable than its all-l-residue counterpart in Aplysia plasma, suggesting that in the case of ATRP, the primary role of the l- to d-residue isomerization may be to protect this peptide from aminopeptidase activity in the extracellular space. Our results indicate that l- to d-residue isomerization can occur even in an all-l-residue peptide with a known biological activity and that in some cases, this PTM may help modulate peptide signal lifetime in the extracellular space rather than activity at the cognate receptor.
Collapse
Affiliation(s)
- James W Checco
- From the Beckman Institute for Advanced Science and Technology and
| | - Guo Zhang
- the State Key Laboratory of Pharmaceutical Biotechnology, Institute for Brain Sciences, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Jiangsu 210046, China
| | - Wang-Ding Yuan
- the State Key Laboratory of Pharmaceutical Biotechnology, Institute for Brain Sciences, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Jiangsu 210046, China
| | - Zi-Wei Le
- the State Key Laboratory of Pharmaceutical Biotechnology, Institute for Brain Sciences, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Jiangsu 210046, China
| | - Jian Jing
- the State Key Laboratory of Pharmaceutical Biotechnology, Institute for Brain Sciences, Collaborative Innovation Center of Chemistry for Life Sciences, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, Advanced Institute for Life Sciences, School of Life Sciences, Nanjing University, Jiangsu 210046, China
| | - Jonathan V Sweedler
- From the Beckman Institute for Advanced Science and Technology and .,the Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 and
| |
Collapse
|
196
|
Abstract
Central to the development of optoelectronic devices is the availability of efficient synthetic molecular photoswitches, the design of which is an arena where the evolving concept of excited-state aromaticity (ESA) is yet to make a big impact. The aim of this minireview is to illustrate the potential of this concept to become a key tool for the future design of photoswitches. The paper starts with a discussion of challenges facing the use of photoswitches for applications and continues with an account of how the ESA concept has progressed since its inception. Then, following some brief remarks on computational modeling of photoswitches and ESA, the paper describes two different approaches to improve the quantum yields and response times of switches driven by E/Z photoisomerization or photoinduced H-atom/proton transfer reactions through simple ESA considerations. It is our hope that these approaches, verified by quantum chemical calculations and molecular dynamics simulations, will help stimulate the application of the ESA concept as a general tool for designing more efficient photoswitches and other functional molecules used in optoelectronic devices.
Collapse
Affiliation(s)
- Bo Durbeej
- Division of Theoretical Chemistry, IFM, Linköping University, SE-581 83, Linköping, Sweden
| | - Jun Wang
- Division of Theoretical Chemistry, IFM, Linköping University, SE-581 83, Linköping, Sweden
| | - Baswanth Oruganti
- Division of Theoretical Chemistry, IFM, Linköping University, SE-581 83, Linköping, Sweden.,Department of Chemistry, GITAM Institute of Science (GIS), GITAM University, Visakhapatnam-, 530045, Andhra Pradesh, India
| |
Collapse
|
197
|
Xu A, Kim HS, Estee S, ViaJar S, Galush WJ, Gill A, Hötzel I, Lazar GA, McDonald P, Andersen N, Spiess C. Susceptibility of Antibody CDR Residues to Chemical Modifications Can Be Revealed Prior to Antibody Humanization and Aid in the Lead Selection Process. Mol Pharm 2018; 15:4529-4537. [PMID: 30118239 DOI: 10.1021/acs.molpharmaceut.8b00536] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A critical part of the clinical development path for a therapeutic antibody involves evaluating the physical and chemical stability of candidate molecules throughout the manufacturing process. In particular, the risks of chemical liabilities that can impact antigen binding, such as deamidation, oxidation, and isomerization in the antibody CDR sequences, need to be controlled through formulation development or eliminated by replacing the amino acid motif displaying the chemical instability. Commonly, the antibody CDR sequence contains multiple sequence motifs (potential hotspots) for chemical instability. However, only a subset of these motifs results in actual chemical modification, and thus, experimental assessment of the extent of instability is necessary to identify positions for potential sequence engineering. Ideally, this information should be available prior to antibody humanization at the stage of parental rodent antibody identification. Early knowledge of liabilities allows for ranking of clones or the mitigation of liabilities by concurrent engineering with the antibody humanization process instead of time-consuming sequential activities. However, concurrent engineering of chemical liabilities and humanization requires translatability of the chemical modifications from the rodent parental antibody to the humanized. We experimentally compared the stability of all sequence motifs by mass spectrometric peptide mapping between the rodent parental antibody and the final humanized antibody and observed a linear correlation. These results have enabled a streamlined developability assessment process for therapeutic antibodies from lead discovery to clinical development.
Collapse
|
198
|
Abbas IM, Vranic M, Hoffmann H, El-Khatib AH, Montes-Bayón M, Möller HM, Weller MG. Investigations of the Copper Peptide Hepcidin-25 by LC-MS/MS and NMR. Int J Mol Sci 2018; 19:E2271. [PMID: 30072660 PMCID: PMC6121404 DOI: 10.3390/ijms19082271] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/06/2018] [Accepted: 07/20/2018] [Indexed: 01/19/2023] Open
Abstract
Hepcidin-25 was identified as the main iron regulator in the human body, and it by binds to the sole iron-exporter ferroportin. Studies showed that the N-terminus of hepcidin is responsible for this interaction, the same N-terminus that encompasses a small copper(II)-binding site known as the ATCUN (amino-terminal Cu(II)- and Ni(II)-binding) motif. Interestingly, this copper-binding property is largely ignored in most papers dealing with hepcidin-25. In this context, detailed investigations of the complex formed between hepcidin-25 and copper could reveal insight into its biological role. The present work focuses on metal-bound hepcidin-25 that can be considered the biologically active form. The first part is devoted to the reversed-phase chromatographic separation of copper-bound and copper-free hepcidin-25 achieved by applying basic mobile phases containing 0.1% ammonia. Further, mass spectrometry (tandem mass spectrometry (MS/MS), high-resolution mass spectrometry (HRMS)) and nuclear magnetic resonance (NMR) spectroscopy were employed to characterize the copper-peptide. Lastly, a three-dimensional (3D) model of hepcidin-25 with bound copper(II) is presented. The identification of metal complexes and potential isoforms and isomers, from which the latter usually are left undetected by mass spectrometry, led to the conclusion that complementary analytical methods are needed to characterize a peptide calibrant or reference material comprehensively. Quantitative nuclear magnetic resonance (qNMR), inductively-coupled plasma mass spectrometry (ICP-MS), ion-mobility spectrometry (IMS) and chiral amino acid analysis (AAA) should be considered among others.
Collapse
Affiliation(s)
- Ioana M Abbas
- Federal Institute for Materials Research and Testing (BAM), Division 1.5 Protein Analysis, Richard-Willstätter-Strasse 11, 12489 Berlin, Germany.
- School of Analytical Sciences Adlershof, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany.
| | - Marija Vranic
- Federal Institute for Materials Research and Testing (BAM), Division 1.5 Protein Analysis, Richard-Willstätter-Strasse 11, 12489 Berlin, Germany.
- School of Analytical Sciences Adlershof, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099 Berlin, Germany.
- Institute of Chemistry/Analytical Chemistry, University of Potsdam, 14476 Potsdam, Germany.
| | - Holger Hoffmann
- Federal Institute for Materials Research and Testing (BAM), Division 1.8 Environmental Analysis, Richard-Willstätter-Strasse 11, 12489 Berlin, Germany.
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
| | - Ahmed H El-Khatib
- Federal Institute for Materials Research and Testing (BAM), Division 1.1 Inorganic Trace Analysis, Richard-Willstätter-Strasse 11, 12489 Berlin, Germany.
- Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Ain Shams University, 11566 Cairo, Egypt.
| | - María Montes-Bayón
- Department of Physical and Analytical Chemistry, University of Oviedo, C/Julian Claveria 8, 33006 Oviedo, Spain.
| | - Heiko M Möller
- Institute of Chemistry/Analytical Chemistry, University of Potsdam, 14476 Potsdam, Germany.
| | - Michael G Weller
- Federal Institute for Materials Research and Testing (BAM), Division 1.5 Protein Analysis, Richard-Willstätter-Strasse 11, 12489 Berlin, Germany.
| |
Collapse
|
199
|
Abstract
A key goal in the development of light-driven rotary molecular motors is to facilitate their usage in biology and medicine by shifting the required irradiation wavelengths from the UV regime to the nondestructive visible regime. Although some progress has been made toward this goal, most available visible-light-driven motors either have relatively low quantum yields or require that thermal steps follow the photoisomerizations that underlie the rotary motion. Here, a minimal design for visible-light-driven motors without these drawbacks is presented and evaluated on the basis of state-of-the-art quantum chemical calculations and molecular dynamics simulations. The design, featuring dihydropyridinium and cyclohexenylidene motifs and comprising only five conjugated double bonds, is found to produce a full 360° rotation through fast photoisomerizations (excited-state lifetimes of ≈170-250 fs) powered by photons with energies well below 3 eV.
Collapse
Affiliation(s)
- Jun Wang
- Division of Theoretical Chemistry, IFMLinköping UniversitySE-581 83LinköpingSweden
| | - Bo Durbeej
- Division of Theoretical Chemistry, IFMLinköping UniversitySE-581 83LinköpingSweden
| |
Collapse
|
200
|
Sytniczuk A, Forcher G, Grotjahn DB, Grela K. Sequential Alkene Isomerization and Ring-Closing Metathesis in Production of Macrocyclic Musks from Biomass. Chemistry 2018; 24:10403-10408. [PMID: 29931831 DOI: 10.1002/chem.201800728] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [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: 02/21/2018] [Revised: 04/16/2018] [Indexed: 11/10/2022]
Abstract
We report successful utilization of sequential alkene isomerization and ring-closing metathesis of dec-9-enoic acid based dienes in synthesis of macrocyclic lactones that possess a strong scent of musk. This catalytic sequence was essential to trim the chain length of starting dienes to yield macrocycles of the right size. Dec-9-enoic acid is conveniently obtainable from oleic esters by Ru-catalysed ethenolysis.
Collapse
Affiliation(s)
- Adrian Sytniczuk
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Gwénaël Forcher
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Douglas B Grotjahn
- Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, California, 92182-1030, USA
| | - Karol Grela
- Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland.,Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, P.O. Box 58, 01-224, Warsaw, Poland
| |
Collapse
|