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Wen T, Li J, Cai W, Wu D, Yin ZZ, Kong Y. Visual and electrochemical chiral discrimination of tryptophan isomers with shikimic acid chiral ionic liquids-copper ions complex. Talanta 2024; 272:125850. [PMID: 38437760 DOI: 10.1016/j.talanta.2024.125850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 01/31/2024] [Accepted: 02/28/2024] [Indexed: 03/06/2024]
Abstract
Efficient discrimination of amino acids (AAs) isomers is of significant importance for life science and analytical chemistry. Here, a dual-mode chiral discrimination strategy is proposed for visual and electrochemical chiral discrimination of tryptophan (Trp) isomers. Shikimic acid chiral ionic liquids (SCIL) is coordinated with copper ions (Cu2+), and the obtained SCIL-Cu2+ can form ternary complexes with the Trp isomers. Owing to the inherent chirality of SCIL and the reverse homochirality of L-Trp and D-Trp, the ternary complex of SCIL-Cu-D-Trp has higher stability than SCIL-Cu-L-Trp, as revealed by the calculated stability constants (K) and changes in Gibbs free energy (ΔG). The difference in the stability can be utilized for the chiral discrimination of L-Trp and D-Trp, resulting in discernible differences in colors and the electrochemical signals of the Trp isomers. Besides Trp, the isomers of phenylalanine (Phe) can also be discriminated by the proposed dual-mode chiral discrimination strategy with the SCIL-Cu2+ complex.
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Affiliation(s)
- Tai Wen
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, China
| | - Junyao Li
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, China
| | - Wenrong Cai
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, China
| | - Datong Wu
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, China
| | - Zheng-Zhi Yin
- College of Biological, Chemical Sciences and Engineering, Jiaxing University, Jiaxing, 314001, China.
| | - Yong Kong
- Jiangsu Key Laboratory of Advanced Catalytic Materials and Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, 213164, China.
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2
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Abstract
The NMR technique is among the most powerful analytical methods for molecular structural elucidation, process monitoring, and mechanistic investigations; however, the direct analysis of complex real-world samples is often hampered by crowded NMR spectra that are difficult to interpret. The combination of fluorine chemistry and supramolecular interactions leads to a unique detection method named recognition-enabled chromatographic (REC) 19 F NMR, where interactions between analytes and 19 F-labeled probes are transduced into chromatogram-like 19 F NMR signals of discrete chemical shifts. In this account, we summarize our endeavor to develop novel 19 F-labeled probes tailored for separation-free multicomponent analysis. The strategies to achieve chiral discrimination, sensitivity enhancement, and automated analyte identification will be covered. The account will also provide a detailed discussion of the underlying principles for the design of molecular probes for REC 19 F NMR where appropriate.
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Affiliation(s)
- Zhenchuang Xu
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Yanchuan Zhao
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
- Key Laboratory of Energy Regulation Materials, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
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3
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Li L, Luo Y, Jia L. Genetically engineered bacterium-modified magnetic particles assisted chiral recognition and colorimetric determination of D/L-tryptophan in millets. Food Chem 2023; 407:135125. [PMID: 36495743 DOI: 10.1016/j.foodchem.2022.135125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 11/16/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022]
Abstract
Chiral recognition of enantiomers has always been a thorny issue since they exhibit the same properties under an achiral environment. Herein, polydopamine-functionalized magnetic particles (MP@PDA) were synthesized to immobilize the genetically engineered bacterium Escherichia coli DH5α (MP@PDA-E. coli). L-tryptophan (Trp) instead of D-Trp can be stereo-specifically degraded by tryptophanase in E. coli. The degradation product indole reacts with 4-dimethylaminobenzaldehyde to generate a rose-red adduct. Thus, MP@PDA-E. coli was employed to fabricate a chiral colorimetric method for chiral recognition and determination of L-Trp. The method averts the purification of tryptophanase. More importantly, tryptophanase demonstrates excellent enantioselective ability for L-Trp. The method can not only quantitatively detect L-Trp but also realize the measurement of the enantiomer percentage in the enantiomeric mixture. The feasibility was verified by detecting L-Trp in millet samples from different origins. Furthermore, a portable device was fabricated to make the method more convenient.
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Affiliation(s)
- Ling Li
- Ministry of Education Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science & Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Yimin Luo
- Ministry of Education Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science & Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Li Jia
- Ministry of Education Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science & Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, China.
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Yang J, Wang X, Ji S, Zhu Y. Chiral discrimination of cyclodecapeptide to anti-COVID-19 clinical candidates: a theoretical study. Struct Chem 2023:1-11. [PMID: 37363041 PMCID: PMC10011793 DOI: 10.1007/s11224-023-02149-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 02/20/2023] [Indexed: 03/29/2023]
Abstract
Various undesirable side effects are frequently associated with isomers of chiral clinical agents. The separation of chiral medicines remains a challenging issue in the medicines research. In this work, we employed cyclic decapeptide as the host molecule and the M06-2X theoretical computational method for chiral recognition of four clinical candidate guests and their isomers, including bucillamine, molnupiravir, azvudine, and VV116, which are relevant for the treatment of COVID-19. The obtained results indicated that bucillamine and molnupiravir and their respective isomers may be distinguished by cyclic decapeptide and that some of the isomers of Azvudine and VV116 may be discriminated by cyclic decapeptide. The inclusion conformation, deformation analysis, and electrostatic potential analysis also visualized the binding modes and binding sites between cyclic peptides and medicine candidates. A series of weak interaction analyses suggest that hydrogen bonding and dispersion interactions may be the primary factors for the recognition and separation of the clinical candidates by cyclic decapeptides. Visualized analyses of noncovalent interaction, hydrogen bond interaction, and NBO, AIM topological demonstrated that the difference of dispersion interaction is not obvious between the complexes, while the type and number of hydrogen bonds are very different, hinting that hydrogen bonds might be crucial for the differentiation of molnupiravir and its isomers. These findings might provide a theoretical reference for the identification and separation of chiral compounds in host-guest interaction. Supplementary Information The online version contains supplementary material available at 10.1007/s11224-023-02149-5.
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Affiliation(s)
- Jian Yang
- Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, 450001 People’s Republic of China
| | - Xinqing Wang
- Base of Sigma-ZZU Postgraduate Co-Cultivation, Zhengzhou, 450000 People’s Republic of China
| | - Shuangshuang Ji
- Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, 450001 People’s Republic of China
| | - Yanyan Zhu
- Green Catalysis Center, College of Chemistry, Zhengzhou University, Zhengzhou, 450001 People’s Republic of China
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5
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Wang H, Wu F, Dai X, Fang X, Ding CF. Rapid discrimination of enantiomers by ion mobility mass spectrometry and chemical theoretical calculation: Chiral mandelic acid and its derivatives. Anal Chim Acta 2023; 1239:340725. [PMID: 36628725 DOI: 10.1016/j.aca.2022.340725] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Because R/S-mandelic acids (MA) and their derivatives are critical starting materials or intermediates in the synthesis of chiral drugs, their chirality discrimination is important. In this study, R/S-MA and its derivatives, including R/S-2-phenylpropionic acid (2-PPA), R/S-methoxyphenylaceticacid (MPA), and R/S-2-hydroxy-4-phenylbutyric acid (HPBA), were accurate simultaneous mobility-discriminated by forming diastereomer complexes for the first time, which were obtained by simply mixing with cyclodextrins (α, β, γ-CD) and transition-metal ions (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+). The mass spectra revealed non-covalent diastereomer complexes formed by CD, enantiomers, and metal ions, and ion-mobility spectrometry (IMS) was performed for 109 pairs of complexes. Significant chiral discrimination was observed in the formed diastereomeric complexes, and their separation peak-to-peak resolution (Rp-p) for the enantiomers depended on the transition metal ion type. In most cases, the Rp-p value gradually increases with CD size, with quaternary complexes having the largest Rp-p value. The greatest chiral distinctions of 2-PPA, MA, MPA, and HPBA were obtained by the diastereomeric complex ions of [(2-PPA)(α)2+Zn2+-H]+, [(MA)(α)2+Zn2+-H]+, [(MPA)2(β)+Co2+-H]+, and [(HPBA)(α)2+Fe2+-H]+, with Rp-p values of 1.35, 1.57, 1.70, and 0.71, respectively. Furthermore, the favorable conformation and collisional cross section (CCS) value of the different [CD + R/S-MA + Cu-H]+ complexes were measured using chemical theoretical calculations to detail their intermolecular interaction, revealing that [α-CD + R/S-MA + Cu-H]+ has two favored gas complexes, and the CCS calculated were consistent with the TIMS observed. In addition, R2 > 0.99 was obtained for the relative quantification of the chiral enantiomers. Overall, the proposed method provides a promising strategy for distinguishing the enantiomers of MA and their derivatives, with the advantages of simplicity, speed, and accuracy, without the need for complex chemical derivatization or chromatographic separation.
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Affiliation(s)
- Huanhuan Wang
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China
| | - Fangling Wu
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China.
| | - Xinhua Dai
- National Institute of Metrology, Beijing, 100084, China
| | - Xiang Fang
- National Institute of Metrology, Beijing, 100084, China.
| | - Chuan-Fan Ding
- Key Laboratory of Advanced Mass Spectrometry and Molecular Analysis of Zhejiang Province, Institute of Mass Spectrometry, School of Material Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China.
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6
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Wang Z, Ji X, Zhao J, Ji J, Li G, Yang G, Xia H, Hou J. Preparation of fluorescein-modified polymer dots and their application in chiral discrimination of lysine enantiomers. Mikrochim Acta 2022; 190:29. [PMID: 36522482 DOI: 10.1007/s00604-022-05608-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 12/03/2022] [Indexed: 12/23/2022]
Abstract
Fluorescein-functionalized fluorescent polymer dots (F-PDs) were prepared by a facile one-pot method by magnetic stirring under mild conditions based on carboxymethylcellulose (CMC) and fluorescein as the precursors. The obtained F-PDs exhibited a nanoscale size of 3.2 ± 1.1 nm, excellent water solubility, and bright yellow fluorescence emission with a fluorescence quantum yield of 12.0%. The fluorescent probe displays rapid and sensitive chiral discrimination for lysine focused on different complexation abilities between lysine enantiomers and Cu2+. The concentration of L-lysine in the range 4 to 14 mM (R2 = 0.997) was measured by the fluorescence intensity ratio (I513/I429); the exitation wavelength was set to λex = 365 nm. The detection limit was 0.28 mM (3σ/slope). Importantly, this sensor accurately predicted the enantiomeric excess (ee) of lysine enantiomers at the designed concentration (lysine: 20 mM; Cu2+: 10 mM) ranges. The proposed sensor was successfully applied to determine L-lys (recovery: 95.8-101%; RSD: 0.465-3.34%) and ee values (recovery: 98.5-102%; RSD: 2.61-3.21%) in human urine samples using the standard addition method.
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Wu F, Tian Y, Luan X, Lv X, Li F, Xu G, Niu W. Synthesis of Chiral Au Nanocrystals with Precise Homochiral Facets for Enantioselective Surface Chemistry. Nano Lett 2022; 22:2915-2922. [PMID: 35362992 DOI: 10.1021/acs.nanolett.2c00094] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Metal surfaces with intrinsic chirality play an irreplaceable role in many significant enantioselective chemical processes such as enantioselective catalysis, sensing, and separation. Nonetheless, current methods for the precise preparation of such chiral surfaces suffer with issues of unscalable production and low surface areas. Herein, we report the synthesis of chiral Au nanoparticles with precisely determined homochiral facets. Though a scalable wet chemical method, {125̅8}R and {85̅12}S high-Miller-index facets are obtained with the l- and d-chiral Au nanocrystals, respectively. The growth process of these homochiral facets is investigated, and a new nanocrystal growth pathway is revealed. More importantly, the remarkable enantioselective recognition properties of these homochiral surfaces are demonstrated and enable an efficient electrochemical method for chiral discrimination of l-/d-tryptophan. These results provide a foundation of fundamental studies of heterogeneous enantioselective processes and may pave way for the development of nanocatalysts for enantioselective chemistry.
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Affiliation(s)
- Fengxia Wu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
| | - Yu Tian
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
| | - Xiaoxi Luan
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
| | - Xiali Lv
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
| | - Fenghua Li
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
| | - Guobao Xu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
| | - Wenxin Niu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- University of Science and Technology of China, Hefei 230026, China
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8
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Thamim M, Thirumoorthy K. Chiral discrimination in a mutated IDH enzymatic reaction in cancer: a computational perspective. Eur Biophys J 2020; 49:549-59. [PMID: 32880665 DOI: 10.1007/s00249-020-01460-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 08/24/2020] [Indexed: 10/23/2022]
Abstract
Chiral discrimination in biological systems, such as L-amino acids in proteins and d-sugars in nucleic acids, has been proposed to depend on various mechanisms, and chiral discrimination by mutated enzymes mediating cancer cell signaling is important in current research. We have explored how mutated isocitrate dehydrogenase (IDH) catalyzes the oxidative decarboxylation of isocitrate to α-ketoglutarate which in turn is converted to d-2-hydroxyglutatrate (d-2HG) as a preferred product instead of l-2-hydroxyglutatrate (l-2HG) according to quantum chemical calculations. Using transition state structure modeling, we delineate the preferred product formation of d-2HG over l-2HG in an IDH active site model. The mechanisms for the formation of d-2HG over l-2HG are assessed by identifying transition state structures and activation energy barriers in gas and solution phases. The calculated reaction energy profile for the formation of d-2HG and l-2HG metabolites shows a 29 times higher value for l-2HG as compared to d-2HG. Results for second-order Møller-Plesset perturbation theory (MP2) do not alter the observed trend based on Density Functional Theory (DFT). The observed trends in reaction energy profile explain why the formation of D-2HG is preferred over l-2HG and reveal why mutation leads to the formation of d-2HG instead of l-2HG. For a better understanding of the observed difference in the activation barrier for the formation of the two alternative products, we performed natural bond orbital analysis, non-covalent interactions analysis and energy decomposition analysis. Our findings based on computational calculations clearly indicate a role for chiral discrimination in mutated enzymatic pathways in cancer biology.
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Vollhardt D, Brezesinski G. Lattice structures and phase behavior of amphiphilic monoglycerol monolayers. Adv Colloid Interface Sci 2019; 273:102030. [PMID: 31494338 DOI: 10.1016/j.cis.2019.102030] [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: 07/16/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 11/28/2022]
Abstract
Due to the Angstrom resolution, Grazing incidence X-ray diffraction (GIXD) represents the most important technique for probing the lateral ordering in condensed monolayers at the air/water interface and allows the construction of phase diagrams of amphiphilic monolayers on the basis of two-dimensional lattice structures and tilt directions of the molecules. The high potential of GIXD is demonstrated by the structural characterization of a variety of amphiphilic monoalkanoylglycerol monolayers in Å-scale. The GIXD results have impressively shown that in the racemic 1-monostearoylglycerol monolayer with the appearance of an oblique intermediate phase (Obl) between the nearest neighbor (NN)- and next-nearest neighbor (NNN)-tilted orthorhombic phases symmetry breaking occurs at low temperatures. The generic lateral pressure-temperature phase diagram of racemic monoacylglycerol monolayers constructed on the basis of reliable two-dimensional lattice structures indicates that the new and surprising presence of the oblique phase depends only on the temperature. The significant effect of the substituted polar groups, chemical structure variations at the position of the glycerol backbone and chirality on the lattice structure in Å-scale was highlighted in a systematic overview on the structure and phase behavior of amphiphilic monoglycerol monolayers. The conspicuous effect of the position of the glycerol backbone at which the polar group is substituted is demonstrated. The monolayers of 2-monopalmitoyl-rac-glycerol behave as that of 1-monomyristoyl-rac-glycerol having a two CH2 groups shorter alkyl chain. Further main topics discussed are chiral discrimination and crossover between homo- and heterochiral discrimination supported by quantum chemical calculations.
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Affiliation(s)
- D Vollhardt
- Max-Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Golm, Germany.
| | - G Brezesinski
- Max-Planck Institute of Colloids and Interfaces, D-14424 Potsdam, Golm, Germany
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10
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Rezende MVCS, Coutinho ND, Palazzetti F, Lombardi A, Carvalho-Silva VH. Nucleophilic substitution vs elimination reaction of bisulfide ions with substituted methanes: exploration of chiral selectivity by stereodirectional first-principles dynamics and transition state theory. J Mol Model 2019; 25:227. [PMID: 31317347 DOI: 10.1007/s00894-019-4126-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 07/07/2019] [Indexed: 10/26/2022]
Abstract
Control of molecular orientation is emerging as crucial for the characterization of the stereodynamics of kinetics processes beyond structural stereochemistry. The special role played in chiral discrimination phenomena has been particularly emphasized by Aquilanti and collaborators after their extensive probes of experimental control of molecular alignment and orientation. In this work, the manifestation of the Aquilanti mechanism has been demonstrated for the first time in first-principles molecular dynamics simulations: stationary points characterized on potential energy surfaces have been calculated for the study of chemical reactions occurring between the bisulfide anion HS- and oriented prototypical chiral molecules CHFXY (where X = CH3 or CN and Y = Cl or I). The important reaction channels are those corresponding to bimolecular nucleophilic substitution (SN2) and to bimolecular elimination (E2): their relative role has been assessed and alternative pathways due to the mirror forms of the oriented chiral molecule are revealed by the different reactivity of the two enantiomers of CHFCNI in SN2 reaction.
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Lu Z, Lu X, Zhong Y, Hu Y, Li G, Zhang R. Carbon dot-decorated porous organic cage as fluorescent sensor for rapid discrimination of nitrophenol isomers and chiral alcohols. Anal Chim Acta 2018; 1050:146-153. [PMID: 30661582 DOI: 10.1016/j.aca.2018.11.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [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: 09/08/2018] [Revised: 10/23/2018] [Accepted: 11/02/2018] [Indexed: 12/24/2022]
Abstract
Isomers discrimination plays a vital role in modern chemistry, and development of efficient and rapid method to achieve this aim has attracted a great deal of interest. In this work, a novel carbon dot-decorated chiral porous organic cage hybrid nanocomposite (CD@RCC3) was prepared and used to fabricate fluorescent sensor. The resultant CD@RCC3 was characterized by using a range of techniques, finding that CD@RCC3 possesses strong and stable fluorescent property in common organic solvents, especially it exhibits chiral property. The potential application of CD@RCC3 in fluorescence sensing was demonstrated by isomers discrimination. The designed sensor was successfully used to rapid discriminate nitrophenol isomers. Meanwhile, it exhibited differentiation ability towards phenylalaninol and phenylethanol enantiomers. Our work enriches the type of synthetic materials for fluorescence sensing, and provides a simple method for distinguishing structural isomers and chiral isomers.
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Affiliation(s)
- Zhenyu Lu
- School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China
| | - Xiaotian Lu
- School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China
| | - Yanhui Zhong
- School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China
| | - Yufei Hu
- School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China
| | - Gongke Li
- School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Runkun Zhang
- School of Chemistry, Sun Yat-sen University, Guangzhou, 510275, China.
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Machado SMT, Castro RAE, Maria TMR, Canotilho J, Eusébio MES. Levetiracetam+nonsteroidal anti-inflammatory drug binary systems: A contribution to the development of new solid dosage forms. Int J Pharm 2017; 533:1-13. [PMID: 28893584 DOI: 10.1016/j.ijpharm.2017.09.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 09/04/2017] [Accepted: 09/06/2017] [Indexed: 01/12/2023]
Abstract
A study has been carried out of binary solid systems made up of the antiepileptic drug levetiracetam, LEV, and a nonsteroidal anti-inflammatory drug, NSAID, capable of managing the inflammation that accompanies epileptic activity. One aim of this research was to identify eutectic mixtures and co-crystals, which are able to impact positively on their biopharmaceutical properties. The NSAIDs studied are (S)- and (R,S)-ibuprofen, (S)- and (R,S)-naproxen, (R,S)-ketoprofen and (R,S)-flurbiprofen, all class II in the Biopharmaceutical Classification System. A green mechanochemical methodology has been used to prepare binary mixtures with different molar ratios, and the binary solid-liquid phase diagrams established. For LEV+(S)-ibuprofen, formation of a single (1:1) co-crystal was confirmed; this was found to melt incongruently. The co-crystal was found to be stable in accelerated stability tests. For the other systems, interesting eutectic mixtures were identified, which showed enhanced dissolution rates of the NSAID relative to the pure drug. For LEV+(R,S)-ibuprofen, LEV+(S)-naproxen and LEV+(R,S)-naproxen, the eutectic mixture compositions have the effective doses of both components. All the NSAIDs investigated are chiral, and their racemates are racemic compounds. Levetiracetam, the (S)-enantiomer of etiracetam, was not efficient in enantiomer discrimination, as all the racemic compound structures are present as the prepared solid mixtures.
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Nath N, Verma A, Baishya B, Khetrapal CL. Real time band selective F 1 -decoupled proton NMR for the demixing of overlay spectra of chiral molecules. Magn Reson Chem 2017; 55:553-558. [PMID: 27813168 DOI: 10.1002/mrc.4547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 10/27/2016] [Accepted: 10/30/2016] [Indexed: 06/06/2023]
Abstract
The small chemical shift dispersion and complex multiplicity pattern in proton NMR limit quantifications, for instance the determination of enantiomeric excess (ee) for an enantiomeric mixture. Herein, we present a simple proton-proton correlation experiment with band selective homonuclear (BASH) decoupling in both F1 and F2 dimensions, for the removal of scalar and residual dipolar couplings to provide collapsed singlet for each chemical site. The method has been demonstrated to separate the severely overlapped spectra of enantiomers using both chiral isotropic and anisotropic phases as well as a small biomolecule, particularly for the diastereotopic protons and also for the determination of ee. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Nilamoni Nath
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Ajay Verma
- Centre of Biomedical Research, SGPGIMS Campus, Lucknow, U. P., India
| | - Bikash Baishya
- Centre of Biomedical Research, SGPGIMS Campus, Lucknow, U. P., India
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Raffaini G, Ganazzoli F. Separation of chiral nanotubes with an opposite handedness by chiral oligopeptide adsorption: A molecular dynamics study. J Chromatogr A 2015; 1425:221-30. [PMID: 26627588 DOI: 10.1016/j.chroma.2015.11.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [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: 09/29/2015] [Revised: 11/02/2015] [Accepted: 11/10/2015] [Indexed: 10/22/2022]
Abstract
The separation of enantiomeric chiral nanotubes that can form non-covalent complexes with an unlike stability upon adsorption of chiral molecules is a process of potential interest in different fields and applications. Using fully atomistic molecular dynamics simulations, we report in this paper a theoretical study of the adsorption and denaturation of an oligopeptide formed by 16 chiral amino acids having a helical structure in the native state on both the inner and the outer surface of the chiral (10, 20) and (20, 10) single-walled carbon nanotubes having an opposite handedness, and of the armchair (16, 16) nanotube with a similar diameter for comparison. In the final adsorbed state, the oligopeptide loses in all cases its native helical conformation, assuming elongated geometries that maximize its contact with the surface through all the 16 amino acids. We find that the complexes formed by the two chiral nanotubes and the chosen oligopeptide have a strongly unlike stability both when adsorption takes place on the outer convex surface of the nanotube, and when it occurs on the inner concave surface. Thus, our molecular simulations indicate that separation of chiral, enantiomeric carbon nanotubes for instance by chromatographic methods can indeed be carried out using oligopeptides of a sufficient length.
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Affiliation(s)
- Giuseppina Raffaini
- Dipartimento di Chimica, Materiali e Ingegneria Chimica 'G. Natta', Politecnico di Milano, and Unità Politecnico INSTM, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
| | - Fabio Ganazzoli
- Dipartimento di Chimica, Materiali e Ingegneria Chimica 'G. Natta', Politecnico di Milano, and Unità Politecnico INSTM, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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