Chirality最新文献

{"title":"First Principles Simulations of Optical Rotation of Chiral Molecular Crystals","authors":"Emmanuel Forson,&nbsp;Taylor Parsons,&nbsp;Marco Caricato","doi":"10.1002/chir.23709","DOIUrl":"10.1002/chir.23709","url":null,"abstract":"<div>\u0000 \u0000 <p>In this work, we present simulations of the optical rotation (OR) for five molecular crystals at density functional theory level with periodic boundary conditions (DFT-PBC). Calculations are compared with experimental measurements and show semi-quantitative agreement with experimental data for three of the crystals: tartatic acid, benzil, and pentaerythritol. For the other two crystals, aspartic acid and glutamic acid, the calculated data are in qualitative agreement with, but two orders of magnitude smaller than, the experimental data. We provide some arguments that support the theoretical predictions and suggest that the experiments should be revisited. We also find that the position of H centers provided in experimental X-ray data is not sufficiently reliable for simulating OR, and better results are obtained when H atoms are allowed to relax while keeping heavier elements fixed at the experimental positions. Comparison with molecular cluster calculations with a better functional and a larger basis set indicate that the role of intermolecular interactions (reproduced with the PBC technique) is as or more important than the choice of model chemistry. Despite the current limitations in the level of theory that can be employed, these simulations provide a promising avenue to investigate the effect of intermolecular interactions on this sensitive electronic property of molecules and materials.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141888650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cover Image, Volume 36, Issue 6","authors":"Massimiliano Gaeta,&nbsp;Gabriele Travagliante,&nbsp;Matteo Barcellona,&nbsp;Maria Elena Fragalà,&nbsp;Roberto Purrello,&nbsp;Alessandro D'Urso","doi":"10.1002/chir.23666","DOIUrl":"10.1002/chir.23666","url":null,"abstract":"<p>The cover image is based on the Research Article <i>Self-Assembled Chiral Film Based on Melanin Polymers</i> by Massimiliano Gaeta et al., https://doi.org/10.1002/chir.23695.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 6","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/chir.23666","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141867573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Helicenes on Surfaces: Stereospecific On-Surface Chemistry, Single Enantiomorphism, and Electron Spin Selectivity","authors":"Karl-Heinz Ernst","doi":"10.1002/chir.23706","DOIUrl":"10.1002/chir.23706","url":null,"abstract":"<p>Helicenes represent an important class of chiral organic material with promising optoelectronic properties. Hence, functionalization of surfaces with helicenes is a key step towards new organic material devices. This review presents different aspects of adsorption and modification of metal surfaces with different helicene species. Topics addressed are chiral crystallization, that is, 2D conglomerate versus racemate crystallization, breaking of mirror-symmetry in racemates, chirality-induced spin selectivity, and stereoselective on-surface chemistry.</p>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/chir.23706","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141791986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Investigations of Cargo Molecules Inside Icosahedrally Symmetric Encapsulin by VUVCD Spectroscopic Measurements","authors":"Shiori Kumamoto,&nbsp;Akima Yamamoto,&nbsp;Yu Shiratsuchi,&nbsp;Koichi Matsuo,&nbsp;Akifumi Higashiura,&nbsp;Daisuke Hira","doi":"10.1002/chir.23700","DOIUrl":"10.1002/chir.23700","url":null,"abstract":"<p>Prokaryotes organize intracellular compartments with protein-based organelles called encapsulins. Encapsulins with icosahedral symmetry can encapsulate specific cargo proteins mediated by targeting peptides or encapsulation-mediating domains. Encapsulins have been used in eukaryotic cells for bioengineering, vaccine development, and nanoparticle alignment. Their versatility makes them attractive for research; however, detailed structural information on encapsulins is crucial for further applied research. However, cargo proteins are randomly oriented inside the icosahedral encapsulins. The random orientation of cargo proteins presents a challenge for structural analysis that relies on averaging processes such as x-ray crystallography and cryo-electron microscopy (cryo-EM) single-particle imaging. Therefore, we aimed to accurately estimate the secondary structure content and elucidate the structure of cargo proteins inside the particle by measuring the circular dichroism (CD) spectra using vacuum ultraviolet circular dichroism (VUVCD) spectroscopy. Thus, the structure of the cargo protein inside encapsulin was evaluated. This approach could potentially set a standard for evaluating cargo proteins inside particles in future applied research on encapsulins.</p>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/chir.23700","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141791987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can Chirality Answer Whether We Are Alone?","authors":"Gintautas Bagdžiūnas","doi":"10.1002/chir.23708","DOIUrl":"10.1002/chir.23708","url":null,"abstract":"<div>\u0000 \u0000 <p>Detecting biosignatures of life in extraterrestrial environments remains one of the primary objectives of scientific inquiry. Currently, both remote and direct detection methods are primarily aimed at identifying key molecular classes fundamental to terrestrial biology. However, a more universally applicable spectroscopic approach could involve searching for homochiral molecules. Thus, this perspective delves into the significance of homochirality as a critical factor in the origin of life. Without homochirality, the formation of self-recognizing and self-replicating complex molecules would be hindered. The various hypotheses concerning the origin of homochiral molecules have been explored and analyzed within this context. This perspective emphasizes the potential for discovering extraterrestrial microscopic life through the detection of homochiral molecules using chirodetecting methods such as chromatography and chiroptical spectroscopy or circular polarimetry as a promising remote technique. This discussion highlights the importance of homochirality in the broader search for life beyond Earth and underscores the need for innovative methodologies and instrumentation in astrobiological research. These techniques can be an effective method for detecting homochirality on future planetary missions.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141757434","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual-Regulation of Supramolecular Chirality in Achiral Side-Chain Azobenzene Liquid-Crystalline Polymers","authors":"Chenrong Yuan,&nbsp;Ge Shi,&nbsp;Junle Zhang,&nbsp;Zhenqian Zhang,&nbsp;Yanjie He,&nbsp;Wenjie Zhang,&nbsp;Xiaoguang Qiao,&nbsp;Minying Liu,&nbsp;Xinchang Pang","doi":"10.1002/chir.23701","DOIUrl":"10.1002/chir.23701","url":null,"abstract":"<div>\u0000 \u0000 <p>Azobenzene (Azo) liquid-crystalline polymers are intriguing due to their unique photo-induced isomerization and supramolecular chirality. However, clarification on multicomponent chiral induction towards Azo polymers remains ambiguous and challenging. Herein, chiral solvents and amines were employed to control the chiroptical activity of achiral Azo polymers. Methyl <i>L</i>-/<i>D</i>-lactate was added as the poor solvent and chiral inducer to achieve the first chiral induction in Azo aggregates. Chiral amines were utilized for the second chiral induction based on the acid–base interactions between the carboxyl groups of polymers and amines. The chiral enhancement and inversion of Azo units could be observed through the synergistic or antagonistic effect between solvents and amines. The impacts of solvent, chemical structures, feed ratio, enantiomeric excess, and temperature on supramolecular chirality were systematically studied. Furthermore, this system displayed the chiroptical switching property and chiral recovery under reversible irradiation.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141733669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical Activity of Nonactin and Its Cation Complexes","authors":"Afton Gustafson,&nbsp;Bart Kahr","doi":"10.1002/chir.23703","DOIUrl":"10.1002/chir.23703","url":null,"abstract":"<div>\u0000 \u0000 <p>Nonactin is a non-enantiomorphous (<i>S</i>₄ symmetric), optically active natural product with a specific rotation of zero in solutions at all frequencies and temperatures. All optically active, non-enantiomorphous natural products have specific rotations of zero as a consequence of the spatial average of bisignate chiroptical (magnetoelectric or gyration) tensors with equal and opposite eigenvalues. Zeros that arise in the spatial average are distinct in principle, though not necessarily in practice, from zeros that arise in optical inactivity—chiroptical tensors with zero values for all elements as in centric molecules. Nonactin would be measurably optically active when oriented. The anisotropy of the optical activity of nonactin and its cation complexes, likewise <i>S</i>₄ symmetric, are studied here by computation to emphasize the infelicitous linkage between optical activity and chirality. Computations show that changes in the conformation of the nonactin macrocycle upon complexation principally are responsible for diminishing the computed optical activity; the metals are incidental.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141733670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tandem Mass Spectrometry Approaches for Differentiation and Quantification Pidotimod and Its Three Isomers in the Gas Phase","authors":"Caiyu Zhang,&nbsp;Yang Liu,&nbsp;Lan He,&nbsp;Wei Li","doi":"10.1002/chir.23699","DOIUrl":"10.1002/chir.23699","url":null,"abstract":"<div>\u0000 \u0000 <p>Pidotimod is a chiral drug that possesses two chiral centers, resulting in three isomeric impurities (analytes, A). This study employs electrospray ionization ion trap mass spectrometry (ESI-MS) through collision-induced dissociation (CID) to investigate the chiral recognition of pidotimod and its three isomers to eliminate chromatographic separation. Three approaches were explored: (1) Protonated molecules in CID exhibited discriminative potential for diastereomers, with the ability to distinguish between <i>S,S</i> and <i>R,R</i> configurations, albeit with an <i>R</i>_{<i>chiral</i>} value of ~1.8. However, differentiation between <i>R,S</i> and <i>S,R</i> configurations was not achievable. (2) Alkali adductions (lithium and sodium) only discerned diastereomers. The <i>R</i>_{<i>chiral</i>} values of the diastereomers obtained from alkali adduct ions were significantly lower than those obtained from protonated ions. (3) Therefore, a third approach was used to address the challenge of distinguishing between <i>R,S</i> and <i>S,R</i> configurations, including the introduction of chiral references (ref) and transition metals (M^II) to form metal-bound complexes [M^II(A)(ref)-H]⁺. Additionally, we synthesized a novel ligand, 4-(N-tert-butoxycarbonyl [Boc]-L-prolinamido)phenol (denoted as ligand A), by modifying N-t-Boc-L-Pro with 2-aminophenol, which, in combination with Cu^II and Ni^II, enabled simultaneous differentiation of all four isomers. Cu^II complexes exhibited significant chiral selectivity between <i>R,S</i> and <i>S,R</i> configurations. Density functional theory calculations were performed to further elucidate the stereodynamic behavior and stoichiometry of these ions in the gas phase. These calculations revealed the interaction energy and coordination sites of the precursor ions in the gas phase, correlating well with MS/MS experiment results. Additionally, the logarithm of the Cu^II complexes' characteristic fragment ion abundance ratio demonstrated a strong linear relationship with enantiomeric excess (<i>ee</i>). This study presents a novel strategy for chiral drug quality control that eliminates chromatographic separation.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141733671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Development of One New Normal Phase Liquid Chromatography Method and Thermodynamic Investigation of Olodaterol Hydrochloride Enantiomer","authors":"Wanbing Rao,&nbsp;Chenxia Zhang,&nbsp;Baolei Luan,&nbsp;Zhongqing Wang,&nbsp;Meiyan Qiu,&nbsp;Shaoyu Cai","doi":"10.1002/chir.23704","DOIUrl":"10.1002/chir.23704","url":null,"abstract":"<div>\u0000 \u0000 <p>In order to improve and replace the enantiomer method outlined in the olodaterol hydrochloride draft monograph (From the European Pharmacopoeia forum), one new, simple, and fast enantioselective normal phase high-performance liquid chromatography chiral method was developed on polysaccharide-based Chiral MX (2) (4.6 × 250 mm, 5 μm) column. n-Hexane, ethanol, and diethylamine in the ratio of 40:60:0.1 (V/V/V) were selected as mobile phase at a flow rate of 0.8 mL/min, and the detection was performed on a photodiode array detector at 225 nm with 5 μL injection volume. The column temperature was set at 40°C for better peak shape and sensitivity. The analysis time can be shortened to 15 min, whereas the resolution between enantiomer and olodaterol was found to be even more than 10.0, which was far better than that obtained with the reported method in this draft monograph. The developed chiral method was validated in accordance with ICH Q2 (R1), including specificity, LOD&amp;LOQ, precision, linearity, accuracy, and robustness. Thereby, the proposed method was demonstrated to be suitable for the determination of enantiomer in olodaterol hydrochloride bulk drug and drug product. Besides, the thermodynamic parameters were evaluated on the basis of Van't Hoff plots that was used to explain correlative chiral recognition mechanisms with the chiral stationary phase.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141733672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the Enantioselectivity and Recognition Mechanism of Allyl-β-CD Modified Organic Polymer Monolithic Capillary Column","authors":"Chaoheng Jia,&nbsp;Futao Li,&nbsp;Anqi Li,&nbsp;Qiwen Li,&nbsp;Lu Huang","doi":"10.1002/chir.23697","DOIUrl":"10.1002/chir.23697","url":null,"abstract":"<div>\u0000 \u0000 <p>Allyl-β-CD was synthesized and used as the chiral functional monomer to prepare chiral organic polymer monolithic columns in capillary HPLC. First, the enantioselectivity of the prepared allyl-β-CD modified organic polymer monolithic capillary columns was investigated. Then, the influences of enantioseparation conditions of chiral drugs were further explored. Finally, the recognition mechanism was studied by molecular docking with AutoDock. Complete enantioseparations of four chiral drugs as well as partial enantioseparations of eight chiral drugs have been achieved. Results showed that the RSD values for run-to-run, day-to-day, and column-to-column variations ranged from 1.2% to 4.6%, 1.4% to 4.7%, and 2.0% to 6.1%, respectively. The enantioselectivity factor rather than resolution is correlated with the binding free energy difference between enantiomers with allyl-β-CD. Furthermore, the abundant ether bonds, hydroxyl groups, and hydrophobic cavities in cyclodextrin are responsible for the enantioseparation ability of the chiral monolithic capillary columns.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"36 7","pages":""},"PeriodicalIF":2.8,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141562746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}