ChiralityPub Date : 2026-09-10DOI: 10.1002/chir.70149
Koichi Kodama, Kosei Katayama, Takuji Hirose
{"title":"Application of threo-2-amino-1,2-diphenylethanol as a Resolving Agent for Racemic Carboxylic Acids via Diastereomeric Salt Formation","authors":"Koichi Kodama, Kosei Katayama, Takuji Hirose","doi":"10.1002/chir.70149","DOIUrl":"10.1002/chir.70149","url":null,"abstract":"<p>The ability of <i>threo</i>-2-amino-1,2-diphenylethanol (<b>1t</b>) as a resolving agent for the enantioseparation of carboxylic acids via diastereomeric salt formation was investigated. Although (−)-<b>1t</b> was not applicable to the enantioseparation of racemic 2-arylalkanoic acids and mandelic acid, enantiomers of tropic acid and 2-halomandelic acids were efficiently separated by salt formation with (−)-<b>1t</b>. This resolving ability was complementary to that of the corresponding <i>erythro</i>-isomer (<b>1e</b>). The hydrogen-bonding patterns and molecular packing mode of the less-soluble diastereomeric salts of (−)-<b>1t</b> were revealed based on the crystallographic analysis.</p>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/chir.70149","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148929153","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":"Mechanistic Insights Into Synephrine Isomerization Under Acidic and Neutral Conditions: A Combined Kinetic, Thermodynamic, and Quantum Chemical Approach","authors":"Koichi Saito, Sae Nobuhira, Aimi Kato, Rie Ito, Hiroshi Akiyama","doi":"10.1002/chir.70148","DOIUrl":"10.1002/chir.70148","url":null,"abstract":"<div>\u0000 \u0000 <p>Synephrine is a chiral compound that exists as two enantiomers, the (<i>R</i>)- and (<i>S</i>)-forms. The present study investigated the effects of pH and heating conditions on the isomerization of synephrine. Each enantiomer was quantified after FMOC derivatization using chiral liquid chromatography with UV detection (chiral-LC/UV). When (<i>R</i>)-synephrine was incubated under acidic or neutral conditions at elevated temperatures, isomerization was promoted in a temperature-dependent manner under both conditions. The isomerization rate under the acidic condition was approximately 10- to 40-fold higher than that under the neutral condition, and the time-dependent progression followed pseudo-first-order kinetics under both conditions. Analysis of physicochemical parameters, including the activation entropy (Δ<i>S</i><sup>‡</sup>), suggested that the reaction mechanisms differ between the acidic and neutral conditions. To elucidate the detailed isomerization mechanisms, quantum chemical calculations based on density functional theory (DFT) were performed. Under acidic conditions, DFT geometry optimization demonstrated that the amino group is preferentially protonated (NH<sub>2</sub><sup>+</sup>), consistent with its higher thermodynamic basicity, followed by departure of the β-hydroxyl group to generate a benzylic carbocation intermediate. LUMO localization at the β-carbon of the benzylic carbocation and its planar sp<sup>2</sup> geometry support nucleophilic water attack from either face, leading to racemization. Under neutral conditions, a retro-Mannich-type fragmentation mechanism was proposed, in which the C–C bond between the α- and β-carbons undergoes heterolytic cleavage—driven primarily by electron donation from the β-hydroxyl oxygen lone pair and assisted by vinylogous conjugation from the phenolic oxygen via the aromatic ring—to generate an aldehyde and an imine as intermediates. Subsequent recombination of these fragments was proposed to yield a racemic mixture. These findings confirmed that synephrine undergoes isomerization upon heating under both acidic and neutral conditions.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148918643","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}
ChiralityPub Date : 2026-09-07DOI: 10.1002/chir.70145
Artemijs Krimovs, Robert Pal
{"title":"Investigating the CPL-Structure Dependence in Arylalkynylpyridyl—Triazacyclononane Sensitized Nine-Coordinate Europium(III) Complexes","authors":"Artemijs Krimovs, Robert Pal","doi":"10.1002/chir.70145","DOIUrl":"10.1002/chir.70145","url":null,"abstract":"<p>A series of novel arylalkynylpyridyl-triazacyclononane sensitized macrocyclic europium(III) complexes (EuL) was prepared, and their circularly polarized luminescence characterized in terms of the spectral profile and dissymmetry factor (<i>g</i><sub>lum</sub>). The series was engineered based on previously reported isostructural complexes by a controlled introduction of structural modifications at different positions with respect to the coordination environment of the emitting europium(III) center. It was established that only those structural features of the macrocyclic ligand that were proximal to the europium(III) center affected CPL properties. These findings could help shape the development of a new class of purpose-built EuL complexes compatible with CPL-unaffecting complex-stage functionalization to introduce advantageous structural features for applications in life and material sciences.</p>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13549766/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148905110","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}
ChiralityPub Date : 2026-09-02DOI: 10.1002/chir.70135
Rua B. Alnoman
{"title":"Post-Crosslinked Hydrazidine-Functionalized Resorcinol–Formaldehyde Imprinted Polymer for Selective S-Ketorolac Recognition","authors":"Rua B. Alnoman","doi":"10.1002/chir.70135","DOIUrl":"10.1002/chir.70135","url":null,"abstract":"<div>\u0000 \u0000 <p>A new enantioselective molecularly imprinted polymer (MIP) was developed for recognizing S-ketorolac (S-KR), a model chiral acidic drug. The synthetic process started with a resorcinol-formaldehyde resin (RSF), which was cyanoethylated under phase-transfer catalytic conditions to obtain RSF-CN. Then, the nitrile groups turned into cationic/basic hydrazidine sites after reacting with hydrazine hydrate, resulting in RSF-HD. Next, S-KR was interacted with RSF-HD in a DMF/water solution at pH 7, before adding glutaraldehyde for post-crosslinker. After that, the S-KR template was removed to get the final S-KR-imprinted polymer (S-KR-P). Tests, such as elemental analysis and solid-state <sup>13</sup>C NMR, verified each step. Adsorption tests showed a strong pH dependence, working best between pH 6 and 7. For isotherm studies, the maximum capacity for S-KR on S-KR-P was 525 mg/g, whereas R-KR had 252 mg/g. The non-imprinted polymers (NIPs) worked similarly for both, around 180 mg/g. The Langmuir model fits better than the Freundlich model, pointing to adsorption on defined binding sites. With a selectivity coefficient of about 12, it shows effective stereoselective recognition, making S-KR-P a great option for separating chiral ketorolac.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148873256","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":"Trifluoroacetylation and Sulfur Oxidation States Modulate Cis–Trans Isomerization and Atropisomerism in N-Aryl Peptoids","authors":"Nithin Kumara Mothahalli Raju, Bishwajit Paul, Jayprakash Prajapati, Sourav Chatterjee, Epari Sai Santosh Kumar, Kshatresh Dutta Dubey","doi":"10.1002/chir.70147","DOIUrl":"10.1002/chir.70147","url":null,"abstract":"<div>\u0000 \u0000 <p>Trifluoroacetylation and varying sulfur oxidation states can modulate the stereodynamic features in <i>N</i>-aryl peptoids. This study elucidates the restricted rotation about both the chiral C<sub>aryl</sub>–N axis and the N–C(O) amide bond, highlighting the inherently flexible nature of tertiary amide scaffolds. Tertiary amide bond isomerization, axial chirality, and multiple stereochemical forms were investigated utilizing <sup>19</sup>F NMR, dynamic HPLC, crystallographic studies, and computational analysis. Notably, the introduction of a sulfoxide moiety as an auxiliary stereogenic element facilitates the formation of multiple and distinct stereochemical forms, as evident from <sup>19</sup>F NMR studies and computational modeling. These structural modifications can provide a robust platform to understand stereodynamic features in <i>N</i>-aryl peptoids.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148873272","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":"Chiral Covalent Organic Frameworks for Circularly Polarized Luminescence and Light Detection Applications","authors":"Zhijia Luo, Xihao Tang, Xuefeng Zhu, Songliang Cai, Weiguang Zhang","doi":"10.1002/chir.70146","DOIUrl":"10.1002/chir.70146","url":null,"abstract":"<div>\u0000 \u0000 <p>Chiral covalent organic frameworks (CCOFs) integrate high crystallinity, permanent porosity, and programmable chiral microenvironments, making them attractive platforms for chiroptical materials and circularly polarized light-responsive devices. This review summarizes recent progress in CCOFs, covering the introduction of chirality through post-synthetic modification, de novo synthesis, chiral induction, and catalytic asymmetric synthesis, as well as the amplification of chirality from molecular units to pore architectures, helical morphologies, thin films, and devices. We further discuss representative CCOF systems for circularly polarized luminescence and circularly polarized light detection, focusing on the relationships among framework structure, host–guest confinement, chirality-induced spin selectivity-mediated transport, and dissymmetry factors. Helical morphology amplifies chirality across scales through ordered chromophore organization and anisotropic charge and spin transport. Together, these advances establish a multiscale design framework for translating molecular chirality into measurable optical and device responses. Finally, we identify key challenges in balancing luminescence efficiency with chiroptical asymmetry, stabilizing helical architectures, fabricating oriented films, and establishing quantitative structure–property relationships.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148863666","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}
ChiralityPub Date : 2026-08-30DOI: 10.1002/chir.70143
Igor E. Oliveira, Daniela Pereira, Ana R. Carvalho, Renata Vidal, Lara da Silva Cabral, Lucas H. Martorano, Fernando M. S. Junior, Cláudia Ribeiro, Ana R. L. Ribeiro, Maria E. Tiritan
{"title":"Nadifloxacin: Multimilligram Enantioresolution and Enantioselective Ecotoxicological Studies","authors":"Igor E. Oliveira, Daniela Pereira, Ana R. Carvalho, Renata Vidal, Lara da Silva Cabral, Lucas H. Martorano, Fernando M. S. Junior, Cláudia Ribeiro, Ana R. L. Ribeiro, Maria E. Tiritan","doi":"10.1002/chir.70143","DOIUrl":"10.1002/chir.70143","url":null,"abstract":"<div>\u0000 \u0000 <p>Emerging contaminants are an increasing global concern, with antibiotics representing a notable case due to their continuous release and possible contribution to antimicrobial resistance. Fluoroquinolones (FQs) combine high stability, low biodegradability, and biological activity at trace levels, which result in persistence, ecotoxicity, and bioaccumulation in aquatic systems. Nadifloxacin (NAD) is a chiral FQ prescribed as a racemate for dermatological infections, but (<i>S</i>)-NAD is more potent than the racemate and 64 to 256 times more active than (<i>R</i>)-NAD against both <i>Staphylococcus aureus</i> and <i>Propionibacterium acnes</i>, as well as other gram-positive and gram-negative pathogens. Though the stereochemistry plays a decisive role in both pharmacological activity and environmental fate, the enantioselective ecotoxicological evaluation of NAD is of high importance. Thus, this work described the enantioseparation of NAD by chiral liquid chromatography (cLC) on a Lux amylose-1 column (4.6 mm I.D. × 250 mm L, particle size 5 μm) under normal-phase conditions. Optimized analytical conditions provided good chromatographic parameters (<i>R</i>s = 5.92, <i>α</i> = 2.77, retention 6–10 min) and were successfully scaled up to semipreparative enantioseparation on a CHIRALPAK <span>AD</span>-H DAICEL column (10 mm I.D. × 250 mm L, particle size 5 μm), allowing the separation of both enantiomers in > 98% enantiomeric purity. The absolute configuration and the elution order of the enantiomers were determined by the agreement between the experimental and calculated data of electronic circular dichroism. The acute ecotoxicity of the NAD racemate and its enantiomers was evaluated using <i>Daphnia magna</i> as an aquatic model organism.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148863709","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}
ChiralityPub Date : 2026-08-28DOI: 10.1002/chir.70140
Yabo Fu, Bing Ni
{"title":"Complexity and Optical Activity Regulation Through Chirality Engineering in Ag-Thiolate Coordination Polymers","authors":"Yabo Fu, Bing Ni","doi":"10.1002/chir.70140","DOIUrl":"https://doi.org/10.1002/chir.70140","url":null,"abstract":"<div>\u0000 \u0000 <p>Extending morphological complexity and thus achieving emergent functions remain a central challenge in materials science. Here, we report a chirality-engineering strategy to tune morphological complexity and optical activity (OA) in Ag-thiolate coordination polymers (ATCPs). By introducing either the opposite enantiomer D-cys or the achiral 3-mercaptopropionic acid (MPA) into L-cys-induced ATCP synthesis, we found two coinduction systems exhibiting distinct molecular mixing behaviors quantified via the entropy of mixing (EoM) of thiol precursors. The resulting morphologies, including triangular nanosheets, flower-like architectures, nanoscrolls, and nanotube-like assemblies, were quantitatively analyzed using a graph-theoretical complexity index (CI). In the L-/D-cys system, increasing EoM led to chirality cancelation, a decreased CI and an attenuated <i>g</i>-factor, demonstrating that maximum EoM does not necessarily generate higher complexity or stronger OA. In contrast, in the L-cys/MPA system, packing mismatch transformed maximum EoM into an enhanced CI alongside OA inversion and enhancement (a maximal 8.3-fold enhancement). These results reveal that the molecular role of the second thiol component, rather than EoM alone, determines whether molecular mixing suppresses or amplifies complexity and OAs. This work provides ligand-modification strategy for programming complex functional coordination-polymer assemblies.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148849213","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":"Herb-Based Chiral Nanomaterials: Potential Application in Wound Healing and Nanomedicine","authors":"Meng Sun, Zhuowei Ren, Hanyue Liang, Jie Gao, Wanying Zhang, Fengli Gao, Chuanliang Feng","doi":"10.1002/chir.70142","DOIUrl":"10.1002/chir.70142","url":null,"abstract":"<div>\u0000 \u0000 <p>The remarkable progress in nanomedicine has opened new frontiers in boosting therapeutic efficacy and reducing off-target side effects. However, fabricating chiral nanomaterials remains challenging due to difficulties in sustaining chiral configuration stability. In this study, chiral injectable liquid formulations are fabricated via the co-assembly of phenylalanine-derived enantiomers, flavonoids and chitosan, to tackle the drawbacks of existing chiral nanomaterials for wound healing. The weakly acidic chitosan solution effectively resolved the low-solubility defect of flavonoids extracted from <i>Scutellaria baicalensis</i>, and the chiral transfer strategy among these co-assembled components overcomes the problem of chiral lability. The resulting chiral formulations displayed strong antioxidant and antibacterial capacities and significantly accelerated wound closure in the <i>Staphylococcus aureus</i>-infected chronic wound model. This research provides valuable insights for the design of herb-functionalized formulations and lays a foundation for the development of advanced chiral nanomaterials with broad applications in nanomedicine.</p>\u0000 </div>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148825695","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}
ChiralityPub Date : 2026-08-27DOI: 10.1002/chir.70128
Maria Sara Raju, Nazanin Kordestani, Elen Duverger-Nédellec, Yann Danten, Patrick Rosa, Elizabeth A. Hillard, Nicolas Daugey
{"title":"Near Resonant Raman Optical Activity Study of the Complex Cation Tris(ethylenediamine)cobalt(III) in Water: Experiment and DFT Calculation","authors":"Maria Sara Raju, Nazanin Kordestani, Elen Duverger-Nédellec, Yann Danten, Patrick Rosa, Elizabeth A. Hillard, Nicolas Daugey","doi":"10.1002/chir.70128","DOIUrl":"10.1002/chir.70128","url":null,"abstract":"<p>Chiral metal complexes are important in catalysis and medicinal chemistry, where understanding their structural and optical properties is crucial. This study presents a combined experimental and theoretical Raman optical activity (ROA) investigation of the chiral tris(ethylenediamine)cobalt(III) complex, Δ- and Λ-[Co(en)<sub>3</sub>]<sup>3+</sup>, in aqueous solution. ROA spectra were recorded using near-resonance excitation at 532 nm. Under these conditions, a significant ECD–Raman contribution from the solution was observed and quantitatively corrected, enabling extraction of the intrinsic ROA spectra. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were used to simulate ROA, Raman, UV–visible absorption, and electronic circular dichroism (ECD) spectra. Four representative conformers were analyzed, and their stability and spectral properties were evaluated using both the polarizable continuum model (PCM) and the solvation model based on density (SMD). While both models reproduced key experimental trends, SMD provided a more accurate description of vibrational features, especially NH<sub>2</sub> scissoring and CH<sub>2</sub> rocking modes. This work shows that near-resonant ROA spectra of a cationic transition-metal complex in water can be accurately reproduced using first-principles methods without empirical adjustments, highlighting the importance of conformational averaging and solvation effects.</p>","PeriodicalId":10170,"journal":{"name":"Chirality","volume":"38 9","pages":""},"PeriodicalIF":2.4,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/chir.70128","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148825741","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}