{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T17:03:25Z","timestamp":1784567005948,"version":"3.55.0"},"reference-count":37,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T00:00:00Z","timestamp":1784505600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Two thiourea-based chiral solvating agents (CSAs), S-1 and S-2, were evaluated for the enantiomeric discrimination of representative \u03b1-arylacetic acids by 1H NMR spectroscopy in the presence of DMAP. Enantiomeric discrimination was assessed by monitoring chemical shift nonequivalence (\u0394\u0394\u03b4) arising from the formation of diastereomeric host\u2013guest complexes. S-1 exhibited concentration-dependent enantiomeric discrimination toward all investigated carboxylic acid derivatives, reaching a maximum \u0394\u0394\u03b4 value of 0.021 ppm. In contrast, S-2 failed to produce detectable signal splitting under identical experimental conditions. A 1D ROESY experiment together with association constant measurements supported the proposed diastereomeric host\u2013guest complexation model and the preferential binding of one enantiomer by S-1. To further expand the substrate scope, two thiohydantoin derivatives were also examined, and S-1 produced measurable chemical shift nonequivalences, with the largest \u0394\u0394\u03b4 value reaching 0.019 ppm. Comparison with previously reported thiourea-based CSAs further highlighted the importance of hydrogen-bonding ability, aromatic anisotropy, and overall molecular architecture in governing enantiomeric discrimination. Overall, these findings provide useful structural insights for the rational design of thiourea-based chiral solvating agents for NMR enantiomeric analysis.<\/jats:p>","DOI":"10.3390\/molecules31142526","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T16:19:27Z","timestamp":1784564367000},"page":"2526","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Enantiodifferentiation of \u03b1-Arylacetic Acid and Thiohydantoin Derivatives by NMR Using Thiourea-Based Chiral Solvating Agents"],"prefix":"10.3390","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2820-7674","authenticated-orcid":false,"given":"Sule","family":"Erol Gunal","sequence":"first","affiliation":[{"name":"Department of Pharmaceutical Chemistry, Faculty of Pharmacy, \u0130stanbul University-Cerrahpa\u015fa, 34500 Istanbul, T\u00fcrkiye"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.2165\/00003495-199600525-00003","article-title":"Drug Chirality and Its Clinical Significance","volume":"52","author":"Hutt","year":"1996","journal-title":"Drugs"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"33429","DOI":"10.1039\/D4RA05694A","article-title":"The Significance of Chirality in Contemporary Drug Discovery-a Mini Review","volume":"14","author":"Senkuttuvan","year":"2024","journal-title":"RSC Adv."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Ceramella, J., Iacopetta, D., Franchini, A., De Luca, M., Saturnino, C., Andreu, I., Sinicropi, M.S., and Catalano, A. 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