Bang, Miyeon Cha, Jin Wook 2025-09-09T07:00:52Z 2025-09-09T07:00:52Z 2025-09-08 2025-09 2468-0834 https://pubs.kist.re.kr/handle/201004/153141 Nuclear Magnetic Resonance (NMR) spectroscopy has become indispensable for elucidating molecular structures in pharmaceutical and natural product chemistry, where precise stereochemical configurations critically determine biological activities and therapeutic efficacy. We present an integrated methodology combining ultraselective NMR techniques (GEMSTONE and UHPT) with quantum chemical calculations to analyze iprovalicarb, a conformationally flexible diastereomeric mixture. By extracting detailed individual J-coupling and NOE data from mixture, we established spatio-conformational constraints that enabled systematic filtering of computationally generated conformers. This approach allowed precise identification of conformers consistent with experimental observations and accurate determination of R/S configurations without chemical derivatization or crystallization. ECD calculations on filtered conformers showed superior agreement with experimental measurements compared to unfiltered calculations, validating our approach. This methodology reduces resource requirements while improving structural analysis accuracy, offering applications in drug development and other field of chemistry for complex stereoisomeric systems. English 한국응용생명화학회 Enhanced diastereomeric mixture analysis through integration of quantum chemical calculations with spatio-conformational information obtained from ultraselective NMR techniques Article 10.1186/s13765-025-01030-9 1 Applied Biological Chemistry, v.68, no.1, pp.1 - 10 Applied Biological Chemistry 68 1 1 10 Y scie scopus kci ART003242342 001564870700001 Food Science & Technology Food Science & Technology Article ABSOLUTE-CONFIGURATION DIASTEREOISOMERS STEREOCHEMISTRY ASSIGNMENT Absolute configuration Diastereomer Mixture analysis Quantum Chemical Calculation Ultraselective NMR spectroscopy