title: Structural and Quantitative Analysis of Three C-Glycosylflavones by Variable Temperature Proton Quantitative Nuclear Magnetic Resonance.
abstract: Quantitative nuclear magnetic resonance is a powerful tool in drug analysis because of its speed, precision, and efficiency. In present study, the application of variable temperature proton quantitative nuclear magnetic resonance (VT-1H-qNMR) for the calibration of three C-glycosylflavones including orientin, isoorientin, and schaftoside as reference substances was reported. Since there was conformational equilibrium due to the restricted rotation around the C(sp3)-C(sp2) bond in C-glycosylflavones, the conformational behaviors were investigated by VT-NMR and verified by molecular mechanics (MM) calculation. The VT-1H-qNMR method was validated including the linearity, limit of quantification, precision, and stability. The results were consistent with those obtained from mass balance approach. VT-1H-qNMR can be deployed as an effective tool in analyzing C-glycosylflavones.
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Jing
authors.identifier: 0000-0002-6680-2757
authors.initials: J
authors.lastname: Liu
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Dai
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Lan
authors.identifier: 0000-0003-1102-8976
authors.initials: L
authors.lastname: He
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Shuangcheng
authors.identifier: 0000-0003-0466-857X
authors.initials: S
authors.lastname: Ma