title: Solvent effect in 1H NMR spectra of 3'-hydroxy-4'-methoxy isoflavonoids from Astragalus membranaceus var. mongholicus.
abstract: Four 3'-hydroxy-4'-methoxy-isoflavonoids: calycosin-7-O-beta-D-glucopyranoside (1), calycosin (2), pratensein-7-O-beta-D-glucopyranoside (3), and pratensein (4) were isolated from Astragalus membranaceus var. mongholicus, among which compound 4 was obtained from this plant for the first time. The solvent effect obscuring (1)H signal patterns of B ring of compounds 1-4 was reported to avoid mis-assignments. Previously reported NMR data of compounds 1 and 2 were corrected based on 1D and 2D NMR experiments.
authors.affiliation: School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100083, China.
authors.forename: Xingang
authors.initials: X
authors.lastname: Du
authors.forename: Yanjing
authors.initials: Y
authors.lastname: Bai
authors.forename: Hong
authors.initials: H
authors.lastname: Liang
authors.forename: Zhiying
authors.initials: Z
authors.lastname: Wang
authors.forename: Yuying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Qingying
authors.initials: Q
authors.lastname: Zhang
authors.forename: Luqi
authors.initials: L
authors.lastname: Huang
mesh_terms: D027885:Astragalus propinquus / Q000737:chemistry*; D007529:Isoflavones / Q000737:chemistry / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D008516:Medicine, Chinese Traditional; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*
chemical_list: D007529:Isoflavones; D012997:Solvents