Solvent effect in 1H NMR spectra of 3'-hydroxy-4'-methoxy isoflavonoids from Astragalus membranaceus var. mongholicus.
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.
Du
Xingang
X
School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100083, China.
Bai
Yanjing
Y
Liang
Hong
H
Wang
Zhiying
Z
Zhao
Yuying
Y
Zhang
Qingying
Q
Huang
Luqi
L
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*
D007529:Isoflavones; D012997:Solvents