New antioxidant phenolic glycosides from Walsura yunnanensis.
Four new polyphenolic glycosides (1-4) were isolated from the BuOH extract of the bark of Walsura yunnanenis C. Y. Wu. These compounds comprise two lignans, i.e., the 9-O-alpha-L-arabinopyranosides 1 and 2 of (-)-isolariciresinol and of (+)-5-methoxyisolariciresinol, respectively, and the two phenolic glycosides 3,4,5-trimethoxyphenyl 2-O-(alpha-L-fucopyranosyl)-beta-D-glucopyranoside (3) and 3,5-dihydroxyphenyl 6-O-(4-hydroxy-3,5-dimethoxybenzoyl)-beta-D-glucopyranoside (walsuraside; 4). In addition, three known compounds, 3,4,5-trimethoxyphenyl beta-D-glucopyranoside, asperglaucide, and butyl alpha-D-fructofuranoside were identified. Their structures were elucidated spectroscopically and by chemical transformation (hydrolysis). The new compounds 1, 2, and 4 displayed significant antioxidant activities, with IC(50) values in the range of ca. 42 to 49 microg/ml.
Luo
Xiao-Dong
XD
State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, PR China. xdluo@mail.kib.ac.cn
Wu
Da-Gang
DG
Cai
Xiang-Hai
XH
Kennelly
Edward J
EJ
D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification*; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification*; D029582:Meliaceae / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification*; D024301:Plant Bark; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification
D000975:Antioxidants; D006027:Glycosides; D010636:Phenols; D010936:Plant Extracts