[Chemical constituents from fresh tubers of Dioscorea bulbifera]

Eighteen compounds were isolated from the 95% ethanol extract of fresh tubers of Dioscorea bulbifera by column chromatography over silica gel,Sephadex LH-20, and ODS. Their structures were elucidated by spectroscopic data analysis as 6-hydroxy-2,10,10-trimethoxy-anthracen-9-one(1), diosgenin (2), stigmasterol(3), 3, 7-dimethoxy-5, 3', 4'-trihydroxyflavone(4), 2, 7-dihydroxy-3, 4-dimethoxyphenanthrene(5), 3, 7-dihydroxy-2, 4-dimethoxy phenanthrene(6), 2, 7-dihydroxy-4-methoxyphenanthrene (7), 2, 7-dihydroxy-3, 4-dimethoxy-9, 10-dihydroxy phenanthrene(8), azelaic acid (9), 8-epidiosbulbin E acetate (10), 1, 7-bis-(4-hydroxyphenyl)-4E, 6E-heptadien-3-one(11), diosbulbin B(12), pentacosanoic acid 2', 3'-dihydroxypropyl ester(13), 2, 7-dihydroxy-4-methoxy-9, 10-dihydroxy-phenanthrene (14), 1, 7-bis-(4-hydroxyphenyl)-1E, 4E, 6E-heptatrien-3-one (15), 6-ethoxy-1H-pyrimidine-2, 4-dione (16), 3, 5, 4'-trihydroxy-bibenzyl (17), and diosbulbin F (18). Compound 1 is a new compound, and compounds 7, 9, 13, and 16 were isolated from this plant for the first time.