Studies on the Constituents of Asclepiadaceae Plants. LIII. The Structures of Glaucogenin-A, -B, and -C Mono-D-thevetoside from the Chinese Drug "Pai-ch'ien, "Cynanchum glaucescens HAND-MAZZ

抄録

The aglycone portion of the glycosides of the chinese crude drug "Pai-ch'ien" was investigated. Three new compounds named glaucogenin-A (1), -B (3), and -C mono-D-thevetoside (8) were isolated and their structures were characterized on the basis of spectroscopic and chemical evidence, and that of 8 was determined by X-ray crystallography. They were found to possess an unprecedented 13, 14 : 14, 15-disecopregnane-type skeleton.