title: Spirostanol tetraglycosides from Ypsilandra thibetica.
abstract: Phytochemical reinvestigation on the whole plants of Ypsilandra thibetica obtained five new spirostane glycosides, ypsilandrosides H-L (1-5), and a known saponin polyphylloside III (6). Among them, 1 and 2 are the first spirostane glycosides which possess novel 5(6-->7) abeo-steroidal aglycones. Compounds 3 and 4 are rare saponins whose aglycones contain a hydroxyl group at C-7. Their structures were elucidated on the basis of MS, 1D and 2D NMR spectroscopic analysis and chemical evidences. The isolated compounds were evaluated for their cytotoxic activity on five tumor cell lines.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Lu
authors.forename: Chang-Xiang
authors.initials: CX
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Ni
authors.forename: Yan
authors.initials: Y
authors.lastname: Hua
authors.forename: Hai-Yang
authors.initials: HY
authors.lastname: Liu
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D006027:Glycosides / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D019684:Magnoliopsida / Q000737:chemistry*; D013150:Spirostans / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D006027:Glycosides; D013150:Spirostans