title: Five new steroidal compounds from Ypsilandra thibetica.
abstract: Five new steroids, including the four new steroidal saponins ypsilandroside B (1), ypsilandroside A (2), isoypsilandroside A (4), and isoypsilandroside B (5), as well as the new steroidal sapogenin isoypsilandrogenin (3), were isolated from the whole plant of Ypsilandra thibetica Franch. Their structures were determined on the basis of spectroscopic analyses, including extensive 2D-NMR techniques. The structure and relative configuration of ypsilandroside B (=(3beta,12alpha,25R)-3-[(alpha-L-rhamnopyranosyl-(1-->2)-beta-D-apiofuranosyl)oxy]spirost-5-ene-12,27-diol; 1) was unequivocally determined by single-crystal X-ray diffraction. The antifungal and antibacterial activities of 1-5 towards various types of fungi and bacteria are reported.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, Yunnan, P.R. China.
authors.forename: Bai-Bo
authors.initials: BB
authors.lastname: Xie
authors.forename: Hai-Yang
authors.initials: HY
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Ni
authors.forename: Chang-Xiang
authors.initials: CX
authors.lastname: Chen
authors.forename: Yang
authors.initials: Y
authors.lastname: Lü
authors.forename: Li
authors.initials: L
authors.lastname: Wu
authors.forename: Qi-Tai
authors.initials: QT
authors.lastname: Zheng
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry; D000935:Antifungal Agents / Q000737:chemistry; D002626:Chemistry, Pharmaceutical / Q000379:methods; D000431:Ethanol / Q000737:chemistry; D005663:Furans / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D019684:Magnoliopsida / Q000378:metabolism*; D008956:Models, Chemical; D008958:Models, Molecular; D010936:Plant Extracts / Q000737:chemistry*; D010946:Plants, Medicinal / Q000378:metabolism; D012502:Sapogenins / Q000737:chemistry; D012503:Saponins / Q000737:chemistry* / Q000302:isolation & purification*; D013256:Steroids / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D005663:Furans; D010936:Plant Extracts; D012502:Sapogenins; D012503:Saponins; D013256:Steroids; D000431:Ethanol