title: Polyoxypregnane steroids with an open-chain sugar moiety from Marsdenia tenacissima and their chemoresistance reversal activity.
abstract: A polyoxypregnane aglycone, 12β-O-acetyl-11α-O-isobutyryltenacigenin B, and four polyoxypregnane glycosides with a pachybionic acid ester moiety, 12β-O-acetyl-3-O-(6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandronyl)-11α-O-isobutyryltenacigenin B, 12β-O-acetyl-3-O-(6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandronyl)-11α-O-tigloyltenacigenin B, 12β-O-acetyl-3-O-(6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandronyl)-11α-O-2-methylbutyryltenacigenin B, and 12β-O-acetyl-3-O-(β-D-glucopyranosyl-(1→4)-6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-D-oleandronyl)-11α-O-tigloyltenacigenin B, were isolated from the canes of Marsdenia tenacissima, together with a disaccharide derivative. Their structures were elucidated by extensive spectroscopic analysis, and the absolute configurations were further determined by X-ray crystallographic analysis. With the exception of the disaccharide derivative, all five compounds are unusual naturally occurring polyoxypregnane glycosides bearing an open-chain sugar moiety. Two of these exhibit a wide spectrum of chemoresistance reversal activity, and potential mechanisms were studied accordingly.
authors.affiliation: State Key Laboratory of Drug Research and Natural Products Chemistry Department, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China; Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yao
authors.affiliation: Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China; School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Kenneth Kin-Wah
authors.initials: KK
authors.lastname: To
authors.affiliation: State Key Laboratory of Drug Research and Natural Products Chemistry Department, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China; Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Ma
authors.affiliation: Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China; School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Drug Research and Natural Products Chemistry Department, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China; Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China.
authors.forename: Chunping
authors.initials: C
authors.lastname: Tang
authors.affiliation: Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China; School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Stella
authors.initials: S
authors.lastname: Chai
authors.affiliation: State Key Laboratory of Drug Research and Natural Products Chemistry Department, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China; Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China.
authors.forename: Chang-Qiang
authors.initials: CQ
authors.lastname: Ke
authors.affiliation: Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China; School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China. Electronic address: linge@cuhk.edu.hk.
authors.forename: Ge
authors.initials: G
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Drug Research and Natural Products Chemistry Department, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu-Chong-Zhi Road, Zhangjiang Hi-Tech Park, Shanghai 201203, China; Joint Research Laboratory of Promoting Globalization of Traditional Chinese Medicines between Shanghai Institute of Materia Medica, Chinese Academy of Sciences and The Chinese University of Hong Kong, China; School of Life Science and Technology, ShanghaiTech University, Shanghai, China. Electronic address: yye@mail.shcnc.ac.cn.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ye
mesh_terms: D029062:Apocynaceae / Q000737:chemistry*; D018360:Crystallography, X-Ray; D031101:Marsdenia; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011278:Pregnanes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: C575295:12-0-benzoyl-8,11-ditigloyl-3,8,11,12-pentahydroxy-pregn-14-ol, 20-one 3-0-methyl-allopyranosyl(1-4)-thevetopyranoside; C000610802:12beta-O-acetyl-11alpha-O-isobutyryltenacigenin B; D011278:Pregnanes; D012503:Saponins
keywords: Absolute configuration; Asclepiadaceae; C(21) steroids; Chemoresistance reversal activity; Marsdenia tenacissima; Open-chain sugars; Structure elucidation; X-ray crystallography diffraction