title: Polyoxypregnane steroids from the stems of Marsdenia tenacissima.
abstract: A new polyoxypregnane aglycone, tenacigenin D (1), and seven new C21 steroid glycosides, tenacissimosides D-J (2-8), were isolated from the stems of Marsdenia tenacissima. Their structures were determined by interpretation of their 1D and 2D NMR and other spectroscopic data, as well as by comparison with published values for related known compounds. Compound 1 was found to circumvent P-glycoprotein (P-gp)-mediated multidrug resistance through an inhibitory effect on P-gp with a similar potency to verapamil. In addition, compound 1 potentiated the activity of erlotinib and gefitinib in epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI)-resistant non-small-cell lung cancer cells.
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, People's Republic of China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Yao
authors.forename: Kenneth Kin-Wah
authors.initials: KK
authors.lastname: To
authors.forename: Ya-Zhou
authors.initials: YZ
authors.lastname: Wang
authors.forename: Chun
authors.initials: C
authors.lastname: Yin
authors.forename: Chunping
authors.initials: C
authors.lastname: Tang
authors.forename: Stella
authors.initials: S
authors.lastname: Chai
authors.forename: Chang-Qiang
authors.initials: CQ
authors.lastname: Ke
authors.forename: Ge
authors.initials: G
authors.lastname: Lin
authors.forename: Yang
authors.initials: Y
authors.lastname: Ye
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D002289:Carcinoma, Non-Small-Cell Lung; D000069347:Erlotinib Hydrochloride; D000077156:Gefitinib; D006027:Glycosides / Q000737:chemistry; D006801:Humans; D031101:Marsdenia / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D011278:Pregnanes / Q000737:chemistry / Q000302:isolation & purification*; D011799:Quinazolines / Q000819:agonists
chemical_list: D000970:Antineoplastic Agents; D006027:Glycosides; D011278:Pregnanes; D011799:Quinazolines; C000594561:tenacigenin D; D000069347:Erlotinib Hydrochloride; D000077156:Gefitinib