title: Four new minor taxanes from cell cultures of Taxus chinensis.
abstract: Four new minor taxanes (1-4) have been isolated from Ts-19 cell cultures of Taxus chinensis together with five known taxanes (5-9) by silica gel chromatography combined with semi-preparative HPLC chromatography. On the basis of the analyses of the chemical and spectroscopic (IR, MS, 1D, and 2D NMR) data, the structures of new compounds were elucidated as 5alpha-hydroxy-2alpha,10beta-diacetoxy-14beta-(3-hydroxy-2-methyl-butyryl)oxytaxa-4(20),11-diene (1), 2alpha,5alpha,10beta-triacetoxy-14beta-(2-hydroxy-propionyl)oxytaxa-4(20),11-diene (2), 2alpha,5alpha,10beta-triacetoxy-14beta-(2-hydroxy-3-methyl-butyryl)oxytaxa-4(20),11-diene (3), and 2alpha-benzoxy-4alpha,9alpha,10beta,13alpha-tetraacetoxytax-11-ene (4), respectively. Compounds 1-5 were pharmacologically evaluated for their cytotoxicities against five human cancer cell lines (HCT-8, Bel-7402, BGC-823, A549, and A2780) and their reversing activity towards multi-drug resistance A549/taxol tumor cell line, and the results showed that all of the tested compounds exhibited very low cytotoxicities, while compound 4 possessed twice the reversing activity as that of verapamil at 10 muM.
authors.affiliation: Key Laboratory of Biosynthesis of Natural Drugs, Peking Union Medical College, Ministry of Public Health and Key Laboratory of Bioactive Substances and Resources Utilization, Ministry of Education, Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Xie
authors.forename: Hong-Ting
authors.initials: HT
authors.lastname: Jia
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Zou
authors.forename: Da-Li
authors.initials: DL
authors.lastname: Yin
authors.forename: Xiao-Guang
authors.initials: XG
authors.lastname: Chen
authors.forename: Yu-Ning
authors.initials: YN
authors.lastname: Yan
authors.forename: Jun-Gui
authors.initials: JG
authors.lastname: Dai
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018929:Cell Culture Techniques; D018432:Drug Resistance, Multiple / Q000187:drug effects; D006801:Humans; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism; D043823:Taxoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D020946:Taxus / Q000737:chemistry*; D014700:Verapamil / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D043823:Taxoids; D014700:Verapamil