title: New 29-nor-cycloartanes with a 3,4-seco- and a novel 2,3-seco-structure from the leaves of Sinocalycanthus chinensis.
abstract: Eight new triterpenoids, including sinocalycanchinensins A-E (1-5) with a 3,4-seco-29-nor-cycloartane skeleton, sinocalycanchinensin F (6) possessing a novel 2,3-seco-29-nor-cycloartane skeleton, and 29-nor-cycloartanes, sinocalycanchinensins G and H (7 and 8), have been isolated from the leaves of Sinocalycanthus chinensis. Their structures were elucidated on the basis of spectroscopic examinations. The cytotoxicities of the isolated new triterpenes against a panel of human cancer cell lines, including multi-drug resistant (MDR) cancer cell lines, were also evaluated. Compound 5 demonstrated enhanced cytotoxicity against MDR KB cells in the presence of colchicine, although all the compounds showed moderate or no cytotoxicities.
authors.affiliation: Graduate School of Pharmaceutical Sciences, University of Tokushima, 1-78 Shomachi, Tokushima 770-8505, Japan. kasiwada@ph.tokushima-u.ac.jp
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kashiwada
authors.forename: Kazuya
authors.initials: K
authors.lastname: Nishimura
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Kurimoto
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Takaishi
mesh_terms: D031237:Calycanthaceae / Q000737:chemistry*; D045744:Cell Line, Tumor; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D018515:Plant Leaves / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity
chemical_list: D014315:Triterpenes; C560286:sinocalycanchinensin E