title: Dyscusins A-C, three new steroids from the leaves of Dysoxylum cumingianum.
abstract: Three new steroids dyscusins A-C (1-3), including a stigmastane-type sterol and two pregnanes, together with two known steroids were isolated from the leaves of Dysoxylum cumingianum (Meliaceae). Their structures were elucidated on the basis of extensive spectroscopic analyses. In a cytotoxicity assay, compound 1 showed ten-fold enhanced cytotoxicity against multi-drug resistant cancer cells (KB-C2) in the presence of 2.5 µM colchicine as compared with the absence of colchicine. This notable finding indicated that 1 possessed a multi-drug resistant reversal effect.
authors.affiliation: Graduate School of Pharmaceutical Sciences, University of Tokushima, Tokushima, Japan.
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Kurimoto
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Kashiwada
authors.forename: Susan Lynne
authors.initials: SL
authors.lastname: Morris-Natschke
authors.forename: Kuo-Hsiung
authors.initials: KH
authors.lastname: Lee
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Takaishi
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D045744:Cell Line, Tumor; D003078:Colchicine / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D029582:Meliaceae / Q000737:chemistry*; D015394:Molecular Structure; D008517:Phytotherapy; D018515:Plant Leaves / Q000737:chemistry; D011278:Pregnanes / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D013256:Steroids / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D013261:Sterols / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D050257:Tubulin Modulators / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D011278:Pregnanes; D013256:Steroids; D013261:Sterols; D050257:Tubulin Modulators; D003078:Colchicine