title: Cytotoxic cytochalasin metabolites of endophytic Endothia gyrosa.
abstract: In addition to the known metabolites cytochalasin H (1), cytochalasin J (2), and epoxycytochalasin H (3), two new 10-phenyl-(11)-cytochalasans, named cytochalasin Z10 and Z11 (4 and 5, resp.) were isolated from the solid substrate culture of Endothia gyrosa IFB-E023, an endophytic fungus residing inside the healthy leaf of Vatica mangachapo (Dipterocarpaceae). The structure determination of 4 and 5 was accomplished through correlative analyses of their spectral data (UV, ESI-MS, IR, (1)H- and (13)C-NMR, COSY, NOESY, HMQC, and HMBC). Metabolites 1-5 were demonstrated to be substantially cytotoxic to the human leukaemia K562 cell line with the IC(50) values of 10.1, 1.5, 24.5, 28.3, and 24.4 microM, respectively, which are comparable to that of 5-fluorouracil (33.0 microM), co-assayed as the positive reference.
authors.affiliation: Institute of Functional Biomolecules, State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, P. R. China.
authors.forename: Shu
authors.initials: S
authors.lastname: Xu
authors.forename: Hui Ming
authors.initials: HM
authors.lastname: Ge
authors.forename: Yong Chun
authors.initials: YC
authors.lastname: Song
authors.forename: Yao
authors.initials: Y
authors.lastname: Shen
authors.forename: Hui
authors.initials: H
authors.lastname: Ding
authors.forename: Ren Xiang
authors.initials: RX
authors.lastname: Tan
mesh_terms: D001203:Ascomycota / Q000254:growth & development / Q000378:metabolism*; D045744:Cell Line, Tumor; D003572:Cytochalasins / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D053958:Dipterocarpaceae / Q000737:chemistry / Q000382:microbiology; D006801:Humans; D020014:K562 Cells; D018515:Plant Leaves / Q000737:chemistry; D013559:Symbiosis
chemical_list: D003572:Cytochalasins; C542663:cytochalasin Z10; C542664:cytochalasin Z11