title: Dioxatricyclic and oxabicyclic polyketides from Trichocladium opacum.
abstract: Five new polyketides, trichocladinols D-H (1-5) with dioxatricyclic (1-3) and oxabicyclic (4 and 5) skeletons, and the known massarilactone C (6) were isolated from the solid-substrate fermentation cultures of the ascomycete fungus Trichocladium opacum. The structures of 1-5 were determined mainly by NMR experiments, and 1, 3, and 4 were confirmed by X-ray crystallography. The absolute configurations of 1 and 3 were assigned by X-ray crystallography using Cu Kα radiation, whereas that of C-5 in 2 and 4 was deduced via the circular dichroism (CD) data. Compounds 2-4 showed weak cytotoxicity against the human tumor cell lines A549, HCT116, and SW480.
authors.affiliation: State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Shenxi
authors.initials: S
authors.lastname: Chen
authors.forename: Fengxia
authors.initials: F
authors.lastname: Ren
authors.forename: Shubin
authors.initials: S
authors.lastname: Niu
authors.forename: Xingzhong
authors.initials: X
authors.lastname: Liu
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Che
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001203:Ascomycota / Q000737:chemistry*; D045744:Cell Line, Tumor; D002942:Circular Dichroism; D018360:Crystallography, X-Ray; D004354:Drug Screening Assays, Antitumor; D045325:HCT116 Cells; D006572:Heterocyclic Compounds, Bridged-Ring / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D006801:Humans; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D061065:Polyketides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D018609:Tibet
chemical_list: D000970:Antineoplastic Agents; D006572:Heterocyclic Compounds, Bridged-Ring; D061065:Polyketides