title: Cytotoxic dihydrothiophene-condensed chromones from marine-derived fungus Penicillium oxalicum.
abstract: Two new dihydrothiophene-condensed chromones and a new natural chromone, namely oxalicumones A-C (1-3), respectively, were isolated from a culture broth of a marine-derived fungus Penicillium oxalicum SCSGAF 0023, Meripilaceae family. The structures of 1-3 and acetylated derivatives of 1 (4-7) were elucidated on the basis of spectroscopic methods and chemical reactions. The absolute configuration of 1 was established by using the modified Mosher ester method and circular dichroism data of in situ formed [Rh₂(OCOCF₃)₄] and [Mo₂(OAc)₄] complexes. (R)-MTPA ester of 1 showed cytotoxicity against A375, SW-620, and HeLa carcinoma cell lines with IC₅₀ values of 8.9, 7.8, and 18.4 µM, respectively. Compound 1 displayed cytotoxicity against A375 and SW-620 cell lines with IC₅₀ values of 11.7 and 22.6 µM, respectively. The structure-biological activity relationship of 1 is discussed.
authors.affiliation: Key Laboratory of Marine Bio-resources Sustainable Utilization/Guangdong Key Laboratory of Marine Materia Medica/RNAM Center for Marine Microbiology, South China Sea Institute of Oceanology, The Chinese Academy of Sciences, Guangzhou, Guangdong, PR China.
authors.forename: Yu-Lin
authors.initials: YL
authors.lastname: Sun
authors.forename: Fei
authors.initials: F
authors.lastname: He
authors.forename: Kai-Sheng
authors.initials: KS
authors.lastname: Liu
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Bao
authors.forename: Yi-Fei
authors.initials: YF
authors.lastname: Wang
authors.forename: Xu-Hua
authors.initials: XH
authors.lastname: Nong
authors.forename: Xin-Ya
authors.initials: XY
authors.lastname: Xu
authors.forename: Shu-Hua
authors.initials: SH
authors.lastname: Qi
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D059001:Aquatic Organisms / Q000737:chemistry; D002867:Chromones / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D006367:HeLa Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D010407:Penicillium / Q000737:chemistry*; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D002867:Chromones