title: Thiodiketopiperazines produced by the endophytic fungus Epicoccum nigrum.
abstract: Thirteen new thiodiketopiperazines, epicoccin I (1), ent-epicoccin G (2), and epicoccins J-T (3-13), together with six known diketopiperazines (14-19), have been isolated from the endophytic fungus Epicoccum nigrum. The structures of 1, 2, and 10 were confirmed by X-ray crystallography, and the absolute configurations of 2, 4, 6, and 8 were assigned using Moshers' method. Compounds 2, 6, 12, and 17 showed potent activities in vitro against the release of beta-glucuronidase in rat polymorphonuclear leukocytes induced by platelet-activating factor, with IC(50) values of 3.07, 4.16, 4.95, and 1.98 microM, respectively. None of the 19 compounds exhibited detectable cytotoxic activities toward six tumor cell lines (A549, Be-l7402, BGC-823, HCT-8, HCT-116, and A2780) in the MTT assay.
authors.affiliation: Key Laboratory of Bioactive Substance and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 1 Xian Nong Tan Street, Beijing People's Republic of China.
authors.forename: Jia-Ming
authors.initials: JM
authors.lastname: Wang
authors.forename: Guang-Zhi
authors.initials: GZ
authors.lastname: Ding
authors.forename: Lei
authors.initials: L
authors.lastname: Fang
authors.forename: Jun-Gui
authors.initials: JG
authors.lastname: Dai
authors.forename: Shi-Shan
authors.initials: SS
authors.lastname: Yu
authors.forename: Ying-Hong
authors.initials: YH
authors.lastname: Wang
authors.forename: Xiao-Guang
authors.initials: XG
authors.lastname: Chen
authors.forename: Shuang-Gang
authors.initials: SG
authors.lastname: Ma
authors.forename: Jing
authors.initials: J
authors.lastname: Qu
authors.forename: Song
authors.initials: S
authors.lastname: Xu
authors.forename: Dan
authors.initials: D
authors.lastname: Du
mesh_terms: D000818:Animals; D001203:Ascomycota / Q000737:chemistry*; D002681:China; D018360:Crystallography, X-Ray; D054659:Diketopiperazines / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D007887:Fabaceae / Q000382:microbiology*; D005966:Glucuronidase / Q000037:antagonists & inhibitors*; D006801:Humans; D020128:Inhibitory Concentration 50; D008968:Molecular Conformation; D015394:Molecular Structure; D009504:Neutrophils / Q000187:drug effects; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000382:microbiology; D051381:Rats
chemical_list: D054659:Diketopiperazines; D005966:Glucuronidase