title: Cyclic tripeptides from the halotolerant fungus Aspergillus sclerotiorum PT06-1.
abstract: Eleven new aspochracin-type cyclic tripeptides, sclerotiotides A-K (1-11), together with three known compounds, JBIR-15 (12), aspochracin (13), and penicillic acid, were isolated from the ethyl acetate extract of the fermentation broth of the halotolerant Aspergillus sclerotiorum PT06-1 in a hypersaline nutrient-rich medium. Their structures were elucidated by spectroscopic analysis and chemical methods. Chemical transformations of 12 and 13 proved that sclerotiotides D-K (4-11) were artifacts probably formed during the fermentation or subsequent isolation steps. All 13 cyclic tripeptides have been evaluated for their antimicrobial and cytotoxic effects. Only sclerotiotides A (1), B (2), F (6), and I (9) and JBIR-15 (12) showed selective antifungal activity against Candida albicans with MIC values of 7.5, 3.8, 30, 6.7, and 30 microM, respectively.
authors.affiliation: Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, People's Republic of China.
authors.forename: Jinkai
authors.initials: J
authors.lastname: Zheng
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Xu
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.forename: Kui
authors.initials: K
authors.lastname: Hong
authors.forename: Peipei
authors.initials: P
authors.lastname: Liu
authors.forename: Weiming
authors.initials: W
authors.lastname: Zhu
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001230:Aspergillus / Q000737:chemistry*; D002176:Candida albicans / Q000187:drug effects; D002681:China; D004354:Drug Screening Assays, Antitumor; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013237:Stereoisomerism
chemical_list: D000935:Antifungal Agents; D010456:Peptides, Cyclic; D012965:Sodium Chloride