Cyclic tripeptides from the halotolerant fungus Aspergillus sclerotiorum PT06-1.
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.
Zheng
Jinkai
J
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.
Xu
Zhihong
Z
Wang
Yi
Y
Hong
Kui
K
Liu
Peipei
P
Zhu
Weiming
W
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
D000935:Antifungal Agents; D010456:Peptides, Cyclic; D012965:Sodium Chloride