Secondary metabolites from endophytic fungus Chaetomium sp. induce colon cancer cell apoptotic death

A rare depsipeptide, chaetomiamide A (1), together with two known diketopiperazines (2, 3) were isolated from the cultures of endophytic fungus Chaetomium sp., which was isolated from the root of Cymbidium goeringii. Compound 1 represents a rare skeleton with a 13-membered ring system. It structure was established on the basis of spectroscopic data interpretation. The configuration of 1 was determined by NOESY and Marfey's analysis. These isolates were evaluated for anticancer activity and 3 displayed more potent cytotoxicity than the positive control cisplatin associated with G2/M cell cycle arrest. In addition, 3 induced apoptosis via caspase-3 induction and PARP cleavage, concomitantly with the increase of Bax and decrease of Bcl-2.

One rare depsipeptide, chaetomiamide A (1), together with two known diketopiperazines (2 and 3) were isolated from the cultures of endophytic fungus Chaetomium sp., which was isolated from root of Cymbidium goeringii. Compound 1 represents a rare skeleton with 13-membered ring system. These structures were established on the basis of spectroscopic data interpretation and Marfey's analysis. Compounds 1-3 were evaluated for their cytotoxic activities against five human cancer cell lines, and 3 displayed cytotoxicity than the positive control cisplatin associated with cell cycle arrest and induced cell apoptotic death.207