Secondary metabolites of Pyrenochaeta sp B36, an endophytic fungus from Annona squamosa L.

Four new metabolites, named pyrenochaetamide A (1), pyrenochaetolide A (2), pyrenochaetoxy A (3) and pyrenochaetolide B (4), together with five known compounds (5-9), were isolated from strain Pyrenochaeta sp. B36, an endophytic fungus of Annona squamosa L. Their structures were elucidated by spectroscopic analyses including 1D- and 2D-NMR (HMQC, HMBC, 1H-1H COSY and NOESY) and HRFT-MS. The cytotoxic activities of these compounds were evaluated and some of them showed substantial effect.