A new sesquiterpene from endophytic fungus Colletotrichum sp. B-89

A new sesquiterpene, named (1S, 4aS, 7 R, 8 R, 8aR) Decahydro-1,4a-dimethyl-7-(1-methylethyl)-1,8-naphthalenediol (1), and six known compounds (2-7) were obtained from Colletotrichum sp. B-89, an endophytic fungus isolated from Dracaena cochinchinensis collected at Xishuangbanna, Yunnan. Their structures were elucidated by detailed analysis of comprehensive spectroscopic data, and the structure of 1 was further determined by X-ray diffraction analysis. The antibacterial activities of above compounds were assayed and compound 6 exhibited certain activities against S. aureus ATCC 25923, B. subtilis ATCC 6633, E. coli ATCC 25922, and K. pneumoniae ATCC 13883.