Eremophilane sesquiterpenes from Hawaiian endophytic fungus Chaetoconis sp. FT087

Bioassay-guided fractionation of an extract from a Hawaiian endophytic fungus Chaetoconis sp. led to the isolation of eight compounds (1-8), including six previously unknown sesquiterpenes, chaetopenoids A-F (1-6). Their chemical structures were determined by HRMS and NMR spectroscopy. All isolates were evaluated for their cytotoxicity against A2780 and cisplatin-resistant A2780 (A2780CisR) cancer cell lines. Dendryphiellin A1 (7) was active against A2780 and A2780CisR cell lines with IC50 values of 6.6 and 9.1 μg/mL, respectively.