Cytotoxic secondary metabolites from mangrove-rhizosphere-associated fungus Emericella sp. strain SWR1718

Abstract

Chemical exploration of mangrove-rhizosphere-associated fungus Emericella sp. strain SWR1718 (Aspergillaceae) was performed through various chromatographic workup procedures. The achieved results afforded one new natural compound, emericelactone E (1) in addition to known compounds (2–7). The planar structures of the purified compounds were unambiguously carried out using several spectroscopic methods. Both relative and absolute configurations of compound 1 were carefully determined based on NOESY experiments, coupling constants and comparing its optical rotation with related congeners. Moreover, a plausible biosynthetic pathway of 1 and its related derivatives is reported for the first time in our study. The cytotoxic potential of isolated metabolites was assessed toward three human tumor cell lines where some of them exhibited moderate activities compared to paclitaxel as a standard anticancer.