Sesquiterpenes and Steroids from an Endophytic Eutypella scoparia

Abstract

A chemical investigation on the EtOAc extract of the endophytic fungus Eutypella scoparia SCBG-8 led to the isolation of eight new sesquiterpenes eutyscoparins A-H (1-8), one C-28 steroid eutyscoparene A (9), one triterpenoid eutyscoparene B (10), six known terpenoids, and two known steroids. Their structures including absolute configurations were established on the basis of spectroscopic data analysis, single-crystal X-ray diffraction experiments, and electronic circular dichroism (ECD) calculations. Compound 7 displayed antibacterial activity against S. aureus and MRSA (methicillin-resistant Staphylococcus aureus) with MIC values of 6.3 μg/mL.