Xylarkarynone A and B:Two Bioactive Eremophilane Sesquiterpenes from Xylaria sp. HHY‐2

Abstract A new compound xylarkarynone A ( 1 ), a first reported natural product compound xylarkarynone B ( 2 ) and eight known compounds ( 3 ‐ 10 ) were isolated from Xylaria sp. HHY‐2. Their structures were elucidated by spectroscopic methods, DP4+ probability analyses and electronic circular dichroism (ECD) calculations. The bioactivities of isolated compounds were assayed. Compound 1 exhibited obvious activity against A549 cells with an IC 50 value of 6.12±0.28 μM. Additionally, compound 1 showed moderate antifungal activities against Plectosphaerella cucumerina and Aspergillus niger with minimum inhibitory concentrations (MICs) of both 16 μg/mL, which was at the same grade with positive control nystatin. Most compounds exhibited varying degrees of inhibitory activity against P. cucumerina , indicating that Xylaria sp. has potential as inhibitors against P. cucumerina .