Xylariaopyrones A-D, four new antimicrobial α-pyrone derivatives from endophytic fungus Xylariales sp

Four new alpha-pyrone derivatives, xylariaopyrones A-D (1-4), together with four known compounds were isolated from the PDB broth of endophytic fungus xylariales sp. (HM-1). Their structures were identified by comprehensive analysis of NMR, MS and CD spectra. The absolute configurations of compounds B-D were determined by calculating their ECD spectra. Compound C (3) and D (4) was a pair of epimer with a ketal function group. The eight obtained metabolites were evaluated to four cancer cell lines, but they showed no significative data with IC50 > 50 mu g/mL. And the antimicrobial assay results appeared that xylariaopyrones A-D displayed the inhibiting activity with MIC value ranging from 20.5 to 50.6 mu g/mL. Finally, the results of brine shrimp inhibiting activity from eight compounds displayed different inhibiting ratio from 40% to 92%.