Three new α-pyrone derivatives from the soil-derived fungus Penicillium herquei MA-370.

Three new α-pyrone derivatives, annularins L–N (1–3), were isolated from the EtOAc extract of Penicillium herquei MA-370, a fungus obtained from the rhizospheric soil of the mangrove plant Rhizophora mucronata. The planar structures of compounds 1–3 were determined based on comprehensive spectral interpretation of the NMR and MS data. The absolute configuration of 1 was determined by X-ray crystallographic data and that of 2 was assigned by TDDFT calculations of its ECD spectrum and cotton effects comparison with those of 1. The antimicrobial activity of compounds 1–3 was evaluated. [ABSTRACT FROM AUTHOR]