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.