A new steroid with 7β,8β-epoxidation from the deep sea-derived fungus Aspergillus penicillioides SD-311

7 beta,8 beta-epoxy-(22E,24R)-24-methylcholesta-4,22-diene-3,6-dione (1), a new steroid, along with five known analogues (2-6), was isolated from the deep sea-derived fungus,Aspergillus penicillioidesSD-311. Strikingly,1possessed a rare 7,8-epoxidation moiety. Meanwhile, this is the first time to report natural products from this fungus species. The structures were established by extensive spectroscopic analysis. The absolute configuration was determined by X-ray diffraction experiments. Compound1showed antibacterial activity againstVibrio anguillarumwith MIC value of 32.0 mu g/mL, while2displayed inhibitions againstEdwardsiella tardaandMicrococcus luteuswith MIC values both of 16 mu g/mL. [GRAPHICS] .

Automated summary

A new steroid, 7 beta,8 beta-epoxy-(22E,24R)-24-methylcholesta-4,22-diene-3,6-dione (1), was isolated from the deep sea-derived fungus, Aspergillus penicillioides SD-311, along with five known analogues. Compound 1 possessed a rare 7,8-epoxidation moiety, and this is the first report of natural products from this fungus species. The structures were determined by extensive spectroscopic analysis, and the absolute configuration was established by X-ray diffraction experiments.