Four Alkaloids from the Rice Fermentation of Fungus Penicillium expansum

Abstract

One pyrrolizidine alkaloid, (3S,4S,5R,6R)-penexpandine (1), and three indole alkaloids, 11S-(–)-penilloid A (2), roquefortine C (3), and roquefortine D (4), were isolated from the rice fermentation of the fungus Penicillium expansum. Their structures were established through NMR spectroscopic data analysis and comparison with reported data. The structure and absolute configuration of compound 1 were elucidated based on comprehensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. Ultimately, the absolute configuration of compound 1 was determined for the first time as (3S,4S,5R,6R)-penexpandine.