Varilactones and wortmannilactones produced by Penicillium variabile cultured with histone deacetylase inhibitor.

Seven polyketides, including four new ones named as varilactones A-B (1-2) and wortmannilactones M-N (3-4), as well as three biogenetically related known wortmannilactones E, F and H (5-7), were isolated from the fungus Penicillium variabile HXQ-H-1, cultivated in potato-based medium with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA). Their structures (1-7) were established by analysis of NMR and MS data, and the absolute configuration of oxabicyclo[2.2.1]heptane unit was deduced from 1H-NMR analyses on MPA esters after chemical reduction reaction. Among them, varilactones A and B (1 and 2), features a novel skeleton with a triene unit linking an oxabicyclo[2.2.1]heptane and an oxabicyclo[3.3.0]octane rings.