beta-Resorcylic acid lactones from a Paecilomyces fungus.

Six new beta-resorcylic acid lactones (1-6), named paecilomycins A-F, and five known compounds, aigilomycin B (7), zeaenol (8), aigialomycin D (9), aigialomycin F (10), and aigialospirol, were isolated from the mycelial solid culture of Paecilomyces sp. SC0924. Their structures were elucidated by extensive NMR analysis, single-crystal X-ray study, and chemical correlations. Compounds 5 and 10 exhibited antiplasmodial activity against Plasmodium falciparum line 3D7 with IC(50) values of 20.0 and 10.9 nM, respectively, and compounds 5-7 showed moderate activity against the P. falciparum line Dd2.