Paecilomycins J–M, four new β-resorcylic acid lactones from Paecilomyces sp. SC0924

Four new β-resorcylic acid lactones, paecilomycins J–M, all possessing an oxygen bridge between C-2′ and C-5′ to form a tetrahydrofuran ring, were isolated from the mycelial solid culture of Paecilomyces sp. SC0924. Their structures were elucidated on the basis of extensive NMR analysis, single-crystal X-ray diffraction, and chemical means. Paecilomycin M exhibited weak antifungal activity against Peronophythora litchii.