New azaphilones from Penicillium variabile , a fungal endophyte from roots of Aconitum vilmorinianum

Two new azaphilone derivatives, comazaphilones G and H (1 and 2), together with eight known analogues (3–10), were isolated from an endophytic fungus Penicillium variabile. Their structures were established on the basis of extensive spectroscopic analysis. Compounds 1, 2 and 4–10 were tested their nitric oxide inhibitory activities in lipopolysaccharide-activated RAW 264.7 macrophage cells. Compounds 1, 2 and 4–9 showed significant nitric oxide inhibitory activities with IC50 values ranged from 4.35 ± 0.05 to 40.52 ± 0.47 μM.