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 IC 50 values ranged from 4.35 ± 0.05 to 40.52 ± 0.47 μM.