Raistrickindole A, an Anti-HCV Oxazinoindole Alkaloid from Penicillium raistrickii IMB17-034

Raistrickindole A (1), a new indole diketopiperazine alkaloid containing an unusual pyrazino[1',2':2,3]-[1,2]oxazino[6,5-b]indole tetraheterocyclic ring system, a new benzodiazepine derivative, raistrickin (2), and the known haenamindole (3) and sclerotigenin (4) were isolated from the marine-derived fungus Penicillium raistrickii IMB17-034. Their structures were elucidated by extensive spectroscopic analyses and TDDFT calculations of the NMR and ECD data. Compounds 1 and 2 showed inhibitory activities against the hepatitis C virus.