Four New Chlorinated Azaphilones, Helicusins A-D, Closely Related to 7-epi-Sclerotiorin, from an Ascomycetous Fungus, Talaromyces helicus

Four new azaphilones, named helicusins A, B, C, and D, were isolated from an Ascomycete, Talaromyces helicus. Helicusins A and B were deduced to be (7S, 13S)-7-deacetyl-7-epi-sclerotiorin-7-yl hydrogen 3'-methyl-2'E-pentenedioate and its 2'Z isomer, and helicusins C and D were deduced to be (7S, 13S)-7-deacetyl-7-epi-sclerotiorin-7-yl hydrogen 3'-methyl-3'Z-pentenedioate and its 3'E isomer, respectively, on the basis of chemical and spectral data.These four new azaphilones showed weak monoamine oxidase-inhibitory effects.