Nigirpexin E, a new azaphilone derivative with anti-tobacco mosaic virus activity from soil-derived fungus Trichoderma afroharzianum LTR-2

A new compound classified as one new azaphilone derivative, nigirpexin E (1), was obtained from the soil-derived fungus Trichoderma afroharzianum LTR-2, together with seven known compounds (2-8). The structures of 1-8 were determined by their HRESIMS, optical rotation, and NMR spectroscopic data. The absolute configuration of nigirpexin E (1) was determined on the basis of comparisons of experimental and theoretically calculated ECD spectra....