Metabolites from an endophytic fungus sphaceloma sp. LN-15 isolated from the leaves of Melia azedarach.

Two new natural compounds, a symmetrical disulfide dimer didodecyl 3,3''-dithiodipropionate (1) and a pregnane steroid 5,16-pregnadien-3beta-ol-20-one acetate (2), were isolated together with two known compounds, ergosta-4,6,8(14),22-tetraen-3-one (3) and ergosterol peroxide (4), from the ethyl acetate soluble extract of fermentation broth of an endophytic fungus, Sphaceloma sp. LN-15 isolated from the leaves of Melia azedarach L. and grown in pure culture. Their structures were determined on the basis of spectroscopic methods including 1D and 2D nuclear magnetic resonance spectroscopy (NMR) experiments and by mass spectrometric measurements (MS). These fungal metabolites were isolated for the first time from the genus Sphaceloma. The structure of 1 was also confirmed by chemical synthesis.