Nodulisporisteroids C-L, new 4-methyl-progesteroid derivatives from Nodulisporium sp.

The fungus Nodulisporium sp. (No. 65-12-7-1), which can produce a rare class of steroids (4-methyl-progesteroids) in rice solid medium, was subjected to a one strain-many compounds (OSMAC) approach. It was found to produce ten new 4-methyl-progesteroid derivatives named nodulisporisteroids C-L (1-10) in potato-dextrose-broth (PDB) medium, which showed that the fungus was a prolific producer of 4-methyl-progesteroids. The structures of 1-10 were elucidated by spectroscopic and X-ray crystallographic analysis. Their cytotoxic activities against five human cancer cell lines had been evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method.