Cytotoxic ergosterols from Paecilomyces sp. J300.

Seven ergosterol derivatives (1-7) were isolated from silkworm larvae infected with Paecilomyces sp. J300. On the basis of spectroscopic means, their structures have been elucidated as 3beta,5alpha-dihydroxy-ergosta-7,22-diene (1), 5alpha,6alpha-epoxy-(22E,24R)-ergosta-8(14), 22-diene-3beta, 7alpha-diol (2), 5alpha,6alpha-epoxy-(22E,24R)-ergosta-8,22-diene-3beta,7alpha-diol (3), ergosta-4,6,8(14),22-tetraene-3-one (4), ergosterol (5), ergosterol endoperoxide (6), 3beta,5alpha-dihydroxy-6beta-methoxyergosta-7,22-diene (7). Compounds 3-7 showed moderate cytotoxicity against five tumor cells.