Abstract: 8 compounds were isolateded from the fermented broth extract of the endophytic fungus Fusarium sp.S13 inhibited in the Pleioblastus amarus. Their structures were identified as cerevisterol (1), (22E, 24S)-24-methyl-5α-cholesta-7,22-diene-3β, 5α, 6β, 9α-tetraol (2), ergosterol peroxide (3), 3β, 5α, 9α-trihydroxy-6β-methoxyergosta-7,22-dien (4), ergosta-7,22-dien-6β-methoxy-3β, 5α-diol (5), ergosta-4, 6, 8 (14), 22-tetraen-3-one (6), 25-hydroxy-ergosta-4,6,8 (14), 22-tetraen-3-one (7), ergosta-7,22-dien-3β, 6β-diol (8). The 8 steroids were found to exert some toxic effects on brine shrimp larvae.

Key words: Pleioblastus amarus, endophytic fungus, chemical constituents, brine shrimp, cytotoxicity