RESUMEN
OBJECTIVE: To study the chemical constituents of the mycelium of a marine microorganism Nigrospora sphaerica. METHODS: Compounds were extracted and isolated by silica gel column chromatography, Sephadex LH-20 column chromatography and HPLC techniques and identified by spectroscopic analysis. RESULTS: Eleven compounds were isolated and identified as ergosta-5, 7, 22-triene-3β-ol(1), cholesterol(2), pyrrolopiperazine-2, 5-dione [cyclo-(Pro-Gly)](3), 3-methylpyrrolopiperazine-2, 5-di-one [cyclo-(Pro-Ala)](4), 3-benzylpyrrolopyrazine-2, 5-dione [cyclo-(Pro-Phe)](5), 3-benzyl-piper-azine-2, 5-dione [cyclo-(Gly-Phe)](6), 5-(hydroxymethyl)furan-2-carbaldehyde(7), leucine(8), 3, 6-dimethylpiperazine-2, 5-dione [cyclo-(Ala-Ala)](9), adenine(10) and uridine(11). CONCLUSION: Compounds 1, 3-7 and 11 are obtained from Nigrospora sphaerica for the first time.