Antitumor screening of deep ocean water and sediment derived fungi and primary investigation of their secondary metabolites

Objective The cytotoxic microbial strains isolated from the deep ocean water and sediments were screened,and the secondary metabolites of bioactive fungus c2b were investi- gated.Methods Active bioactive microbial strains were screened using brine shrimp and chro- nic medulla leucocythemia leukocythemia(K562)cell line.The cytotoxic components of fun- gus c2b were isolated by bioassay-guided fractionation and solvent extraction,silica gel col- umn chromatography and preparative HPLC.Their structures were established by pbysico- chemical properties and spectral analyses.The cytotoxicities of compounds were evaluated by SRB method.Results and Conclusion Twenty-nine strains of fungi were isolated.Among them,seven strains showed cytotoxic activities.Six compounds(1～6)were isolated and i- dentified as N-acetyl histamine(1),chrysogine(2),ergosterol peroxide(3),5,8-epidioxy- 24-methylcholesta-6,22-dien-3β-ol(4)cerevisterol(5)and(4E,8E)-N-[(2'R,3'E)-2'-hy- droxy-3'-hexadecenoyl]-1-O-β-D-glycopyranosyl-9-methyl-4,8-sphingadiene(6),respective- ly.Compound 3 and 4 showed median cytotoxicity.