[Screening of antitumor antibiotics, formed by molds]

A system for screening fungal metabolites with cytotoxic activity against tumor cells is described and the results obtained using this system are discussed. It was found that 35.2 per cent of the strains isolated from uranium mines had a cytotoxic effect on the EAC cells in vitro. As for the strains isolated from other sources only 6.85 and 9.87 per cent of them inhibited the EAC cells in vitro. Five substances, i. e. vermiculline, PSX-I, Frequentine, bikaverin and duclauxin isolated from 227 evaluated cultures showed a strong inhibitory effect on the EAC cells and other tumors in vitro.