MUTAGENIC ACTIVITY OF THE ANTITUMOR AGENT HOMO-AZA-STEROIDAL ESTER OFP-N,N-BIS(2-CHLOROETHYL)AMINOPHENOXYACETIC ACID (NSC-294859) IN THE SALMONELLA MICROSOME ASSAY/

The mutagenic activity of the new antitumour agent lactam-p-N,N-bis(2- chloroethyl)aminophenoxyacetate (NSC 294859) was studied in the Salmon ella/microsome assay. It was found to induce base pair substitutions, causing dose-dependent increases in his' revertants in strains TA100 a nd TA1535. The alkylating moiety, p-N,N-bis(2-chloroethyl)aminophenoxy acetic acid, was shown to be less effective than the parent compound, while the modified steroid moiety, o-13,17-seco-5alpha-androstan-17-oi c-13,17-lactam, showed no mutagenic effect in all strains used. The pr esence of metabolic activation enzymes in the test system induced a fu rther increase in his+ revertants in strains TA100 and TA1535, in both the parent compound and the alkylating moiety of the parent compound, while it had no effect in the case of the steroidal lactam.