New derivatives of CNC-amino acids and -oligopeptides: experimental antitumor activity.

The experimental antitumor activity of a series of new nitrosoureas is described in which the chloroethylnitrosocarbamoyl (CNC) group is attached to different carrier molecules: amino acids and oligopeptides. Of a group of 10 CNC-amino acid amide derivatives the majority displayed high therapeutic activity in L 5222 leukemia. Some compounds, especially the proline and sarcosine derivatives, showed favorable therapeutic ratios; 12 CNC-oligopeptides displayed a more or less pronounced therapeutic activity in L 1210 leukemia. Compounds bearing a free carboxy group were less active than the corresponding unsubstituted or N-methyl substituted amides.