Antineoplastic activity of esters and amides of N-[N'-(2-chloroethyl)-N'-nitrosocarbamoyl]-aminoacids.

The antineoplastic activity of 7 ester derivatives and 15 amide derivatives of N-[N'-(2-chloroethyl)-N'-nitrosocarbamoyl (CNC)]-aminoacids was examined in transplanted rat leukemia L 5222. All esters except the ethylester of CNC-L-isoleucine showed only a moderate antitumor activity. CNC-L-isoleucine ethylester effected some cures and showed the lowest toxicity of this series of compounds. The amide derivatives on the other hand were highly active in L 5222; all compounds effected cures in the dose range investigated.