[Acute toxicity of the N-acyl derivatives of carminomycin and rubomycin].

Synthesis of 2 new N-acyl derivatives of carminomycin and rubomycin (N-L-leucylcarminomycin and N-sarcolysylrubomycin) is described. Acute toxicity of the new and 4 known N-acyl derivatives: N-acetylcarminomycin, N,L-alanylcarminomycin, N-D-phenylalanylcarminomycin and N-D-phenylalanylrubomycin was studied on albino mice. It was shown that the N-acyl derivatives of carminomycin and rubomycin had lower acute toxicity than the initial drugs. When added to blood serum in vitro N-D-phenylalanylcarminomycin and N-D-phenylalanylrubomycin induced precipitation. The carminomycin derivatives containing the residues of L-leucine and L-alanine were less toxic than the initial antibiotic, still they had a markedly pronounced retarded toxicity.