[Synthesis and antitumor action of 14-N-substituted derivatives of rubomycin and karminomycin].

The reaction of nucleophilic substitution of 14-bromine derivatives of carminomycin and rubomycin with respective nitrogen-containing heterocycles yielded six novel derivatives of carminomycin and rubomycin: 14-N-imidazolyl-carminomycin, 14-carminomycyl-N-pyridinium bromide, 14-carminomycyl-N-(3-aminocarbonyl)-pyridinium chloride, 14-rubomycyl-N-(3-amino-carbonyl)-pyridinium chloride, 14-N-succinimidocarminomycin and 14-N-succinimidorubomycin. In vitro and in vivo antitumor activity of the above derivatives and three other derivatives described earlier: 14-rubomycyl-N-pyridinium bromide, 14-N-imidazolylrubomycin and 14-N-phthalimidorubomycin was studied. It was shown that in vitro all the 9 semisynthetic derivatives had a lower (by 1.5-6 times) cytostatic action on murine lymphadenosis cells NK/LI as compared to the initial antibiotics. The in vivo experiments on mice revealed that by acute toxicity the rubomycin derivatives administered intravenously were close to rubomycin, whereas the toxicity of the analogous derivatives of carminomycin was 5-17 times lower. The in vivo experiments also showed that seven out of the nine 14-N-substituted derivatives of carminomycin and rubomycin were practically deprived of antitumor activity (strain LIO-1), while 14-carminomycyl-N-pyridinium bromide and 14-N-succinimidocarminomycin inhibited the tumor growth by 40-60 per cent.