ANTITUMOR AND ANTIVIRAL EFFECT OF RIBOSIDE OF BENZIMIDAZOLE DERIVATIVES

It was previously reported that thirty six compounds of 2-alkyl and 2-alkyl-5 (or 6) -nitro benzimidazol derivatives were synthesized and screened for antitumor effects using a solid type of Ehrlich ascites tumor cells (Komai et al., 1959) . Among these compounds, a slight antitumor effect was found with 2-propyl-benzimidazole, and its 5- (or 6) -nitro derivatives showed increased activities. It has been generally accepted that 9-β-D-ribofuranoside of purine antimetabolite is more active against tumor or more toxic to normal cells than its original free base (e.g. Biesele, 1956) . We intended to extend our previous findings in synthesizing 1-riboside of these benzimidazole derivatives. The present report deals with the synthesis of 2-propyl- and 2-propyl-5 (or 6) -nitro benzimidazole-1-riboside and the test for antitumor activity of these substances. On the other hand these substances now synthesized by us are related to antivirall activity. Tamm et al. (1951, 1953) examined extensively an anti-influenza virus activity in vitro of 2-substituted and halogenated ribofuranosyl benzimidazole derivatives andd reported a marked effect of isopropyl and n-butyl derivatives among 2-alkyl substitutedd benzimidazoles and a high inhibitory activity of certain halogenated ribofuranosyl benzimidazoles. These results led us to test the antiviral actions in ovo and in mice of 2-alkyl substituted benzimidazole derivatives previously synthesized and their riboside now synthesized by us.