In vitro inhibition of the measles virus by novel ringexpanded(\u27fat\u27) nucleoside analogues containing the imidazo[4,5-e]diazepine ring system

The synthesis and in vitro anti-measles virus (anti-MV) activity of a class of ring-expanded (‘fat’) nucleoside analogues (1–4) containing the title heterocyclic ring system are reported. The target compounds were synthesized by base-catalyzed condensations of 4,5-dicarboxylic acidesters of the appropriately substituted imidazole-1-ribosides with suitably substituted guanidine derivatives. Compounds were screened for anti-MV activity in African green monkey kidney cells (CV-1), employing ribavirin as the control standard. While the parent compound 1 itself failed to show any significant antiviral activityagainst MV, its analogues containing hydrophobic substituents at the 2-position (2) or the 6-position (4) showed promising antiviral activityat submicromolar or micromolar concentration levels with no apparent toxicity to the host cell line. Both compounds showed higher anti-MV activity than the control drug ribavirin. The synthesis and in vitro anti-measles virus activity of ring-expanded nucleosides 1–4 are reported