Factors related to the growth of psittacosis virus (strain 6BC) II. Purines, pyrimidines, and other components related to nucleic acid.

In various amounts and mixtures, adenine, guanine, xanthine, hypoxanthine, thymine, thymidine, cytidylic acid, and an enzymatic digest of desoxyribonucleic acid all failed to influence the inhibition by sulfadiazine of the growth of psittacosis virus (6BC) in embryonated eggs. A number of purine analogues, including benzimidazole, 2,6-diaminopurine, and 8-azaguanine, inhibited the growth of psittacosis virus (6BC) in tissue cultures at concentrations which had no obvious toxic effects on the host tissues. The virus inhibitory action of 2,6-diaminopurine was reversed by addition of adenine and that of 8-azaguanine by guanine. The growth of psittacosis virus (6BC) was inhibited by the pteridine compounds 2-ammo-4-hydroxy-6-formylpteridine and xanthopterin, while other related substances had little or no inhibitory activity. Xanthine reversed the inhibitory effects of 2-amino-4-hydroxy-6-formylpteridine. There was no correlation between the inhibitory activity of the pteridines on xanthine oxidase and multiplication of the virus.