Structure-activity studies on open-chain analogues of nucleosides: Inhibition of S-adenosyl-L-homocysteine hydrolase and antiviral activity 1. Neutral open-chain analogues

Over 70 alkyl derivatives of purine bases were examined for their inhibitory effects toward rat liver S-adenosyl-L-homocysteine hydrolase and their antiviral activity. The following structural features must be fulfilled by an inhibitor of SAH-hydrolase: an intact adenine moiety, an alkyl chain bound at the 9-position and bearing a vicinal diol at the 2',3'-position, with 2 S configuration. An additional substitution at the 3-position lowers or annihilates the inhibitory activity. The enzyme inhibition is reversible. Some of the compounds are substrates of adenosine aminohydrolase. All inhibitors of SAH-hydrolase exhibit antiviral activity, e.g. against vesicular stomatitis virus and vaccinia virus in cell culture, and this antiviral correlates with the inhibition of SAH-hydrolase.