A Unique Ring-Expanded Acyclic Nucleoside Analogue that Inhibits Both Adenosine Deaminase (ADA) and Guanine Deaminase (GDA; Guanase): Synthesis and Enzyme Inhibition Studies of 4,6-Diamino-8H-1-hydroxyethoxymethyl-8-iminoimidazo[4,5-e][1,3]diazepine

The synthesis and enzyme inhibition studies of a novel ring-expanded acyclic nucleoside analogue 1 are reported. Compound 1 has been found to be a competitive inhibitor of both adenosine deaminase (ADA) and guanine deaminase (GDA; guanase) with Kiʹs equal to 1.52±0.34×10−4 M and 2.97±0.25×10−5 M, respectively. Inhibition of two enzymes of purine metabolism may bear beneficial implications in antiviral therapy.