AMP-DEAMINASE AS A NOVEL PRACTICAL CATALYST IN THE SYNTHESIS OF 6-OXOPURINE RIBOSIDES AND THEIR ANALOGS

Adenylic acid deaminase from Aspergillus niger (AMP deaminase; AMPDA; EC 3.5.4.6) has been introduced as a novel practical catalyst in the synthesis of 6-oxopurine riboside and their analogs. This enzyme has a very broad substrate specificity and has been used on a preparative scale for deamination of several derivatives of adenosine including phosphorylated, cyclic, carbocyclic as well as acyclic analogs. In addition, AMPDA catalyzes dechlorination and demethoxylation of the purine ribosides. Overall substrate specificity of AMPDA is much broader than that of adenosine deaminase which can also be used for the synthesis of 6-oxopurine ribosides. Although the stereoselectivity of AMPDA is modest, this enzyme has successfully been used in the synthesis of a novel antiviral agent, carbovir phosphonate (14), after the carbocyclic component was resolved via lipase-catalyzed hydrolysis or acylation.