3'-Beta-ethynyl and 2'-deoxy-3'-beta-ethynyl adenosines: first 3'-beta-branched-adenosines substrates of adenosine deaminase.

The 3'-C-branched-adenosine and 2'-deoxyadenosine analogues 1-7 were tested as substrate of adenosine deaminase. The 9-(3'-C-ethynyl-beta-D-ribo-pentofuranosyl)adenine 1 and its 2'-deoxy analogue 7 were deaminated by the enzyme while the vinyl and ethyl derivatives 2 and 3 were not. The 9-(3'-C-branched-beta-D-xylo-pentofuranosyl)adenines 4-6 were deaminated by the deaminase.