Analogues of S-adenosylmethionine with modifications in the 5'group were prepared as potential inhibitors of S-adenosylmethionine decarboxylase (AdoMet-DC). These new analogues contained carbonyl-reactive end groups in the 5'side chain, designed to interact favorably with the pyruvate prosthetic group of AdoMet-DC. Several of the analogues proved to be outstanding inhibitors of the enzyme. The analogues were also evaluated for their activity against human cytomegalovirus in vitro. © 1987, Taylor & Francis Group, LLC. All rights reserved.