摘要:
On the basis of potent and selective A(3) adenosine receptor (AR) antagonist, 2-chloro-N-6-(3-iodobenzyl)-4'-thioadenosine-5'-N,N-dimethyluronamide, structure-activity relationships were studied for a series of 5'-N,N-dialkyluronamide derivatives, synthesized from D-gulonic gamma-lactone. From this study, it was revealed that removal of the hydrogen bond-donating ability of the 5'-uronamide was essential for the pure A(3)AR antagonism. 5'-N,N-Dimethyluronamide derivatives exhibited higher binding affinity than larger 5'-N,N-dialkyl or 5'-N,N-cycloalkylamide derivatives, indicating that steric factors are crucial in binding to the human A(3)AR. A N-6-(3-bromobenzyl) derivative 6c (K-i = 9.32 nM) exhibited the highest binding affinity at the human A3AR with very low binding affinities to other AR subtypes. (c) 2008 Elsevier Ltd. All rights reserved.