A number of I\ rs-phenyladenosines with various substitutions on the phenyl ring have been synthesized and tested for their affinities toward brain Al and A2 adenosine receptors. Compounds with meta substituents, such (m-hydroxyand m-iodophenyl) adenosine, were found to have high Al selectivity. Meta substitution caused a selective decrease in the affinity of these compounds for A2 receptors. The results suggest that, in contrast to what is ...
