Design, synthesis and binding affinity of 3′-fluoro analogues of Cl-IB-MECA as adenosine A3 receptor ligands

Abstract

Several 3′-fluoro analogues, 1a, 1b, and 1c of selective and potent adenosine A3 receptor agonist, Cl-IB-MECA were synthesized from D-xylose via highly regioselective opening of lyxo-epoxides, 8a and 8b with fluoride anion. Compared to the high binding affinity of Cl-IB-MECA to the A3 adenosine receptor, the corresponding 3′-fluoro derivative showed remarkably decreased binding affinity, indicating that 3′-hydroxyl group acts as hydrogen bonding acceptor, not hydrogen bonding donor like fluorine atom in binding to the A3 adenosine receptor. © 2003 Elsevier Science Ltd. All rights reserved.