(5-Arylfuran-2-ylcarbonyl)guanidines as cardioprotectives through the inhibition of Na+/H+ exchanger isoform-1.

A series of (5-arylfuran-2-ylcarbonyl)guanidines was synthesized and evaluated for the NHE-1 inhibitory activity and cardiprotective efficacy against ischemia-reperfusion injury. Starting with (5-phenylfuran-2-ylcarbonyl)guanidine 47 with a moderate inhibitory effect on NHE-1, the compounds with various substituents at the phenyl ring were investigated with the aim to optimize the potency. In this study, the 2,5-disubstituted compounds appeared to have better activities than the other analogues, and the 2-methoxy-5-chlorophenyl compound 85 was found as a potent inhibitor of NHE-1 (IC(50) = 0.081 microM). Furthermore, 85 showed a marked reduction of infarct size in the rat myocardial infarction model in vivo and significant improvement of cardiac contractile function in the isolated rat heart ischemia model in vitro.