Design and synthesis of novel sulfonamide-containing bradykinin hB2 receptor antagonists. Synthesis and structure-relationships of α,α-tetrahydropyranylglycine

A series of alpha,alpha-cycloalkylglycine sulfonamide compounds of general formula 1 has previously been identified by our group as selective human B-2(hB(2)) receptor antagonists. Here we report the in vitro and in vivo BK antagonist activity of a further evolution of the series, consisting in compounds of the general formula 2, containing either an alkyl piperazine or a 4-alkyl piperidine ring bearing various positively charged groups (R'). These studies unexpectedly revealed quite a flat nanomolar/subnanomolar SAR for the binding affinity, while differences were seen in the in vitro functional activities. We propose that variations in the residence time may explain these results. (C) 2012 Elsevier Ltd. All rights reserved.