Synthesis and biological activity of new bradykinin pseudopeptide B1 receptor agonists containing alkylic spacers

The tetrapeptide in the central portion of bradykinin and desArg10-kallidin was replaced by alkyl spacers of various lengths (-NH---(CH2)n---CO-, n=5–11). When tested as agonists at the kinins receptors, these pseudopeptides showed significant activity only at the B1 receptor. In particular, the introduction of a dodecanoic spacer in the central portion of desArg10-kallidin reduces only tenfold the agonist activity at the B1 receptor.