Peptide antagonist of the B2 bradykinin receptor (pKi = 10.3); conformationally constrained cyclized analog of HOE 140. Blocks hypotension and bronchoconstriction in vivo. Displays selectivity for B2 over 29 other receptors and ion channels (pIC50 < 5.5).
WIN 66306 is a cyclic heptapeptide antagonist of neurokinin-1 (NK1) and NK2 receptors originally isolated from A. flavipes. It binds to NK1 and NK2 receptors and inhibits contractions induced by substance P in isolated guinea pig ileum in a concentration-dependent manner.
Lonaprisan is an orally bioavailable pentafluoroethyl derivative of a mifepristone-related steroid with antiprogestagenic activity. Lonaprisan is a pure, highly receptor-selective progesterone receptor (PR) antagonist; binding of this agent to PRs inhibits PR activation and the associated proliferative effects. Unlike many other antiprogestins such as mifepristone, this agent does not appear to convert to an agonist in the presence of protein kinase A (PKA) activators and shows high antiprogestagenic activity on both progesterone receptor (PR) isoforms PR-A and PR-B.