BQ-788

BQ‑788 is a potent and selective small molecule antagonist of the endothelin receptor type B (ETB). It competitively inhibits binding of endothelin‑1 to ETB receptors with high affinity (IC₅₀ ≈ 1.2 nM), while showing much lower activity at ETA receptors (IC₅₀ ≈ 1300 nM)[2][3][5][10]. Developed by Banyu as a research tool compound, it has been widely used in vitro and in vivo to elucidate the physiological and pathological roles of ETB signaling. In preclinical studies, BQ‑788 blocks ETB-mediated vasodilation and other effects such as bronchoconstriction and cell proliferation[2][4]. It has also shown antitumor effects in some models[10]. Clinical development for hypertension was discontinued[4].

Other names

D-norleucine, n-(((2r,6s)-2,6-dimethyl-1-piperidinyl)carbonyl)-4-methyl-l-leucyl-1-(methoxycarbonyl)-d-tryptophyl-, sodium salt (1:1)N-cis-2,6-Dimethylpiperidinocarbonyl-beta-tBu-Ala-D-Trp(1-methoxycarbonyl)-D-Nle-OH2,6-Dimethylpiperidinecarbonyl-gamma-Methyl-Leu-Nin-(Methoxycarbonyl)-D-Trp-D-Nle