BQ-123

• CAT Number: I001407
• CAS Number: 136553-81-6
• Molecular Formula: C31H42N6O7
• Molecular Weight: 610.70
• Purity: ≥95%
• Synonyms: 2-[(3R,6R,9S,12R,15S)-6-(1H-indol-3-ylmethyl)-9-(2-methylpropyl)-2,5,8,11,14-pentaoxo-12-propan-2-yl-1,4,7,10,13-pentazabicyclo[13.3.0]octadecan-3-yl]acetic acid
• InChI: InChI=1S/C31H42N6O7/c1-16(2)12-21-27(40)33-22(13-18-15-32-20-9-6-5-8-19(18)20)28(41)35-23(14-25(38)39)31(44)37-11-7-10-24(37)29(42)36-26(17(3)4)30(43)34-21/h5-6,8-9,15-17,21-24,26,32H,7,10-14H2,1-4H3,(H,33,40)(H,34,43)(H,35,41)(H,36,42)(H,38,39)/t21-,22+,23+,24-,26+/m0/s1
• InChIKey: VYCMAAOURFJIHD-PJNXIOHISA-N
• SMILES: CC(C)CC1C(=O)NC(C(=O)NC(C(=O)N2CCCC2C(=O)NC(C(=O)N1)C(C)C)CC(=O)O)CC3=CNC4=CC=CC=C43

BQ-123 is a potent and selective endothelin A (ETA) receptor antagonist with an IC50 of 7.3 nM and a Ki of 25 nM. BQ-123 inhibits endothelin-1-mediated proliferation of human pulmonary artery smooth muscle cells and lowers blood pressure in different rat models of hypertension[1][2][3].
Sustained infusions of BQ-123 (0.16-164 nmol/kg per min, intravenously, for 6 h) produces dose-dependent reductions in mean arterial pressure in spontaneously hypertensive rats (SHR), the maximal reduction being obtained with a dose of 16 nmol/kg per min[4].?
BQ-123 (3 mg/kg; i.v.; given 15 minutes before pentylenetetrazole (PTZ)) impedes the formation and spread of seizure to a great degree in PTZ (50 mg/kg; i.p.) +BQ-123 groups[5].

Reference

[1]. Ihara M, et al. In vitro biological profile of a highly potent novel endothelin (ET) antagonist BQ-123 selective for the ETA receptor. J Cardiovasc Pharmacol. 1992;20 Suppl 12:S11-S14.
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[2]. Sakamoto A, et al. Distinct subdomains of human endothelin receptors determine their selectivity to endothelinA-selective antagonist and endothelinB-selective agonists. J Biol Chem. 1993 Apr 25;268(12):8547-53.
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[3]. Zamora MA, et al. BQ123, an ETA receptor antagonist, inhibits endothelin-1-mediated proliferation of human pulmonary artery smooth muscle cells. Am J Respir Cell Mol Biol. 1993;9(4):429-433.
 [Content Brief]

[4]. Douglas SA, et al. BQ-123, a selective endothelin subtype A-receptor antagonist, lowers blood pressure in different rat models of hypertension. J Hypertens. 1994;12(5):561-567.
 [Content Brief]

[5]. Erdogan H et al. The protective effects of endothelin-A receptor antagonist BQ-123 in pentylenetetrazole-induced seizure in rats. Hum Exp Toxicol, 2014 Oct, 33(10):1008-16.
 [Content Brief]