L-732,138

L-732,138 is a potent and highly selective small molecule antagonist of the neurokinin-1 receptor (NK1R), also known as the substance P receptor. It acts competitively at the NK1R with an IC50 of approximately 2.3 nM[1][2][4]. Developed originally by Merck & Co., Inc., this compound is a synthetic tryptophan derivative designed for research purposes and has not been approved for clinical use[9]. Mechanistically, L-732,138 blocks substance P-mediated signaling through NK1R, thereby inhibiting cell proliferation and promoting apoptosis in various cancer cell lines including gastrointestinal cancers and melanoma[3][5]. Its antitumor effects are attributed to its ability to counteract substance P-induced mitogenesis via specific antagonism of NK1R. The drug has also been studied in preclinical models for potential anti-inflammatory effects but remains at a preclinical development stage.

Other names

N-acetyl-L-tryptophan 3,5-bis(trifluoromethyl)benzyl esterN-acetyl-L-Trp-3,5-bis(trifluoromethyl)benzyl ester