Discovery of (S)–N-(3-isopropylphenyl)-2-(5-phenylthiazol-2-yl)pyrrolidine-1-carboxamide as potent and brain-penetrant TRPV1 antagonist.

Transient receptor potential vanilloid 1 (TRPV1) antagonists can inhibit the transmission of nociceptive signals from the peripheral to the central nervous system (CNS), providing a new strategy for pain relief. In this work, in order to develop potent, CNS-penetrant, and orally available TRPV1 antagonists, three series of novel molecules based on the key pharmacophore structures of classic TRPV1 ligands SB-705498 and MDR-652 were designed and synthesized. Through systematic in vitro and in vivo bioassays, (S)– N -(3-isopropylphenyl)-2-(5-phenylthiazol-2-yl)pyrrolidine-1-carboxamide (7q) was finally identified, which had enhanced TRPV1 antagonistic activity (IC 50 (capsaicin) = 2.66 nM), excellent CNS penetration (brain/plasma ratio = 1.66), favorable mode-selectivity, good bioavailability, and no side effects of hyperthermia. Molecular docking and dynamics studies indicated that the high binding affinity of compound 7q to TRPV1 was related to multiple interactions, which resulted in significant conformational changes of TRPV1. Overall, our findings have led to a potent, mode-selective, and CNS-penetrant TRPV1 antagonist as a valuable lead for development of novel TRPV1 antagonists. In this work, in order to find a potent, mode-selective, CNS-penetrant, and orally available TRPV1 antagonist, two series of novel TRPV1 antagonists based on the key pharmacophore structures of classic TRPV1 ligands SB-705498 and MDR-652 were designed and synthesized, and their in vitro and in vivo activities were evaluated. [Display omitted] • Two series of novel TRPV1 antagonists based on the key pharmacophore structures of classic TRPV1 ligands SB-705498 and MDR-652 were designed and synthesized. • The most promising compound 7q was a mode-selective TRPV1 antagonist which could effectively block the capsaicin-activated channel (IC 50 = 2.66 nM) without increasing core body temperature. • More importantly, compound 7q demonstrated excellent CNS-penetrant, favorable ClogP, good bioavailability, and high binding affinity to TRPV1. [ABSTRACT FROM AUTHOR]