Systematic Data Mining Reveals Synergistic H3R/MCHR1 Ligands
ACS MEDICINAL CHEMISTRY LETTERS
Authors: Schaller, David; Hagenow, Stefanie; Alpert, Gina; Nass, Alexandra; Schulz, Robert; Bermudez, Marcel; Stark, Holger; Wolber, Gerhard
Abstract
In this study, we report a ligand-centric data mining approach that guided the identification of suitable target profiles for treating obesity. The newly developed method is based on identifying target pairs for synergistic positive effects and also encompasses the exclusion of compounds showing a detrimental effect on obesity treatment (off-targets). Ligands with known activity against obesity-relevant targets were compared using fingerprint representations. Similar compounds with activities to different targets were evaluated for the mechanism of action since activation or deactivation of drug targets determines the pharmacological effect. In vitro validation of the modeling results revealed that three known modulators of melanin-concentrating hormone receptor 1 (MCHR1) show a previously unknown submicromolar affinity to the histamine H3 receptor (H3R). This synergistic activity may present a novel therapeutic option against obesity.
Amine-free melanin-concentrating hormone receptor 1 antagonists: Novel 1-(1H-benzimidazol-6-yl)pyridin-2(1H)-one derivatives and design to avoid CYP3A4 time-dependent inhibition
BIOORGANIC & MEDICINAL CHEMISTRY
Authors: Igawa, Hideyuki; Takahashi, Masashi; Shirasaki, Mikio; Kakegawa, Keiko; Kina, Asato; Ikoma, Minoru; Aida, Jumpei; Yasuma, Tsuneo; Okuda, Shoki; Kawata, Yayoi; Noguchi, Toshihiro; Yamamoto, Syunsuke; Fujioka, Yasushi; Kundu, Mrinalkanti; Khamrai, Uttam; Nakayama, Masaharu; Nagisa, Yasutaka; Kasai, Shizuo; Maekawa, Tsuyoshi
Abstract
Melanin-concentrating hormone (MCH) is an attractive target for antiobesity agents, and numerous drug discovery programs are dedicated to finding small-molecule MCH receptor 1 (MCHR1) antagonists. We recently reported novel pyridine-2(1H)-ones as aliphatic amine-free MCHR1 antagonists that structurally featured an imidazo[1,2-a] pyridine-based bicyclic motif. To investigate imidazopyridine variants with lower basicity and less potential to inhibit cytochrome P450 3A4 (CYP3A4), we designed pyridine2( 1H)-ones bearing various less basic bicyclic motifs. Among these, a lead compound 6a bearing a 1H-benzimidazole motif showed comparable binding affinity to MCHR1 to the corresponding imidazopyridine derivative 1. Optimization of 6a afforded a series of potent thiophene derivatives (6q-u); however, most of these were found to cause time-dependent inhibition (TDI) of CYP3A4. As bioactivation of thiophenes to form sulfoxide or epoxide species was considered to be a major cause of CYP3A4 TDI, we introduced electron withdrawing groups on the thiophene and found that a CF3 group on the ring or a Cl adjacent to the sulfur atom helped prevent CYP3A4 TDI. Consequently, 4-[(5-chlorothiophen-2-yl) methoxy]-1-(2-cyclopropyl-1-methyl-1H-benzimidazol-6-yl)pyridin-2(1H)-one (6s) was identified as a potent MCHR1 antagonist without the risk of CYP3A4 TDI, which exhibited a promising safety profile including low CYP3A4 inhibition and exerted significant antiobesity effects in diet-induced obese F344 rats. (C) 2016 Elsevier Ltd. All rights reserved.