1
|
Wang W, Ranjan A, Zhang W, Liang Q, MacMillan KS, Chapman K, Wang X, Chandrasekaran P, Williams NS, Rosenbaum DM, De Brabander JK. Novel orexin receptor agonists based on arene- or pyridine-fused 1,3-dihydro-2H-imidazole-2-imines. Bioorg Med Chem Lett 2024; 99:129624. [PMID: 38272190 DOI: 10.1016/j.bmcl.2024.129624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 12/15/2023] [Accepted: 01/18/2024] [Indexed: 01/27/2024]
Abstract
A structurally novel class of benzo- or pyrido-fused 1,3-dihydro-2H-imidazole-2-imines was designed and evaluated in an inositol phosphate accumulation assay for Gq signaling to measure agonistic activation of the orexin receptor type 2 (OX2R). These compounds were synthesized in 4-9 steps overall from readily available starting materials. Analogs that contain a stereogenic methyl or cyclopropyl substituent at the benzylic center, and a correctly configured alkyl ether, alkoxyalkyl ether, cyanoalkyl ether, or α-hydroxyacetamido substituted homobenzylic sidechain were identified as the most potent activators of OX2R coupled Gq signaling. Our results also indicate that agonistic activity was stereospecific at both the benzylic and homobenzylic stereogenic centra. We identified methoxyethoxy-substituted pyrido-fused dihydroimidazolimine analog 63c containing a stereogenic benzylic methyl group was the most potent agonist, registering a respectable EC50 of 339 nM and a maximal response (Emax) of 96 % in this assay. In vivo pharmacokinetic analysis indicated good brain exposure for several analogs. Our combined results provide important information towards a structurally novel class of orexin receptor agonists distinct from current chemotypes.
Collapse
Affiliation(s)
- Wentian Wang
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Alok Ranjan
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Wei Zhang
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Qiren Liang
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Karen S MacMillan
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Karen Chapman
- Department of Biophysics, University of Texas Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390-9041, USA
| | - Xiaoyu Wang
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Preethi Chandrasekaran
- Department of Biophysics, University of Texas Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390-9041, USA
| | - Noelle S Williams
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA
| | - Daniel M Rosenbaum
- Department of Biophysics, University of Texas Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390-9041, USA.
| | - Jef K De Brabander
- Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9038, USA.
| |
Collapse
|