Fluoro-naphthyl M1 PAMs for Selective Muscarinic Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current muscarinic receptor-targeting compounds for treating neurological and psychiatric disorders, such as Alzheimer's disease and schizophrenia, suffer from insufficient selectivity and adverse effects due to non-specific activation of muscarinic receptor subtypes, particularly at the orthosteric acetylcholine binding sites.
Innovation Solution
Development of muscarinic M1 receptor positive allosteric modulators (PAMs) that act at the less conserved allosteric binding sites, reducing side effects and enhancing subtype selectivity, thereby providing a safer and more effective therapeutic approach.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If orthosteric acetylcholine binding sites are targeted, then muscarinic receptor activation is achieved, but subtype selectivity is insufficient and adverse effects occur
Solution Approach 1:
The patent introduces allosteric modulators as intermediary compounds that bind to a distinct site on the muscarinic M1 receptor rather than the orthosteric acetylcholine binding site. This intermediary binding mechanism allows modulation of receptor activity indirectly, achieving subtype-selective activation without triggering the adverse effects associated with orthosteric agonists. The allosteric site acts as a mediator that enables selective M1 receptor modulation while sparing other muscarinic subtypes.
Solution Approach 2:
The patent applies local quality by designing compounds with specific molecular features that target the unique structural characteristics of the M1 receptor's allosteric site. The naphthyl core structure with specific substituents (fluorine at position 1, hydroxycycloalkyl at position 2, and benzyl at position 4) creates localized interactions with amino acid residues in the allosteric binding pocket, enabling selective M1 receptor modulation without cross-reactivity with other muscarinic subtypes.
2Reliability
If orthosteric agonists are used, then cognitive effects are achieved, but side effects increase due to non-specific activation
Solution Approach 1:
The allosteric modulator compounds serve as intermediaries that indirectly activate the M1 receptor's acetylcholine binding site. Rather than directly competing with acetylcholine at the orthosteric site, these compounds bind to the allosteric site and induce conformational changes that enhance acetylcholine's affinity and efficacy at the orthosteric site. This intermediary mechanism provides cognitive benefits while avoiding the non-specific activation of other muscarinic subtypes that causes side effects.
Solution Approach 2:
The patent utilizes parameter changes by modifying the binding characteristics of the M1 receptor through allosteric modulation. The compounds alter key parameters such as acetylcholine's binding affinity (Kd) and activation efficacy (Emax) at the orthosteric site, while maintaining selectivity for M1 over other muscarinic subtypes. This parameter modulation approach enables cognitive enhancement with a more favorable side effect profile compared to direct orthosteric agonists.
3Reliability
If M1 selective allosteric modulators are developed, then subtype selectivity is enhanced, but compound complexity increases
Solution Approach 1:
The patent achieves M1 subtype selectivity through local quality by incorporating specific functional groups at defined positions on the naphthyl core. The fluorine atom at position 1, the hydroxycycloalkyl group at position 2, and the benzyl group at position 4 create localized interactions with M1-specific amino acid residues in the allosteric binding pocket. This localized structural design enables high M1 selectivity without requiring overly complex molecular architectures.
Solution Approach 2:
The patent employs composite molecular design by combining a naphthyl core structure with specific substituent groups that together create the allosteric modulator activity. The composite structure integrates the flat naphthyl scaffold with three-dimensional substituents (fluorine, hydroxycycloalkyl, and benzyl groups) that collectively enable selective binding to the M1 allosteric site while maintaining appropriate molecular complexity for drug development.
Data Source
AI summary
The present invention relates to compounds of formula wherein R1 is C4-6-cycloalkyl or C4-6-heterocycloalkyl, which are optionally substituted by one or two substituents, selected from hydroxy or lower alkyl; A is phenyl, pyridinyl or piperidinyl; R2 is hydrogen, halogen, lower alkyl, cyano, C4-6-cycloalkyl, lower alkoxy, lower alkoxy substituted by halogen, or is a five-or six-membered heteroaryl, optionally substituted by lower alkyl; n is 1 or 2; or to a pharmaceutically acceptable acid addition salt, to a racemic mixture or to its corresponding enantiomer and/or optical isomers thereof. The compounds may be used for the treatment or prophylaxis of Alzheimer's disease, cognitive impairment, schizophrenia, pain or sleep disorders.