Design, Synthesis, and Biological Evaluation of 4,4’-Difluorobenzhydrol Carbamates as Selective M1 Antagonists

Abstract

Due to their important role in mediating a broad range of physiological functions, muscarinic acetylcholine receptors (mAChRs) have been a promising target for therapeutic and diagnostic applications alike; however, the list of truly subtype-selective ligands is scarce. Within this work, we have identified a series of twelve 4,4’-difluorobenzhydrol carbamates through a rigorous docking campaign leveraging commercially available amine databases. After synthesis, these compounds have been evaluated for their physico–chemical property profiles, including characteristics such as HPLC-logD, tPSA, logBB, and logPS. For all the synthesized carbamates, these characteristics indicate the potential for BBB permeation. In competitive radioligand binding experiments using Chinese hamster ovary cell membranes expressing the individual human mAChR subtype hM1-hM5, the most promising compound 2 displayed a high binding affinitiy towards hM1R (1.2 nM) while exhibiting modest-to-excellent selectivity versus the hM2-5R (4–189-fold). All 12 compounds were shown to act in an antagonistic fashion towards hM1R using a dose-dependent calcium mobilization assay. The structural eligibility for radiolabeling and their pharmacological and physico–chemical property profiles render compounds 2, 5, and 7 promising candidates for future position emission tomography (PET) tracer development.

Synthesis, Biological Evaluation, and Docking Studies of Antagonistic Hydroxylated Arecaidine Esters Targeting mAChRs

“…In addition, the carbonyl oxygen of 18b serves as a hydrogen bond acceptor for both Cys407 7.42 and Asn382 6.52 . Noteworthy, with the exception of 8b , the hydrogen bonding interaction with Cys407 7.42 is shared among all docked compounds, and has been observed in previous studies with structurally similar compounds [ 10 , 11 , 25 ]. Taken together, the sum of these pharmacophoric features explains 18b ’s higher affinity towards h M 1 R compared to 8c .…”

“…The arecaidine esters’ affinities towards the human mAChR subtypes h M 1 – h M 5 were studied in a competitive radioligand binding assay using CHO-K1 cell membrane homogenates expressing a single mAChR subtype and tritiated N -methyl scopolamine methyl chloride ([ 3 H]NMS). To speed up our affinity testing regime, we subjected all test substances to preliminary single-concentration displacement assays, as described previously [ 25 ]. Compounds with percent displacements below 75% at any of the subtypes were dropped from further investigations ( Table S1 ).…”

“…For the biological evaluation of the herein synthesized compounds, we essentially followed our previously described workflow and steps [ 25 ].…”

Hydrolysis of a carbamate triggered by coordination of metal ions

“…The reaction of the carbamate ligand H 2 L with the Zn(II) salt has also been monitored by 1 H NMR spectroscopy (Fig. 1).…”

“…The chemistry of carbamates has been intensively studied in the last few years. [1][2][3] The interest in this type of system lies in a wide variety of applications in fields as different as medicinal chemistry 4,5 or new environmentally related materials. 3 Thus, the capture of CO 2 using ligands with amino groups that give rise to carbamates can be highlighted as a methodology for reducing greenhouse gas emissions.…”