In vivo phenotypic screening for treating chronic neuropathic pain: modification of C2-arylethynyl group of conformationally constrained A3 adenosine receptor agonists. J Med Chem 2014 Dec 11;57(23):9901-14
Date
11/26/2014Pubmed ID
25422861Pubmed Central ID
PMC4266358DOI
10.1021/jm501021nScopus ID
2-s2.0-84918572262 (requires institutional sign-in at Scopus site) 52 CitationsAbstract
(N)-Methanocarba adenosine 5'-methyluronamides containing 2-arylethynyl groups were synthesized as A3 adenosine receptor (AR) agonists and screened in vivo (po) for reduction of neuropathic pain. A small N(6)-methyl group maintained binding affinity, with human > mouse A3AR and MW < 500 and other favorable physicochemical properties. Emax (maximal efficacy in a mouse chronic constriction injury pain model) of previously characterized A3AR agonist, 2-(3,4-difluorophenylethynyl)-N(6)-(3-chlorobenzyl) derivative 6a, MRS5698, was surpassed. More efficacious analogues (in vivo) contained the following C2-arylethynyl groups: pyrazin-2-yl 23 (binding Ki, hA3AR, nM 1.8), fur-2-yl 27 (0.6), thien-2-yl 32 (0.6) and its 5-chloro 33, MRS5980 (0.7) and 5-bromo 34 (0.4) equivalents, and physiologically unstable ferrocene 36, MRS5979 (2.7). 33 and 36 displayed particularly long in vivo duration (>3 h). Selected analogues were docked to an A3AR homology model to explore the environment of receptor-bound C2 and N(6) groups. Various analogues bound with μM affinity at off-target biogenic amine (M2, 5HT2A, β3, 5HT2B, 5HT2C, and α2C) or other receptors. Thus, we have expanded the structural range of orally active A3AR agonists for chronic pain treatment.
Author List
Tosh DK, Finley A, Paoletta S, Moss SM, Gao ZG, Gizewski ET, Auchampach JA, Salvemini D, Jacobson KAAuthor
John A. Auchampach PhD Professor in the Pharmacology and Toxicology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adenosine A3 Receptor AgonistsAnimals
CHO Cells
Cricetulus
Humans
Mice
Neuralgia
Structure-Activity Relationship
