Referenced in: none

Automatically associated channels: Kv11.1

Title: Novel N-linked aminopiperidine inhibitors of bacterial topoisomerase type II with reduced pK(a): antibacterial agents with an improved safety profile.

Authors: Folkert Reck, Richard A Alm, Patrick Brassil, Joseph V Newman, Paul Ciaccio, John McNulty, Herbert Barthlow, Kosalaram Goteti, John Breen, Janelle Comita-Prevoir, Mark Cronin, David E Ehmann, Bolin Geng, Andrew Aydon Godfrey, Stewart L Fisher

Journal, date & volume: J. Med. Chem., 2012 Aug 9 , 55, 6916-33

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/22779424

Abstract
Novel non-fluoroquinolone inhibitors of bacterial type II topoisomerases (DNA gyrase and topoisomerase IV) are of interest for the development of new antibacterial agents that are not impacted by target-mediated cross-resistance with fluoroquinolones. N-Linked amino piperidines, such as 7a, generally show potent antibacterial activity, including against quinolone-resistant isolates, but suffer from hERG inhibition (IC(50) = 44 μM for 7a) and QT prolongation in vivo. We now disclose the finding that new analogues of 7a with reduced pK(a) due to substitution with an electron-withdrawing substituent in the piperidine moiety, such as R,S-7c, retained the Gram-positive activity of 7a but showed significantly less hERG inhibition (IC(50) = 233 μM for R,S-7c). This compound exhibited moderate clearance in dog, promising efficacy against a MRSA strain in a mouse infection model, and an improved in vivo QT profile as measured in a guinea pig in vivo model. As a result of its promising activity, R,S-7c was advanced into phase I clinical studies.