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Atlanta, GA, United States

Zielonka J.,Medical College of Wisconsin | Cheng G.,Medical College of Wisconsin | Zielonka M.,Medical College of Wisconsin | Ganesh T.,Medical College of Wisconsin | And 6 more authors.
Journal of Biological Chemistry | Year: 2014

Recent progress characterizing the reaction mechanism(s) of fluorescent probes with reactive oxygen species has made it possible to rigorously analyze these reactive species in biological systems. We have developed rapid high throughput-compatible assays for monitoring cellular production of superoxide radical anion and hydrogen peroxide using hydropropidine and coumarin boronic acid probes, respectively. Coupling plate readerbased fluorescence measurements with HPLC-based simultaneous monitoring of superoxide radical anion and hydrogen peroxide provides the basis for the screening protocol for NADPH oxidase (Nox) inhibitors. Using this newly developed approach along with the medium-throughput plate readerbased oximetry and EPR spin trapping as confirmatory assays, it is now eminently feasible to rapidly and reliably identify Nox enzyme inhibitors with a markedly lower rate of false positives. These methodological advances provide an opportunity to discover selective inhibitors of Nox isozymes, through enhanced conceptual understanding of their basic mechanisms of action. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc. Source

Zhao H.,Emory Institute for Drug Development | Prosser A.R.,Emory University | Liotta D.C.,Emory Institute for Drug Development | Liotta D.C.,Emory University | Wilson L.J.,Emory University
Bioorganic and Medicinal Chemistry Letters | Year: 2015

A novel series of CXCR4 antagonists with substituted piperazines as benzimidazole replacements is described. These compounds showed micromolar to nanomolar potency in CXCR4-mediated functional and HIV assays, namely inhibition of X4 HIV-1IIIB virus in MAGI-CCR5/CXCR4 cells and inhibition of SDF-1 induced calcium release in Chem-1 cells. Preliminary SAR investigations led to the identification of a series of N-aryl piperazines as the most potent compounds. Results show SAR that indicates type and position of the aromatic ring, as well as type of linker and stereochemistry are significant for activity. Profiling of several lead compounds showed that one (49b) reduced susceptibility towards CYP450 and hERG, and the best overall profile when considering both SDF-1 and HIV potencies (6-20nM). © 2015 Elsevier Ltd. Source

Truax V.M.,Emory University | Zhao H.,Emory Institute for Drug Development | Katzman B.M.,Emory University | Prosser A.R.,Emory University | And 12 more authors.
ACS Medicinal Chemistry Letters | Year: 2013

A de novo hit-to-lead effort involving the redesign of benzimidazole- containing antagonists of the CXCR4 receptor resulted in the discovery of a novel series of 1,2,3,4-tetrahydroisoquinoline (TIQ) analogues. In general, this series of compounds show good potencies (3-650 nM) in assays involving CXCR4 function, including both inhibition of attachment of X4 HIV-1IIIB virus in MAGI-CCR5/CXCR4 cells and inhibition of calcium release in Chem-1 cells. Series profiling permitted the identification of TIQ-(R)-stereoisomer 15 as a potent and selective CXCR4 antagonist lead candidate with a promising in vitro profile. The drug-like properties of 15 were determined in ADME in vitro studies, revealing low metabolic liability potential. Further in vivo evaluations included pharmacokinetic experiments in rats and mice, where 15 was shown to have oral bioavailability (F = 63%) and resulted in the mobilization of white blood cells (WBCs) in a dose-dependent manner. © 2013 American Chemical Society. Source

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