Mycobacterium tuberculosis (Mtb) relies on a specialized set of metabolic pathways to support growth in macrophages. By conducting an extensive, unbiased chemical screen to identify small molecules that inhibit Mtb metabolism within macrophages, we identified a significant number of novel compounds that limit Mtb growth in macrophages and in medium containing cholesterol as the principle carbon source. Based on this observation, we developed a chemical-rescue strategy to identify compounds that target metabolic enzymes involved in cholesterol metabolism. This approach identified two compounds that inhibit the HsaAB enzyme complex, which is required for complete degradation of the cholesterol A/B rings. The strategy also identified an inhibitor of PrpC, the 2-methylcitrate synthase, which is required for assimilation of cholesterol-derived propionyl-CoA into the TCA cycle. These chemical probes represent new classes of inhibitors with novel modes of action, and target metabolic pathways required to support growth of Mtb in its host cell. The screen also revealed a structurally-diverse set of compounds that target additional stage(s) of cholesterol utilization. Mutants resistant to this class of compounds are defective in the bacterial adenylate cyclase Rv1625/Cya. These data implicate cyclic-AMP (cAMP) in regulating cholesterol utilization in Mtb, and are consistent with published reports indicating that propionate metabolism is regulated by cAMP levels. Intriguingly, reversal of the cholesterol-dependent growth inhibition caused by this subset of compounds could be achieved by supplementing the media with acetate, but not with glucose, indicating that Mtb is subject to a unique form of metabolic constraint induced by the presence of cholesterol.

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The discovery of new antibacterial agents with novel mechanisms of action is necessary to overcome the problem of bacterial resistance that affects all currently used classes of antibiotics. Bacterial DNA gyrase and topoisomerase IV are well-characterized clinically validated targets of the fluoroquinolone antibiotics which exert their antibacterial activity through inhibition of the catalytic subunits. Inhibition of these targets through interaction with their ATP sites has been less clinically successful. The discovery and characterization of a new class of low molecular weight, synthetic inhibitors of gyrase and topoisomerase IV that bind to the ATP sites are presented. The benzimidazole ureas are dual targeting inhibitors of both enzymes and possess potent antibacterial activity against a wide spectrum of relevant pathogens responsible for hospital- and community-acquired infections. The discovery and optimization of this novel class of antibacterials by the use of structure-guided design, modeling, and structure-activity relationships are described. Data are presented for enzyme inhibition, antibacterial activity, and in vivo efficacy by oral and intravenous administration in two rodent infection models.

In our effort to develop agents for the treatment of influenza, a phenotypic screening approach utilizing a cell protection assay identified a series of azaindole based inhibitors of the cap-snatching function of the PB2 subunit of the influenza A viral polymerase complex. Using a bDNA viral replication assay (Wagaman, P. C., Leong, M. A., and Simmen, K. A. Development of a novel influenza A antiviral assay. J. Virol. Methods 2002, 105, 105-114) in cells as a direct measure of antiviral activity, we discovered a set of cyclohexyl carboxylic acid analogues, highlighted by VX-787 (2). Compound 2 shows strong potency versus multiple influenza A strains, including pandemic 2009 H1N1 and avian H5N1 flu strains, and shows an efficacy profile in a mouse influenza model even when treatment was administered 48 h after infection. Compound 2 represents a first-in-class, orally bioavailable, novel compound that offers potential for the treatment of both pandemic and seasonal influenza and has a distinct advantage over the current standard of care treatments including potency, efficacy, and extended treatment window.

The present study found that canagliflozin, dapagliflozin and empagliflozin were associated with a significantly higher risk of genital infections compared with placebo and other active treatments. Only dapagliflozin had a dose-response relationship with UTIs and genital infections.

This meta-analysis showed trough concentrations of 0.5 mg/L to be the lower limit of voriconazole during treatment, whereas trough concentrations of 3.0 mg/L were associated with an increased risk of moderate to severe hepatotoxicity, particularly for the Asian population.

Tuberculosis is the leading killer among infectious diseases worldwide. Increasing multidrug resistance has prompted new approaches for tuberculosis drug development, including targeted inhibition of virulence determinants and of signaling cascades that control many downstream pathways. We used a multisystem approach to determine the effects of a potent small-molecule inhibitor of the essential Mycobacterium tuberculosis Ser/Thr protein kinases PknA and PknB. We observed differential levels of phosphorylation of many proteins and extensive changes in levels of gene expression, protein abundance, cell wall lipids, and intracellular metabolites. The patterns of these changes indicate regulation by PknA and PknB of several pathways required for cell growth, including ATP synthesis, DNA synthesis, and translation. These data also highlight effects on pathways for remodeling of the mycobacterial cell envelope via control of peptidoglycan turnover, lipid content, a SigE-mediated envelope stress response, transmembrane transport systems, and protein secretion systems. Integrated analysis of phosphoproteins, transcripts, proteins, and lipids identified an unexpected pathway whereby threonine phosphorylation of the essential response regulator MtrA decreases its DNA binding activity. Inhibition of this phosphorylation is linked to decreased expression of genes for peptidoglycan turnover, and of genes for mycolyl transferases, with concomitant changes in mycolates and glycolipids in the cell envelope. These findings reveal novel roles for PknA and PknB in regulating multiple essential cell functions and confirm that these kinases are potentially valuable targets for new antituberculosis drugs. In addition, the data from these linked multisystems provide a valuable resource for future targeted investigations into the pathways regulated by these kinases in the M. tuberculosis cell.

Noscapine and its 7-hydroxy and 7-amino derivatives were characterized for their binding to tubulin. A solution NMR structure of these compounds bound to tubulin shows that noscapine and its 7-aniline derivative do not compete for the same binding site nor does its small molecule crystal structure match its tubulin-bound conformation. These compounds were also tested for their antiproliferative effects on a panel hepatocellular carcinoma cell lines.