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North Brunswick, NJ, United States

Kaul M.,Rutgers Robert Wood Johnson Medical School | Zhang Y.,TAXIS Pharmaceuticals Inc. | Parhi A.K.,TAXIS Pharmaceuticals Inc. | Lavoie E.J.,Rutgers University | Pilch D.S.,Rutgers Robert Wood Johnson Medical School
Biochemical Pharmacology | Year: 2014

Infections caused by Gram-negative bacterial pathogens are often difficult to treat, with the emergence of multidrug-resistant strains further restricting clinical treatment options. As a result, there is an acute need for the development of new therapeutic agents active against Gram-negative bacteria. The bacterial protein FtsZ has recently been demonstrated to be a viable antibacterial target for treating infections caused by the Gram-positive bacteria Staphylococcus aureus in mouse model systems. Here, we investigate whether an FtsZ-directed prodrug (TXY436) that is effective against S. aureus can also target Gram-negative bacteria, such as Escherichia coli. We find that the conversion product of TXY436 (PC190723) can bind E. coli FtsZ and inhibit its polymerization/bundling in vitro. However, PC190723 is intrinsically inactive against wild-type E. coli, with this inactivity being derived from the actions of the efflux pump AcrAB. Mutations in E. coli AcrAB render the mutant bacteria susceptible to TXY436. We further show that chemical inhibition of AcrAB in E. coli, as well as its homologs in Klebsiella pneumoniae and Acinetobacter baumannii, confers all three Gram-negative pathogens with susceptibility to TXY436. We demonstrate that the activity of TXY436 against E. coli and K. pneumoniae is bactericidal in nature. Evidence for FtsZ-targeting and inhibition of cell division in Gram-negative bacteria by TXY436 is provided by the induction of a characteristic filamentous morphology when the efflux pump has been inhibited as well as by the lack of functional Z-rings upon TXY436 treatment. © 2014 Elsevier Inc.

Kaul M.,Rutgers Robert Wood Johnson Medical School | Mark L.,TAXIS Pharmaceuticals Inc. | Zhang Y.,TAXIS Pharmaceuticals Inc. | Parhi A.K.,TAXIS Pharmaceuticals Inc. | And 2 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013

The bacterial cell division protein FtsZ represents a novel antibiotic target that has yet to be exploited clinically. The benzamide PC190723 was among the first FtsZ-targeting compounds to exhibit in vivo efficacy in a murine infection model system. Despite its initial promise, the poor formulation properties of the compound have limited its potential for clinical development. We describe here the development of an N-Mannich base derivative of PC190723 with enhanced drug-like properties and oral in vivo efficacy. The N-Mannich base derivative (TXY436) is~100-fold more soluble than PC190723 in an acidic aqueous vehicle (10 mMcitrate, pH 2.6) suitable for oral in vivo administration. At physiological pH (7.4), TXY436 acts as a prodrug, converting to PC190723 with a conversion half-life of 18.2±1.6 min. Pharmacokinetic analysis following intravenous administration of TXY436 into mice yielded elimination half-lives of 0.26 and 0.96 h for the TXY436 prodrug and its PC190723 product, respectively. In addition, TXY436 was found to be orally bioavailable and associated with significant extravascular distribution. Using a mouse model of systemic infection with methicillin-sensitive Staphylococcus aureus or methicillin-resistant S. aureus, we show that TXY436 is efficacious in vivo upon oral administration. In contrast, the oral administration of PC190723 was not efficacious. Mammalian cytotoxicity studies of TXY436 using Vero cells revealed an absence of toxicity up to compound concentrations at least 64 times greater than those associated with antistaphylococcal activity. These collective properties make TXY436 a worthy candidate for further investigation as a clinically useful agent for the treatment of staphylococcal infections. Copyright © 2013, American Society for Microbiology. All Rights Reserved.

Rutgers University and Taxis Pharmaceuticals Inc. | Date: 2014-11-07

The invention provides compounds of formula (I): wherein R

Parhi A.,TAXIS Pharmaceuticals Inc. | Kelley C.,Rutgers University | Kaul M.,Johnson University | Pilch D.S.,Johnson University | Lavoie E.J.,Rutgers University
Bioorganic and Medicinal Chemistry Letters | Year: 2012

Antibiotic resistance has prompted efforts to discover antibiotics with novel mechanisms of action. FtsZ is an essential protein for bacterial cell division, and has been viewed as an attractive target for the development of new antibiotics. Sanguinarine is a benzophenanthridine alkaloid that prevents cytokinesis in bacteria by inhibiting FtsZ self-assembly. In this study, a series of 5-methylbenzo[c]phenanthridinium derivatives were synthesized and evaluated for antibacterial activity against Staphylococcus aureus and Enterococcus faecalis. The data indicate that the presence of a 1- or 12-phenyl substituent on 2,3,8,9-tetramethoxy-5-methylbenzo[c]phenanthridinium chloride significantly enhances antibacterial activity relative to the parent compound or sanguinarine. © 2012 Elsevier Ltd. All rights reserved.

Taxis Pharmaceuticals Inc. and Rutgers University | Date: 2015-05-06

The invention provides compounds of formula (I): wherein R

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