ABSTRACT
Novel (non-fluoroquinolone) inhibitors of bacterial type II topoisomerases (NBTIs) are an emerging class of antibacterial agents. We report an optimized series of cyclobutylaryl-substituted NBTIs. Compound 14 demonstrated excellent activity both in vitro (S. aureus MIC90=0.125µg/mL) and in vivo (systemic and tissue infections). Enhanced inhibition of Topoisomerase IV correlated with improved activity in S. aureus strains with mutations conferring resistance to NBTIs. Compound 14 also displayed an improved hERG IC50 of 85.9µM and a favorable profile in the anesthetized guinea pig model.
Subject(s)
Anti-Bacterial Agents/pharmacology , DNA Gyrase/metabolism , DNA Topoisomerase IV/antagonists & inhibitors , Quinolines/pharmacology , Topoisomerase II Inhibitors/pharmacology , Topoisomerase Inhibitors/pharmacology , Animals , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , DNA Topoisomerase IV/metabolism , Dose-Response Relationship, Drug , Ether-A-Go-Go Potassium Channels/metabolism , Guinea Pigs , Humans , Microbial Sensitivity Tests , Molecular Structure , Quinolines/chemical synthesis , Quinolines/chemistry , Staphylococcus aureus/drug effects , Staphylococcus aureus/enzymology , Streptococcus pyogenes/drug effects , Streptococcus pyogenes/enzymology , Structure-Activity Relationship , Topoisomerase II Inhibitors/chemical synthesis , Topoisomerase II Inhibitors/chemistry , Topoisomerase Inhibitors/chemical synthesis , Topoisomerase Inhibitors/chemistryABSTRACT
Herein we describe the structure-aided design and synthesis of a series of pyridone-conjugated monobactam analogues with in vitro antibacterial activity against clinically relevant Gram-negative species including Pseudomonas aeruginosa , Klebsiella pneumoniae , and Escherichia coli . Rat pharmacokinetic studies with compound 17 demonstrate low clearance and low plasma protein binding. In addition, evidence is provided for a number of analogues suggesting that the siderophore receptors PiuA and PirA play a role in drug uptake in P. aeruginosa strain PAO1.
Subject(s)
Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Monobactams/pharmacology , Pyridones/pharmacology , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacokinetics , Escherichia coli/drug effects , Inhibitory Concentration 50 , Klebsiella pneumoniae/drug effects , Male , Microbial Sensitivity Tests , Molecular Structure , Monobactams/chemistry , Monobactams/pharmacokinetics , Pseudomonas aeruginosa/drug effects , Pyridones/chemistry , Pyridones/pharmacokinetics , Rats , Rats, WistarABSTRACT
The synthesis and antibacterial activity of heterocyclic methylsulfone hydroxamates is presented. Compounds in this series are potent inhibitors of the LpxC enzyme, a key enzyme involved in the production of lipopolysaccharide (LPS) found in the outer membrane of Gram-negative bacteria. SAR evaluation of compounds in this series revealed analogs with potent antibacterial activity against challenging Gram-negative species such as Pseudomonas aeruginosa and Klebsiella pneumoniae.
Subject(s)
Amidohydrolases/antagonists & inhibitors , Anti-Bacterial Agents/chemistry , Enzyme Inhibitors/chemistry , Gram-Negative Bacteria/drug effects , Hydroxamic Acids/chemistry , Amidohydrolases/metabolism , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Heterocyclic Compounds/chemistry , Hydroxamic Acids/chemical synthesis , Hydroxamic Acids/pharmacology , Klebsiella pneumoniae/drug effects , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/enzymology , Structure-Activity Relationship , Sulfones/chemistryABSTRACT
The synthesis and biological activity of a new series of LpxC inhibitors represented by pyridone methylsulfone hydroxamate 2a is presented. Members of this series have improved solubility and free fraction when compared to compounds in the previously described biphenyl methylsulfone hydroxamate series, and they maintain superior Gram-negative antibacterial activity to comparator agents.
Subject(s)
Amidohydrolases/antagonists & inhibitors , Anti-Bacterial Agents/chemical synthesis , Gram-Negative Bacteria/drug effects , Gram-Negative Bacterial Infections/drug therapy , Hydroxamic Acids/chemical synthesis , Pyridones/chemical synthesis , Sulfonic Acids/chemical synthesis , Animals , Anti-Bacterial Agents/pharmacokinetics , Anti-Bacterial Agents/pharmacology , Crystallography, X-Ray , Humans , Hydroxamic Acids/pharmacokinetics , Hydroxamic Acids/pharmacology , Microbial Sensitivity Tests , Models, Molecular , Molecular Structure , Protein Conformation , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/enzymology , Pyridones/pharmacokinetics , Pyridones/pharmacology , Rats , Stereoisomerism , Structure-Activity Relationship , Sulfonic Acids/pharmacokinetics , Sulfonic Acids/pharmacologyABSTRACT
In this paper, we present the synthesis and SAR as well as selectivity, pharmacokinetic, and infection model data for representative analogues of a novel series of potent antibacterial LpxC inhibitors represented by hydroxamic acid.
Subject(s)
Amidohydrolases/antagonists & inhibitors , Anti-Bacterial Agents/chemical synthesis , Biphenyl Compounds/chemical synthesis , Hydroxamic Acids/chemical synthesis , Phenyl Ethers/chemical synthesis , Pseudomonas Infections/drug therapy , Sulfides/chemical synthesis , Sulfones/chemical synthesis , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Biphenyl Compounds/chemistry , Biphenyl Compounds/pharmacology , Catalytic Domain , Crystallography, X-Ray , Drug Resistance, Bacterial , Hydrogen Bonding , Hydroxamic Acids/chemistry , Hydroxamic Acids/pharmacology , Mice , Models, Molecular , Molecular Conformation , Phenyl Ethers/chemistry , Phenyl Ethers/pharmacology , Pseudomonas aeruginosa , Rats , Stereoisomerism , Structure-Activity Relationship , Sulfides/chemistry , Sulfides/pharmacology , Sulfones/chemistry , Sulfones/pharmacologyABSTRACT
The development of a novel intermolecular oxidative amination reaction, a synthetic transformation that involves the simultaneous functionalization of both a N-H and C-H bond, is described. The process, which is mediated by an I(III) oxidant and contains no metal catalysts, provides a rapid and green method for synthesizing protected anilines from simple arenes and phthalimide. Mechanistic investigations indicate that the reaction proceeds via nucleophilic attack of the phthalimide on an aromatic radical cation, as opposed to the electrophilic aromatic amination that has been reported for other I(III) amination reactions. The application of this new reaction to the synthesis of a variety of substituted aniline derivatives is demonstrated.
