Tailored phenyl ureas eradicate drug-resistant by targeting mycolic acid cell wall assembly.

Treatment of infections is a challenging task due to long treatment regiments and a growing number of resistant clinical isolates. To identify new antibiotic hits, we screened a focused library of 400 synthetic compounds derived from a recently discovered molecule with promising anti-mycobacterial activity. A suite of more potent hit molecules was deciphered with sub-micromolar activity.

Toward a Bactericidal Oral Drug Combination for the Treatment of Lung Disease.

Treatment of lung disease relies on underperforming drug combinations and includes parenteral, poorly tolerated, and bacteriostatic antibiotics. We posit that safe, oral, and bactericidal regimens are needed to improve cure rates and shorten treatment. Here, we combined oral representatives of three well-tolerated bactericidal drug classes, the β-lactam tebipenem (together with the β-lactamase inhibitor avibactam), the fluoroquinolone moxifloxacin, and the rifamycin rifabutin, and profiled the combination in vitro and in vivo.

Evolution of Small Molecule Inhibitors of Menaquinone Biosynthesis.

A dire need exists for novel drugs to treat infection. In an effort to build on our early efforts targeting the MenG enzyme within the menaquinone biosynthetic pathway, we have pursued the optimization of diaryl amide JSF-2911 to address its poor metabolic stability and modest potency. A hit evolution campaign focused on modification of the amine substructure within this hit compound, resulting in a range of analogues that have been profiled extensively.

Chemical genetic interactions elucidate pathways controlling tuberculosis antibiotic efficacy during infection.

Successful tuberculosis therapy requires treatment with an unwieldy multidrug combination for several months. Thus, there is a growing need to identify novel genetic vulnerabilities that can be leveraged to develop new, more effective antitubercular drugs. Consequently, recent efforts to optimize tuberculosis (TB) therapy have exploited (Mtb) chemical genetics to identify pathways influencing antibiotic efficacy, novel mechanisms of antibiotic action, and new targets for TB drug discovery.

Identification of Antituberculars with Favorable Potency and Pharmacokinetics through Structure-Based and Ligand-Based Modeling.

Drug discovery is inherently challenged by a multiple criteria decision making problem. The arduous path from hit discovery through lead optimization and preclinical candidate selection necessitates the evolution of a plethora of molecular properties. In this study, we focus on the hit discovery phase while beginning to address multiple criteria critical to the development of novel therapeutics to treat infection.

Metabolically Stable Adenylation Inhibitors of Biotin Protein Ligase as Antibacterial Agents.

The antibacterial agent Bio-AMS is metabolized in vivo through hydrolysis of the central acyl-sulfamide linker leading to high clearance and release of a moderately cytotoxic metabolite . Herein, we disclose analogues designed to prevent the metabolism of the central acyl-sulfamide moiety through steric hindrance or attenuation of the acyl-sulfamide electrophilicity. was identified as a metabolically stable analogue with a single-digit nanomolar dissociation constant for biotin protein ligase (BPL) and minimum inhibitory concentrations (MICs) against and ranging from 0.

Chemical genetic interactions elucidate pathways controlling tuberculosis antibiotic efficacy during infection.

Unlabelled: Successful tuberculosis therapy requires treatment with an unwieldy multidrug combination for several months. Thus, there is a growing need to identify novel genetic vulnerabilities that can be leveraged to develop new, more effective antitubercular drugs. Consequently, recent efforts to optimize TB therapy have exploited Mtb chemical genetics to identify pathways influencing antibiotic efficacy, novel mechanisms of antibiotic action, and new targets for TB drug discovery.

Enhancing the therapeutic window for Spectinamide anti-tuberculosis Agents: Synthesis, Evaluation, and activation of phosphate prodrug 3408.

Spectinamides are a novel class of narrow-spectrum antitubercular agents with the potential to treat drug-resistant tuberculosis infections. Spectinamide 1810 has shown a good safety record following subcutaneous injection in mice or infusion in rats but exhibits transient acute toxicity following bolus administration in either species. To improve the therapeutic index of 1810, an injectable prodrug strategy was explored.

Novel Pan-Coronavirus 3CL Protease Inhibitor MK-7845: Biological and Pharmacological Profiling.

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) continues to be a global threat due to its ability to evolve and generate new subvariants, leading to new waves of infection. Additionally, other coronaviruses like Middle East respiratory syndrome coronavirus (MERS-CoV, formerly known as hCoV-EMC), which first emerged in 2012, persist and continue to present a threat of severe illness to humans. The continued identification of novel coronaviruses, coupled with the potential for genetic recombination between different strains, raises the possibility of new coronavirus clades of global concern emerging.

Inhibitors of the Thioesterase Activity of Pks13 Discovered Using DNA-Encoded Chemical Library Screening.

DNA-encoded chemical library (DEL) technology provides a time- and cost-efficient method to simultaneously screen billions of compounds for their affinity to a protein target of interest. Here we report its use to identify a novel chemical series of inhibitors of the thioesterase activity of polyketide synthase 13 (Pks13) from (Mtb). We present three chemically distinct series of inhibitors along with their enzymatic and Mtb whole cell potency, the measure of on-target activity in cells, and the crystal structures of inhibitor-enzyme complexes illuminating their interactions with the active site of the enzyme.

Small Molecule Benzothiophene with Efficacy in a Mouse Model of Drug-Resistant Infection.

Hospital-acquired infections, caused by ESKAPE bacteria, are a challenging global public health concern, in part due to the emergence of drug-resistant strains. While profiling a diverse set of compounds for activity this class of bacteria, we noted that the benzothiophene JSF-2827 exhibited promising antibacterial activity against . A hit evolution campaign ensued, involving the design, synthesis, and biological assay of analogues designed to address early issues such as a short mouse liver microsome half-life and a modest mouse pharmacokinetic profile.

Lung microenvironments harbor phenotypes with distinct treatment responses.

Tuberculosis lung lesions are complex and harbor heterogeneous microenvironments that influence antibiotic effectiveness. Major strides have been made recently in understanding drug pharmacokinetics in pulmonary lesions, but the bacterial phenotypes that arise under these conditions and their contribution to drug tolerance are poorly understood. A pharmacodynamic marker called the RS ratio quantifies ongoing rRNA synthesis based on the abundance of newly synthesized precursor rRNA relative to mature structural rRNA.

Investigation into the Mechanism of Action of the Tuberculosis Drug Candidate SQ109 and Its Metabolites and Analogues in Mycobacteria.

We tested a series of SQ109 analogues against and , in addition to determining their uncoupling activity. We then investigated potential protein targets, involved in quinone and cell wall biosynthesis, using "rescue" experiments. There was little effect of menaquinone on growth inhibition by SQ109, but there were large increases in the IC of SQ109 and its analogues (up to 20×) on addition of undecaprenyl phosphate (Up), a homologue of the mycobacterial decaprenyl (C) diphosphate.

Activity of Oral Tebipenem-Avibactam in a Mouse Model of Mycobacterium abscessus Lung Infection.

The combination of the β-lactam tebipenem and the β-lactamase inhibitor avibactam shows potent bactericidal activity against Mycobacterium abscessus . Here, we report that the combination of the respective oral prodrugs tebipenem-pivoxil and avibactam ARX-1796 showed efficacy in a mouse model of M. abscessus lung infection.

Profiling of the Synthetic RNA Polymerase Inhibitor MMV688845 against Mycobacterium abscessus.

In a library screen of tuberculosis-active compounds for anti-Mycobacterium abscessus activity, we previously identified the synthetic phenylalanine amide MMV688845. In Mycobacterium tuberculosis, this class was shown to target the RpoB subunit of RNA polymerase, engaging a binding site distinct from that of the rifamycins. Due to its bactericidal activity, rifampicin is a key drug for the treatment of tuberculosis (TB).

Mycobacterium tuberculosis DprE1 Inhibitor OPC-167832 Is Active against Mycobacterium abscessus .

The antituberculosis candidate OPC-167832, an inhibitor of DprE1, was active against Mycobacterium abscessus. Resistance mapped to M. abscessus , suggesting target retention.

Strongly Bactericidal All-Oral β-Lactam Combinations for the Treatment of Mycobacterium abscessus Lung Disease.

Bioactive forms of oral β-lactams were screened against Mycobacterium abscessus with and without the bioactive form of the oral β-lactamase inhibitor avibactam ARX1796. Sulopenem was equally active without avibactam, while tebipenem, cefuroxime, and amoxicillin required avibactam for optimal activity. Systematic pairwise combination of the four β-lactams revealed strong bactericidal synergy for each of sulopenem, tebipenem, and cefuroxime combined with amoxicillin in the presence of avibactam.

Activity of Tricyclic Pyrrolopyrimidine Gyrase B Inhibitor against Mycobacterium abscessus.

Tricyclic pyrrolopyrimidines (TPPs) are a new class of antibacterials inhibiting the ATPase of DNA gyrase. TPP8, a representative of this class, is active against Mycobacterium abscessus . Spontaneous TPP8 resistance mutations mapped to the ATPase domain of M.

Spatial quantitation of antibiotics in bone tissue compartments by laser-capture microdissection coupled with UHPLC-tandem mass spectrometry.

Bones are the site of multiple diseases requiring chemotherapy, including cancer, arthritis, osteoporosis and infections. Yet limited methodologies are available to investigate the spatial distribution and quantitation of small molecule drugs in bone compartments, due to the difficulty of sectioning undecalcified bones and the interference of decalcification methods with spatially resolved drug quantitation. To measure drug concentrations in distinct anatomical bone regions, we have developed a workflow that enables spatial quantitation of thin undecalcified bone sections by laser-capture microdissection coupled to HPLC/tandem mass spectrometry, and spatial mapping on adjacent sections by mass spectrometry imaging.

CRISPRi chemical genetics and comparative genomics identify genes mediating drug potency in Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb) infection is notoriously difficult to treat. Treatment efficacy is limited by Mtb's intrinsic drug resistance, as well as its ability to evolve acquired resistance to all antituberculars in clinical use. A deeper understanding of the bacterial pathways that influence drug efficacy could facilitate the development of more effective therapies, identify new mechanisms of acquired resistance, and reveal overlooked therapeutic opportunities.