DprE1 Inhibitor Discovery for Tuberculosis Treatment

Decaprenyl-phosphoryl-β-D-ribose 2′-oxidase (DprE1) is a flavoenzyme essential for the biosynthesis of arabinan polymers in the cell wall of Mycobacterium tuberculosis and has emerged as a validated target for antitubercular drug discovery. Since its identification in 2009, DprE1 has attracted extensive efforts to design both covalent and non-covalent inhibitors that block arabinose precursor formation and provoke cell lysis. Early lead compounds such as benzothiazinones established the principle of mechanism-based inactivation by forming covalent adducts at the active-site cysteine, while subsequent structure-guided campaigns yielded advanced candidates including piperazine-benzothiazinones (Macozinone), carbostyril derivatives (OPC-167832) and novel heterocyclic scaffolds. Parallel advances in quantum mechanics modelling, high-content screening and crystallography have refined our understanding of enzyme activation pathways, metabolic transformations and resistance mutations. Ongoing challenges include optimisation of pharmacokinetics, minimisation of off-target effects and mitigation of resistance, with the ultimate goal of integrating DprE1 inhibitors into shorter, more effective regimens against drug-resistant and latent tuberculosis.

Research from Nature Portfolio

Recent studies have dissected the chemical determinants of nitroaromatic inhibitor activation and enzyme inactivation mechanisms. A 2024 investigation of benzothiazinone derivatives demonstrated that electron-withdrawing substituents at C-6 can modulate formation of hydride-Meisenheimer complexes in whole cells, with quantum-mechanics-derived Gibbs free energy and Mulliken charge analyses predicting in vitro propensity for intermediate formation. This work provides a blueprint for rational pharmacokinetic optimisation of nitroaromatic DprE1 inhibitors. Complementing these findings, mechanistic probes of oxidised and reduced benzothiazinone analogues have revealed unexpected pathways for covalent suicide inhibition of DprE1 and confirmed that steps upstream of covalent adduct formation critically determine potency and selectivity. Foundational preclinical evaluation of benzothiazinethione analogues highlighted a potent SKLB-TB1001 candidate with superior in vivo efficacy and synergistic interactions with rifampicin, underscoring the therapeutic promise of next-generation covalent inhibitors.

DprE1 Inhibitor Discovery for Tuberculosis Treatment publication trend

The graph below shows the total number of articles in dpre1 inhibitor discovery for tuberculosis treatment across all publications each year (not limited to Nature Index journals).

Technical terms

DprE1: A flavin-dependent epimerase that catalyses oxidation of decaprenyl-phosphoryl-ribose, an essential step in the synthesis of mycobacterial arabinan cell-wall polymers.

Benzothiazinones (BTZs): Mechanism-based covalent inhibitors of DprE1 that form irreversible adducts at an active-site cysteine residue, blocking arabinan precursor synthesis.

Meisenheimer complex: A hydride-bound intermediate formed when nitroaromatic compounds are reduced in bacterial cells, influencing inhibitor stability and activity.

Minimum inhibitory concentration (MIC): The lowest concentration of an antimicrobial agent required to prevent visible growth of a microorganism in vitro.

References

1. Modulation of the Meisenheimer complex metabolism of nitro-benzothiazinones by targeted C-6 substitution. Communications Chemistry (2024).
2. High Content Screening Identifies Decaprenyl-Phosphoribose 2′ Epimerase as a Target for Intracellular Antimycobacterial Inhibitors. PLOS Pathogens (2009).
3. Synthesis, Activity, Toxicity, and In Silico Studies of New Antimycobacterial N-Alkyl Nitrobenzamides. Pharmaceuticals (2024).
4. OPC-167832, a Novel Carbostyril Derivative with Potent Antituberculosis Activity as a DprE1 Inhibitor. Antimicrobial Agents and Chemotherapy (2020).
5. Benzothiazinethione is a potent preclinical candidate for the treatment of drug-resistant tuberculosis. Scientific Reports (2016).
6. Development of Macozinone for TB treatment: An Update. Applied Sciences (2020).
7. Novel insight into the reaction of nitro, nitroso and hydroxylamino benzothiazinones and of benzoxacinones with Mycobacterium tuberculosis DprE1. Scientific Reports (2018).