Isatin-pyrimidine hybrid derivatives as enoyl acyl carrier protein reductase (InhA) inhibitors against Mycobacterium tuberculosis

New coumarin linked thiazole derivatives as antimycobacterial agents: Design, synthesis, enoyl acyl carrier protein reductase (InhA) inhibition and molecular modeling

Tuberculosis is a global serious problem that imposes major health, economic and social challenges worldwide. The search for new antitubercular drugs is extremely important which could be achieved via inhibition of different druggable targets. Mycobacterium tuberculosis enoyl acyl carrier protein reductase (InhA) enzyme is essential for the survival of M. tuberculosis. In this investigation, a series of coumarin based thiazole derivatives was synthesized relying on a molecular hybridization approach and was assessed against thewild typeMtb H37Rv and its mutant strain (ΔkatG) via inhibiting InhA enzyme. Among the synthesized derivatives, compounds 2b, 3i and 3j were the most potent against wild type M. tuberculosis with MIC values ranging from 6 to 8 μg/ mL and displayed low cytotoxicity towards mouse fibroblasts at concentrations 8-13 times higher than the MIC values. The three hybrids could also inhibit the growth of ΔkatGmutant strain which is resistant to isoniazid (INH). Compounds 2b and 3j were able to inhibit the growth of mycobacteria inside human macrophages, indicating their ability to penetrate human professional phagocytes. The two derivatives significantly suppress mycobacterial biofilm formation by 10-15 %. The promising target compounds were also assessed for their inhibitory effect against InhA and showed potent effectiveness with IC50 values of 0.737 and 1.494 µM, respectively. Molecular docking studies revealed that the tested compounds occupied the active site of InhA in contact with the NAD+ molecule. The 4-phenylcoumarin aromatic system showed binding interactions within the hydrophobic pocket of the active site. Furthermore, H-bond formation and π -π stacking interactions were also recorded for the promising derivatives.

Design, synthesis and computational studies of new azaheterocyclic coumarin derivatives as anti-Mycobacterium tuberculosis agents targeting enoyl acyl carrier protein reductase (InhA)

In this study, we designed and synthesized a series of coumarin derivatives as antitubercular agents targeting the enoyl acyl carrier protein reductase (InhA) enzyme. Among the synthesized compounds, the tetrazole derivative 4c showed the most potent antitubercular effect with a minimum inhibitory concentration value (MIC) of 15 μg mL-1 against Mtb H37Rv and could also inhibit the growth of the mutant strain (ΔkatG). Compound 4c was able to penetrate Mtb-infected human macrophages and suppress the intracellular growth of tubercle bacilli. Moreover, the target derivative 4c showed a potent inhibitory effect against InhA enzyme with an IC50 value of 0.565 μM, which was superior to the reference InhA inhibitor triclosan. Molecular docking of compound 4c within the InhA active site revealed the importance of the 4-phenylcoumarin ring system and tetrazole moiety for activity. Finally, the physicochemical properties and pharmacokinetic parameters of 4c were investigated.

Recent Advances in Pyrimidine-Based Drugs

Pyrimidines have become an increasingly important core structure in many drug molecules over the past 60 years. This article surveys recent areas in which pyrimidines have had a major impact in drug discovery therapeutics, including anti-infectives, anticancer, immunology, immuno-oncology, neurological disorders, chronic pain, and diabetes mellitus. The article presents the synthesis of the medicinal agents and highlights the role of the biological target with respect to the disease model. Additionally, the biological potency, ADME properties and pharmacokinetics/pharmacodynamics (if available) are discussed. This survey attempts to demonstrate the versatility of pyrimidine-based drugs, not only for their potency and affinity but also for the improved medicinal chemistry properties of pyrimidine as a bioisostere for phenyl and other aromatic π systems. It is hoped that this article will provide insight to researchers considering the pyrimidine scaffold as a chemotype in future drug candidates in order to counteract medical conditions previously deemed untreatable.