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Tuberculosis (TB) is an infectious disease and caused by various strains of mycobacteria. In the present study, pharmacophore model was developed using single ligand by ligand-based drug discovery approach. The key features responsible for DprE1 inhibitory activity were taken into consideration for developing pharmacophore. After the virtual screening, top 1000 hits were further subjected to docking study using GLIDE module, Schrödinger. Docking studies have shown promising interaction with amino residues with better glide score. Ligand-based drug design approach yielded a series of 15, 2-(6-nitrobenzo[d]thiazol-2-ylthio)-N-benzyl-N-(6-nitrobenzo[d]thiazol-2-yl)acetamide derivatives. All synthesized derivatives were characterized using NMR, mass, CHN analysis. The synthesized compounds were screened for In vitro antitubercular activity against Mycobacterium tuberculosis (H37Rv). Four compounds, 5g (MIC-1.01 μM); 5i (MIC-0.91 μM); 5k (MIC-0.82 μM); and 5o (MIC-1.04 μM) has shown promising activity compared to MIC of standard isoniazid (INH) and DprE1 enzyme inhibition was compared to BTZ043. Two halogen-substituted compounds have exhibited drastic enzyme inhibition. [ABSTRACT FROM AUTHOR]

A series of N′-[3,4-disubstituted-1,3-thiazol-2(3H)-ylidene]-2-(pyrazin-2-yloxy)acetohydrazide 11–66 and N′-[(2Z)-3-(4-bromophenyl)-4-oxo-1,3-thiazolidin-2-ylidene]-2-(pyrazin-2-yloxy)acetohydrazide 68–74 were synthesized using appropriate synthetic route. The entire test compounds 11–66 and 68–74 were assayed in vitro for antibacterial activity against two different strains of Gram-negative (E. coli and S. typhi), Gram-positive (S. aureus and B. subtilis) bacteria and the antimycobacterial activity was evaluated against H37Rv strain of Mycobacterium tuberculosis. The minimum inhibitory concentration (MIC) was determined for test compounds and for reference standards. The test compounds showed significant antibacterial and antimycobacterial activity against the microbial strains used, when tested in vitro. In general, pyrazine ring and substituted thiazoline ring are essential for antimicrobial activity. Among the compounds tested, compounds 11, 12 and 40 were found to be most potent. The toxicity of most potent compounds 11, 12 and 40 were determined using hemolytic assay and minimal hemolytic concentration (MHCs) were determined. The test compounds were found to be nontoxic up to a dose level of 250 μg/mL. [Copyright &y& Elsevier]

In a search of new potentially active antitubercular agents, here we have initiated with pharmacophore development, virtual screening and molecular docking studies to know flexible binding modes with target cavity of DprE1 enzyme. We have designed and synthesized 6-(trifluoromethyl)-N-(4-oxothiazolidin-3-yl)quinazoline-2-carboxamide derivatives and evaluated for antitubercular activity with specific DprE1 inhibition. The various steps have been completed by performing condensation of 6-(trifluoromethyl)quinazoline-2-carboxylic acid, aromatic aldehydes, methanol, Hydrazine hydrate, -(trifluoromethyl)quinazoline-2-carbohydrazide, 6-(trifluoromethyl)-N′-methylenequinazoline-2-carbohydrazide to obtained 6-(trifluoromethyl)-N-(4-oxothiazolidin-3-yl)quinazoline-2-carboxamide derivatives (3a–r) in better yields. Synthesized derivatives were characterized for their spectral analysis. These compounds have been screened for their in vitro antitubercular activity against Mycobacterium tuberculosis H 37 RV. The compounds 3a (MIC-1.27 μM); 3e (MIC-1.12 μM); 3p (MIC-1.18 μM); and 3r (MIC-0.96 μM); exhibited notable in vitro antitubercular activity compare to the reference standard, Isoniazid. These four compounds were screened for DprE1 enzyme assay. Among those 3e and 3r has shown strong DprE1 inhibition, these compounds were substituted with nitro and hydroxyl group. Image 1 • As per WHO report, tuberculosis (TB) is one of the leading cause of death in infectious disease across the globe. • Molecular modeling approach yielded 18 new quinazoline-2-carboxamide derivatives. • Newly synthesized derivatives studied for In vitro antitubercular activity. • Four compounds have shown better DprE1 Inhibitory Activity. [ABSTRACT FROM AUTHOR]

Tuberculosis has proved harmful to the entire history of mankind from past several decades. Decaprenyl-phosphoryl-ribose 2′-epimerase (DprE1) is a recent target which was identified in 2009 but unfortunately it is neither explored nor crossed phase II. In past several decades few targets were identified for effective antitubercular drug discovery. Resistance is the major problem for effective antitubercular drug discovery. Arabinose is constituent of mycobacterium cell wall. Biosynthesis of arabinose is FAD dependant two step epimerisation reaction which is catalysed by DprE1 and DprE2 flavoprotein enzymes. The current review is mainly emphases on DprE1 as a perspective challenge for further research. [ABSTRACT FROM AUTHOR]