Structure based design, synthesis, and biological evaluation of imidazole derivatives targeting dihydropteroate synthase enzyme.

In this study, we have designed and synthesized 2-((5-acetyl-1-(phenyl)-4-methyl-1H-imidazol-2-yl)thio)-N-(4-((benzyl)oxy)phenyl) acetamide derivatives. Antimicrobial activities of all the imidazole derivatives have been examined against Gram-positive and Gram-negative bacteria and results showed that the conjugates have appreciable antibacterial activity. Besides, several analogous were evaluated for their in vitro antiresistant bacterial strains such as Extended-spectrum beta-lactamases (ESBL), Vancomycin-resistant Enterococcus (VRE), and Methicillin-resistant Staphylococcus aureus (MRSA). The SAR revealed that the 12l compound resulted in potency against all bacterial strains as well as ESBL, VRE, and MRSA strains. Lipinski's rule of five, and ADME studies were preformed for all the synthesized compounds with Staphylococcus aureus dihydropteroate synthase (saDHPS) protein (PDB ID: 6CLV) and were found standard drug-likeness properties of conjugates. Moreover, the binding mode of the ligands with the protein study has been examined by molecular docking and results are quite promising. Besides, all the analogous were tested for their in vitro antituberculosis, antimalarial, and antioxidant activity.

Antimycobacterial and antimicrobial study of new 1,2,4-triazoles with benzothiazoles.

In this study, we report the antimycobacterial and antimicrobial evaluation of newly synthesized 3-(3-pyridyl)-5-(4-methoxyphenyl)-4-(N-substituted-1,3-benzothiazol-2-amino)-4H-1,2,4-triazole 6a-j in good yields. All the synthesized compounds have been established by elemental analysis, IR, ¹H NMR, ¹³C-NMR and Mass spectral data. In-vitro antimycobacterial activity was carried out against (Mycobacterium tuberculosis) H37Rv strain using Lowenstein-Jensen medium and antimicrobial activity against two Gram positive bacteria (Staphylococcus aureus, Streptococcus pyogenes), two Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa) and three fungal species (Candida albicans, Aspergillus niger, Aspergillus clavatus) using the broth microdilution method. Compounds 2e, 6a, 6g, 6h, and 6j exhibited promising antimicrobial activity whereas compound 6j showed very good antimycobacterial activity.

Pharmacological evaluation and characterizations of newly synthesized 1,2,4-triazoles.

The triazole analogs were obtained via. multistep synthesis sequence beginning with ethyl nicotinoate 3 which on treatment with hydrazine hydrate yields nicotinoyl hydrazide 4. Intermolecular cyclisation of 4 with 4-methylbenzoic acid in presence of phosphorous oxy chloride affords 2-(3-pyridyl)-5-(4-methylphenyl)-1,3,4-oxadiazole 5. Condensation of 5 with various substituted 2-hydrazino benzothiazole 2a-j results in 3-(3-pyridyl)-5-(4-methylphenyl)-4-(N-substituted-1,3-benzothiazol-2-amino)-4H-1,2,4-triazole 6a-j analogs. All the compounds have been characterized by elemental analysis, IR, (1)H NMR, (13)C NMR and mass spectral data. In vitro antitubercular activity was carried out against Mycobacterium tuberculosis H(37)Rv strain using Lowenstein-Jensen medium and antimicrobial activity against various bacteria and fungi using broth microdilution method. Compounds 2e, 6a, 6b, 6c, 6d, 6g, 6h and 6i emerged as promising antimicrobials. It was also observed that the promising antimicrobials have proved to be better antituberculars. Compound 6j showed better antitubercular activity compared to rifampicin.