Design, synthesis and mechanistic study of new 1,2,4-triazole derivatives as antimicrobial agents.

Novel 5-amino-1,2,4-triazole derivatives and their cyclized 1,2,4-triazolo[1,5-a]pyrimidine analogues were designed, synthesized and evaluated for their antimicrobial activities. They were tested against five bacterial strains (Methicillin Resistant S. aureus (MRSA), E. coli, K. pneumoniae, A. baumannii and P. aeruginosa) using ciprofloxacin as a positive control and against two fungal strains (C. albicans and C. neoformans) using fluconazole and amphotericin B as positive controls. Compounds 9, 13a and 13b showed high to moderate antifungal activities against candida albicans (MIC values = 4-32 µg/ml), with considerable safety profiles; where no cytotoxicity against human embryonic kidney or red blood cells were detected at concentrations up to 32 µg/mL. Furthermore, compound 9 showed significant inhibitory activity against lansterol 14α-demethylase (IC50 = 0.27 µM), compared to the reference drug fluconazole (IC50 = 0.25 µM). Molecular docking of compound 9 into the active site of the cytochrome P450 enzyme revealed comparable binding modes and docking scores to those of fluconazole. Finally, in silico ADME studies prediction and drug-like properties of these compounds revealed favorable oral bioavailability results.

Design, synthesis, molecular docking and antiproliferative activity of some novel benzothiazole derivatives targeting EGFR/HER2 and TS.

Multi-targeted anticancer drugs are in focus as a promising research topic. A new series of benzothiazoles hybridized with pyrimidine moiety was designed and synthesized using the lead compound 4a. Various chemical modifications on the pyrimidine ring of 4a at four different positions were done in a trial to get new multi-targeted anticancer agents. The structures of the newly synthesized compounds were established on their elemental analyses and spectral data. All final synthesized derivatives were submitted to the National Cancer Institute (NCI), USA, to be screened for their in vitro anticancer activity. Further evaluation for the cytotoxic activity of the most active compounds was performed using the MTT assay method. Compounds 4d, 8d, 8h, 8i and 17 were then selected for examining their in vitro enzyme inhibitory activities against EGFR, HER2 and TS enzymes using lapatinib and 5FU as standards. Furthermore, cell cycle analysis and apoptosis induction detection were also evaluated. Finally, molecular docking studies were carried out for compounds 4d, 8d, 8h, 8i and 17 to interpret their observed enzymatic activities based on the ligand-protein interactions.