ORIENTAL JOURNAL OF CHEMISTRY Catecholase Activity Investigations using in situ Copper Complexes Continuing Schiff Base Derivatives with a Theoretical Calculation

ABSTRACT The study of catecholase activity of a series of Schiff base compounds using in situ copper complexes of 4-hydroxy-6-methyl-3-(1-(phenylimino)ethyl)-2H-pyran-2-one derivatives has been reported. The reaction rate depends on four parameters: The nature of the substitution in para position to the benzene ring, the nature of counter anion, the concentration of ligand and the nature of solvent. The highest rate activity is given by complex resulting from one equivalent of ligand L2 and two equivalents of copper acetate in methanol, which equal to 62.25 µmol.min .In other part, a theoretical study of such ligands using the semi-empirical method AM1 were also investigated. A good relationship founded between the maximal reaction rate (V max ) and the HOMO energy (Pearson correlation: r=-0.794)

Synthesis, Molecular Docking, MEP and SAR Analysis, ADME-Tox Predictions, and Antimicrobial Evaluation of Novel Mono- and Tetra-Alkylated Pyrazole and Triazole Ligands

Newly synthesized compounds of N-alkylated heterocyclic compounds were prepared by condensation of amine with alcohol which undergoes a reaction of SN2. These newly synthesized derivatives were characterized by spectral analysis. The objective is to prepare new potent nontoxic antimicrobial agents which are easy to synthesize and could be scaled up in pharmaceutical industries. Thirteen new heterocyclic compounds containing a pyrazole moiety were synthesized with good yields (29.79 to 99.6%) and were characterized by FTIR, 1H NMR, 13C NMR, and CG-MS techniques. The compounds were divided into two series—monoalkylated compounds (1–11) and tetra-alkylated compounds (12 and 13)—and then evaluated for their in vitro antifungal and antibacterial activities against several fungal and bacterial strains. None of the monoalkylated compounds had antibacterial or antifungal activity. However, the two tetra-alkylated pyrazole ligands displayed strong antibacterial potential. Moreover, compound 12 was more potent against all tested bacterial strains than compound 13. Interestingly, compounds 12 and 13 acted as weak antifungal agents against Saccharomyces cerevisiae. ADME-Tox studies suggested that compounds 12 and 13 exhibit better toxicity profiles than the commercial antibiotic streptomycin. MEP studies suggested that compounds 12 and 13 have the same charge locations but differ in their values which are due to the condensed geometry of compound 13 that make it more polarizable than compound 12. Of particular interest, these different MEPs were evident in ligand protein docking, suggesting that compound 12 has better affinity with MGL enzyme than compound 13. All these findings suggested that these novel compounds represent promising antibacterial lead compounds

Synthesis, crystal structure, antimicrobial activity and docking studies of new imidazothiazole derivatives

International audienceA series of imidazothiazole derivatives were synthesized via Claisen–Schmidt condensation of aldehyde 3, and different methyl ketones and their chemical structures were confirmed using 13C NMR, 1H NMR and LC–MS. In addition, the molecular structure of compound 3 was defined by single-crystal X-ray diffraction. The antibacterial and antifungal activities of synthesized compounds were investigated by diffusion method against three pathogenic bacteria (Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus) and one pathogenic fungus (Fusarium oxysporum). Compound 3 displayed significant antibacterial activity against E. coli and P. aeruginosa (MIC ≤ 0.2 mg/ml). Concerning the antifungal activity, all the molecules show very interesting results versus F. oxysporum (IC50 ≤ 0.07 mg/ml). These results were confirmed by the molecular docking studies such as some compounds showing optimum binding energy and affinity to the active site of the receptor