Curcumin Based Diazoles and Oxazoles with Potential Antibacterial Activities

A new series of curcumin based heterocyclic compounds pyrazoles, isoxazoles and others have been prepared via reactions of curcumin with hydrazine derivatives. The reactions were conducted in the presence of acetic acid as catalyst and solvent. In addition to these heterocyles, curcumin based β-iminoalcohol (7) was also prepared. the details of the synthetic procedures are described in the experimental part. The prepared heterocyclic compounds have been characterized by various spectroscopic techniques such as , FT-IR, 13C and 1H NMR spectroscopy.Some of the compounds were analyzed by elemental analysis and others by LC/MS. The curcumin based heterocyclic compounds were then evaluated for potential antibacterial activities against four different types of bacteria: Staphylococcus aureus, Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa. Bioactivities against Proteus mirabilis and Pseudomonas aeruginosa, were negative with all compounds.However some of them showed some activities against Escherichia coli.All compounds were active against S. aureus, mainly in the case of 4-((1E,1’E)-(3,6-dihydro-2H-1,4-diazepine-5,7- diyl)bis(ethene-2,1-diyl))bis(2-methoxyphenol), compound no. 4, was the best.