Synthesis, Antibacterial and Antioxidant Activities of Some New Nsubstituted Azachalcone, Schiff base and Pyrazole Derivatives

Abstract

Pyrazoles, Schiff bases and the quaternary ammonium compounds (QAC) such as N-alkyl substituted azachalcones are the important group of chemical individuals with widespread usage in many fields of science. In particular, these compounds have proven biological activities. In addition, the emergence of resistance against antibiotics used is the cause of an increasing necessity of new effective substances. Therefore, new N-alkyl substituted derivatives (4-7), 1,3,5-trisubstituted-2- pyrazoles (8-10) and Schiff bases (11-13) with biological activities such as phenolic. antioxidants or QAC were synthesized, starting from azachalcones. The structures of the compounds were elucidated with spectral methods including IR, 1H-NMR, 13C-NMR, COSY spectral data and elemental analyses. The prepared compounds were evaluated for antibacterial activity against four Gram-positive bacteria, and four Gram-negative bacteria. The minimum inhibitory concentration (MIC) of the N-alkylated azachalcone derivatives 5 and 7 (7.8 mg/mL) showed strong antimicrobial activities, especially against Bacillus cereus. Antioxidant capacities of the synthesized compounds were determined by using CUPRAC and FRAP methods. As a result, compound 9 was observed to be more effective than other compounds.