Synthèse de bases de Mannich de N-(1-(4-méthoxSynthesis of Mannich bases of N-(1-(4-methoxyphenyl)-3-oxo-3-phenyl propyl) acetamide and 3-(4-methoxyphenyl)-1-phenyl-3-(piperidin-1-yl) propan-1-one and investigation of their toxicity, antimicrobial and antioxidant activities

Abstract

Mannich bases of N-(1-(4-methoxyphenyl)-3-oxo-3-phenylpropyl) acetamide (A) and 3-(4- methoxyphenyl)-1-phenyl-3-(piperidin-1-yl) propan-1-one (B) were synthesized and their purities were confirmed by melting point and Thin Layer Chromatography. The compounds were characterized by NMR, IR and UV. Antimicrobial analyses were carried out using the Agar well diffusion method. The antioxidant activity was assessed using the 2,2-diphenyl-1-picryl hydrazyl radical (DPPH) and hydrogen peroxide (H2O2) methods. Toxicity was carried out following the Brine Shrimp Toxicity assay. Results of toxicity analysis gave LC50 values of 119.91 mg/mL (A) and 178.14 mg/mL (B) which showed that both compounds were non-toxic compared to the standard (cyclophosphamide). Both compounds possessed significant antimicrobial activity against bacterial and fungal strains (Escherichia coli, Staphylococcus aereus, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonellae typhi, Candida albican, Rhizopus stolonifer, Aspergillus Niger, and Penicillium notatum) as compared to the standards, gentamicin and thioconazole for bacteria and fungi respectively. In vitro antioxidant screening by DPPH free radical scavenging method and H2O2 scavenging effect showed that the compounds possessed notable antioxidant activity compared to the antioxidant standards (ascorbic acid (vitamin C), vitamin A and butylated hydroxyanisole). The results showed that these two Mannich bases are synthetic drug promoters and could be the basis for synthesis of other antimicrobial and antioxidant drugs.