A FACILE AND ENVIRONMENT FRIENDLY SYNTHESIS OF ARYLALDIMINES AND THEIR SIGNIFICANT ANTIMICROBIAL, ANTIOXIDANT AND ENZYME INHIBITION ACTIVITIES.
Environmental benign method was used to synthesize Schiff bases of benzaldehyde (??-1 to ??-10), cinnamaldehyde (??-11 to ??-15) and salicylaldehyde (??-16 to ??-24) by using natural acid (Lemon estract) as catalyst in sonicator. The structural elucidation of these products were performed by various spectroscopic techniques like elemental analysis, Infrared (IR), Electron impact mass spectroscopy (EIMS) and Nuclear magnetic resonance (1H-NMR). Title products were also examined for their antimicrobial, antioxidant and enzymes inhibition activities. The results of antibacterial activity revealed that compounds ??-10, ??-12 and ??18 showed highest zone of inhibition ranging between 10-35 mm against both kinds of bacteria gram positive and negative. The most remarkable antifungal activity was observed in compounds ??-7 and ??-9 to ??-12 with zone of inhibition in the range between 11–33 mm. The Schiff bases ??-6, ??-7, ??-15 and ??-21 showed excellent antioxidant activity with 80-90% inhibition. In enzyme inhibition assay compounds ??-2 and ??-19 showed significant activity against tyrosinase showing IC50 values 95.2 ± 0.59 and 97.2 ± 0.55 µM, respectively as compared to Kojic acid (IC50=16.67 ± 0.06) as standard. The compounds ??-4, ??-7 and ??-10 appeared active for urease inhibition with IC50 values 42.7 ± 0.56, 38.6 ± 0.86 and 49.3 ± 0.38 µM against standard thiourea (IC50=21.6 ± 0.12 µM).