Synthesis, antibacterial and antioxidant activity of caffeic acid vitamin C ester

A facile one-pot method for synthesis of caffeic acid vitamin C ester via Knoevenagel condensation and esterification from 3, 4-dihydroxybenzaldehyde, malonate and vitamin C were studied.Antibacterial and antioxidant activity of caffeic acid vitamin C ester were determined.In the presence of SO2-4/ZrO2 catalyst, caffeic acid was synthesized by Knoevenagel condensation of 3, 4-dihydroxybenzaldehyde with malonate, then esterified with vitamin C to give caffeic acid vitamin C ester in 85.1% yield.The structure of target compound was confirmed by1H NMR and IR spectrum.The antibacterial tests indicated that caffeic acid vitamin C ester exhibited good inhibition activity on Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Saccharomyces cerevisiae, Penicillium chrysogenum, Aspergillus flavus and Aspergillus niger.And the inhibition activity of caffeic acid vitamin C ester on bacteria and yeast were much higher than those on mould.The antioxidant tests indicated that caffeic acid vitamin C ester could efficiently scavenge DPPH free radical and hydroxyl free radical, which was significantly higher than that of vitamin C.