SYNTHESES VIA PHENOLIC OXIDATIVE COUPLING USING CRUDE PEROXIDASE FROM BRASSICA JUNCEA (L) CZERN LEAVES AND ANTIOXIDANT EVALUATION OF DIMERIC THYMOL

Abstract

The ability of a crude Brassica juncea (L) Czern peroxidase as green and edible catalyst for phenolic oxidative dimerization of thymol is presented. Crude peroxidase was isolated and partially purified using precipitation method with gradient concentration of ammonium sulphate and dry ice-acetone combination as temperature regulator. The crude peroxidase was then analyzed qualitatively and quantitatively using guaiacol as a model substrate and amino antypirin activity test, respectively, and the positive result was confirmed. From the phenolic oxidative reaction, dimerization of thymol was carried out under extremely mild reaction condition in aqueous medium. The product was checked by using Fourier Transform Infrared (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS). Furthermore, the biological activity test using DPPH radical scavenging method was confirmed that the dimeric thymol showed 15 times greater than monomeric thymol in term of antioxidant capacity.