Selective Esterification and Antioxidant Activity of Rutin

Abstract

Rutin is a natural medicine which is widely presented in plants. Modified by the esterification of rutin in the introduction of long hydrocarbon chain molecules, in order to increase its solubility and stability in the lipophilic, thus increasing the antioxidant activity. This paper reports the reaction solvents, acyl donor chain length, molecular sieve and enzyme. Experimental results show that tert-amyl alcohol is the best solvent for the reaction; Rhizopus arrhizus whole-cell lipase or Lipase Novozym435 is used as biological catalyst enzyme; the molar ratio of lauric acid:rutin is 5:1, the reaction temperature is 60 ºC, the reaction time is ca. 96 h, within the esterification, we should add molecular sieve in order to increase the esterification conversion. Antioxidant effect is tested by the ultraviolet spectrophotometer. The ester has stronger scavenging effect for •OH and •O₂ − than rutin. So the ester has more antioxidant capacity than rutin and mannitol.