Poster: Secondary metabolism

Abs # P25016: Antioxidizing Activity and Antimicrobial Activity of Catechins from Tea(Camellia sinensis, Diospyros kaki Thumb

Presenter:	Prof. Kim, Younghee       Contact Presenter
Authors	Prof. Kim, Younghee  (A)
Affiliations:	(A): Dept. Biotechnology and Informatics, Engineering of College, Sangmyung University

Antioxidizing activity and antimicrobial activity of catechins from tea plants (Camellia sinensis, Diospyros kaki Thumb) were examined. Catechin contents and biochemical activities were measured from the green tea, black tea and persimmon leaves. Catechin contents of green tea was the highest, and Catechin contents of black tea was higher than that of persimmon leaves. Antioxidizing activity on lipid peroxidation of catechin was examined. Catechin of green tea showed comparatively strong antioxidizing activity. From the result of biochemical assay to meaure antioxidizing activity. we used the thiobarbituricacid(TBA) measurement method measuring the production of malondialdehyde(MDA) producing on lipid peroxidation. The contents of malondialdehyde(MDA) was observed. Malondialdehyde contents measuring the antioxidizing activity was decreased on 5 days after incubation of catechin on pork lipids. But MDA contents was increased on 7 days after incubation of catechin on pork lipids. We assumed that the production of MDA was increased by oxidation of lipid fatty acid during the early time and then the level of MDA was decreased as time passed. We obtained the lowest MDA value from green tea. We also measured the antimicrobial activity of catechin measuring the size of clear zone of bacterial colonies. The inhibitory zone of catechins from green tea was largest. We assumed that the result was due to the highest contents of catechin of green tea. Therefore, we concluded that the catechins of green tea showed comparatively strong antioxidizing activity on lipid peroxidation with the lowest MDA value and strong antimicrobial activity. The antioxdizing and antimicrobial activity of the natural materials which we examined, was green tea, black tea and persimmon leaves in order.