A Study of Catechin Photostability Using Photolytic Processing

Processes

Jeu-MingP. Yuann¹  Chien-Wei Cheng¹  Ji-Yuan Liang¹  Shiuh-Tsuen Huang²  Shwu-Yuan Lee³  Meei-Ju Yang⁴ 

[1] Department of Biotechnology, Ming-Chuan University, Gui-Shan 33343, Taiwan;Department of Science Education and Application, National Taichung University of Education, Taichung 40306, Taiwan;Department of Tourism and Leisure, Hsing-Wu University, New Taipei City 24452, Taiwan;Tea Research and Extension Station, Taoyuan 32654, Taiwan;

关键词: aluminum;    catechin;    light;    proanthocyanidin;    tea;   

DOI  :  10.3390/pr9020293

来源: DOAJ

【 摘 要 】

Catechin exhibits numerous physiological characteristics. In this study, we determined the photosensitivity of catechin to various lights under alkaline conditions, and the mechanisms by which catechin generates free radical species and polymerizes via a photoreaction. In addition to this, the application of catechin photolysis was investigated. A solution of catechin is transparent, but turns yellowish under blue light illumination (BLI) in neutral or weak alkaline solutions. When catechin is subjected to BLI, a dimeric catechin (proanthocyanidin) and a superoxide anion radical (${\mathrm{O}}_2^{•-}$) are generated in a photolytic reaction. When ascorbic acid or gallic acid is added to catechin and the mixture is subjected to BLI at alkaline pH, fewer catechin dimers and less ${\mathrm{O}}_2^{•-}$ are produced, because both acids inhibit the photosensitive oxidation of catechin. When AlCl₃ is added to catechin and the mixture is subjected to BLI at pH 8, a photolytic reaction is suppressed by AlCl₃, and AlCl₃ acts as a catalyst for the disconnection of proanthocyanidin during photolysis. Under alkaline conditions, catechin generates ${\mathrm{O}}_2^{•-}$ via photosensitive oxidation, which suppresses the growth of Acinetobacter baumannii (A. baumannii) by at least 4 logs, and deactivates its multi-drug-resistant strain. This study shows that catechin photolysis is a process of oxidation, and that it can be safely applied as a tool for environmental applications.

【 授权许可】

Unknown