标题: Effects of Tryptophan and Tyrosine on the Transformation of Monophenols in Chromophoric Dissolved Organic Matter Solutions: Enhance the Forward Transformation and Reduce the Reverse Transformation

作者: Zhou, RY (Zhou, Ruiya); Zhang, X (Zhang, Xu)

来源出版物: ENVIRONMENTAL SCIENCE & TECHNOLOGY 卷: 58 期: 23 页: 10108-10115 DOI: 10.1021/acs.est.4c02518 Early Access Date: MAY 2024 Published Date: 2024 MAY 30

摘要: Tryptophan (Trp) and tyrosine (Tyr) are the primary precursors of protein-like components in dissolved organic matter. Phenolic compounds are ubiquitous in aquatic environments and are considered the main electron donor in chromophoric dissolved organic matter (CDOM). Our results showed that Trp and Tyr (50 mu M) enhanced the transformation of six monophenols (20 mu M) with varying numbers of -CH3 and -OCH3 substituent groups by a factor of 1.0-1.8. The enhancement factor increased with the ratio of Trp (Tyr) to monophenols. In four different CDOM solutions (5 mg C/L, pH 8.0), a maximum enhancement factor of 3.2-6.7 was observed at a Trp/monophenol concentration ratio of 50. Conversely, monophenols greatly inhibited the transformation of Trp or Tyr. The enhancement factor decreased as the initial pH increased from 3.0 to 10.0. Additionally, the enhancement factor was not directly proportional to the oxidation potential of monophenol. We propose that the promotion effects are generated through the direct oxidation of monophenols by Trp (Tyr) radicals as well as through the reaction between Trp (Tyr) radicals and the one-electron reductant of CDOM.

作者关键词: CDOM; monophenol; tryptophan; tyrosine; phototransformation

地址: [Zhou, Ruiya; Zhang, Xu] Wuhan Univ, Sch Resources & Environm Sci, Dept Environm Sci, Wuhan 430079, Peoples R China.

通讯作者地址: Zhang, X (通讯作者)，Wuhan Univ, Sch Resources & Environm Sci, Dept Environm Sci, Wuhan 430079, Peoples R China.

电子邮件地址: xuzhangwhu@gmail.com

影响因子：10.8