Development of a quantitative structure-activity relationship model for mechanistic interpretation and quantum yield prediction of singlet oxygen generation from dissolved organic matter

Jianchen Zhao; Yangjian Zhou; Chao Li; Qing Xie; Jingwen Chen; Guangchao Chen; Willie J G M Peijnenburg; Ya-Nan Zhang; Jiao Qu

doi:10.1016/j.scitotenv.2019.136450

Development of a quantitative structure-activity relationship model for mechanistic interpretation and quantum yield prediction of singlet oxygen generation from dissolved organic matter

Sci Total Environ. 2020 Apr 10:712:136450. doi: 10.1016/j.scitotenv.2019.136450. Epub 2020 Jan 7.

Authors

Jianchen Zhao¹, Yangjian Zhou¹, Chao Li¹, Qing Xie², Jingwen Chen², Guangchao Chen³, Willie J G M Peijnenburg⁴, Ya-Nan Zhang⁵, Jiao Qu⁶

Affiliations

¹ State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China.
² Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
³ Institute of Environmental Sciences, Leiden University, Leiden, the Netherlands.
⁴ Institute of Environmental Sciences, Leiden University, Leiden, the Netherlands; National Institute of Public Health and the Environment (RIVM), Center for Safety of Substances and Products, Bilthoven, the Netherlands.
⁵ State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China. Electronic address: zhangyn912@nenu.edu.cn.
⁶ State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, China. Electronic address: quj100@nenu.edu.cn.

PMID: 31931195
DOI: 10.1016/j.scitotenv.2019.136450

Abstract

Singlet oxygen (¹O₂) is capable of degrading organic contaminants and inducing cell damage and inactivation of viruses. It is mainly generated through the interaction of dissolved oxygen with excited triplet states of dissolved organic matter (DOM) in natural waters. The present study aims at revealing the underlying mechanism of ¹O₂ generation and providing a potential tool for predicting the quantum yield of ¹O₂ (Φ_1O2) generation from DOM by constructing a quantitative structure-activity relationship (QSAR) model. The determined Φ_1O2 values for the selected DOM-analogs range from (0.54 ± 0.23) × 10^-² to (62.03 ± 2.97) × 10^-². A QSAR model was constructed and was proved to have satisfactory goodness-of-fit and robustness. The QSAR model was successfully used to predict the Φ_1O2 of Suwannee River fulvic acid. Mechanistic interpretation of the descriptors in the model showed that hydrophobicity, molecular complexity and the presence of carbonyl groups in DOM play crucial roles in the generation of ¹O₂ from DOM. The presence of other heteroatoms besides O, such as N and S, also affects the generation of ¹O₂. The results of this study provide valuable insights into the generation of ¹O₂ from DOM in sunlit natural waters.

Keywords: Dissolved organic matter; Quantitative structure-activity relationship; Quantum yield; Singlet oxygen.