Complexation of caffeine and theophylline with epigallocatechin gallate in aqueous solution: Nuclear magnetic resonance, molecular docking and thermodynamics studies

Cheng Guo; Jing Li; Yijie Chen; Fang Geng; Bin Li

doi:10.1016/j.foodres.2021.110587

Complexation of caffeine and theophylline with epigallocatechin gallate in aqueous solution: Nuclear magnetic resonance, molecular docking and thermodynamics studies

Food Res Int. 2021 Oct:148:110587. doi: 10.1016/j.foodres.2021.110587. Epub 2021 Jul 3.

Authors

Cheng Guo¹, Jing Li², Yijie Chen², Fang Geng³, Bin Li⁴

Affiliations

¹ College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Environment Correlative Dietology (Huazhong Agricultural University), Ministry of Education, China; College of Food and Biology Science and Technology, Wuhan Institute of Design and Sciences, Wuhan 430205, China.
² College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Environment Correlative Dietology (Huazhong Agricultural University), Ministry of Education, China.
³ College of Food and Biological Engineering, Chengdu University, No. 2025.Chengluo Avenue, Chengdu 610106, China.
⁴ College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China; Key Laboratory of Environment Correlative Dietology (Huazhong Agricultural University), Ministry of Education, China. Electronic address: libinfood@mail.hzau.edu.cn.

PMID: 34507732
DOI: 10.1016/j.foodres.2021.110587

Abstract

Epigallocatechin gallate (EGCg) and methylxanthines are representative bioactive compounds in tea leaves, the strong affinity between them will elicit destruction of tea quality. In order to elucidate the mechanism of complexation between EGCg and methylxanthines, we compared the bindings of theophylline and caffeine to EGCg by nuclear magnetic resonance (NMR), molecular docking and isothermal titration calorimetry (ITC). The results revealed that the stoichiometries of caffeine to EGCg and theophylline to EGCg were both 1:1. Caffeine and theophylline were captured in the hydrophobic space formed by aromatic rings of EGCg. The affinity between EGCg and caffeine was stronger than that between EGCg and theophylline, which could be partially attributed to the two extra CH-π interactions between N₇-Me of caffeine and aromatic rings of EGCg. Furthermore, the results of ITC were agreed well with NMR and molecular docking, indicating that ITC was possible to accurately evaluate the complexation.

Keywords: Caffeine; Epigallocatechin gallate; Isothermal titration calorimetry; Molecular docking; Nuclear magnetic resonance; Theophylline.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Caffeine*
Catechin* / analogs & derivatives
Magnetic Resonance Spectroscopy
Molecular Docking Simulation
Theophylline
Thermodynamics

Substances

Caffeine
Catechin
epigallocatechin gallate
Theophylline