ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Designing structural derivatives of EGCG from Chinese tea for improved antioxidant activity: DFT study

Asim Maqbool, Aqsa Laraib, Noman Ali, Mehboob Hassan, Muhammad Umar Nadeem, Muhammad Shahzad, Shamsa Bibi, and Fu-Quan Bai

Department of Chemistry, University of Agriculture Faisalabad, Faisalabad, Pakistan

E-mail: shamsa.shafiq@uaf.edu.pk

Received: 5 May 2025  Accepted: 10 November 2025

Abstract:

Reactive oxygen species (ROS) are produced in the body as a byproduct of cellular respiration and are related to several diseases, including cancer, cell damage, DNA mutation, and cardiovascular diseases. Antioxidants protect our body from oxidative stress by neutralizing reactive oxygen species. Epigallocatechin-3-Gallate is the most abundant and effective antioxidant found in Chinese tea, especially in green tea. In this research, we computationally designed four novel structural derivatives (M₁–M₄) of EGCG, substituting specific positions with various electron-withdrawing groups (–COCH₃, –NO₂, –NF₂, –COOH). This study presents the first DFT-based investigation into the influence of these specific electron-withdrawing groups on the antioxidant activity of EGCG via the HAT mechanism, aiming to identify superior antioxidant scaffolds. We employed DFT calculations to evaluate their antioxidant properties. The hydrogen atom transfer mechanism, bond dissociation energy values, reactivity indices, non-bonding orbitals, non-covalent interactions, Mulliken charges, and MEP analyses were performed to evaluate the antioxidant activities of all the designed molecules. Results indicated that M₂ and M₃ exhibited prominent antioxidant activity due to their lower BDE values, smaller HOMO–LUMO energy gap, and higher reactivity indices. NBO analysis confirmed higher charge density on the phenolic hydrogens in M₂ and M₃, enhancing their hydrogen-donating ability. NCI analysis revealed stronger hydrogen bonding in M₂, contributing to its stability. M₁ and M₄ showed relatively lower antioxidant power. These findings suggest that introducing electron-withdrawing groups can enhance EGCG antioxidant properties. These computational results will be beneficial in future development of better antioxidants.

Keywords: EGCG; Antioxidants; DFT; HAT mechanism; BDE

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-025-04495-6

Chemical Papers 80 (2) 1871–1879 (2026)