The radical scavenger capacity and mechanism of prenylated coumestan-type compounds: a DFT analysis

Abstract

The antiradical capacity and mechanisms of two representative coumestan-type compounds, namely isosojagol (Iso) and phaseoul (Pha), were examined using quantum chemistry calculations and computational kinetics methods. From a thermodynamic point of view, the 18CH groups of the prenyl substituent have been found to be the most suitable sites for radical attacks via the formal hydrogen transfer (FHT) mechanism. However, the kinetic study revealed that the reaction at these CH groups is slow and does not contribute to the overall reactivity of these compounds, which the phenolic groups mainly define. The kinetic study also revealed that the studied compounds are good free radical scavengers with overall rate coefficients as high as recognized antioxidants such as carnosic acid, artepillin C, thymol, and rosefuran.

Keywords:

• Prenylated coumestans
• DFT calculations
• antiradical activity
• kinetic study
• reaction mechanisms

Acknowledgments

We would like to thank MESRS (Ministère de l’Enseignement Supérieur et de la Recherche Scientifique, Algeria) and DGRSDT (Direction Générale de la Recherche Scientifique et du Développement Technologique, Algeria), for financial support, as well as the HPC resources of UCI-UFMC (Unité de Calcul Intesif of the university Fréres Mentouri Constantine 1) for the computational resource used.

Disclosure statement

No potential conflict of interest was reported by the author(s).