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

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.

Automated summary

This study examined the antiradical capacity and mechanisms of two representative coumestan-type compounds using quantum chemistry calculations and computational kinetics methods. It was found that the 18CH groups of the prenyl substituent are the most suitable sites for radical attacks from a thermodynamic perspective. However, kinetic study revealed that the reaction at these CH groups is slow and does not significantly contribute to the overall reactivity of these compounds.