QSAR Study of Phenols: Relation between the Phenoxyl Radical Formation and the Antiinflammatory Activity via an Antioxidant Mechanism

The antiinflammatory mechanism of phenols as radical scavengers was analyzed. The biradical formation process Ph‐OH → Ph‐O + H was studied by the reaction coordinate method using the semiempirical AM1 quantum‐mechanical method. The enthalpies of formation of ground, transition, and radical states were determined; other parameters like the reaction, stabilization and activation enthalpies for phenoxyl radical formation of fifteen phenolic compounds were also calculated and correlated with their antiinflammatory activities. The results suggest that the ability of phenols to form the phenoxyl radical and the stability of this derived radical are important in the antiinflammatory activities of phenols via neutralization of harmful radicals.