Among Phyllanthus orbicularis K phytocompounds, 2,4-di-terbutilfenol o el 2,6-di-secbutilfenol are proposed as potent mutagenicity inhibitors produced by hydrogen peroxide, in S. tiphimurium. This DNA protected capacity, against oxidative damage can be explained, theoretically, by several ways. To date, has not been reported neither molecular mechanics as support to the antimutagenic activity of this compounds. In the present work in silico modelation was performed in order to propose a chemistry explanation of the scavenging mechanism versus hydroxyls radicals mediated by these phenols. To carried out the model, a quantum mechanics methodology was employed with: i) DFT calculations, employing B3LYP/6-31G** functional, to the structures of the 2,4-di-terbutilfenol o el 2,6-di-secbutilfenol, and the open shell uB3LYP/6-31G** functional to all proposed radicals, ii) Semi empiric calculations to model the final products obtained in the last stage of free radical reaction. The modelled mechanism proposed a hydrogen abstraction from the hydroxyl group mediated by the radical OH· generating phenoxyl free radicals in the propagation stage. These are eliminated in the termination stage by annihilation with other radicals or self-annihilation, generating both monomeric and dimeric of quinonic and phenolic-derived compounds, as final products in the proposed mechanism.