R.A. Mendes, S.K.C. Almeida, I.N. Soares, C.A. Barboza, R. G. Freitas, A. Brown, and G.L.C. de Souza
J. Mol. Model. 25:89 (2019)
Publication year: 2019

In this work, we present a computational study on the antioxi- dant potential of myricetin 3-O-α-L-rhamnopyranoside (Compound M3) and myricetin 4′-O-α-L-rhamnopyranoside (Compound M4′). Structural parame- ters, bond dissociation enthalpies (BDEs), ionization potentials (IPs), proton dissociation enthalpies (PDEs), proton affinities (PAs), and electron transfer enthalpies (ETEs), which are properties connected with different mechanisms related to antioxidant activity, were determined using density functional theory (DFT) with B3LYP, LC-ωPBE, M06-2X, and BMK functionals along with 6-311+G(d,p) basis sets in the gas-phase, water, and pentylethanoate. The values obtained were compared with results previously available in the liter- ature for myricetin (the parent molecule and a well known antioxidant) and myricetin 3,4′-di-O-α-L-rhamnopyranoside (Compound M3,4′). As the BDEs are considerably lower than the IPs, the HAT mechanism is preferred over SET for the compounds M3 and M4′. The present study indicates Compound M3 as having its lowest bond dissociation enthalpy from the several di↵erent OH groups with similar value to the lowest for myricetin (74.72 kcal/mol versus 74.8 kcal/mol, respectively, at the B3LYP/6-311G(d,p) level of theory in the gas-phase) and, thus, presenting antioxidant potential as good as its parent