Structural and electronic features of baicalein and its radicals

Abstract

Baicalein (5,6,7-trihydroxy-2-phenyl-4H-chromen-4-one) was investigated by using the B3LYP/6-311+G** level of theory in the gas phase. The results for bond order, bond dissociation enthalpy, highest occupied molecular orbital (HOMO), and Mulliken spin density for baicalein are presented. The structure-activity relationship was examined in the light of these results. Particular attention was devoted to the density functional theory (DFT) interpretation of the reactivity of the OH groups in baicalein, and the radicals formed after hydrogen removal from this molecule. A detailed analysis of the obtained results revealed that the 6-OH group is responsible for the significant antioxidant activity of this molecule. © 2011 Springer-Verlag.