Singlet oxygen quenching activity of furan fatty acids: Kinetic and thermodynamics study

Abstract

AbstractWe have undertaken a detailed study of the reactivity of furan fatty acids (F‐acids) with singlet oxygen (1O2) produced by thermal decomposition of endoperoxide and photosensitizer reaction of rose bengal in ethanol. Accordingly, we measured the second order rate constant (kQ) for the reaction of F‐acids with 1O2. As a result, the reactivity of F‐acids against 1O2 exhibited a decrease in the order tetra‐alkyl F‐acid (F3) > tri‐alkyl F‐acid (F2) > di‐alkyl F‐acid (NMF). In addition, we also employed the density functional theory (DFT) and quantum chemical calculations to predict the chemical reactivity, stability, and thermodynamic properties of F‐acids with respect to the quenching 1O2. In consequence, it is clear that log kQ values of F‐acids correlate with the energy level of the highest occupied molecular orbital (EHOMO), and HOMO of F‐acids may react with the lowest unoccupied molecular orbitals (LUMO) of 1O2. Moreover, the reaction of F‐acids with 1O2 proceeds spontaneously in ethanol based on the calculation by thermodynamics method. These results suggest that the F‐acids may contribute to the protection of oxidative damage in animals by quenching 1O2.