Study on the interaction and antioxidant activity of theophylline and theobromine with SOD by spectra and calculation

Theophylline (TP) and theobromine (TB) are the methyl derivatives of xanthine. The antioxidation of TP and TB as well as the effect of the antioxidation and activity of copper-zinc superoxide dismutase (SOD) with TP and TB were investigated. The contents of MDA in cells showed that both TP (14.49 mu mol/g) and TB (14.25 mu mol/g) are active in oxidation resistance and closed to the antioxidant effect of SOD (13.77 mu mol/g). With the formation of TP-SOD and TB-SOD, the antioxidant ability can be superimposed. The interactions between TP/TB and SOD were studied by ultraviolet spectrum, fluorescence spectrum and molecular docking. The results showed that the complex of TP/TB and SOD with 1:1 component was stabilized by hydrogen bonding and van der Waals forces. The analysis also indicated that the microenvironment and structure of SOD were changed. All of the results indicate that the complex formation of TP-SOD and TB-SOD canmaintain their respective antioxidant effects without changes in the activity of SOD. (C) 2019 Elsevier B.V. All rights reserved.