Thermodynamic study on antioxidative action of cynandione A: a DFT approach

Abstract

Naturally occurring compounds type biacetophenone derivatives have recently received much interest due to their wide spectrum of pharmacological activities. Cynandione A is a promising agent in drug discovery since it inhibited various oxidative stress agents. Our current paper applies DFT approach to consider thermodynamic and kinetic actions in the antioxidative treatment of this compound. At the theoretical level B3LYP/6-311++G(d,p), the SPL-ET route (the sequential proton loss-electron transfer) is the main antioxidative mechanism of cynandione A in methanol and water, and 6-OH can be seen as the best site for antiradical action. In the kinetic reaction with HOO•, 6-OH also establishes the lowest Gibbs energy of activation ΔG# value of 11.7 kcal/mol and the highest rate constant K value of 3.393 ×107 L/mol s in methanol. The complex [Zn(cynandione A)2(H2O)2] is formed with band gap energy Egap of 3.255 eV and induces redshift in the UV-Vis.