Antioxidant properties of novel curcumin analogues: a combined experimental and computational study

A small series of new synthetic analogues of curcumin (Curc ) in monomeric and dimeric (biphenyl) 18 form was prepared by straightforward procedures. Chain-breaking antioxidant activity of the studied 19 compounds was evaluated during bulk phase lipid autoxidation and the effect of an alkyl group in para 20 position to the aromatic ring directly bonded to the keto-enol unit was studied. The lack of phenolic 21 OH group in this aromatic ring allowed us to evaluate also the influence of the guaiacyl and keto-enol 22 units on the oxidative process. New binary antioxidant compositions of studied compounds with DL23 ?-tocopherol (TOH) and ternary mixtures with TOH and ascorbylpalmitate (AscPH), respectively, 24 have been created and their antioxidant potential and effects have been studied. All monomers 25 manifest good to high synergism in equimolar mixtures with TOH at both concentrations. The effect 26 of their mixtures with TOH raises up to 70% at 0.1 mM concentration