Antioxidative effect of some hydroxy substituted aromatic bisimines.

This work deals with antioxidative properties of some derivatives 4,4'-bis(dihydroxybenzylanilidenamino) diphenylmethanes and diphenylethers, which structure is similar to resveratrol. Four derivatives of above-mentioned compounds were synthesized with hydroxyl (OH) groups in various positions. It was found that derivatives with two OH groups in 2 and 5 positions were very good scavengers of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals in both methanol and chloroform. On the other hand derivatives with OH groups in positions 2 and 4 did not scavenge DPPH radicals. The calculation of free enthalpies (by quantum chemical method AM1) necessary for the formations of anions or radicals support above mentioned findings because the enthalpies for effective derivatives were lesser, than for ineffective ones. Also, it was found that studied compounds did not scavenge hydroxyl radicals whereas resveratrol did it.