Взаимосвязь антиоксидантного действия и синергической активности стерически затрудненных производных β-(4-гидрокси-3,5-ди-трет-бутилфенил)пропионовой кислоты в композициях с α-токоферолом

Abstract

We have studied the inhibitory action of spatially hindered phenolic antioxidant (AO) derivatives of β-(4-hydroxy-3,5-di-tert-butylphenyl)propionic acid, which are modified by including the residue of ethanolamine substituted at nitrogen atom with N alkyl radicals R with various chain length (from 1 to 16 carbon atoms). The AO activity has been studied in the reaction of initiated oxidation of homogenous methyloleate (MO) solution in chlorobenzene. It is shown that AOs act according to two mechanisms. First, they react with peroxide radicals at a reaction rate constant of k7 = (0.59 - 1.06) × 104 (М sec) -1 and destroy hydroperoxides with the formation of molecular products. The AO properties of β-(4-hydroxy-3,5-di-tert-butylphenyl)propionic acid derivatives substantially depend on their chemical structure and oxidation conditions. In lipid solution, these AOs effectively slow down MO oxidation. A synergism in the joint inhibitory action of α-tocopherol and AO derivatives of β-(4-hydroxy-3,5-di-tert-butylphenyl)propionic acid has been observed. Independent methods (UV spectroscopy and high-performance fluid chromatography) were employed to study the kinetics of α-tocopherol consumption (used separately and in a binary mixture with synthetic AOs) in the course of MO oxidation. In the synergistic composition, the rate of α-tocopherol consumption is significantly decreased.