In modeling system of the initiated oxidation of methyl oleate the antioxidation activity of a series of dipeptide derivatives of betulonic and glycyrrhetic acids, natural quinones (ubiquinone, philloquinone and menadione) and the kinetic effects of their combined action with alpha-tocopherol were studied. The same extreme character of the dependence of inhibitory action on the concentration of all investigated substances was found. Combined addition of triterpenoids or quinones together with alpha-tocopherol attenuated their effect. The mechanism of intermolecular interactions of tocopherol with quinones and triterpenoids is offered. The biological importance of these effects is discussed.