EN
A comprehensive study of biogenic amines and related drugs as free radical scavengers and potential antioxidants was carried out using the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH·). The results of the effect of test duration and the relative concentration on the ability of the compounds to scavenge the DPPH· were investigated and discussed. The antiradical activity of amines was compared with the activity of some reference antioxidants (phenols, phenolic acids, flavonols and other antioxidants). Some particular insights related to the mechanism of reactivity toward the DPPH· were investigated by carrying out kinetic studies in methanol for different relative concentrations. According to the obtained results, catecholamines and especially their related drugs (D-dopa, adrenalone, S-(−)-carbidopa and isoprenaline) showed a fast reactivity towards DPPH· and the highest antiradical activity which increased in a concentration-dependent manner. Moreover, catecholamines proved to be more powerful scavengers than ascorbic and caffeic acids even at low concentrations while their related drugs (D-dopa, adrenalone and S-(−)-carbidopa) showed higher antiradical activity than gallic acid for all of the investigated concentrations. [...]