DETERMINATION OF COMPOUNDS WITH POTENTIAL ANTIOXIDANT AND ANTIRADICAL CAPACITY IN DIFFERENT OREGANO EXTRACTS

摘要

Oregano is an aromatic plant used both as a condiment and for medicinal purposes, with a great number of antioxidant compounds (43). The study analyzes the main groups of antioxidant compounds – flavonoids, polyphenolcarboxilic acids and polyphenols and the antiradical capacity of this plant. The determinations are done spectrophotometrically, based on the reactions with?AlCl 3 – for the flavonoids, with Arnow reagent – for the polyphenolcarboxilic acids and Folin – Ciocalteau reagent for total polyphenols. Because it is very important to know the way the observed antioxidant compounds can be extracted from plants eight extractions from two samples of dried oregano – condiment and medicinal plant were performed: with water, with methanol solution 50% and ethanol, hot and cold, and two mixtures: of methanol – water – acetic acid and methanol – acetone – water – formic acid, cold. Water and methanolic solution had the capacity to extract the compounds both from the condiment and the medicinal plant, the temperature influencing in a positive way the extractability of the antioxidant compounds. A valuable extract was obtained at low temperature, too, with the mixture of solvents methanol – acetone - water – formic acid (S 5 ). Its scavenger activity against the free radicals, determined by the capacity of elimination of the radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), was very good in the majority of the extracts. At the opposite end, there was the extract with ethanol, at low temperature.