QUANTITATIVE DETERMINATION OF POLYPHENOL COMPOUNDS FROM RAW EXTRACTS OF ALLIUM, ALLIARA AND URTICA GENUS. A COMPARATIVE STUDY

Abstract

Flavonoids are a large family of plant secondary metabolites, one of the largest groups of natural compounds known, principally recognized for their health-promoting properties in human diets. Most flavonoids outperform well-known antioxidants, such as ascorbate (vitamin C) and α-tocopherol (vitamin E), in vitro antioxidant assays because of their strong capacity to donate electrons or hydrogen atoms. Flavonoids have been demonstrated to accumulate with oxidative stress during abiotic and biotic environmental assaults. There are many foods that contain flavonoids and phenolic acids, besides these being dietary plants. This paper presents the spectroanalytical profile of the flavonoids and polyphenolic compouns from organs of Allium, Brassicaceae and Urticaceae genus raw hydroalcoholic extracts. The quantitative analysis of the examined chemical compounds showed that 70% ethanol solution was the best solvent used in order to obtain the highest polyphenolic content. The content of phenol compounds was determined colourimetrically with the Folin–Ciocalteu (FC) reagent and was expressed in gallic acid equivalents (GAE). The flavonoid contents was determined using a method based on the formation of complex flavonoid-aluminium and was expressed in quercetin equivalents (QE). The results show that the plants may be potent sources of natural antioxidants.