cyanidin-3-o-beta-glucopyranoside and 1-1-diphenyl-2-picrylhydrazyl

The main goal of this work was to propose an authentication model based on the phenolic composition and antioxidant and metal chelating capacities of purple grape juices produced in Brazil and Europe in order to assess their typicality. For this purpose, organic, conventional, and biodynamic grape juices produced in Brazil (n = 65) and in Europe (n = 31) were analyzed and different multivariate class-modeling and classification statistical techniques were employed to differentiate juices based on the geographical origin and crop system. Overall, Brazilian juices, regardless of the crop system adopted, presented higher contents of total phenolic compounds and flavonoids, total monomeric anthocyanins, proanthocyanidins, flavonols, flavanols, cyanidin-3-glucoside, delphinidin-3-glucoside, and malvidin-3,5-glucoside. No differences were observed for trans-resveratrol, malvidin-3-glucoside, and pelargonidin-3-glucoside between countries and among crop systems. A total of 91% of Brazilian and 97% of European juices were adroitly classified using partial least squares discriminant analysis when the producing region was considered (92% efficiency), in which the free-radical scavenging activity toward 2,2-diphenyl-1-picrylhydrazyl, content of total phenolic compounds, gallic acid, and malvidin-3-glucoside were the variables responsible for the classification. Intraregional models based on soft independent modeling of class analogy were able to differentiate organic from conventional Brazilian juices as well as conventional and organic/biodynamic European juices.

Topics: Anthocyanins; Beverages; Biphenyl Compounds; Brazil; Europe; Flavonoids; Fruit; Geography; Glucosides; Humans; Organic Agriculture; Oxidation-Reduction; Phenols; Picrates; Plant Extracts; Resveratrol; Stilbenes; Vitis

Anthocyanins, colored flavonoids, are water-soluble pigments present in the plant kingdom; in fact they are secondary plant metabolites responsible for the blue, purple, and red color of many plant tissues. Present in beans, fruits, vegetables and red wines, considerable amounts of anthocyanins are ingested as constituents of the human diet (180-215 mg daily). There is now increasing interest in the in vivo protective function of natural antioxidants contained in dietary plants against oxidative damage caused by free radical species. Recently, the antioxidant activity of phenolic phytochemicals, has been investigated. Since the antioxidant mechanism of anthocyanin pigments is still controversial, in the present study we evaluated the effects of cyanidin and cyanidin 3-O-beta-D-glucoside on DNA cleavage, on their free radical scavenging capacity and on xanthine oxidase activity. Cyanidin and cyanidin 3-O-beta-D-glucoside showed a protective effect on DNA cleavage, a dose-dependent free radical scavenging activity and significant inhibition of XO activity. These effects suggest that anthocyanins exhibit interesting antioxidant properties, and could therefore represent a promising class of compounds useful in the treatment of pathologies where free radical production plays a key role.

Topics: Anthocyanins; Antioxidants; Biphenyl Compounds; DNA; Free Radicals; Glucosides; Hydrazines; Models, Chemical; NAD; Picrates; Plasmids; Xanthine Oxidase