Main Flavonoids, DPPH Activity, and Metal Content Allow Determination of the Geographical Origin of Propolis from the Province of San Juan (Argentina)

BEATRIZ LIMA; ALEJANDRO TAPIA; LORENA LUNA; MARÍA P. FABANI; GUILLERMO SCHMEDA-HIRSCHMANN; NATALIA S. PODIO; DANIEL A. WUNDERLIN; GABRIELA E. FERESIN

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

American Chemical Society

Lugar: California ; Año: 2009 vol. 57 p. 2691 - 2691

0021-8561

he chemical characterization as well as the assessment of geographical origin of propolis from several areas of the Provincia de San Juan (Argentina) is reported. Chemical characterization of propolis was performed by measuring total phenolic (TP), total flavonoids (FL), free radical scavenging capacity (DPPH bleaching), and metal content in samples of six different districts. Methanolic propolis extracts (MEP) showed TP ranging from 25.7 to 39.3 g of gallic acid equivalents per 100 g of MEP, whereas flavonoids ranged from 6.6 to 13.3 g of quercetin equivalents per 100 g of MEP. Six main flavonoids were isolated and identified from the propolis samples, comprising the flavanones 7-hydroxy-8-methoxyflavanone (1), pinocembrin (2), and pinobanksin (3), the flavones chrysin (4) and tectochrysin (5), and the flavonol galangin (6). Compounds 1-6 were quantified by HPLC-PDA. Free radical scavenging activity, measured as percent DPPH ble