Green Propolis: Thirteen Constituents of Polar Extract and Total Flavonoids Evaluated During Six Years through RP-HPLC.

In order to verify the chemical qualities of polar extract of Green Propolis produced in the State of Minas Gerais, Brazil, was analyzed by means of RP-HPLC, the concentration of eleven flavonoids, Artepillin C and p-coumaric acid were analyzed by means of RP-HPLC. Samples were collected in the months of February, March, May, July, September, and October, during a period of six years (2008 to 2013) and the results compared with purchased standards. Artepillin C was the main constituent (80-90%) found in all samples. Lower concentrations of p-coumaric acid, chrysin and kaempferide were observed in March, and of ricin and galangin in September. Respectively, these months correspond to the end of Summer and Spring period in Brazil. The variation in concentration of the analyzed constituents always occurred in the same month, during the entire six years of evaluation period. All thirteen constituents of Green Propolis were detected throughout the study period, and the average concentration of each one was similar in relation to the respective monthly collection period of each year. Due to similarities among chemical constituents of Green Propolis with those present in B. dracuncufolia, this plant was identified as being the principal source of Green Propolis.