Chemical variability in propolis from Santiago del Estero, Argentina, related to the arboreal environment as the sources of resins

BACKGROUND: Propolis composition is extremely variable and depends on the plant resin sources that grow around the apiary. Polyphenols have been reported to be responsible of its pharmacological and biological properties. The contents of polyphenols and flavonoid aglycones were studied in propolis from different provenances to correlate these contents with the nature of the flora surrounding the hive. RESULTS: Nineteen of these bioactive substances were identified in 30 samples classified into three arboreal categories according to their main species. A noticeable variability was observed in the concentration of each component depending on the plant origin of the samples. Higher amounts were found for pinocembrin (0.2-102.3 g kg(-1)), quercetin (0.08-86.6 g kg(-1)) and chrysin (0.8-18.8 g kg(-1)). Salicylic, 4-hydroxybenzoic, benzoic, ferulic and gallic acids were other remarkable constituents. CONCLUSION: Statistical significant differences in polyphenol and flavonoid contents were observed among arboreal groups, while very strong linear correlations were found between polyphenol and flavonoid contents for all the samples as well as for all the groups (R-2% > 87). (c) 2009 Society of Chemical Industry