Antioksidacijski učinak i HPLC analiza listova planike - Arbutus unedo L.

Abstract

Some of the major constituents of strawberry tree are flavonoids and phenolic acids that are responsible for some of the pharmacological activities i.e. adstringent, antihypertensive, antidiarrheal and antibacterial. Objective of this work was to determine flavonoid aglycones and phenolic acids in strawberry tree leaves collected during 12 months of 2013 using RP-HPLC-DAD and assess antioxidant activity using ABTS stable free radical. Antioxidant activity of strawberry tree leaves varied between 11% and 28%. The content of individual polyphenols was: chlorogenic acid 0.8 to 6.5 mg/g, caffeic acid 0.6–1.0 mg/g, p-coumaric acid 0.2–6.6 mg/g and quercetin 0.5–10.7 mg/g. The highest content of polyphenols was during winter months. Compared to the thin-layer chromatography analysis we have determined presence of additional phenolic acids (caffeic and p-coumaric) and quercetin – aglycone of quercitrin, isoquercitrin and hyperoside