Extracting and studying the antioxidant capacity of polyphenols in dry linden leaves (Tilia cordata)

Abstract

Medicinal potentials of the flowers and leaves of Tilia species (Linden) make them valuable plants in pharmacognosy researches. The present study is an attempt to investigate the optimal conditions for the extraction of phenolic compounds from Tilia cordata leaves harvested from the coastal mountains located at the west of Syria. The optimal extraction conditions of phenolic compounds were determined using the conventional liquid–solid method using different ethanol–water ratio, temperature and extraction time. Total phenolic content and the radical scavenging activity of a number of the dried leaves extracts were determined by Folin-Ciocalteu reagent and scavenging of DPPH (2,2- diphenyl-1-picrylhydrazyl) radical respectively. The best phenolic yield (1.37±0.0021 g/100 g DW) was obtained using 40% ethanol at 75 °C for 30 min. Whereas the best IC50 (0.3303±0.0896 mg/ml) was obtained using ethanol 60% at 75 °C for 30 min and was correlated with a phenolic yield of 0.49±0.0014 g/100g DW. The high content of phenolic compounds and antioxidant activity found in the dried leaves extract of linden leaves indicated that it might be considered as a potential source of nutraceuticals in the future.