Effects of extraction methods on total phenolic content and antioxidant activity of Litsea glutinosa (Lour.) C.B. Rob. leaves

The objective of this research was to determine the effects of 3 extraction methods: maceration, ultrasound-assisted extraction and Soxhlet extraction on total phenolic contents and antioxidant activities of crude extracts from Litsea glutinosa (Lour.) C.B. Rob. leaves. Three concentrations of ethanol (50%, 70% and 95% by volume) were used as solvent for the extraction. It was found that the extraction of sample with 70%
(v/v) ethanol by Soxhlet extractor for 5 hours gave the highest crude extract yield (22.21% w/w on dry basis)
and the highest total phenolic content (862.75 μg GAE/g dry weight of sample). The antioxidant activity of
crude extract from the optimal extraction condition was further investigated by the 1,1-diphenyl-2-
picrylhydrazyl (DPPH). The result revealed that the crude extract exhibited relatively high antioxidant activity
with IC₅₀ value of 833.47 μg/ml.