Compare different methods of phenolic and flavonoid compounds extraction from Urtica dioica L.

The present study was conducted to examine the efficiency of the traditional soaking extraction، Ultrasound-assisted extraction (UAE) and Microwave-assisted extraction (MAE) methods on the content of phenolic and flavonoid compounds extracted from nettle (Urtica dioica L.) leaves with three different solvents (water، 80% methanol and chloroform). In traditional method، water and chloroform solvents extracted the maximum phenolic and flavonoid contents، respectively. In UAE and MAE methods، the effect of different extraction times، with used solvent type were examined. In UAE method، the water-90 min and chloroform-90 min treatments had extracted the highest phenolic and flavonoid contents، respectively. Also، between the times 60 and 90 minutes، no significant difference were observed (p<0. 05). The best solvent-time treatments with maximum extraction contents of phenolic and flavonoid compounds in MAE method were water-9 min and methanol-9 min treatments. In MAE method، chloroform solvent had the lowest extraction contents of phenolic and flavonoid compounds، and the extraction times were not significant. A comparison among the three methods revealed that the MAE method with water-9 min treatment (11. 57±0. 41) and traditional method (24 h) with chloroform solvent (13. 64±0. 53) had the highest extraction power of phenolic and flavonoid compounds، respectively.