Background: Raphanus sativus (Radish) is a plant of the Brassicaceae family which is grown worldwide. This plant has been used in Iranian traditional medicine as a laxative, abortifacient and also recently as anti-tumor, anti-proliferative and anti-diabetic agent. Quercetin, the most important flavonoid which is found in this plant, serves as an antioxidant and as a result an anticancer agent. Methods: The present study was designed to compare extraction efficiency of different methods with various solvents in quercetin extraction from R. sativus leaves. The analysis of extracts was performed using high performance liquid chromatography (HPLC) and the quantification was carried out by the use of quercetin calibration curve. Results: In consequence, Ultrasonic Assisted Extraction (UAE) method at 50% of ultrasound intensity (Frequency of 50/60 KHz) for 10 min in methanol proved to be the most efficient technique in quercetin extracting (11.8% yield). Conclusions: This study demonstrated the optimized condition for quercetin extraction from R. sativus leaves, which is due to promoting larger agitation (cavitation) in UAE method.

Keywords: Raphanus sativus L., Quercetin, Extraction methods, Ultrasonic Assisted Extraction