Quercetin is a plant derived flavonoid, specifically a flavone which is found in high amount in onion, caper, red wine and green tea.It is one of the most active antioxidants because of its high ability to scavenge free radicals.In this study the content of quercetin was quantitatively determined in different plant parts ofC.spinosa at the mature fruiting stage, using HPLC analysis.Collection of plant materials were made from Tafresh,Iran. Plants were separated into root,stem, leaf, floral bud,flower,fresh fruit and seed which were dried at an ambient room and subsequently assayed for total quercetin contents.The content of quercetin varied from 1.7 mg/g to 12.8 mg/g among different parts of caper. Flower, floral bud and fruit had higher content of quercetin respectively. The significant amounts of these antioxidants confirm the nutritional and medicinal value of caper.
