Hesperetin is a flavanone metabolite, found in large quantities in many citrus fruits such as lemons, limes and oranges. Both hesperetin and its co-occurring rutinose-glycoside, hesperidin, are potent antioxidants having demonstrated activity in many assays including DPPH and ABTS radical scavenging. Hesperetin has antiviral, antimicrobial, antiinflammatory and antitumor activity.