Quercetin is an anti-oxidant, anti-inflammatory, and (possible) anti-viral found in a number of different fruits and vegetables - apples, tea, onion, citrus, tomato, broccoli, cherry, raspberry, cranberry, sea buckthorn, gingko biloba, olive oil, St John's Wort, mango, and grapeseed oil.
Quercetin offers anti-inflammatory properties by inhibiting both the release and maintenance of histamine and other allergic mediators.
Rutin is a variation on quercetin with a glucose molecule substituted for the H on the right side. Mostly found in citrus fruits and berries, it is a good anti-oxidant - better than quercetin. It is used for UVA protection and circulation improvement, and is often found in anti-cellulite products for the latter property.
Rutin can chelate iron metal ions (Fe2+), binding to them to prevent them from binding to hydrogen peroxide, which could create a free radical.