Rutin, also called rutoside, is a citrus flavonoid glycoside compounds found in various plants and their fruits like buckwheat, the leaves and petioles of Rheum species, and asparagus, in citrus fruits such as orange, grapefruit, lemon, and lime and apple; berries such as mulberry, ash tree fruits, aronia berries and cranberries. Its name comes from the name of Ruta graveolens, a plant that also contains rutin. It contributes to the antibacterial, anti-inflammatory and antioxidant properties.

Rutin (quercetin rutinoside), like quercitrin, is a glycoside of the flavonoid quercetin. As such, the chemical structures of both are very similar, with the difference existing in the hydroxyl functional group. Both quercetin and rutin are used in many countries as medications for blood vessel protection, and are ingredients of numerous multivitamin preparations and herbal remedies.