Peanut roots as a source of resveratrol

A potent antioxidant, resveratrol (3,4',5-trihydroxystilbene), was extracted using 80% methanol from peanut roots (Arachis hypogaea L.), isolated with a solid-phase extraction column, purified by a semipreparative HPLC, and identified with H-1 NMR and MS. The highest and lowest resveratrol contents in the peanut roots of 2000 fall and 2001 spring crops were 1.330 and 0.130 mg/g and 0.063 and 0.015 mg/g, respectively. When the dehydrated peanut root powders of spring and fall crops were combined and cooked with pork-fat patties (1%, w/w) and the separated oils were stored at 60 degreesC for conjugated diene hydroperoxide (CDHP) determination, CDHP contents of the control oils increased after 3 days of storage, whereas the contents in the peanut root-treated oils of spring and fall crops did not increase after 9 and 15 days of storage, respectively. It is of merit to find that peanut roots, usually left in the field as agricultural waste, contain resveratrol and bear potent antioxidative activity.