Rutin. one of the flavonoids derived from plants, is increasingly in demand in the food, pharmaceutical, and cosmetic industries due to its various biological and physiological activities including antioxidation, anti-inflammation, and anti-hypertension. The whole plant of buckwheat (Fagopyrum esculentum Moench) is a major source of natural rutin. This study developed a low-cost process encompassing the efficient extraction, fractionation, and recrystallization to obtain high-purity rutin from buckwheat, and it could improve the economic utilization of this abundant low-value agricultural product. The sequential separation and purification procedures established in this study involved extraction with 50% (v/v) aqueous ethanol at 80 degrees C for 1 h followed by elution with water and aqueous ethanols at 20% and 30% (v/v) on a styrene-based resin column, and recrystallization at 4 degrees C for 12 h. These conditions resulted in the recovery of 92% of total rutin with over 95% purity. In the present study, high-purity rutin was obtained from whole buckwheat through low-cost processes, the separation and purification strategy established in this study could provide valuable information to the relevant industries. (c) 2005 Elsevier Ltd. All rights reserved.