Patent ID: 7361371

Claim:
An extract of Petasites japonicus having antioxidant activity and therapeutic activity for a brain disease produced by the steps of: 1) extracting and concentrating Petasites japonicus with an alcohol to obtain an alcohol extract; 2) fractionating the alcohol extract from the step 1) with hexane and water into a hexane phase and a water phase and separating the water phase; 3) fractionating the water phase from the step 2) with chloroform into a chloroform phase and a water phase and separating the water phase; 4) fractionating the water phase from the step 3) with ethyl acetate into an ethyl acetate phase and a water phase and separating the water phase; 5) fractionating the water phase from the step 4) with butanol into a butanol phase and a water phase and separating the butanol phase; and 6) vaporizing the butanol phase from the step 5) at a low temperature and a low pressure to purify the butanol phase, or adding butanol to the butanol phase from the step 5) to obtain an extract that comprises a butanol-soluble phase having antioxidant activity.