| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject new active substance useful for technology for culturing fishes, health foods and the like and effective in vivo. SOLUTION: A compound of formula I [R1 , R2 are each H, CO(CH2 )n H; (n) is an integer of 1-3; R3 is OH, COOH or the like] or a compound of formula II or the like. For example, a compound of formula III. The compound is obtained by drying the stems of Stevia.Rebaudiana.Bertoni and its analogous plants, grinding the dried stems into a particles of <=20 μm, preferably 1-8 μm, extracting the ground product with hot water, fermenting the extract, and subsequently extracting the obtained liquid with pure water and a 30% methanol by the use of reverse column chromatography. The addition of the Stevia liquid to Salmo gairdneri together with an oxidized oil feed and the like enables to recognize a remarkable antioxidative activity. |
