抄録
It was demonstrated that an aqueous ethanolic extract of the fruits of Prunus japonica THUNB., dry seeds of which have been used as a diuretic, had a purgative activity. A physiologically active constituent was isolated as crystals, and named "prunuside". Prunuside (I) was hydrolysed to one mole each of kaempferol, glucose, rhamnose, and acetic acid, or gave 3-rhamnoglucosylkaempferol (IV) by mild hydrolysis with 2% aqueous NaOH solution. It was thereby clarified that the chemical structure of I was a monoacetyl derivative of IV. IV had already been isolated from Calystegia japonica CHOISY, Rhamnus japonica MAXIM., and Rosa multiflora THUNB., which are known as purgative crude drugs. The purgative activity of I was far stronger than that of IV and I may be attractive as a new active constituent.
