A STUDY OF THE BACTERIOSTATIC PRINCIPLE ISOLATED FROM FORSYTHIA SUSPENSA VAHL.(LIEN-CHIAO)

The concentrated alcoholic extract of the capsules of Forsythia suspensa Vahl,was subjected to repeated extraction with water.As a result,an amorphous phenolic compound with an empirical formula of C₁₅H₁₈O₇ was isolated,which was soluble in sodium hydroxide solution and turned FeCl₃ test solution to green.The compound gave an emerald green fluorescence in water.It is hygroscopic,and forms a 1:80 supersaturated solution in water.It is soluble in alcohol,but insoluble in ethyl ether,chloroform or petroleum ether.Its optical activity could not be detected. The compound has not yet been mentioned in literature concerning F.suspensa Vahl.,and hence named Forsythin.It inhibited the growth of Staphylococcus aureus in vitro at a dilution of 1:5120,and Shigella dysteriae at a dilution of 1:1280. In the same alcoholic extract from the plant,a crystalline sterol compound was obtained after alkaline hydrolysis.This sterol gives elongated prismatic crystals of m.p.200—202℃ with a molecular formula C₄₉H_74-80O₆ (759—765).Its optical activity could not be detected,Ar acetyl derivative with a melting point of 147—149℃ was prepared.