Identification of biologically active substances from lilac (Syringa vulgaris L.)

Inhibitory substance in the water extracts from lilac(Syringa vulgaris) leaves was determined in terms of the allelopathic chemicals. The water extracts from S. vulgaris leaves inhibited the germination and root growth of Digitaria sanguinalis and L. sativa, indicating that a biological substances are presented in the lilac leaves. The phenolic acids were separated and tentatively identified from S. vulgaris leaves by gas chromatography and there were composed of higher contents of p-coumaric acid, salicylic acid, pyrogallol, and catechol. Polyphenolic compounds such as rutin (5.3%), scopoletin (3.3%), kaempferol (2.9%), and other polyphenolic compotmds were detected from lilac leaves. The mixtures of of pyrogallol with all the concentrations of catechol had high inhibition of the shoot growth on D. sanguinalis and E. crus-galli regardless of the catechol concentrations.