Study on chemical constituents and their biological activities from the stems of Syringaoblata Lindl.

This study investigates the chemical constituents and biological activities of the stems of the Mongolian medicinal plant Syringa oblata Lindl. ("Alashan-Agaru"). Through chromatographic separation and spectroscopic analysis, 34 compounds were isolated from the ethyl acetate fraction, including four new and ten first-reported in Syringa species. Using an LPS-induced RAW264.7 macrophage model, several compounds significantly inhibited NO production. It is known that compound 34 significantly reduced the levels of interleukin - 1β, interleukin - 6 and CD14. In addition, among the 23 lignans detected by the DPPH method, five showed strong antioxidant activity, with half - maximal inhibitory concentration (IC₅₀) values lower than that of vitamin C. These results provide a scientific basis for the medicinal use of the stems of Syringa reticulata var. amurensis.