Study On Chemical Constitents And Biological Activity Of Sorbus Keissleri (Schneid.) Rehd

Sorbus L. are perennial deciduous or shrubs plants and there are about 80 species in the north temperate zone of the world, the extracts of the root, stem and fruit have been reported to have antioxidant, antitumor, antibacterial and treatment of asthma activitities. Sorbus keissleri (Schneid.) Rehd.,belonging to Sorbus L. Rosaceae, is a peculiar plant of China, Which distributes in the northwest, southwest and northeast of China mainland widely,but there is no report on its chemical constituents. In this paper, the chemical constitutions of S. keissleri were studied and 8 compounds were isolated and purified from this species. Their structures were determined by UV, MS, and NMR analysis respectively. All of them were isolated from this species for the first time and biological activity of some compounds were studied.1. The chemical constituents and bioactivities of Sorbus L. were reviewed, which can provide the basis for the research of S. keissleri.2. The chemical constituents in the petroleum ether extract of S. keissleri were separated by Silica gel column chromatography and Sephadex LH-20 chromatography repeatedly to obtain two compounds, their chemical structures were determined by physical and chemical constants, spectral data analysis:24-Ethylcholest-5-ene-3,22-diol (Ⅰ) and Stigmast-5-ene-3,7-diol (Ⅱ).3. The chemical constituents in the ethyl acetate extract of S. keissleri were separated by Silica gel column chromatography, thin layer chromatography, Sephadex LH-20 chromatography, analytical, preparative HPLC to obtain 6 compounds, their chemical structures were elucidated asβ-daucosterol (Ⅲ), (-)-epicatechin (Ⅳ), (+)-catechins (Ⅴ), syringaldehyde (Ⅵ), Glycerintetracosanate (VII),1,3,5-Trimethoxybe-nzene (Ⅷ) on the basis of spectral and chemical evidence respectively.4. Among the eight compounds isolated from the S. keissleri, compoundⅣand compound V show the strong antioxidant capacity, the scavenging of DPPH radical is up to 80% at low concentrations (300μg/mL), which is stronger than BHT.The results of present study will be useful to further phytochemical investigation on S. keissleri.