Chemical Constitutes From The Stem Bark Of Syringa Reticulata And Their Anti-Inflammatory Activities

Syringa reticulate(Bl.)Hara,a dwarf tree that belongs to the family Oleaceae and the genus Syringa,is mainly distributed in Jilin,Heilongjiang,Liaoning Provinces.The bark,trunk,stem and branches of this plant have been used as expectorant and anti-asthmatic drugs in traditional Chinese medicine.To obtain more clearly the active chemical constituents from this plant and to evaluate their inhibitory effects on lipopolysaccride(LPS)-induced inflammatory response in human embryonic lung fibroblast(HELF)cells,twenty compounds(1-20)were isolated from the n-Bu OH extract of S.reticulate stem bark using silica gel column,octade-cylsilyl(ODS),preparative middle pressure liquid chromatography(MPLC).The chemical structures of isolated compounds were identified by Nuclear Magnetic Resonance(NMR)and other spectroscopic methods,including 1-(5-hydroxy-4-methoxyphenyl)ethane-7,8-diol(1),4-hydroxyphenylethanol(2),sinapic aldehyde 4-O-β-D-glucopyranoside(3),butylconiferin(4),methyloleoside-7-ethyl ester(5),oleonin(6),oleoside-7,11-dimethyl ester(7),oleuropein(8),syringing(9),oleanolic acid(10),kaempferol(11),liguseroside(12),liguluciridoid B(13),β-sitosterol(14),(+)-jasminoids D(15),3β-hydroxy-20α-methylolean-13(18)-en-29-oic acid(16),β-sitosterol-3-O-β-D-glucopyranoside(17),ethyoxyl-O-β-D-glucopyranoside(18),4,5-dihydroxyphenyl ethanol(19)and 5-methoxyfurfural(20).Among them,compounds 3,6 and 12 were isolated from the Oleaceae family for the first time,and compounds 1,10 and 11 were reported from the S.reticulate for the first time.Anti-inflammatory effects of the isolated compounds and solvent extracts were evaluated in terms of inhibition of nitric oxide(NO),tumour-necrosis factor(TNF)-αand interleukin(IL)-6 productions in LPS-induced HELF cells.Compounds 5,7,8,12 and 15 significantly inhibited the levels of NO,TNF-α and IL-6 in LPS-induced HELF cells at doses of 3 μM、10 μM and 30 μM.The present study not only enriched the chemical constituents of S.reticulata,but also increased comprehensive understanding of the material basis of S.reticulata.These results can be able to provide theoretical support for the research and development of anti-fibrosis agents for pulmonary fibrosis from anti-inflammatory natural products.