Studies On Chemical Constituents Of F.rhynchophylla Hance And F.mandshurica Rupr. From Changbai Mountain

Fraxinus rhynchophylla Hance's dried bark was called Cortex fraxini. This plant belongs to the genus Fraxinus and is distributed widely in northeastern and northwestern of China. Cortex fraxini is a commonly used Chinese herb and has been proven to be effective in the treatment of diarrhea, dysentery of intense heat type and lung heat syndrome. It has been recorded in Chp. Pharmacological action demonstrates that C. fraxini can inhibit the growth of dysentery bacillus and staphylococcus and has the antitussive, antifebrile, expectorant function. The dried bark of Fraxinus mandshurica Rupr. is sometimes used as a substitute for C. fraxini.In order to exploit the natural resources of the genus Fraxinus from Changbai Mountain, we study the chemical constituents of the barks of F. rhynchophylla Hance and F. mandshurica Rupr.The bark used in this experiment was collected in autumn from Changbai county in Jilin province. Two kinds of dried andwell-ground barks were respectively extracted three times with 95% alcohol. The alcohol solutions were concentrated to a small volume under reduced pressure. Then they were diluted with water and filtered. The filtrate was extracted successively with ether and EtoAc. Each layer was evaporated to dryness, and the extract was analyzed on silica gel chromatography repeatedly, eluted with different kinds of solvent according to the indication of thin-layer chromatography. Pure compounds were obtained through crystallization, Prep.TLC et al.Thirteen compounds have been isolated. Eight of them had been identified structures according to the spectrum characters (HNMR, 13NMR, UV, IR, MS, HMBC) and chemical properties. They are respectively p-sitoststerol(QA), fraxidin(QB), esculin(QC), fraxetin(QD), esculetin(QH), fraxinol(QJ), fraxetin(QL) and daucosrerol(QK). This is the first report of the presence of compound QA and QK. in C fraxini. At the same time, this is also the first time that we obtained compound QJ and QL from bark of F. mandshurica Rupr.