Study On Chemical Constituents Of Crepis Tectorum

Crepis is a plant of Crepis species of Asteraceae, annual or perennial herb. It is found invarious places, mainly distributed in the Shanxi, Nei Menggu. It grows in mountain slope androadside. It is riched in resources and used among the people widely. Its bitter, and nature ofslightly cold have the efficacy of relieving cough and asthma and benefiting vital energy, andit is used to cure the sore throat, bronchitis, phthisis, asthmatic brouchitis and other disease.The thesis studied on the chemical constituents of Crepis tectorum．The plant wereextracted with ethanol at room temperature. The extract was concentrated in vacuum and theresultant dark brown syrup was dissolved in redistilled water，and extracted with thepetroleum ether，ethyl acetate，butyl alcohol to the extraction to get several kinds of distilledmatter．And each of them weight for2.02%，0.47%and0.57%of gross weight of the plant．Sixteen kinds of monomeric compounds had been obtained by silica gel columnchromatography，thin layer chromatography，HPLC and recrystallization etc．The structuresof sixteen compounds were elucidated on the basis of1H NMR，13C NMR．They wereidentified as β-sitosterol (1)，oleanolic acid (2)，hexacosanic acid (3)，hexacosanol (4)，octacosanol (5)，taraxasteryl acetate (6)，chlorophyll (7)，triacontanol (8)，umbelliferone (9)，cofficic acid(10)，ω-taraxasteryl acetate (11)，ursolic acid(12)， chlorogenic acid (13)，daucosterol (14)，α-glucose (15)，sucrose (16)．The compoundes3，4，9and12were isolatedfrom this plant for the first time．...