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Objective: To study the chemical constituents of Brassica rapa L. seed. and to establishes the method of determination the content of active ingredients in Brassica rapaL. seed. Methods:①The dry seed of Brassica rapa L. were extracted with 95% EtOH. The 95% EtOH extract was distributed with solvents of diffrernt polarity into four fractions, namely the petroleum ether fraction, EtOAc fraction, BuOH fraction and H2O fractions. Then adopt silica gel column chromatography, macroporous adsorptive resins, sephadex LH-20, preparation of thin layerchromatography, crystallization and recrystallization for separation and purification of the petroleum ether fraction, EtOAc fraction, BuOH fraction. Apply chemical method and modern spectroscopy such as 1H-NMR, 13C-NMR to identify the structure of the compounds.②To assay six acids in the fatty oil of Brassica rapa L. seed by GC.③To assay the composition of monosaccharide in the polysaccharide of Brassica rapa L. seed. by HPCE. Results:①Nine monomer compounds were isolated from petroleum ether fraction, EtOAc fraction and BuOH fraction. to identify eight structure of the compounds, they were identified as oleanolic acid (1),β-sitosterol (2), palmitic monoglycerolester (3), dibutylphthalate (4), ursolicacid (5), quercetin (6), kaempferol-3-O-rutinoside (7), 5-hydroxy-3’,4’,6,7- tetramethoxyflavone (8).②Through to assay six acids in the fatty oil of Brassica rapa L. seed by GC, the experimental result to indicate that the content of palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid and erucic acid were 19.99mg/g, 2.22mg/g, 25.63mg/g, 31.67mg/g, 12.06mg/g, 50.94mg/g.③Through to determine the composition of monosaccharide in the polysaccharide of Brassica rapa L. seed. by HPCE, to calculate the molar ratio of arabinose, amylaceum, rhamnose, galactose, mannose, glycuronic acid, galacturonic acid were 8.09/1.79/0.28/5.11/0.78/0.32/0.38 bycorrection factor method. Conclusion:①We study the chemical compositions of Brassica rapa L. seed., the compound (1), (3), (4), (5), (6), (7), (8) were discovered in Brassica rapa L. seed. for the first time.②To determine the content of effective constituent in Brassica rapa L. seed. by GC, the method were perfect, accurate, and reliable.③To assay the composition of monosaccharide in the polysaccharide of Brassica rapa L. seed. by HPCE, the method were convenient and feasible.
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