Study On The Chemical Constituents From The Defatted Seeds Of Linum Usitatissimum L. And Nicotiana Tabacum L. Leaves

Linum usitatissimum L. is an economic crop widely distributed in China, especially in Neimeng, Heilongjiang, Xinjiang and Gansu provinces. Traditionally, the oil of flaxseed is used in the manufacture of paints, varnishes and linoleum, because of its drying and hardening properties when exposed to air and sunlight. Flaxseed is an interesting raw material for functional foods because it contains omega-3 fatty acids, fibre and lignans. Previous chemical investigations on this plant demonstrated the presence of lignans, flavones, cycliceptides, cyanogenic glycosides and phenylpropanoid glycosides. These chemical constituents have a high potential in the prevention of some diseases like atherosclerosis, cardiovascular diseases, cancer and postmenopausal complaints.Nicotiana tabacum L., an important plant grown around world. Its leaves, a traditional Chinese medicine, is the first appeared in the ancient Chinese medicinal literature JingYueQuanShu. It has been used to detumescence ,detoxification, pesticides in clinical. Now chemical research indicated that the mian active constituents are considered to be alkaloid, putrescine and fatty ethano. Our nation's planting area of the two plants is large, but the most of them are often used in low-usage. So it is very significant to study on our nation's native resource.In the thesis, the chemical constituents of defatted flaxseed and tobacco leaves were investigated. Twenty-five pure compounds were isolated by chromatography methods. Of these compounds, the structure of were elucidated on the basis of spectral evidence, including UV,IR, ¹H-NMR,¹³C-NMR, DEPT and chemical methods.Eleven compounds were isolated from defatted flaxseed by using macroporous adsorption resin, column chromatography and preparative TLC. Nine of compounds were elucidated on the basis of spectral evidence and chemical methods. They are tetracosane (â… ),myristic acid (â…¡),stearic acid (â…¢),ethyl laurate (â…£),β-sitosterol (â…¤), daucosterol (â…¥),a-D-glucopyranosyl-a-D-glucop-yranoside (â…¦), a-D-glucopyranosyl-β-fructofuranose (â…§), cyclolinopeptide C(â…¨). Most of the compounds were obtained for the first time from Linum usitatissimum L.Fourteen compounds were isolated from tobacco leaves by using column chromatography and preparative TLC. Twelve of compounds were elucidated on the basis of spectral evidence and chemical methods. They are tetracosane(â… ), myristic acid(â…¡),4-hydroxyphenethyl icosanoate(â…¢),4,4'-bis(dimethylamino)benzophenone (â…£), β-sitosterol (â…¤), solanesol (â…¥), stigmasterol (â…¦), scopoletin(â…§), scopolin(â…¨),nicotine (â…©),stigmasterol-3-O-glucopyranoside(â…ª),β-carotene (â…«). Most of the compounds were obtained for the first time from Nicotiana tabacum L.