| Soybean, a traditional Chinese food and a main source of dietary protein and fat in China, plays multiple roles in pharmacological and biological functions. It was proved that Soyasaponin (SS) and soybean isoflavone (SI) were its important bioactive components. This paper was performed on extracting technology of bioactive components of soy, physicochemical characteristics of purified fractions and antitumor mechanism of a chemical fraction (SS-II) by apoptosis. The studies were conducted on hypoglycemic activity by a purified fraction (Si- II) in order to ensure its believable and scientific degree as a functional factor of Soy in the third generation of functional food. The antioxygenic activity of SS and SI were also investigated. The main results are as follows:1. Extracting technology of SI, SS and soybean oligosaccharides (SO) from soybeanThe optimum extracting conditions was that powders of defatted soy were immersed in 27 times the volumes of the 50% alcohol and extracted by reflux for three times at 60 , each time for 5 hours. The extracting rate of SI, SS and SO in extract was 0.28%, 2.38% and 10.68% respectively. The spectrophotometer method was convenient, rapid and precise to analyze the contents of bioactive substance of soybean in course of extracting and refining.After removal of the solvent, the ethanol extracts was extracted with mixture n-BuOH-water (1:1, v/v). This operation was repeated for two times. After the organic layer was separated, the water layer was decolorized, desalted and dehydrated to obtain the total SO. The determination of purity by TLC indicated that the total SO consisted of sucrose, raffinose and stachyose.2. Isolation, purification and identification of SSThe organic phase of n-BuOH extract prepared by the above method was concentrated under vacuum and dissolved in a mixture of MeOH and EtOAc. The solution was left overnight at room temperature and the precipitate was collected by filtration and treated with 95% ethanol. The ethanol solution was chromatographed on D101A macroporous resin column and eluted with Ethanol-Water to obtain three fractions of SS (SS- I and SS-II and SS-III). The yields of three fractions were 0.118%, 0.097% and 0.026% respectively (compared with the defatted soy). HPLC/MS, HPLC, UV-Vis, IR, TLC etc indicated that the three fractions consisted of a mixture of group A soyasaponins, group B soyasaponins and few isoflavone aglycone. HPLC-MS showed that soyasaponin Aa, a kind of group A soyasponins which exhibited a [M+H]+ protonated molecule at m/z 1239.2, was included in SS-II andGenistin, 5,7,4'-trihydroxyisoflavone -glucoside which exhibited a [M+H]+ protonated molecule at m/z 433, was included in SS-1 .3. Isolation, purification and identification of SIThe EtOAc-MeOH extract was prepared by the above method. After filtration and removal of the solvent successively, the residue was immersed in 10% HC1 and hydrolyzed for 4 hours at 90 . The filtrate was dehydrated and chromatographed on HPD600 macroporous resin column and eluted with Ethanol-Water to obtain three fractions of SI (SI- I and SI- II and SI-III). The yields of three fractions were 0.078%, 0.030% and 0.024% respectively (compared with the defatted soy). The content of total isoflavone in three fractions were 75.80%, 94,04%, 75.49% respectively. It was indicated by HPLC-MS, HPLC, UV, IR and TLC that the three fractions were composed of genistein, daidzein anda litter glycitein. And SI- II was elucidated as genistein (82.84%).4. Affection of SS-11 on liver cancer lines QGY-7703 cells apoptosisSS-II could inhibit the growth of human liver tumor cell lines QGY-7703 effectively and showed obviously (p<0.01) dose-response and time-response relationship at the doses of 0.4 - 0.8 mg/ml. The morphological observation by the acridine orange/eihidium bromide double fluorescent dye staining suggested that SS-II could increase the apoptosis of liver cancer cells markedly (p<0.01) . Confoca! laser scan microscopy revealed for the first time that SS- II induce...
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