| Dendrobium nobile is the precious traditional Chinese medicine, which have the effect of nourishing Yin and clearing heat and benefiting stomach fluid. It is widely used in clinic and TCM compounds and mainly contain alkaloids, bibenzyls, phenanthrenes, amino acids, sesquiterpenoids, polysaccharide and other chemical component. Bibenzyl compounds as one of the active ingredient in Dendrobium nobile have broad bioactivities, such as anticancer, antioxidant, antiangiogenic, inhibit NO production.Through review of the literature without report on the research of extraction and purification process. Our research determine to make the bibenzyl compounds from Dendrobinm denneanum as the study object. And to systematic research its’content determination, extraction process, purification process and antioxidant. So as to lay a foundation for the further development of antioxidant new drug.The main contents and results are as follows:Firstly, to establish the content determination method for bibenzyl compounds and gigantol. Gigantol as the standard substance, using Ultraviolet-visible spectrophotometric determination and HPLC to detect the content of bibenzyl compounds and gigantol. Drawing standard curve for bibenzyl compounds and gigantol, respectively, the regression equation A=0.0153C+0.0054, r=0.9999; Y=813.17X+13.084, r=0.9998, establishing quantitative detection method.Secondly, to research the extraction process of bibenzyl compounds from Dendrobinm denneanum. The extraction rate of bibenzyl compounds, gigantol as the index, to study the single factor of the bibenzyl compounds from Dendrobinm denneanum’s extraction process by solvent reflux. Based on single factor experiment to make the main factors design L9(34) orthogonal test and select out the best process parameters:70%ethanol, solid-liquid ratio lg:12ml,2h each extraction, extraction of3times.Again, to extract large amount of bibenzyl compounds, then to research the crude extract purification process. Five types of macroporous resin:X-5, HPD-300, D-101, AB-8, S-8were used to purify bibenzyl compounds with static adsorption capacity and elupurifytion ratio as evaluation factors, through static adsorption-elution test.Screening out HPD-300macroporous resin as the best one to separate and purify bibenzyl compounds from Dendrobinm denneanum. By investigating the performance of adsorption and desorption, we got the process conditions by macroporous resin to separate and purify bibenzyl compounds. The optimum conditions were as follows:the sample concentration was0.4g(native herbs)/ml, the largest sample volume was3BV. For desorption, the optimal conditions were eluant water and70%ethanol volume10BV, separately, flow velocity of eluant1ml/min,0.5ml/min through macroporous resin column, collect70%ethnol elution part. After purification the purity of bibenzyl compounds and gigantol was67.07%,0.224%, separately, increased4.25,4.92folds than before, separately. Finally, Vc as the control, through the methods of oxygen radical absorbance capacity (ORAC),DPPH method, pyrogalbl autoxidation method and Fenton reaction to comparative study the vitro antioxidant activity of Dendrobinm denneanum, crude extract and purification samples. The results showed that the antioxidant ability of the purified bibenzyl compounds from Dendrobinm denneanum was increased.Establishing the content determination method for bibenzyl compounds, and systematically and deeply research the extraction and purification process of bibenzyl compounds from Dendrobinm denneanum. After purifying the activities of bibenzyl compounds got increased. And through the determination of antioxidant capacity experiment show that its have good oxidation resistance. It can be used as a kind of natural antioxidants and new dosage to be developed and have some practical and theoretical value.
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