Study On The Technology Of Extraction And Puriifcation Of Lignans And Pinoresinol Diglucoside In Eucommia Uhnoides Oliv

Eucommia ulmoides Oliv. is one of the valuable tonic Chinese herbal medicines.Eucommia bark contains lignans, iridoids and flavonoids and so on. It has manypharmacological effects such as adjusting blood pressure, blood fat and inhibiting tumorcells, etc. Research shows that lignans in Eucommia ulmoides Oliv. has obvious diastoleeffects on the blood vessel. Pinoresinol Diglucoside(PDG) belongs to the double epoxylignans which is the main antihypertension component in Eucommia ulmoides Oliv.The drying methods and the selection of harvest time of Eucommia ulmoides Oliv.,then the extraction methods and purification methods for lignans and PDG were studiedsystematically in this paper.(1) The off-color method was used to determine lignan. The detection wavelengthwas525nm. The high performance liquid chromatography (HPLC) method wasestablished to detect PDG. Detailed test conditions were as follows: dimamonsilC18(250mm×4.6mm,5μm); injection volume was20μL;25℃; mobile phase wasV(methyl cyanide)︰V(0.05%phosphoric acid)15︰85; detection wavelength was228nm; flow rate was1.0mL/min. There was a good linear relation within the range of59~944μg/mL. Thin-layer chromatography (TLC) method was established to test PDG.Developing solvent was chloroform-methanol system that the volume ratio was7︰3.The chromogenic agent was10%of chromotropic acid and concentrated sulfuric acid.High performance liquid chromatography (HPLC) methods were established to detectchlorogenic acid and geniposidic acid. Total flavonoids and aucubin were detected byUV.(2) The drying methods and the selection of harvest time of Eucommia ulmoidesOliv. were discussed in this part. The effect of different drying methods on the contentof several active ingredients was investigated in this paper. Barks and leaves ofEucommia ulmoides Oliv. were dried by different methods. The results indicated thatmicrowave deactivation was a good method. Specific data were as follows: contents ofchlorogenic acid, total flavonoid and aucubin in these leaves were2.129%、7.005%and4.420%, geniposidic acid, PDG and aucubin in these barks were0.4420%,5.393%and4.242%, respectively. Accordingly, they were5.14,1.52and17.06times,4.70,1.09and1.78times more than those processed by drying in the sun. It was a better method that50℃stoving after processed by microwave deactivation, because it could effectivelyreduce the loss of active ingredients. The results of dynamic accumulation conditionsshowed that barks gathered in May could be extracted as raw materials for lignans andPDG, because the sap could flow smoothly at the same time, so that the skin and xylemcould be separated most appropriately, and the effect of regeneration was better,moreover, contents of lignans and PDG were8.910%and0.3500%which were relatively higher.(3) Ultrasonic and enzymatic extraction technologies of lignans and PDG wereresearched. Firstly, the optimal processing conditions for ultrasonic and enzymaticextraction of lignans from Eucommia ulmoides Oliv. were obtained by orthogonalexperiments. Secondly, the PDG yields at the above best processing conditions werecompared respectively to determine the optimal extraction method of PDG. The resultsshowed that the optimum parameters for the ultrasonic extraction were EtOH volumefraction65%, ratio of liquor to material20︰1, and ultrasonic extracting for45minutesonce after soaking for12hours. The yield of lignans was7.652%, extraction ratio was97.78%, and the yield of PDG was0.3050%. And the optimal processing conditions forenzymatic extraction were pH4, liquid-solid ratio15︰1, quantity of enzyme0.7%,extracting for3hours once after soaking for12hours. The yield of lignans was8.309%,and the extraction ratio was93.27%, the yield of PDG was0.1060%. It turned out thatenzymatic extraction was higher than ultrasonic extraction for the yield of lignans,while for the yield of PDG, ultrasonic extraction is better.(4) Purification of PDG from Eucommia bark extract was researched via threecombination methods which are macroporous adsorption resin-C18columnchromatography and silica gel column chromatography. The result indicated that AB-8resin was the best one on the adsorption and desorption rates by comparing with theother3kinds of resins. Then adsorption kinetics, adsorption thermodynamics,breakthrough curve were studied. And the result showed that the purity of effective partof lignans and the crude product of PDG were71.61%and8.070%through AB-8resinonce. Then the purity of PDG increased to53.12%after C18purification. Afterwards,high purity PDG that was91.50%was obtained after silica gel column chromatography...