Preparative Isolation And Purification Of Phosphatidyl-choline (PC) From Rapeseed Phospholipid

Phosphatidyl-choline(PC)has multiple special character and physiological function;such as prevention of occurrence of hepatitis,alzheimer disease,cardiovascular disease,et al.PC may help reducing the cholesterol levels and regulating blood pressure,and so on.It has been widely used in food,cosmetic,pharmaceutical industries.In particular,it is promising to prepare liposomes and pharmic emulsifier.The aim of this dissertation is to establish a practical method for the isolation and purification of PC.Powder phosphatide prepared from rapeseed oil sediment was used as the raw materials to obtain the high purity PC by solid-liquid extraction,liquid-liquid extraction,and adsorption column chromatography.There may be a positive function for the industrial production of PC.First,the Box-Behnken design combined with response surface methodology was used to optimize the solid-liquid extraction and liquid-liquid extraction conditions to obtain the high purity PC.The optimum solid-liquid extraction conditions were as follows:ratio of ethanol to diethyl ether 8:1,ratio of liquid to solid 26,extraction temperature 4℃,acetone insoluble 99.0%,extraction time 90 min.Under this condition,the purity of PC in the sample is 49.0%,and the extraction rate is 90.3%.The recovery of PC increased by about 10%,comparison of ethanol extraction.The optimum liquid-liquid extraction conditions were prepared by methanol to raw materials ratio 38,petroleum ether-methanol-water ratio 51:50:3,40 ℃,and 40 min.Under this condition,the purity of PC is 60.9%,the extraction rate of PC is 56.6%.Then,the separation and enrichment of PC were studied on six macroporous resins.The performance of PC on macroporous resins was compared according to their adsorption and desorption properties.ZGD152 provided a much higher adsorption capacity for PC than other resins,and its adsorption data fitted well to the Langmuir and Freundlich isotherm.In order to optimize parameters of separation,dynamic adsorption and desorption experiments were carried out on the columns packed with ZGD152 resin.The optimal conditions were:24 mg·mL-1 crude extract solutions at the flow rate lmL·min-1 and pH 5.4;the high purity PC was obatain with ethanol as the eluent.The optimal conditions for the adsorption were that 20%ethanol was used as eluent firstly to separate the impurities,and then 95%ethanol was used as elution for the separation and purification of PC.The flow rate of the adsorption was 1.0 mL·min-1.The purity of PC was 87.7%,and the recovery of PC was 70.5%.