Preparation Of Silica Gel Supported Choline And Its Catalytic Performance For Ester Exchange Of Natural Phospholipid

The glycerolphosphoryl substances are the hydrolysate of phospholipid side chains.Mainly include glycerolphosphorylcholine(GPC),glycerolphosphorylethanolamine(GPE),glycerolphosphorylinositol(GPI),and glycerolphosphorylserine(GPS),which are indispensable nutrients in organisms and have preventive and therapeutic effects on cerebral apoplexy,liver cirrhosis,and amnesia.and other diseases.Therefore,its preparation method and process research have significant application value.In this paper,soybean phospholipids as raw materials,through the choline catalyst loading and the catalytic transesterification reaction research,the establishment of the natural source of green glycerophosphates preparation process.The choline analogue 2,3-epoxypropyltrimethylammonium chloride(GTA)was chosen as the catalyst precursor and was synthesized by reacting trimethylamine hydrochloride with epichlorohydrin(GTA).The result of orthogonal test optimization design indicated that the yield of 96.55% which determined by hydrochloric acetone method was obtained under the following conditions: epichlorohydrin/trimethylamine hydrochloride molar ratio of 1.2:1.0,reaction temperature of 40 ?,p H of 9,reaction time of 3.5 h.The resulting precursor was analyzed by FT-IR and melting point determination.Catalyst precursor GTA was loaded with aminopropyl-coupled silica gel to prepare a supported choline catalyst.The optimal reaction conditions for silane coupling agent(KH550)coupled silica gel are: reaction temperature of 80 oC,silica gel/silane coupling agent ratio of 1:1.5(g/v),reaction time of 8 h.Experimental results revealed that the highest coupled amount was 1.2 mmol/g.And then loading reactions optimize reaction conditionst revealed that the highest amount of active groups immobilized as 1.1 mmol/g was obtained under the following conditions: reaction temperature of 30 ?,the reaction time of 7h,the silica gel/active substance mass ratio of 5:1,the amount of deionized wate to 20 m L.Furthermore,the FT-IR,SEM,TG were used to analyze the supported catalyst.The resulting catalyst was employed to catalyze the transesterification of PC with ethanol to prepare glycerolphosphoryl substances.It catalyzed the transesterification of PC with 97% PC conversion and 90% yield under the optimal conditions: reaction time of 4 h,thereaction temperature of 45 ?,catalyst loading of 20 g/L,stirring intensity of 250 rpm,the initial phospholipid concentration of 10 mmol/L.stability testing result manifested that the catalyst could be readily separated by simple centrifugation and retain 92% catalytic activity with 6 re-uses.The final product was detected by TLC and HPLC.The results showed that glycerophosphoryl compounds were successfully prepared.