Extration, Separation And Purification Of Alkaloids From Sophora Alopecuroides L.

Sophora alopecuroides L. is widespread naturally in the northwest China. The seeds contain high levels of active alkaloids ingredients. It is known that the alkaloids have been used in treatment of viral hepatitis, cancer, asthma and female reproductive system infection.In this paper, the extraction, separation and purification of alkaloids from Sophora alopecuroides L were investigated. The main results were as following:The content of the total alkaloids in Sophora alopecuroides L is analyzed by the acid dye colorimetry method and the result is 8.21%. A quantitative method of alkaloidal monomers is established by HPLC/MS.The The sepatation was performed on a XTerraTM ODS column(5μm,4.6mm id×150mm) with acetonitrile -water-acetic ammonium as mobile phase at the flow –rate of 1mL/min. Mass spectrometry was used as the detector and SIR model was selected. The contents in dried seeds of oxymatrine, sophoridine, oxysophocarpine are 0.93%, 0.35% and 1.67% respectively.The optimal parameters of extraction were obtained by single factor experiments and orthogonal tests: raw material 0.3mm diameter, pH 0.5 water/ hydrochloric acid, 25℃, liquid-to-solid ratio 20:1(V/W), extracting two times and 18h one time. According to the analysis of extract, the total amount of alkaloids reaches to 21.8% in total solid substance. The extraction ratio was7.76%.The extraction solution was preliminarily treated by hollow-fibre ultrafitration membrane. The effects of membrane pore size, operating pressure, pH value, and diafiltration were studied. It was shown that the polysulfone membrane with the molecular weight cut-off (MWCO) of 6KD were the most effective to recover the alkaloids.The optimal ultrafiltration conditions were: Pressure 0.12Mpa; Concentration ratio 4.5; pH 3.5 after microfiltration; three diafiltrations. The content of the alkaloids in total solid substance was 52.3% with the 93.5% recovery of alkaloids and 87.3% removal of proteins. 0.5mol/L NaOH solution was applied to refresh the ultrafitration membrane .The different effects of six types of resin on the decolorization of the ultrafiltration solution were investigated. The results showed that the resin DA201-D was the best. The optimal decolorization conditions were the flow rate of 1BV/h, pH 2.0~4.0,and 25℃; The treatment capacity of DA201-D resin was up to 8BV, the recovery of alkaloids was 94.2%. The content of the alkaloids in total solid substance was 69.3% The conditions of resin regeneration were also studied.The result was that 2mol/L NaOH (containing 50% ethanol) has an effective regeneration performance on the resin.The silica gel preparation column was used to separate and purify the monomer of alkaloids and three monomers of alkaloids are separated and then crystallized. On the basis of IR spectra and HPLC-MS, these alkaloids were identificated as oxymatrine, oxysophocarpine and sophoridine. The purity of them was analyzed by HPLC and was 99.9%, 99.9% and 97.4% respectively. The yields of them from the raw seeds are 0.22%, 0.38%, 0.12% respectively.