The Technics Research On Seperation And Purification Of S-Adenosyl-L-Methionine

S-adenosyl-L-methionine(SAM) is an important small molecule in all living organisms, and has a great pharmaceutical effect on liver disease and psychopathy. As China has many patients with these diseases, SAM has a wide market demand in China.We successfully applied high-cell-density fermentation technique to SAM production. In a5L fermentation,40g pre-L-methionine addition in fermentantion for58hours, we can get about10.0g·L-1SAM.We studied two ways to release SAM from yeast. One way is using ethyl acetate and vitriol to release SAM. The optimum condition is:50ml ethyl acetate (50%) with100g wet yeast extracting for40min, and then using0.4mol/L vitriol extracting for80min. In this condition, the recovery can reach92.0%. Anotherway is extracting SAM with hot water. According to our experiment, the optimum condition is:temperature70℃,100ml hot water with30g wet yeast, the concentration of vitriol0.25mol/L,rotating speed160r/min. In this condition, the extraction can reach91.5%.We chosed a weak acid ion-exchange resin called NK110which had a better for adsorption of SAM. Its adsorption isotherm fit for Langmuir model.Its static adsorption condition and result was:pH=5, adsorption capacity162.6mg/g, desorption with vitriol0.5mol/L, desorption rate97.4%. Its dynamic adsorption condition and result was:pH=5,0=5cm, H:φ=7.5,the initial C0=8.3g/L, the adsorption velocity ml/min, the adsorption capacity reached56.0mg/cm3, adsorption reached86.0%, desorption reached89.7%. Using gradent desorption and then5BV acetone was used to deposit the desorption liquid, we got SAMsulfate at purity of95.2%(HPLC). Its total recovery reached58.3%. According to some articles, we prepared SAMsulfate P-toluensulphonic acid and its purity was97%(HPLC). Its total recovery reached47.4%. According to the analysis of MS, we got that SAMsulfate molecular formula was SAM+· HSO-1·H2SO4·1.54(H2O)We studied a new kind salt of SAM made by polyaspartate and SAM. The preparation condition was pH<2.5, ethanol dosage3.5BV, Mole rate (PPA:SAM)>3:1.The recovery reached90%. The new salt was11%much more stable than SAMsulfate in liquid. According to the analysis of UV-VIS, IRand NMR, we concluded that these two substances had reacted, not only simple mixed. In this preparation process, SAM was stable with (S-S) form.