Study On The Synthesis Of L-Selenocystine And L-Selenocysteine

Objective As natural selenoamino acids,L-selenocystine and L-selenocysteine are important components of organoselenium compounds,but there are few reports on the research of the synthesis process of L-selenocystine and L-selenocysteine,which limits their application in many fields.The purpose of this study is to obtain a technology route with inexpensive raw materials,simple reaction operation,high yield and suitable for scale-up production,and establish a foundation for the research,production and application of L-selenocystine and L-selenocysteine.Methods The existing synthesis methods were investigated and a reasonable synthesis route was designed.The optimal small-scale synthesis process was obtained by optimizing various reaction conditions in the route by single factor experiment.The stability of the small-scale synthesis process was verified by repeated experiments,and the small-scale synthesis process was verified and improved by scale-up experiments.Results In the small-scale experiment,L-serine was used as the raw material,and L-selenocystine and L-selenocysteine were obtained with an average total yield of 44.4% and 31.4% after the steps of esterification,chlorination,hydrolysis,substitution,and reduction.In the scale-up experiment,L-Serine methyl ester hydrochloride was used as the raw material,and L-selenocystine and L-selenocysteine were obtained with an average total yield of 52.3% and 36.8% after the steps of chlorination,hydrolysis,substitution and reduction.The average total yields from L-serine methyl ester hydrochloride to L-selenocystine and L-selenocysteine in the small-scale experiment were 52.6 and 37.3%,which was basically the same as that in the scale-up experiment.Conclusion The synthesis processes of L-selenocystine and L-selenocysteine obtained in this study is stable and reliable.After the initial scale-up experiment,the average total yield is still close to that of the small-scale experiment,and the quality of the intermediate product and the target product is comparable to that of the small-scale experiment.The whole process is simple and reproduceable,which is suitable for the production process of L-selenocystine and L-selenocysteine.