Synthesis Of Amino Acid Ester Derivatives And Their Percutaneous Permeability Activity

Amino acids are important components of proteins.Their general molecular formula is?RCHNH₂COOH?.They contain two functional groups,amino and carboxyl groups.They are widely applied in various fields due to their easy to modify structures,unique chirality and safety.Their ester derivatives also play important role in chemistry,biology and pharmacy.In this paper,The synthesis technology of amino acid methyl ethyl ester hydrochloride has been studied.The synthesis of L-phenylalanine methyl ester hydrochloride and L-glycine ethyl ester hydrochloride has been systematically studied.The effects of amino acid ester hydrochloride on the solubilization and infiltration of caffeine transdermal delivery were preliminarily explored.Firstly,the direct synthesis method of dry HCL gas catalytic reaction was used to establish the quadratic polynomial regression equation between the yield of amino acid esters and reaction temperature,reaction time and material ratio.The experimental results show that the optimum conditions of the synthesis of L-phenylalanine methyl ester hydrochloride as the reaction temperature is 76.8?,the reaction time is 3.6h,the material ratio was 1:15,the optimum conditions of L-phenylalanine methyl ester hydrochloride was 88.03%;the optimum synthesis conditions of L-glycine ethyl ester hydrochloride as the reaction temperature is 75?,the reaction time is 6h,material ratio 1:18,the optimal conditions of L-glycine ethyl ester hydrochloride was 79.19%,compared with the traditional synthesis method has been improved.In addition,with caffeine as raw materials,the study of lysine methyl ester hydrochloride,cysteine methyl ester hydrochloride,phenylalanine methyl ester hydrochloride,leucine methyl ester hydrochloride,tryptophan methyl ester hydrochloride five amino acid ester hydrochloride on the percutaneous absorption of caffeine,caffeine for transdermal absorption studies provide the basis for.Methods:Franz vertical diffusion cell in physiological saline receiving medium,with excised mouse skin as permeation barrier,determination of caffeine content through HPLC,mobile phase of methanol water?70:30?,the detection wavelength of 270nm,the cumulative transdermal effects of caffeine preparations through excessive and various penetration enhancers enhancers effect.Results:the promoting effects of several amino acid ester derivatives enhancers on the transdermal penetration of caffeine in vitro were:lysine methyl ester,hydrochloric acid,cysteine methyl ester hydrochloride,phenylalanine methyl ester hydrochloride,leucine methyl ester hydrochloride,tryptophan methyl ester hydrochloride.Conclusion:the five amino acid ester hydrochloride can significantly improve the percutaneous absorption of caffeine in vitro,especially the lysine methyl ester hydrochloride.