【摘要】 以表没食子儿茶素没食子酸酯(EGCG)为原料,用硫酸二甲酯对其进行部分甲基化。甲基化产物经乙酸乙酯萃取,再经硅胶柱、凝胶柱和反相硅胶柱分离得到EGCG的甲基化衍生物,再经ESI-MS,MS/MS和1HNMR鉴定。利用高效液相色谱技术测定分离到的甲基化EGCG和EGCG在人工模拟体胃液与肠液中的变化。结果表明,该体系合成甲基化EGCG的最佳条件是:硫酸二甲基酯与EGCG的摩尔比1∶1,在60℃水浴条件下回流反应5h。通过分离,最后得到纯度为93.86%的单甲基化产物242 mg,得率约为9%,经鉴定其结构为EGCG4″Me。在人工模拟胃液中,EGCG4″Me脱去甲基,生成EGCG,起到缓释作用;而在人工模拟肠液中,EGCG4″Me由于甲基化,稳定性提高。更多还原

【Abstract】 To study partial methylation of EGCG(Epigallocatechin gallate) with dimethyl sulfate,methylated products were extracted by ethyl acetate,then isolated by silica gel column,HL-20 gel column and reversed-phase silica gel column derivatives,and identified by ESI-MS,MS/MS and 1HNMR.The difference of methylated EGCG and EGCG in artificial simulation gastric juice and artificial simulation intestinal juice was determined by HPLC.The results showed the best condition for synthesis of EGCG4″Me is that the molar ratio of dimethyl sulfate and EGCG is 1∶1,reflux for 5 h at 60℃ water bath.Through separation and structure identification,242 mg EGCG4″Me(methylated EGCG) was obtained,and its yield and purity was 9% and 93.86% respectively.EGCG4″Me kept sustained-release due to taking off methyl and generating EGCG in artificial simulation gastric juice.The stability of EGCG4″Me is improved as methylation in artificial simulation intestinal fluid.更多还原