氨基叔丁酯基八甘醇的制备及改善姜黄素溶解性

Preparation of amino tert-butyl octaglycol and improvement of curcumin solubility

以廉价易得的双羟基四甘醇为起始原料,通过异端官能团转化、Williamson成醚反应、端基衍生化制备了氨基叔丁酯基八甘醇,并将其与姜黄素分子通过烯胺键偶联后脱除叔丁基,制备得到羧基八甘醇化姜黄素(C-OEG_(8)-Cur),利用1H NMR,HRMS,HPLC对合成的试样进行了表征,并考察了C-OEG_(8)-Cur的溶解度。实验结果表明,利用叠氮三苯基八甘醇合成氨基叔丁酯基八甘醇的优化反应条件为:四氢呋喃为溶剂、NaH为碱、n(叠氮对甲苯磺酰基四甘醇)∶n(单端三苯基四甘醇)∶n(NaH)=1.2∶1∶4、25℃,在此条件下,收率达95%。合成叔丁酯基八甘醇化姜黄素适宜的方法为将氨基叔丁酯基八甘醇和姜黄素溶解在乙醇中,加热回流并补加溶剂,反应收率为65%。C-OEG_(8)-Cur的设计合成路线成本低、反应温和、分离纯化收率高,所得C-OEG_(8)-Cur溶解度较姜黄素显著提高。姜黄素的寡聚乙二醇衍生化对提高姜黄素的应用价值具有重要意义。

Amino tert-butyl-octaglycol was prepared by heterodox functional group transformation,Williamson etherification and end-group derivation by using cheap dihydroxytetracycol as the starting material.It was then coupled with curcumin molecules to prepare carboxyl octaglycol-curcumin(C-OEG_(8)-Cur)through an enamine bond to remove tert-butyl.The synthesized sample was characterized by 1H NMR,HRMS and HPLC,and the solubility of C-OEG_(8)-Cur was investigated.The experimental results show that the optimum synthesis conditions for triphenyl-octaglycol azide to amino tert-butyl-octaglycol are as follows:tetrahydrofuran as solvent,NaH as base,n(p-toluenesulfonyl tetraglycol azide)∶n(ingle-ended triphenyl-tetraglycol)∶n(NaH)=1.2∶1∶4,25℃.Under these conditions,the yield is 95%.The optimum method for the synthesis of tert-butyloctaglycol-curcumin is to dissolve amino tert-butyl-octaglycol and curcumin in ethanol,then add solvent after ethanol is refluxed.The reaction yield is 65%.The designed synthesis route of C-OEG_(8)-Cur has low cost,mild reaction and high separation and purification yield.The solubility of C-OEG_(8)-Cur is significantly higher than that of curcumin.The derivatization of oligoethylene glycol in curcuminis is great significance for improving the application value of curcumin.