手性药物萃取拆分及分子印迹整体柱的制备研究

【作者】 王珍；

【导师】 陈晓青；

【作者基本信息】 中南大学 ， 分析化学， 2009， 硕士

【摘要】 本文采用萃取、双水相萃取、分子印迹整体柱技术分别对扁桃酸（Mandelic acid,MA）、苯丙氨酸（Phenylalanine,Phe）和萘普生外消旋体的手性拆分进行了研究。（1）研究了MA对映体在含二（2-乙基己基）磷酸（D2EHPA）与酒石酸衍生物对映单体复合手性选择剂的正辛醇和水两相系统萃取分配行为及其热力学性质,考察了酒石酸衍生物对映单体的种类、初始浓度,D2EHPA的初始浓度,MA的初始浓度,萃取温度对分配系数、分离因子的影响。实验表明:复合手性选择剂能提高分配系数和分离因子;D2EHPA与D-酒石酸衍生物对映单体的复合手性选择剂与L-MA对映体比与D-MA对映体能形成更稳定的非对映体复合物;且D2EHPA与二对甲基苯甲酰酒石酸对映单体（DTTA）的复合手性选择剂的手性选择性大于D2EHPA与二苯甲酰酒石酸对映单体（DBTA）的复合手性选择剂;同时,MA的初始浓度、萃取温度对分配系数和分离因子的影响也比较大,对萃取过程热力学分析表明该萃取过程为焓控过程。（2）研究了MA对映体在含β-环糊精（β-cyclodextrin,β-CD）手性选择剂的聚乙二醇/硫酸铵（PEG/（NH₄）₂SO₄）双水相体系萃取分配行为,考察了pH、PEG和（NH₄）₂SO₄的质量分数、β-CD的浓度、MA的浓度与萃取温度等因素对拆分效果的影响,结果表明:当温度为30℃、pH=1.0、PEG2000质量分数为30%,（NH₄）₂SO₄质量分数为20%,β-CD的浓度为0.008 mol/L,MA的浓度为0.05 mol/L时,分离因子（α）达到2.46。双水相手性萃取具有很强的手性分离能力,对外消旋体化合物的制备性分离具有重要的意义。（3）将组合拆分技术应用于Phe外消旋体的双水相萃取分离,主要研究了Phe对映体在双水相体系中的萃取分配行为,考察了不同手性选择剂、组合手性选择剂的摩尔浓度比、组合手性选择剂的总浓度、下相中pH值及缓冲液的种类和浓度等因素对Phe分配行为的影响,结果表明:组合手性选择剂的总浓度为0.01 mol/L（其中,β-CD与羟丙基β-环糊精（HP-β-cyclodextrin,HP-β-CD）的摩尔浓度比为2:3）,Na₂HPO₄-H₃PO₄为缓冲溶液,pH值为5.5时,分离因子（α）达到1.53。（4）以L-（-）-萘普生为模板分子、丙烯酰胺（Acrylamide,AM）为功能单体、二甲基丙烯酸乙二醇酯（Ethylene glycol dimethacrylate,EGDMA）作为交联剂、甲苯和十二醇混合溶液为致孔剂、偶氮二异丁睛（azobisisobutyronitrile,AIBN）为引发剂,采用原位分子印迹技术,合成了萘普生分子印迹整体柱。主要从模板-单体比例、交联剂比例、致孔剂中甲苯含量三方面对合成条件进行了优化,结果表明:模板-单体比例以1:4最佳,交联剂含量以占本身和单体总量的85%为最佳,致孔剂中甲苯的最佳含量为20%（体积比）,其中,聚合温度和聚合时间分别为55℃和16 h;考察了萘普生外消旋体在制得的印迹整体柱上的拆分效果,研究发现,通过调整流动相中醋酸含量及流动相的流速和分离温度可以优化分离效果,实现L-（-）-萘普生与其对映体的手性拆分。当温度为60℃,以乙腈-醋酸（99.9:0.1,v/v）作流动相,流速0.6 mL/min,30 min内可完成萘普生外消旋体的手性拆分,分离因子达2.13。更多还原

【Abstract】 Enantioseparation of MA,Phe,naproxen were investigated using co-extraction,aqueous two-phase extraction,molecular imprinting technique.(1) The distribution behavior of MA enantiomers was examined in a two-phase aqueous-organic solvent mixture containing D2EHPA and tartaric acid derivatives as co-extractants.The influence of tartaric acid derivative’s species and its initial concentration,the initial concentration of D2EHPA,D,L-MA and extractive equilibrium temperature on the distribution ratio and enantioselectivity were studied.The results showed that both the distribution ratio and enantioselectivity were greatly improved by using D2EHPA and tartaric acid derivatives as co-extractants in comparison with that using tartaric acid derivatives individually;the co-extractants of D2EHPA and D-tartaric acid derivatives formed more stable diastereomeric complexs with L-MA than with D-MA;the enantioselectivity of D2EHPA and DTTA co-extractants were better than D2EHPA and DBTA co-extractants;The influence of the intial concentration of D,L-MA and the extractive equilibrium temperature on the distribution ratio and enantioselectivity were insignificant.The thermodynamic studies on enantiomer separation of MA by chiral extraction indicated that the enantiomeric separation is an enthalpy-controlled process.(2) The distribution behavior of MA enantiomers was investigated in aqueous two-phase systems composing of polyethylene glycol and ammonium sulfate containingβ-cyclodextrin as chiral selector.The influences of the pH,the mass fraction of polyethylene glycol and ammonium sulfate,the polymerization degree of polyethylene glycol,the initial concentration ofβ-cyclodextrin,MA enantiomers and extractive temperature on the distribution behavior were studied,respectively.The results showed thatβ-cyclodextrin is inclined to recognize L-enantiomer; under the optimized conditions,the enantioselectivity reaches 2.46. Aqueous two-phase chiral extraction is of strong chiral separation ability, plays a great role in preparative separation of racemic compounds and is important for the development of aqueous two phase extraction technique.(3) The distribution behavior of Phe enantiomers was investigated in aqueous two-phase systems composing of polyethylene glycol and ammonium sulfate containing combinatproal chiral selector:β-CD and HP-β-CD in order to establish the optima chiral extraction conditions in this experiment.The influences of the molar concentration ratios of combinatorial chiral selectors,the total molar concentration of combinatorial chiral selectors,pH values,buffer type and its concentraction were investigated.The results showed that the enantioselectivity reaches 1.53 under the optima chiral extraction conditions.(4) An naproxen molecularly imprinted monolithic column was prepared by in situ polymerization using AM as a functional monomer, EGDMA as a cross-linking agent,toluene and dodecanol as porogenic solvents,and AIBN as an initiator.The synthesis condition was optimized. The results showed the best ratio of template to functional monomer was 1:4,the crosslinker content in monomer mixture was 85%and the toluene content in porogen was 20%.Some chromatographic conditions such as the acetic acid concentration in mobile phase,the flow rate and temperature were characterized.The separation factor reached 2.13 under conditions of the temperature of 60℃,the flow rate of 0.6mL/min and the volume ratio of 99.9:0.1 between acetonitrile and acetic acid in mobile phase.更多还原