环糊精/活性有机分子的配位包合与3-环己基苯丙氨酸的不对称合成

【作者】 杨睿；

【导师】 林军；

【作者基本信息】 云南大学 ， 有机化学， 2012， 博士

【摘要】 环糊精及其衍生物是超分子化学中最重要的一类“主—客”体化学中的主体化合物,具有“内疏水,外亲水”的特殊结构及生物友好性、良好的水溶性和化学修饰性,可以在水溶液中装载各种活性客体分子形成主—客体分子包合物或超分子体系,形成分子胶囊,增强活性有机分子的水溶性、稳定性及生物利用度。因此,研究环糊精与活性有机分子的包合行为具有十分重要的意义。光学活性氨基酸是构筑肽类药物和许多天然产物分子的基本结构单元。由于不对称合成非天然氨基酸可以用于肽类药物的设计筛选和构效关系的研究,多年来一直受到有机化学家的关注。因此,设计合成可以探索支链构象的非天然氨基酸具有重要意义。本论文研究了环精对赤霉酸(GA3)及其衍生物(GA-13315和GA-13315CDO-4-MOBE)的包合行为,探讨了包合物的键合能力、化合物表征、溶解和稳定效应；同时,在Evans和Hruby的合成路线和方法基础上,以4(R/S)-4-苯基噁唑烷-2-酮为手性助剂对反应的立体选择性进行控制,设计合成一对Boc保护的β-环己基苯丙氨酸衍生物。本论文共分为五章。第一章主要综述了环糊精包合物的制备、表征、应用研究进展以及环糊精对活性有机分子(农业用类和药物用类)包合配位行为的近期研究。第二章制备了多种环糊精及其衍生物(α-CD, β-CD, γ-CD、HPβCD, SEBβCD和en(βCD)与赤霉酸(GA3)客体分子的包合物,通过粉末X-射线衍射、热分析、一维和二维核磁、紫外-可见光谱和扫描电镜等手段和方法,研究了这些环糊精与GA3分子之间的包合行为、包合能力以及化合物表征。研究结果显示,天然环糊精与GA3分子具有较强的键合能力,所形成的环糊精包合物能提高GA3的水溶性和稳定性。(Scheme1)第三章选择药学“安全”的β-CD环糊精及其衍生物(2-羟丙基-β-环糊精,HPβCD和磺丁基醚-β-环糊精,SBEβCD),制备了与具有肿瘤细胞毒活性的赤霉酸衍生物(GA-13315)客体分子形成的水溶性包合物。探讨了GA-13315环糊精包合物的键合能力、化合物表征、溶解和稳定效应。对包合物进行细胞毒性实验显示,包合物仍表现出抗肿瘤活性(Scheme2)。第四章制备了赤霉酸衍生物(GA-13315CDO-4-MOBE)与p-CD环糊精及其衍生物(磺丁基醚-β-环糊精,SBEβCD)的包合物,通过一维和二维核磁研究了环糊精与GA-13315CDO-4-MOBE分子之间的包合行为,探讨了主客体之间可能的包合模式,使用热分析和粉末X-射线衍射分析方法表征固体包合物的性能,研究结果显示,包合物大大提高了客体分子的水溶性和稳定性(Scheme3)。第五章以易得原料反式肉桂酸出发,在手性助剂(4(R/S)-4-苯基/噁唑烷-2-酮)立体选择性控制下,经过不对称Michael加成、直接叠氮化、氢化和氨基保护一锅法,再经碱性水解得到一系列活性中间体1a/b-4a/b和构象受阻的新颖手性α-氨基酸衍生物(3-环己基-2-叔丁氧碳酰胺苯丙酸)5a/5b,总产率为10-20%且de大于90%(Scheme4)。更多还原

【Abstract】 Cyclodextrins and their derivatives (CDs) are the most important class of host compounds in host-guest chemistry in the area of supramolecular chemistry. They have many merits such as the unique structure of "hydrophobic interior hollow and hydrophilic outer surface", the biological affiliation, the good solubility in water and can be modified chemically. So CDs can encapsulate active molecules to form host-guest complexes or supramolecular species. This usually enhances and improves the water solubility, stability and bioavailability of the encapsulated active organic molecules. Therefore, it is of great importance to study the complex behaviors of active organic products with cyclodextrins.Optically active amino acids are fundamental building blocks for the preparation of peptide Pharmaceuticals and many natural product molecules. Due to the asymmetric synthesis of non-natural amino acids can be used for designing and screening peptide drugs and studying the structure-activity relationship, the organic chemists have paid great attentions to synthesize these compounds for years. Therefore, design and synthesis of non-natural amino acids that can explore their chain conformations have very important significance.This thesis describes studies towards the inclusion complexation behavior, binding ability, characterization, stabilization and solubilization effect of cyclodextrins (CDs) with gibberellin acid (GA3) and its derivatives (GA-13315and GA-13315CDO-4-MOBE). In addition, a pair of novel Boc protected β-branched non-natural amino acids were designed and synthesized by use of the chiral auxiliary4(R/S)-4-pheny1-oxazolidin-2-one according to the basic synthesis route and method of Evans and Hruby in this thesis.This thesis is composed of five chapters.In Chapters1, a review of the preparation, characterization and their applications of the cyclodextrin complexes is presented. The study on the complex behaviors of cyclodextrins with the active organic molecules in recent years is also reported.In Chapters2, several kinds of inclusion complexes between natural, modified cyclodextrins (a-CD, β-CD, γ-CD, HPβCD, SEBβCD and enβCD) and guest molecule gibberellin acid were prepared. The binding behavior, characterization and binding ability were investigated in both solution and the solid state by means of XRD, DSC,1H and2D NMR, SEM and UV-vis spectroscopy. The results showed that natural CDs possessed the higher binding constants, the water solubility and stabilization of GA3can be improved obviously after forming inclusion complex with cyclodextrins (Scheme1).In Chapters3, the water-soluble inclusion complexes formed by GA-13315, which is one of gibberellin derivatives possessed antitumor active, with β-cyclodextrin and its derivatives (2-hydroxypropyl-(β-cyclodextrin, HPβCD and sulfobuty ether-β-cyclodextrin, SBEpCD), which are safety in pharmacy, were researched. The binding ability, characterization, solubilization and stabilization effect of GA-13315with CDs were also studied (Scheme2).In Chapters4, the water-soluble inclusion complexes were prepared by the reaction of gibberellin derivative (GA-13315CDO-4-MOBE) with β-cyclodextrins and its derivatives (sulfobuty ether-β-cyclodextrin, SBEPCD). The inclusion mode was deduced according to the1D and2D NMR (ROESY) data. The characterization of inclusion complexes was carried out in the solid state by means of DSC, TG and XRD. The results showed that the water solubility and stability of GA-13315CDO-4-MOBE can be enhanced greatly after forming inclusion complex with cyclodextrins (Scheme3).In Chapters5, a series of active intermediates1a/1b-4a/4b and the novel chiral α-amino acid derivatives ((2R/3S) or (2S/3R)2-(tert-butoxycarbonylamino)-3-cyclo hexyl-3-phenylpropanoic)5a/5b with hindered conformation were synthesized. In the synthesis, easily available trans-cinnamic acid was used as starting material, and the reaction was controlled stereoselectively by use of chiral auxiliary. The synthetic process includes a series of key reactions, such as ammonolysis, asymmetric Michael addition reaction, direct azidation, one pot of hydrogenation and amine protection, as well as alkaline hydrolysis. The overall yields can reach10-20%and de90%(Scheme4).更多还原