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1.
Dendrimers are known for their well-defined, regular, highly branched architectures with a large number of functional groups1. Recently, dendrimers have been widely researched in different fields, such as molecular light havesting, catalysts, liquid cryst…  相似文献   

2.
three kinds of N-(diisopropyloxyphosphoryl) amino acids containing hydroxyl group were prepared in high yield by using diisopropyl phosphite as the phosphorylating agent, sodium hypochlorite as the chlorinating agent and tetrabutyl ammonium bromide as the phase transfer catalyst in basic aqueous media.  相似文献   

3.
杨洪  周闯  田桂玲  叶蕴华 《中国化学》2002,20(11):1354-1357
IntroductionEnzymaticpeptidesynthesishasdrawnmuchatten tionbecauseofitsadvantageofenzymestereospecificity ,mildreactionconditions ,minimumside chainprotectionandavoidanceofracemization .Butthestrictsubstratespecificityoftheenzymeslimitstheirapplications .…  相似文献   

4.
以4-碘-L-苯丙氨酸为初始原料,经羧基和氨基的保护得到化合物2;化合物2与4-氟苯乙烯进行Heck反应得化合物3;化合物3脱去保护基得氟代二苯乙烯氨基酸(4,47.4%);其结构经1H NMR,13C NMR,IR和MS(ESI-TOF)确证。光学性质研究结果表明:4的激发、发射波长分别为314 nm和355 nm,斯托克斯位移为41 nm,荧光量子产率为0.22。化合物4在甲醇溶液中存在光致顺反异构现象,反式→顺式结构转变速率常数为0.026 min^-1。  相似文献   

5.
The chemical total synthesis of proteins using solid supports has made great progress. It is therefore becoming a reality what E. Fischer already predicted in 1902 1 1 Cited from Nobel Lectures—Chemistry 1901-1921, Elsevier, Amsterdam 1966, p. 34.
: “I foresee the time when physiological chemistry… is able to prepare synthetic enzymes.” The synthesis of peptides of up to 20 amino acids by the well-established solid-phase procedure on polymeric supports (SPPS) has made great progress through the development of newer supports. At the same time, methods have emerged which facilitate the separation and characterization of peptides, thus allowing optimization of the synthesis of pure materials. The new supports which enable one to synthesize peptides by a rapid continuous flow procedure are characterized by hydrophilicity, beads of approximately equal size, similar swelling properties in the solvents used for peptide synthesis, and stability at high pressure. With graft copolymers of weakly cross-linked polystyrene and linear polyethylene glycol (PEG), the synthetic cycle for coupling of one amino acid can routinely be reduced to 10–20 min with a concomitant higher yield. With beads of monodispersed graft copolymer of 10 μm diameter, a synthetic cycle can, in principle, be shortened to 1–5 min. By utilizing this high-speed solid-phase procedure, larger peptides up to the size of proteins could also be prepared in a few hours. With newer mass spectroscopic methods such as ion-spray mass spectrometry, peptides of up to a molecular mass of 100 kDa can be characterized, and with the advent of capillary electrophoresis, another very efficient separation tool, besides HPLC, is at our disposal.  相似文献   

6.
7.
N-二异丙氧磷酰化氨基酸的合成   总被引:4,自引:0,他引:4  
以亚磷酸二异丙酯为磷酰化试剂、次氯酸钠为氯代试剂首次对20种常见的α-氨基酸进行了磷酰化.通过添加适量四丁基溴化铵为相转移催化剂,使用过量的亚磷酸二异丙酯以补偿其在强碱环境中的水解,从而提高了反应产率.所得产物经核磁共振谱、红外光谱和质谱鉴定结构并分析总结了该类化合物的谱图特征规律.  相似文献   

8.
Two orthogonally protected PNA monomers were prepared having the mercaptomethyl moiety attached to the PNA backbone. These building blocks were employed in solid-phase PNA synthesis and it was shown that Boc/S-p-methoxybenzyl protection scheme was only satisfactory for the introduction of N-terminal thiol modification while the Fmoc/S-butylthio protected monomer proved to be amenable to elongation. The mercaptomethyl modification did not influence the thermal stability of a PNA/RNA duplex. The feasibility of PNA-PNA native ligation was demonstrated.  相似文献   

9.
Membrane-associated D-proteins are an important class of synthetic molecules needed for D-peptide drug discovery, but their chemical synthesis using canonical ligation methods such as native chemical ligation is often hampered by the poor solubility of their constituent peptide segments. Here, we describe a B ackbone- I nstalled S plit I ntein- A ssisted L igation (BISIAL) method for the synthesis of these proteins, wherein the native L-forms of the N- and C-intein fragments of the unique consensus-fast (Cfa) (i.e. L–CfaN and L–CfaC) are separately installed onto the two D-peptide segments to be ligated via a removable backbone modification. The ligation proceeds smoothly at micromolar (μM) concentrations under strongly chaotropic conditions (8.0 M urea), and the subsequent removal of the backbone modification groups affords the desired D-proteins without leaving any “ligation scar” on the products. The effectiveness and practicality of the BISIAL method are exemplified by the synthesis of the D-enantiomers of the extracellular domains of T cell immunoglobulin and ITIM domain (TIGIT) and tropomyosin receptor kinase C (TrkC). The BISIAL method further expands the chemical protein synthesis ligation toolkit and provides practical access to challenging D-protein targets.  相似文献   

10.
The Synthesis of Cyclic Amino Acids   总被引:4,自引:0,他引:4  
Several cyclic amino acids (1-4) were synthesized from glycine. Isocyanate ester was prepared as the key intermediate and reacted with dibromoalkanes to afford the target compounds.  相似文献   

11.
以L-苯丙氨酸、L-色氨酸、L-酪氨酸和组氨酸为原料,在Me3SiCl-MeOH(Ⅲ)体系中反应合成了相应的甲酯盐酸盐(2a~2d);以7-羟基香豆素为原料,经两步反应制得7-(乙酸氧基)香豆素(6); 6与3a经酰胺化反应合成了一种新型的香豆素衍生物--N-乙酰基-(氧-7-香豆素)-3-苯基-2-氨基-丙酸甲酯,其结构经1H NMR, 13C NMR和FT-IR表征。  相似文献   

12.
夏仕文 《分子催化》2015,(3):288-298
<正>非天然手性氨基酸是已经上市的和正在研发的手性药物、手性农药和手性食品添加剂的关键中间体[1-2].随着相关产业的发展,非天然手性氨基酸的市场需求与日俱增.非天然手性氨基酸不能像天然L-氨基酸一样采用发酵法生产,主要制备方法包括化学法和生物法.化学法包括化学不对称合成法和化学拆分法.化学不对称合成法采用价格昂贵的手性源、手性助剂或手性金属催化剂.化学拆分法采用手性酸为拆分剂,经历与消旋氨基酸成盐、解  相似文献   

13.
含氨基酸单元的手性主体的合成及手性识别研究   总被引:1,自引:0,他引:1  
L-丙氨酸和2,7-二萘酚为原料通过简单的方法合成了二种带有荧光基团萘的手性阴离子主体(12), 用红外光谱、质谱、元素分析、核磁共振氢谱及碳谱表征了它们的结构. 用荧光光谱及核磁共振氢谱研究了主体与二苯甲酰酒石酸阴离子的相互作用, 结果表明1, 2D-或L-二苯甲酰酒石酸阴离子均形成1∶1的配合物, 主体1展现出良好的对二苯甲酰酒石酸阴离子对映选择性识别能力.  相似文献   

14.
田静  常霄巍  巴俊杰 《合成化学》2016,24(5):393-397
以2-巯基苯并噻唑为原料,经弱氧化和氨化制得2-苯并噻唑次磺酰胺(2); 2经高锰酸钾氧化制得2-苯并噻唑磺酰胺(3); 3与氯甲酸乙酯反应制得2-苯并噻唑磺酰胺甲酸乙酯(4); 4与L-氨基酸甲酯反应制得一系列2-苯并噻唑磺酰脲氨基酸甲酯(6a~6j); 6经水解合成了10个新型的2-苯并噻唑磺酰脲氨基酸(7a~7j),其结构经1H NMR, IR和ESI-MS表征。并研究了6和7对Cdc25B的抑制活性。结果表明:在用药浓度为20 μg·mL-1时,6c, 6j, 7d, 7h和7j对Cdc25B抑制活性较好,抑制率分别为78.1%, 71.2%, 65.6%, 57.2%和65.9%。  相似文献   

15.
16.
利用氮气火花放电产生离子 ,其中的正离子在阴极位降的加速下“注入”到三种羧酸盐的水溶液中 ,诱发其中的化学反应并沉积在水溶液中 .利用高效液相色谱 (HPLC)对离子注入后的样品进行分析 ,结果表明 ,氮离子注入可使氮沉积在溶液中 ,生成氨及氨基酸 ,这一结果不仅验证了低能离子注入样品时的“质量沉积”效应 ,而且还是原始地球条件下氨基酸生成的一种可能的途径  相似文献   

17.
《中国化学》2017,35(10):1540-1548
An operationally convenient, asymmetric synthesis of chiral trifluoromethyl containing heterocyclic amino acids has been developed via Michael addition reaction of chiral equivalent of Ni(II)‐complex of glycine and β ‐trifluoromethylated‐α ,β ‐unsaturated ketones. The simplicity of the experimental procedures and high stereochemical outcome of the presented method render these heterocyclic amino acids readily available for systematic medicinal chemistry studies and de novo peptide design.  相似文献   

18.
在聚乙二醇辛基苯基醚(OP)/正己醇/环己烷/水反相微乳液和甘氨酸、精氨酸、组氨酸3种含不同氨基酸的反相微乳液体系中成功地制备了胆红素钙,考察了氨基酸对胆红素钙的组成、形貌、配位方式及稳定性的影响。采用透射电子显微镜、表面Zeta电位、红外光谱和紫外光谱等测试技术对样品进行了表征。结果表明,此反相微乳体系中所得球形颗粒为中性胆红素钙,平均粒径80nm,在水分散体系中颗粒的稳定性随分散体系pH值的升高而先降低后增加,当pH=4.9时,颗粒表面Zeta电位值为0。3种亲水性氨基酸的加入促进胆红素钙颗粒的成核,最终影响胆红素钙的微结构、颗粒形貌和稳定性。当加入的氨基酸为组氨酸、甘氨酸时,所得胆红素钙球形颗粒形貌无明显变化,但平均粒径依次减小至60和40nm,其水分散体系中的稳定性明显增加;当加入的氨基酸为精氨酸时,所得胆红素钙颗粒形貌不规则,粒径非常小,不稳定,易形成聚集体。  相似文献   

19.
杨学军  钟熠  谭炯  赵志刚 《合成化学》2007,15(3):312-315
L-氨基酸甲酯盐酸盐与三光气和苯胺反应合成了手性不对称脲氨基酸甲酯(2),2经NaBH4还原得到8个手性不对称脲氨基醇,其结构经1H NMR,IR和MS确证。  相似文献   

20.
Although solid-phase peptide synthesis combining with chemical ligation provides a way to build up customized polypeptides in general, many targets are still presenting challenges for the conventional synthetic process, such as hydrophobic proteins. New methods and strategies are still required to overcome these obstacles. In this study, kinetic studies of Cys/Pen ligation and its acidolysis were performed, from which the fast acidolysis of substituted N,S-benzylidene thioacetals (NBTs) was discovered. The study demonstrates the potential of NBTs as a promising Cys switchable protection, facilitating the chemical synthesis of peptides and proteins by efficiently disrupting peptide aggregation. The compatibility of NBTs with other commonly adopted Cys protecting groups and their applications in sequential disulfide bond formation were also investigated. The first chemical synthesis of the native human programmed death ligand 1 immunoglobulin V-like (PD-L1 IgV) domain was achieved using the NBT strategy, showcasing its potential in difficult protein synthesis.  相似文献   

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