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1.
通过大分子引发剂引发ε-苄氧羰基-L-赖氨酸-N-羧酸酐(Lys-NCA)开环聚合和大分子缩合的方法合成了聚(N-异丙基丙烯酰胺)-b-聚(ε-苄氧羰基-L-赖氨酸)-b-聚乙二醇单甲醚三嵌段共聚物(PNIPAM-b-PZLL-b-mPEG).用GPC和1H-NMR对其结构进行了表征.用芘荧光探针法证明了该三嵌段聚合物形成胶束的性质并测定了临界胶束浓度(CMC).动态光散射(DLS)研究表明,在固定PNIPAM-b-PZLL链段长度的情况下,mPEG分子量为2000时,胶束在温度高于临界溶解温度(LCST)时发生聚集,mPEG分子量为5000时,胶束在LCST以上没有发生聚集. 相似文献
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用端氨基聚乳酸做引发剂,在DMF中引发Nε-苄氧羰基-L-赖氨酸酐(Lys(Z)-NCA)聚合,合成了端氨基聚(Nε-苄氧羰基-L-赖氨酸)-b-聚乳酸两嵌段共聚物.以端羧基聚乙二醇经NHS活化与端氨基聚(Nε-苄氧羰基-L-赖氨酸)-b-聚乳酸偶联,合成了聚(乳酸-b-Nε-苄氧羰基-L-赖氨酸-b-乙二醇)三嵌段聚合物.利用IR、1H-NMR、GPC和TEM对它们的结构、形态进行了表征,结果表明,所合成的分子量可控、分子量分布窄(Mw/Mn=1.07)的嵌段共聚物,酰化反应产率达70%以上.同时聚乙二醇和Nε-苄氧羰基-L-赖氨酸被引入到聚乳酸主链中,在聚合物侧链脱保护后有望改善聚乳酸的细胞亲和性。 相似文献
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聚乙二醇单甲醚-聚L-赖氨酸嵌段共聚物的合成及其表征 总被引:1,自引:0,他引:1
以L-赖氨酸为原料,先制备Nε-苄氧羰基-L-赖氨酸,光气法合成Nε-苄氧羰基-L-赖氨酸-N-羧酸酐[Lys-(Z)-NCA]。以聚乙二醇单甲醚(MPEG)为原料,制备了端氨基聚乙二醇单甲醚(MPEG-NH2),并以此为大分子引发剂,在氯仿中引发Lys-(Z)-NCA开环聚合,经无水溴化氢脱苄,合成不同组成和分子量的聚乙二醇单甲醚-聚L-赖氨酸嵌段共聚物。用IR1、H-NMR、GPC、DSC等对共聚物结构进行了表征。结果表明:MPEG-NH2引发Lys-(Z)-NCA开环聚合得到的是嵌段共聚物,通过1H-NMR谱计算得到了共聚物MPEG-PLL-1、MPEG-PLL-2、MPEG-PLL-3、MPEG-PLL-4中PLL链段的摩尔分数分别为0.553、0.795、0.848、0.861,共聚物数均分子量(Mn)分别为2.3×104、6.1×104、8.6×104、9.5×104。 相似文献
4.
报道了用硫代硫酸钠脱去侧链保护氨基酸铜络合物中铜离子的新方法,该方法适用于合成Nδ-苄氧羰基鸟氨酸、Nδ-叔丁氧羰基鸟氨酸、Nδ-芴甲氧羰基鸟氨酸、Nδ-乙酰基鸟氨酸、Nδ-邻苯二甲酰基鸟氨酸、Nε-苄氧羰基赖氨酸、Nε-叔丁氧羰基赖氨酸、Nε-芴甲氧羰基赖氨酸、Nε-乙酰基赖氨酸、Nε-邻苯二甲酰基赖氨酸、γ-苄基谷氨酸、β-苄基天门冬氨酸.产物用元素分析法与1H NMR法进行了表征.探讨了反应温度、时间、投料比例、溶剂对脱铜反应的影响.实验结果表明,以硫代硫酸钠作为脱铜试剂,侧链保护氨基酸铜络合物与硫代硫酸钠的物质的量比为1∶1或1∶2,60℃反应1.5~2.0h,收率与产物纯度均较高.该方法简便、高效、环境友好. 相似文献
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叔丁氧羰基碳酸酐((Boc)2O)和氨基丙醇反应合成叔丁氧羰基氨基丙醇(Boc-氨基丙醇),以此为引发剂在辛酸亚锡的催化下,引发L-丙交酯开环聚合合成叔丁氧羰基氨基封端聚乳酸(BocNH-PLLA),叔丁氧羰基(Boc)经三氟乙酸处理脱除后得到端氨基聚乳酸(PLLA-NH2).以PLLA-NH2为大分子引发剂,引发ω-苄氧羰基L-赖氨酸-N-羧酸酐(ω-Z-L-Lysine-NCA)开环聚合,合成聚L-乳酸-聚ω-苄氧羰基L-赖氨酸两嵌段共聚物(P(LLA-LLz)).采用红外光谱(FT-IR)、核磁共振氢谱(1H-NMR)、凝胶渗透色谱(GPC)对聚合物结构进行了表征.结果表明:PLLA-NH2端基亲核性明显提高,可引发ω-Z-L-Lysine-NCA开环聚合制备嵌段共聚物,PLLA-NH2的合成方法简便,氨基封端率高,其分子量和单体与引发剂的摩尔比具有良好的线性关系. 相似文献
8.
设计合成了溴基功能化的赖氨酸单体(Br-lys)并通过关环反应制备了对应的溴代L-赖氨酸N-羧酸酐(Br-Lys-NCA)单体.利用过渡金属引发剂Ni(COD)depe调控的NCA活性开环聚合和顺序添加单体的方法,得到了组成和结构明确的聚(ε苄氧羰基L-赖氨酸)-b-PBrLL(PZLL-PBrLL)两嵌段共聚肽.利用PZLL-b-PBrLL两嵌段共聚肽为大分子引发剂,通过ATRP引发甲基丙烯酸寡聚乙二醇酯(EGMA),合成了以聚赖氨酸为骨架的牙刷状分子刷.研究发现PZLL-PBrLL两嵌段在四氢呋喃中形成α-螺旋结构,螺旋度随着PBrLL链段的增长而降低,而PZLL-b-(PBrLL-g-PEGMA)形成部分α-螺旋构象,螺旋度随侧链PEGMA增长而减小. 相似文献
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聚(Nε-苄氧羰基赖氨酸)-聚乙二醇-聚(Nε-苄氧羰基赖氨酸)的合成及其表征 总被引:2,自引:0,他引:2
利用三光气合成了N^E-苄氧羰基赖氨酸酸酐(Lys(z)-NCA),并用双端氨基聚乙二醇做引发剂,在DMF中引发Lys(z)-NCA聚合,合成了聚(N^E-苄氧羰基赖氨酸)-聚乙二醇-聚(N^E-苄氧羰基赖氨酸)三嵌段共聚物。利用IR、^1H NMR、DSC和GPC对其结构进行了表征,结果表明,这种方法能够合成分子量可控、分子量分布窄(Ip=1.06)的嵌段共聚物,产率95.4%。 相似文献
10.
以N-(苄氧羰基)-L-天冬氨酸和亚硫酰氯反应制备了N-苄氧基天冬氨酸酐,将其与不同链长的二醇(乙二醇、二缩三乙二醇、聚乙二醇200和600)缩聚,合成了含端羟基的天冬氨酸-二醇交替预聚物(ASP-Di-ol)x;以其为大分子引发剂,辛酸亚锡为催化剂进行丙交酯/乙交酯(摩尔比75∶25)开环共聚,合成系列含侧氨基的天冬氨酸-二醇-聚乙丙交酯[PLGA-(ASP-Diol)x-PLGA]多元三嵌段共聚物.用FTIR,1HNMR,EA,DSC和GPC对共聚物结构进行表征.结果表明,影响预聚物分子量的主要因素不是二醇的分子量,而是其端羟基的活性.随着二醇链段长度增加,多元共聚物中氨基含量降低,玻璃化转变温度也明显下降.通过改变二醇链段的长度(或分子量)可有效地控制PLGA-(ASP-Diol)x-PLGA中侧氨基的密度及分布. 相似文献
11.
In the present work lysine was coupled through a water-soluble carbodiimide to several restriction enzymes. The work was carried
out to assess the effects on enzyme activity of attaching a small molecule to the enzyme carboxyl groups, with the intent
of using carboxyl groups for subsequent immobilization of restriction enzymes on solid supports. Lysine was coupled to Eco
RI, Bam HI, and Bgl I with partial to complete retention of enzyme activity. The commercial enzymes contained a large relative
concentration of bovine serum albumin (BSA). Therefore, commercial Eco RI, a sample of electrophoretically pure Eco RI, and
some high purity BSA each were separately labeled with3H-lysine and the products separated by dialysis and polyacrylamide gel electrophoresis. For the commercial Eco RI preparation,
0.9 μmol of lysine was attached to each μmole of the enzyme fraction; lysine was attached to the BSA and enzyme fractions
in the ratio 2.3. The results agreed reasonably well with the amount coupled to the high purity Eco RI and the high purity
BSA. The results suggest that carbodiimide coupling through enzyme carboxylic acid groups may be a useful approach for subsequent
immobilization of restriction enzymes on solid supports. 相似文献
12.
Andreas HerrmannGueorgui Mihov Guido W.M VandermeulenHarm-Anton Klok Klaus Müllen 《Tetrahedron》2003,59(22):3925-3935
This contribution describes the synthesis of polyphenylene dendrimers that are functionalized with up to 16 lysine residues or substituted with short peptide sequences composed of 5 lysine or glutamic acid repeats and a C- or N-terminal cysteine residue. Polyphenylene dendrimers were prepared via a sequence of Diels-Alder cycloaddition and deprotection reactions from cyclopentadienone building blocks. Single amino acids could be introduced on the periphery of the dendrimers by using amino acid substituted cyclopentadienones in the last Diels-Alder addition reaction. Alternatively, peptide sequences were attached via a chemoselective reaction, which involved the addition of the sulfhydryl group of a cysteine residue of an oligopeptide to a maleimide moiety present on the surface of the dendrimer. These amino acid and peptide functionalized dendrimers may be of interest as model compounds to study DNA complexation and condensation or as building blocks for the preparation of novel supramolecular architectures via layer-by-layer self-assembly. 相似文献
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聚赖氨酸修饰电极在抗坏血酸共存时测定肾上腺素 总被引:3,自引:0,他引:3
在pH8.0磷酸盐缓冲溶液(PBS)中利用循环伏安法制备了聚赖氨酸修饰电极,在pH4.0 PBS中,聚赖氨酸膜对肾上腺素(EP)的电化学氧化具有明显的催化作用.利用循环伏安法测定EP还原峰电流可排除抗坏血酸(AA)干扰.肾上腺素还原峰电流与其浓度分别在6.3×10-7mol/L~1.0×10-5 mol/L与1.0×10-5mol/L~1.2×10-4 mol/L范围内呈良好线性关系,相关系数分别为0.9978与0.9975,;检出限(S/N=3)为7.2×10-8mol/L.该方法具有良好的灵敏度、选择性,已用于针剂样品分析. 相似文献
16.
赖氨酸-甲醇-1,2-萘醌-4-磺酸钠体系褪色光度法测定甲醇 总被引:3,自引:0,他引:3
赖氨酸与1,2-萘醌-4-磺酸钠在碱性条件下发生亲核取代反应,生成红褐色的产物,在该体系中加入甲醇后发生褪色反应,褪色最大波长λmax=559 nm,甲醇质量浓度在0.050~7.61 g/L范围内与吸光度降低程度呈良好线性关系,线性回归方程为A=-0.005 17-0.086 79c(g/L),线性相关系数r=0.999 6,检测限为49.5 mg/L,平均回收率为99.1%~102.6%。 用于甲醇样品测定,结果满意。 相似文献
17.
Atefeh Ghorbani Aghdam Iran Almzadeh Majid Zeinali 《Journal of Dispersion Science and Technology》2013,34(8):1062-1065
Gold nanoparticles are potentially very attractive components for therapeutic delivery since they can be synthesized with any diameter from 1 to 200 nm to carry a payload of therapeutic molecules into a cell without triggering an immune response. Gold nanoparticles must undergo surface transformations before coupling to therapeutic molecules to become eligible for this purpose. It is now more understood that amine groups can bind to gold nanoparticles strongly, which has enabled surface modification of gold nanoparticles with amino acid lysine through its amine group. These lysine capped gold nanoparticles can further be coupled to therapeutic molecules for delivery purposes. In this study gold nanoparticles were first synthesized and capped with lysine molecules. TEM and FTIR measurements demonstrated the synthesis of lysine-capped gold nanoparticles with an average diameter of 10 nanometers. Interferon alpha molecules-one of the most important therapeutic protein were then chemically bound to lysine-capped gold nanoparticles through a two-step process of diimide-activated amidation. The conjugation of interferon molecules to lysine capped gold nanoparticles was carried out via the reaction between the free amine group of lysine and carboxyl groups of interferon using N-ethyl-N′-13-dimethyl-aminopropyl (EDAC) as a coupling agent. The process of conjugation has also been studied by transmission electron microscopy. 相似文献
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The title compound(S)-N-(2-oxoazepan-3-yl)biphenyl-4-carboxamide(C19H20N2O2, Mr = 308.37) was synthesized by the reaction of(S)-α-amino-∑-caprolactam with 4-phenyl-benzoyl chloride. Its chemical structure was determined by 1H NMR, 13 C NMR, H RMS and X-ray single-crystal diffraction. The crystal belongs to the triclinic system, space group P1 with a = 8.2650(17), b = 13.774(3), c = 15.109(3) ?, β = 90.20(3)o, V = 1645.6(6) ?3, Z = 4, Dc = 1.245 g/cm3, μ = 0.081 mm-1, F(000) = 656, R = 0.0756 and w R = 0.1491 for 5964 observed reflections with I 2σ(I). The title compound was also used to prepare polyamide. 相似文献
19.
《Journal of Coordination Chemistry》2012,65(4):225-230
Abstract The 1H nmr spectra of freshly prepared CDCl3 solutions of the complexes trans-[PtCl2(olefin)(L)], where L is pyridine or a substituted pyridine, show no coupling between 1 9 5Pt and the α protons of pyridine (3Jpt–NCH) owing to rapid exchange of complexed L with free L. On standing, the adventitious free L is gradually consumed by formation of trans-[PtCl2(L)2] and the spectra of the aged solutions show the coupling. When CDCl, solutions of [PtBr2(Olb)(Lb)] and [PtCl2(Ola)(La)], where Ola =C2H4, are mixed, a total of 6 ethylene complexes can be identified in solution. Accordingly halogen trading, Ol trading or/and L trading occurs and the solution probably contains a total of 12 complexes. 相似文献
20.
Ruiyuan Liu Fumio Sanda Toshio Masuda 《Journal of polymer science. Part A, Polymer chemistry》2008,46(12):4175-4182
Copolymerization of ornithine‐ and lysine‐derived N‐propargylamides, N‐α‐tert‐butoxycarbonyl‐N‐δ‐fluorenylmethoxycarbonyl‐L ‐ornithine N′‐propargylamide ( 1 ), N‐α‐tert‐butoxycarbonyl‐N‐ε‐fluorenylmethoxycarbonyl‐L ‐lysine N′‐propargylamide ( 2 ), N‐α‐fluorenylmethoxycarbonyl‐N‐δ‐tert‐butoxycarbonyl‐L ‐ornithine N′‐propargylamide ( 3 ), and N‐α‐fluorenylmethoxycarbonyl‐N‐ε‐tert‐butoxycarbonyl‐L ‐lysine N′‐propargylamide (4) with dipropargyl adipate was carried out using (nbd)Rh+[η6‐C6H5B?(C6H5)3] as a catalyst in THF to obtain polymer gels in 80–93% yields. The gels adsorbed N‐benzyloxycarbonyl L ‐alanine, N‐benzyloxycarbonyl L ‐alanine methyl ester, and (S)‐(+)‐1‐phenyl‐1,2‐ethanediol preferably than the corresponding optical isomers. The order of chiral discrimination was poly( 1 ) > poly( 4 ) > poly( 2 ), poly( 3 ) gels. The fluorenylmethoxycarbonyl groups of the gels could be partly removed by piperidine treatment, leading to increase of adsorptivity but decrease of chiral recognition ability. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4175–4182, 2008 相似文献