粉末涂料用丙烯酸改性聚酯树脂的合成研究

采用溶液聚合法,合成了含一定量羧基官能团的丙烯酸树脂预聚体;用熔融聚合法合成了含羟基官能团的聚酯树脂预聚体;通过丙烯酸预聚体上的部分羧基官能团与聚酯预聚体上的羟基官能团发生的酯化反应而将两种预聚物接枝到一起,形成接枝共聚物来改善聚酯与丙烯酸树脂之间的相容性问题。红外、DSC测试表明,丙烯酸预聚物与聚酯预聚物发生了化学交联反应。对丙烯酸改性聚酯树脂制备的粉末涂料涂层性能进行了测试,所配制的涂料涂膜表面光滑无缺陷,无失光现象出现,具有良好的机械性能与耐老化性能。     

高分子合金反应性共混体系研究近况

综述了反应性增容技术研制高分子合金的最新进展 ,分别讨论了各种反应性增容技术 ,着重阐述了带有活性官能团的反应性聚合物的增容作用 ,包括含酸酐官能团的反应性共混、含羧酸官能团的反应性共混、含羧酸衍生物官能团的反应性共混及含有环氧基团或羧基的反应性共混等     

氨基酸修饰的MOF-808催化降解神经毒剂的模拟酶性质研究

通过后合成修饰方法制备了一系列不同氨基酸（amino acid,AA）接枝的MOF-808-AA催化剂,研究了孔结构和孔道微环境对神经毒剂模拟剂催化性能的影响,探索了MOF-808和MOF-808-AA的模拟酶性质。结果表明：氨基酸修饰造成MOF-808的孔结构和孔道微环境发生变化,从而影响催化剂对模拟剂的催化性能。其中,氨基酸侧链提供的氢键以及疏水作用使得MOF-808-AA对模拟剂的亲和力有所提升;氨基酸接枝后,MOF-808原始结构中的活性金属位点数量减少造成了降解速率的降低;氨基酸侧链官能团的酸碱性会导致孔道微环境差异,当侧链为氨基等碱性官能团时,催化效率明显提高,而当侧链为羧基时,催化效率则明显降低。     

高分子反应性共混体系研究近况

综述了反应性增容技术研制高分子合金的最新进展,分别讲座了各种反应性增容技术,着重阐述了带 性官能闭的反应性聚合物的增容作用,包括含酸酐官能团的反应性共混、含羧酸官能团的反应性共混、含羧酸衍生物官能团的反应性共混及含有环氧基团或羧基的反应性共混等。     

聚乳酸-天冬氨酸生物降解材料的合成

含亲水性羧基的聚乳酸-天冬氨酸（PAL）的合成方法有直接法和间接法,但是其产物降解周期难以控制,韧性和抗冲击能力较差。文章通过共聚得到了较好力学性能的生物降解材料。含亲水性羧基的聚乳酸-天冬氨酸（PAL）的结构通过理化常数及光谱分析得到确证。文章所述的合成方法是一条简便,可行的且具备重复强的合成工艺路线。     

甘氨酸及其衍生物的应用

甘氨酸是最简单的氨基酸。氨基酸类通式为 (?)。当R=H时为甘氨酸,分子式NH_2-CH_2-COOH,分解温度在220℃左右。甘氨酸分子中含有胺基、羧基和亚甲基三个官能团,反应活性大,可制备许多在工业中有重要用途的化合物。现按氨基酸官能团反应,分以下几类简述之:     

α-氨基酸-N-羧基内酸酐（NCAs）合成工艺研究进展

α-氨基酸-N-羧基内酸酐类化合物（NCAs）是一类重要的有机合成中间体,它被广泛用于多肽的合成。本文从不同的环合试剂出发概述了α-氨基酸-N-羧基内酸酐（NCAs）的合成方法。     

有机硅保护剂及其在有机合成中的应用

介绍了有机硅保护剂的分类及其对有机官能团的保护原理,并对有机硅保护剂在有机合成中的应用进行了概述,重点介绍了有机硅保护剂对化合物结构中含不饱和键或羟基、羰基、羧基、氨基及其它官能团的保护的应用情况。     

新型无毒可生物降解氨基酸衍生环氧树脂的合成与表征

用天然氨基酸为起始材料,合成了一种具有双酚羟基官能团的环肽,并以此环肽为联酚合成了主链包含酰胺键的可生物降解环氧树脂。用FT-IR与NMR表征了合成氨基酸衍生环肽与对应环氧树脂的化学结构,结果表明合成了预期结构。用盐酸丙酮法测定了合成环氧树脂的环氧值。     

一种新型四元聚合缓蚀阻垢剂的合成和性能评价

以马来酸酐(MA)、丙烯酸(AA)、烯丙基磺酸钠(SAS)和丙烯酸羟丙酯(HPA)为单体,水为溶剂,过氧化氢/次磷酸钠为引发剂,合成了四元聚合缓蚀阻垢剂PMASH.通过大量试验确定了最佳合成条件.实验结果表明:PMASH质量浓度为5 mg/L时,对碳酸钙垢和磷酸钙垢阻垢率分别达87.6%和85.4%,缓蚀率为83.9%.红外光谱检测表明PMASH分子结构含羧基、膦酰基和磺酸基等官能团.     

Pyrrole‐Assisted and Easy Oxidation of Cyclic α‐Amino Acid‐ Derived Diketopiperazines under Mild Conditions

A new procedure for the aerobic oxidation of α‐amino acids acylated by pyrrole‐carboxylic acid with triplet dioxygen is introduced. The reaction is general for a variety of pyrrole‐amino acid derivatives and represents a very practical and controllable method for the selective preparation of α‐hydroperoxy‐ or α‐hydroxy‐α‐amino acid diketopiperazines with molecular dioxygen. Furthermore, the non‐catalyzed direct oxidation of amino acid derivatives at the α‐position with molecular dioxygen represents a fundamental question.     

离子色谱-直接电导法同时测定常见氨基酸和无机阳离子

采用阳离子交换色谱-直接电导法测定部分常见氨基酸和无机阳离子,以酒石酸和吡啶二羧酸溶液为淋洗液,利用阳离子色谱系统等度洗脱,通过对色谱分析条件的优化,无需衍生化即可同时测定谷氨酸、丙氨酸、甲硫氨酸、亮氨酸、苯丙氨酸、赖氨酸及Na+, NH4+, K+, Ca2+和Mg2+. 选择12 min内出峰的5种氨基酸和3种无机阳离子进行定量分析,结果表明,其相对标准偏差RSDn=5≤4.690%,标准曲线的线性相关系数不低于0.9984,检出限在0.27~10.34 mg/L之间. 以建立的方法测定味精等电母液中的氨基酸,结果显示,氨基酸的回收率为88.7%~107.2%.     

The Application of 3-Amino-2H-Azirines as Amino Acid Equivalents

3-amino-2H-azirines undergo a number of ring opening reactions. The cleavage of the azirine-N(1), C(3) double bond leads thereby to synthons which can be considered as amino acid equivalents. The reaction of 3-amino-2H-azirines with carboxylic acids yields N-acyl amino acid amides, which can be converted by a selective amide cleavage to the corresponding N-acyl amino acids. 2-Oxazolin-5-ones are intermediates of this amide cleavage. This reaction sequence has been used for the extension of peptide chains as well as for a number of heterocycle syntheses. Likewise, the described synthesis of cyclic depsipeptides and lactones by direct amide cyclization proceeds via 2-oxazolin-5-one intermediates. The selective amide cleavage was also applied to a novel method for the resolution of enantiomeric amino acid derivatives.     

Thermostable polyesters containing imide and phenylquinoxaline units

Thermostable, heterocyclic polyesters containing imide and phenylquinoxaline units have been synthesized by solution polycondensation of bis(hydroxyphenylquinoxaline) derivatives with diacid dichlorides containing preformed imide rings or by the reaction of bis(aminophenylquinoxaline) derivatives with dianhydrides containing ester groups. The thermal stability of these compounds is discussed and compared with related heterocyclic polymers. Electrical properties of the polycondensates were also studied.     

Quantitative analysis of copolyamides and copolyesters by gas chromatography

Procedures were developed for the analysis of copolyesters and copolyamides by saponification or hydrolysis of the copolymers to their component dicarboxylic acids, glycols, amino acids, or diamines and quantitatively identifying these by gas chromatography. The alcohols, amines and acids were converted to volatile trimethylsilyl derivatives for the analysis, and linear correlations were observed between carbon atom contents of these derivatives and retention times in the chromatograph.     

磷酰化多巴胺肽类衍生物的合成及结构表征

将磷酰化氨基酸引入多巴胺分子中,合成了6个新的标题化合物.其结构分别通过IR、~1HNMR、~(13)CNMR、~(31)PNMR、ESI-MS等测试手段得到了确认.     

代谢工程调控策略在生物合成氨基酸及其衍生物中的应用

氨基酸的工业化生产已有上百年历史,多用于动物饲料和食品添加剂;很多种类的氨基酸如L-半胱氨酸、β-丙氨酸、S-腺苷甲硫氨酸、4-羟基异亮氨酸和高丝氨酸等也具有很高的应用价值。相较于化工合成或分离提取的方式,利用微生物细胞作为平台生产氨基酸及其衍生物具有绿色安全、可持续等独特的优势。本文综述了近年来微生物合成氨基酸及其衍生物的研究进展,分别介绍了碳源的高效利用、限速步骤的调节、碳通量的调节、转录和反馈抑制调节以及转运调节等代谢调控策略在提高微生物生产氨基酸及其衍生物效率的研究及应用,分析了不同调控策略的优势和缺点,总结了不同氨基酸及其衍生物的应用价值,最后展望了微生物作为细胞工厂生产各类氨基酸及其衍生物的广阔前景。     

Metabolic engineering strategies in biosynthesis of amino acids and their derivatives

The industrial production of amino acids has a history of more than 100 years, and is mostly used in animal feed and food additives. Many types of amino acids such as L-cysteine, β-alanine, S-adenosylmethionine, 4-hydroxyisocyanine acid and homoserine also have broad applications. Plant extraction and chemical synthesis are the commonly used methods to produce these amino acids and their derivatives. Compared with the way of chemical synthesis or separation and extraction, the use of microbial cells as a platform for the production of amino acids and derivatives has unique advantages such as green safety and sustainability. This review highlights the recent advances in developing metabolic engineering strategies including increase of the carbon sources uptake rate, elimination of the rate-limiting steps, enhancement of the carbon flux through the target pathway, remove of the feed-back inhibition effect and regulation of the intermediates and products transportation for biological production of amino acids and their derivatives. Our goals are to provide a landscape of current works and present guidelines to address future challenges in biosynthesis of amino acids and their derivatives using engineered microorganisms.     

Palladium‐Catalyzed Cyclization Reactions of Acetylene‐Containing Amino Acids

Enantiomerically pure acetylene‐containing α‐amino acids were used as versatile starting materials for the synthesis of a variety of heterocycles via Pd‐mediated cyclization reactions. Depending on the protecting group strategy, both the carboxylate and the amine function of the amino acids could participate in the cyclizations, thus giving rise to oxygen heterocycles (α‐aminolactones) and nitrogen heterocycles (cyclic α‐amino acid derivatives), respectively. Beside the straightforward cyclization, cyclization/cross‐coupling reactions were also successfully carried out to provide the corresponding substituted cyclic amino acid derivatives.     

柱前衍生化-HPLC测定蓝圆鲹蛋白的氨基酸组成

采用柱前衍生化反相高效液相色谱法测定蓝圆鲹蛋白的氨基酸组成,以邻苯二甲醛-9-芴甲基氯甲酸酯为衍生化试剂,醋酸钠缓冲液,甲醇及乙腈为流动相,用Hypersil ODS C18柱和二极管阵列检测器。结果表明,18种氨基酸在38 min内分离效果良好,在一定浓度范围内,氨基酸的峰面积与浓度线性相关系数在0.993 2～0.999 8,相对标准偏差为1.93%～4.89%(n=5)。并测定了蓝圆鲹蛋白的氨基酸组成。该方法简便快速、准确可靠,蓝圆鲹蛋白中含有至少18种氨基酸,其中8种必须氨基酸占总含量的42.68%。