酸基

Capric betaine was prepared through ammonolysis of α-chlorododecanoic acid with trimethylamine. The participation effect of the neighboring carboxyl group of α-CDA on dynamics and thermodynamics of the reaction was investigated.

以α-氯代十二酸与三甲胺的氨解反应制备α-癸基甜菜碱，研究了α-CDA在与三甲胺氨解反应中邻位羧基对反应动力学和热力学的影响。

CA-CTSs including N,O-carboxymethyl chitosan,N,O-1-carboxyethyl chitosan (N,O-1-CEC),N,O-2-carboxyethyl chltosan(N,O-2-CEC),N-carboxymethyl chitosan and N-1-carboxyethyl chitosan(N-1-CEC) are quaternized using active quaternary salts prepared in laboratory.5 series including 25 kinds amphoteric chitosans characterized with polymeric ampholyte,in which 24 kinds are synthesized firstly,are obtained, 2-Hydroxypropyl dimethylbenzyl ammonium N,O-(1-carboxyethyl) chitosan chloride (GDMBA-N,O-1-CEC) is hydrolyzed into serial low molecular weight GDMBA-N, O-1-CEC with acid as catalyst and microwave as assistant instrumentality innovately.

以合成的活性季铵盐改性了N，O-羧甲基壳聚糖、N，O-1-羧乙基壳聚糖(N，O-1-CEC)、N，O-2-羧乙基壳聚糖(N，O-2-CEC)、N-羧甲基壳聚糖和N-1-羧乙基壳聚糖(N-1-CEC)等羧烷基壳聚糖，得到5个系列25种具有两性高分子电解质特征的新季铵化羧烷基壳聚糖，其中24种为首次合成；创新提出以微波辅助酸催化的方法催化2-羟丙基二甲基苄基-N，O-(1-羧乙基)壳聚糖氯化铵(GDMBA-N，O-1-CEC)水解，得到了低分子量的GDMBA-N，O-1-CEC。

It is now well understood that asparagine synthetase is composed of two parts: a wedge-shaped place in the two antiparallel β-overlapping layers near the N-terminus that functions in glutamine hydrolysis; a C-terminus responsible for binding of Mg2+ ATP and aspartate.

现又明确天冬酰胺合成酶是由两部分组成：N基末端的两个反平行式β-折叠片层中的楔形部分是负责水解谷氨酰胺的活性部位；C基末端负责结合Mg2+ATP和天冬氨酸。

The results show that all the hmgr genes from pigs, cattle and chickens are astable enzyme proteins with the same gene sequence characteristics and encoding protein and physical and chemical properties; all the amino acid sequences have a high degree of homology, containing two conservative HMG-CoA binding motifs and two NADPH binding motifs; all the amino acid sequences, containing signal peptide, are secreted proteins; they are all hydrophobic transmembrane proteins with five transmembrane domains; random coil and α-helix are the main structural elements in the HMGR polypeptide chain; all the predictions of three-dimensional structure are V- shaped; there are more closer evolution relationship between the HMGR gene from pigs and cattle.

结果表明：猪、牛和鸡HMGR基因序列特点及编码蛋白质理化性质基本相同，均属不稳定类酶蛋白；保守结构域氨基酸序列具有高度的同源性，均含有保守的2个β-羟基-β-甲基戊二酸单酰辅酶A结合基序和2个还原性烟酰胺腺嘌呤二核苷酸结合基序；均有信号肽，属分泌型蛋白质；属于跨膜的疏水性蛋白，均有5个跨膜结构域；无规则卷曲和α-螺旋是HMGR多肽链中的主要结构元件；三维结构预测都呈"V"字形；猪和牛HMGR基因的进化关系最近。

METHODS 3-methoxy-7α-methylestra-1,3,5(10)-trien-17β-ol was reducted with lithium and ammonia,then the intermediate was hydrolyzed in oxalic acid and reacted with malonic acid to get 3,3-dimethoxo-7α-methylestra-5(10)-en-17-ol(compound 4),which was oxidated by pyridium bichromate ,reacted with acetylene,and hydrolyzed in oxalic acid again to get the product tibolone.

方法以3-甲氧基-7α-甲基雌甾-1，3，5(10)-三烯-17β-羟基为起始原料经锂胺还原、草酸水解、缩酮化得3，3-二甲氧基-7α-甲基雌甾-5(10)-烯-17β-羟基(化合物4)，然后用温和的氧化剂重铬酸吡啶盐氧化、炔化、再水解得目的产物。

With the catalyst TiO2/SO(superscript 2- subscript 4), 2, 4, N-trinitroanilinoacetic acid was synthesized from chlorobenzene and glycine with yield of 71.6%.

以纳米固体酸TiO2/SO(上标 2-下标 4)为催化剂，氯苯和氨基乙酸为原料直接合成了2，4，N-三硝基苯胺基乙酸，收率为71.6%。

The dilational viscoelastic properties of partly hydrolyzed polyacrylamide and alkyl benzene sulfonate in the absence or presence of electrolyte were investigated at the decane water interface by means of longitudinal method and the interfacial tension relaxation method.

采用小幅低频振荡和界面张力弛豫技术，研究了部分水解聚丙烯酰胺(Mo-4000)和阴离子表面活性剂2-丙基-4，5-二庚基苯磺酸钠(377)体系在癸烷/水界面上的扩张黏弹性质，并考察了电解质对体系界面流变性质的影响。

Eleven novel 2-alkylthio-5-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-5-yl)-1,3,4-oxadiazole derivatives (5) and six novel 2-alkylthio-5-(5,7-dimethyl-1,2,4-triazolo[1,5-a]pyrimidine-5-yl)-1,3,4-thia- diazole derivatives (8) have been designed and synthesized by using 5-amino-3-ethoxycarbonyl-1H-1,2,4-triazole as a starting material.

以5-氨基－1H-1，2，4-三唑－3-羧酸乙酯为起始原料，设计合成了11个新型的2-取代硫醚－5-（5，7-二甲基－1，2，4-三唑并[1，5-a]嘧啶基）-1，3，4-恶二唑类化合物(5)和6个新型的2-取代硫醚－5-（5，7-二甲基－1，2，4-三唑并[1，5-a]嘧啶基）-1，3，4-噻二唑类化合物(8)。

The intermediate of flazasulfuron weedicide ,2-amino-4,6-dimethoxypyrimidineis conveniently obtained by treating 2-amino-4,6-dihydroxypyrimidinewith diazomethane at 20 °C for 24h.

本文利用硝酸胍和丙二酸二乙酯为起始原料，经环合及甲氧基化两步反应得到除草剂啶嘧磺隆的中间体：2-氨基-4，6-二甲氧基嘧啶。

In further studies, we will use the biophysical techniques, such as Circular Dichroism, to investigate the structural and functional roles of these 6 mutants.

未来我们将利用双圆旋光谱仪等技术，进一步研究这些胺基酸残基在Ku与DNA结合的角色。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。