糖基

The article includes three parts. The first, a steroselective and regioselective synthesis of digitoxin with glycosyl ortho-alkynylbenzoates as doners. The second, synthesis of different length chain of L-fucose with a SO3Na group in the position of C-2 hydroxy.

本文工作主要包括三部分内容，分别为采用全新发展的一种邻炔基苯甲酸酯的糖基供体进行地高辛的全合成并与常规的Schimidt供体及三氟亚胺酯供体进行结果比较；合成不同长度的2位硫酸化的岩藻糖糖链；对现有的合成伏格列波糖的一条合成路线进行工艺优化。

Glycoside of lectins was mainly composed of D-mannose, D-glucose and N-GlcNAc. However, Lec3 also contain some fucose.

研究表明三种凝集素的糖基主要由甘露糖，葡萄糖，N-乙酰氨基葡萄糖构成，Lec3糖基中还含有部分岩藻糖。

Selectivity modification of glycoside by glycosidase is one of the most fascinating topics.

利用糖苷酶对糖基化合物的糖基定向改造工程是目前一个研究的热点。

Kowaltowski AJ, Vercesi AE. Mitochondrial damage induced by conditions of oxidative stress ［J］. Free Radic Biol Med, 1999,26(3-4):463～471.［6］Hauptmann N, Grimsby J, Shih JC.

4.1 碱基切除修复碱基切除修复被证实是通过一种DNA糖基酶，这种酶可以识别损伤的碱基，裂解其糖苷键。

Two gene fragments of DEN-1(GenBank accession number DQ886390)and DEN-2(GenBank accession number DQ886391),differentially expressed between the ocular skin tissues of normal and albino turbot,were isolated by mRNA differential display and sequenced.It was confirmed by RT-PCR method that the expression levels of both DEN-1 and DEN-2 were down-regulated in the ocular skin tissue of albino turbot.The sequence homology search of DEN-1 revealed high sequence homologies with the UGGT genes of zebrafish and cattle,and the Ugcgl1 gene of Norway rat.High sequence homologies of DEN-2 were observed with the eya4 gene(the eye absent homolog 4)from red jungle fowl,zebrafish,human,Norway rat,mouse and dog.

应用mRNA差异显示技术，对比研究正常与白化大菱鲆有眼侧皮肤组织，克隆差异表达基因，经测序，RT-PCR 验证，差异表达基因片段DEN-1(GenBank登录号：DQ886390)与DEN-2(GenBank登录号：DQ886391)均在白化大菱鲆有眼侧皮肤组织中下调表达；通过BLAST检索发现，DEN-1与GenBank中的斑马鱼和牛的类似尿苷二磷酸-葡萄糖：糖蛋白葡糖基转移酶基因、与挪威鼠类似尿苷二磷酸-葡萄糖：神经酰氨葡糖基转移酶1(Ugcgl1)基因有较高同源性；DEN-2 与原鸡、斑马鱼、人、挪威鼠、家鼠和狗的眼缺乏同源框4(eya4)基因的同源性均较高。

Compound 9 is glycosylated in the presence of TMSOTf with rhamose-derived trichloroacetimidates to provide target trisaccharide Saponin 1, oleanolic acid 3-yl-2,4-di-O-a-L-rhamnopyranosyl -p-D-glucopyranosideCoumpond 18 is prepared with oleanic acid and Bromide 11 through phase-thansfer catalysis glycosylation manner.

三糖皂苷Saponin 1是以葡萄糖齐墩果酸皂苷为起始原料，用BBTZ(1-苯甲酰苯并噻唑)选择性保护葡萄糖3′，6′-羟基得到化合物9，然后以化合物9为糖基受体，进行一步糖苷化可以在化合物9的2′，4′-羟基上同时引入两分子鼠李糖，最后脱掉所有的保护基得到目标化合物Saponin1。

Four new salicylaldehyde derivatives with a glucose or mannose moiety were synthesized with 2-tert-butylphenol or 4-tert-butylphenol as the starting material, followed by the formylation, chloromethylation, nucleophilic substitution reaction with the desired carbohydrate. The salicylaldehyde derivatives condensed with ethylenediamine to give the Schiff bases, which coordinated with Mn to afford four novel sugar-based Salen Mn complexes.

首先，分别以2-叔丁基苯酚和4-叔丁基苯酚为起始原料，经过甲酰化反应、氯甲基化反应、和糖类衍生物的亲核取代反应制得了四种新型并入葡萄糖基或甘露糖基的水杨醛衍生物，将它们与乙二胺缩合生成希夫碱配体，得到的配体与过渡金属Mn~(3+)配位制备出四种新型含糖基的Salen Mn配合物。

MethodsOur study was to treat gastric ulcer by invigorating spleen and benefiting vital energy Chinese drugs through clinical observation and experimental research, and compared with mucosa protectant -gastropine and H2 receptor antagonist -famotidine about the mucosa mitochondrion 8-oxygen guanine DNA glycosylase, thymine glycol DNA glycosylase,3-methyl adenine DNA glycosylase, the effect of gastralgia, splenic asthenia and quality of ulcer recovery.

比较健中愈疡片、黏膜保护剂胃舒平以及H2受体拮抗剂法莫替丁对胃黏膜线粒体 8－氧鸟嘌呤DNA糖基化酶、胸腺嘧啶乙二醇DNA糖基化酶、3－甲基腺嘌呤DNA糖基化酶的影响，并进行健脾益气方药与黏膜保护剂胃舒平以及H2受体拮抗剂法莫替丁对胃溃疡愈合质量的比较和评价。

The position , type and number of sugar moieties incorporated to the antibiotics have great impact on its bioactivity .

2 糖苷类抗生素中糖基的主要作用糖基化的作用和意义主要体现在以下三个方面：第一，增加化合物的水溶性。

L-fucose, as raw material, protected with ortho ester, synthesized the glycosyl acceptor 60, 76, thioglycoside doner 57、61、62, fluorglycoside 65、66 and Schimidt doner 68, 70 in a simple and efficient way.

本文从L-岩藻糖出发，以原酸酯保护的方法简单高效的合成了具有合适保护基的糖基受体60、76，糖基供体57、61、62、65、66、68及70。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了