酰化

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。

Started from D-tyrosine, we obtained the tetramic acid 96 using Jouin reaction. The assembly of the second fragment 109 was stared from 1,4-butandiol,using asymmetric alkylation reaction developed by Oppolzer as a key step. Coupling of the tetramic acid 96 with 109 provided the key intermediate 110 according to Yoshii\'s procedure. After remove protective group and Sharpless epoxidation, we obtained the key intermediate 113. Its macrocyclization to form the final product is in progress.

本论文的第二章主要对Macrocidin A开展了合成工作，我们从D构型的酪氨酸出发，经过官能团转换；利用Jouin反应生成Tetramic acid 96，另外一个片断从1，4-丁二醇开始经过多步反应生成碘化物104，利用Oppolzer发展的手性樟脑磺酰胺为辅基参与的不对称烷基化反应，引入手性甲基，生成关键中间体109，接着通过Yoshii发展的方法连接96和109生成110，经过Sharpless不对称环氧化反应建立环氧化合物，然后脱去保护基得到关环前体113，分子内的Mitsunobu反应进行关大环反应正在进行之中。

The acetated and hydrogenated urushiol dimer has been separated,and studied by hetero-J resolved 2D-NMR,homo- and heteronuclearchemical shift correlation 2D-NMR and long-range coupled chemicalshift correlation 2D-NMR.The results show that the urushiol dimerare most diphenyl and alkyl phenyl ether structures.Furthermore,IR and MS data also has conformed this structures.

本文将酶催化预聚后的生漆，催化加氢后，乙酰酯化，再进行离心旋转薄层层析，分离得到二聚体主要组分，用异核J分辨谱，同核化学位移相关，异核化学位移相关，远程偶合异核化学位移相关等2D—NMR技术，全面研究了其结构，得到了联苯型和烷基芳醚型聚合结构的结论。

Various reaction parameters such as ratio of ethyl acetoacetate to ethylene glycol,catalyst amount,reaction time and water-carrying reagent amount were studied.

讨论了酯醇比、催化剂用量、反应时间、带水剂用量对酯化率的影响。最佳反应条件为：n：n=1：1.8，催化剂用量为乙酰乙酸乙酯质量的2%，带水剂用量为20mL，反应时间3h。

The influence of reed produced allelopathy material eathyl-2-methyl acetoacetate on respiration action, photosynthesis action and antioxidant enzymes system of Microcystis aeroginosa were studied.

研究了芦苇产生的化感物质2-甲基乙酰乙酸乙酯对铜绿微囊藻呼吸作用、光合作用和抗氧化酶体系的影响。

Permethylation analysis, periodate oxidation,Smith degradation, acetolysis and partial acid bydrolysis revealed the main chains of XP as mannose of (1-6)-linkages and its side chains were mannose of (1-2)linkages.

甲基化分析、过碘酸盐氧化、Smith降解、乙酰解和部分酸水解显示XP的主链是1→6连接的甘露糖，侧链是1→2连接的甘露糖。1H及13CNMR谱表明所有糖苷键均为a型，结合元素分析XP基本是酵母甘露多糖和蛋白质以及锌的络合物。

However, there is no difference for NAT2 rapid and slow acetylator between two groups.

吃红烧鱼因素在NAT2的快速酶中，特别是在野生纯合型中直肠腺瘤复发的相对危险度有增高趋势，提示了NAT2〓4等位基因编码快酶型NAT，可能在红烧鱼产生的杂环胺类化合物中代谢中加速其N-乙酰基化代谢过程，从而加速其代谢为终致癌物而与肠粘膜上皮细胞的DNA产生加成物，损伤其遗传物质。

Nevertheless, Smoking could interact with wild type of NAT2 and increase the relative risk of rectal adenoma recurrence significantly. It is suggested that NAT2 might involve the metabolism of pre-carcinogen generating from tobacco and alter the susceptibility of cancer. Meanwhile, the NAT2〓4 alleles encode rapid acetylator of NAT2 would increase the risk of adenoma recurrence among those high-risk people with habit of fried fish intake.

吃红烧鱼因素在NAT2的快速酶中，特别是在野生纯合型中直肠腺瘤复发的相对危险度有增高趋势，提示了NAT2〓4等位基因编码快酶型NAT，可能在红烧鱼产生的杂环胺类化合物中代谢中加速其N-乙酰基化代谢过程，从而加速其代谢为终致癌物而与肠粘膜上皮细胞的DNA产生加成物，损伤其遗传物质。

Irreversible inhibitor of Thrombin and other serine proteases. Inhibits by acylation of the active site of the enzyme.

凝血酶及其他丝氨酸蛋白酶的不可逆抑制剂，将活性位点酰基化。

The transesterification reaction were studied under organic solvents systemThe dosage of diatomite immobilized lipase of Enterobacter aerogenes is 1000 U, ethanol as acyl receptors(alcohol:oil molar ratio is 4:1,2 times add),5 mL n-hexane, 180 r/min,35℃,48 h,and the conversion rate of 92.91%.

有机溶剂体下催化生产生物柴油硅藻土固定化产气肠杆菌脂肪酶用量为1000 U，乙醇为酰基受体(醇：油摩尔比为4：1，2次等量加入)，5 mL正己烷，180 r/min，35℃，反应48 h，转化率达92.91%。

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。