羟基化作用

Then Doripenem came into the market in the July ,2005. We studied the synthesis of Doripemen.Firstly, we synthesized the chemical 2 from the starting material------o-hydroxylphenylacylamine through Reformastky reaction, alkylation, Diekmann reaction, enolization, esterification and etc. Secondly, we synthesized the chemical 3 from L — hydroxylproline through the protection of carboxyl, amidogen and hydroxyl group, reduction by NaBr, SN_2 substitution and Mitsumobu reaction.

我们以水杨酰胺为起始原料，经Reformatsky反应、烷基化、Diekmann环合、烯醇化、酯化等反应合成双环母核2；再从L-羟基脯氨酸出发，经酯化保护羧基、保护氨基、保护羟基、硼氢化还原酯得醇、Sn2取代和Mitsumobu反应等合成巯基侧链3；最后由化合物3经脱保护、水解得硫醇，和化合物2在二异丙基乙基胺的作用下缩合，最后Pd／C催化脱保护，历经16步反应最终得到产物多尼培南。

1H NMR spectroscopic analysis of aromatic protons combined with theoretical analysis of molecular structures proved the existence of two rotational isomers at 300 K, as well as a rapid interconversion equilibrium at 330 K for both compounds Ⅰ and Ⅱ. However, only one conformer exists for compound Ⅲ and puerarin containing 7-phenolic hydroxyl instead of propyl in A-ring as the case of compounds Ⅰ and Ⅱ. Based on UV-Visible absorption data of neutral and basic solutions, and on the density function calculations, the 7-phenolic hydroxyl group in A-ring was found to be more acidic than the 4'-phenolic hydroxyl group in B-ring. The mechanism of derivation reaction and the structure-reactivity relationship of puerarin as an antioxidant were further discussed.

其中7-丙基葛根素Ⅱ属于新型取代衍生物；变温1H NMR和理论计算结果表明，在300 K时，葛根素和4'-丙基葛根素以单一构型存在；而7，4'-二丙基葛根素和7-丙基葛根素则存在两种核磁可分辨的旋转异构体，当温度升至330 K时，两种异构体可以相互转化；通过对比分析葛根素及其衍生物脱质子产物的紫外可见吸收光谱并结合理论计算，确定了A环上7位酚羟基比B环上4'位酚羟基先脱去质子，并由此进一步阐明了葛根素衍生化反应机理以及在抗氧化作用中可能的活性位点和结构活性关系。

This is exactly opposite to the order of E465/E665 in HA and the order ofΔ~ K. It shows that the larger the extent of humification, the larger the effect for reducing the rate of Phoxim hydrolysis, because the extent of HA humification is closely related to the extent of benzene in HA and the amount of carbonyl, aryl, phenolic hydroxide.

因腐殖酸腐殖化程度与腐殖酸芳构化程度、羧基、羰基和酚羟基的含量等相关，因此用腐殖酸腐殖化程度反映腐殖酸对农药水解作用大小比仅用腐殖酸中有机碳含量等因素反映更为合理。

ABSTRACT Immobilized penicillin acylase (from E.coli) was used to catalyze 7 phenylacetamido 3 E propenyl cephalosporanic acid hydrolyzation into 7 amino 3 E propenyl cephalosporanic acid. Then, trans APRA was acylated with hydroxyethyl ester of 4 hydroxy D phenylglycine to obtain trans cefprozil.

以7 苯乙酰氨基 3 E 丙烯基 3 头孢菌素 4 羧酸为原料，在青霉素酰化酶作用下，首先酶法水解得到3 E 丙烯基 3 头孢菌素 4 羧酸，过滤固相酶，滤液调pH分离得到反式APRA固体；在青霉素酰化酶作用下，反式APRA再与对羟基苯甘氨酸乙二醇酯缩合，得到反式头孢丙烯；酶法合成所得的产品与进口反式头孢丙烯对照品一致。

In the presence of alkalinity and tetraethyl ammonium bromide, 2,4-dihydroxy benzophenone reacts with allyl glycidyl ether to form an ethylenic derivative of benzophenone, 2-hydroxy-4-(β-hydroxy-γ-allyloxy) propyloxy benzophenone, which can further undergo hydrosilylation with polyhydromethylsiloxane.

在相转移催化剂四乙基溴化按作用下，利用2，4-二羟基二苯甲酮与烯丙基缩水甘油醚在碱性水溶液中的开环加成反应，合成了中间体4-丙氧基－2-羟基二苯甲酮，将其进一步与聚甲基氢硅氧烷进行硅氢化加成反应。

According to the distribution of the positive charges inthe surface of the cage, it can be expected that two -OH groups finally adding at two sites which arewithin one hexacyclic ring and in different sides of equator, which is accord with the conclusion resultedfrom thermodynamics

通过寻找并分析过度态的结构，发现酸化阳离子中处于赤道带6-6类碳原子上的羟基和两极区域5-5类碳原子上的羟基都有朝邻近赤道带碳原子上迁移的可能，结合碳笼上正电荷的分布特征，预计亲核水解作用将发生在赤道异侧六员环的对位，说明考虑动力学因素，最终获得1，4-加成富勒醇的可能性最大，该结论与热力学的结果一致。

The pyridinium salts was transformed by the base to 1-hydroxy or 3-hydroxy-quinolizinylides, which undergo 1,3-dipolar cycloadditionreaction with alkenes,and then aromatizated to cycl[3,3,2]azinone in thepresence of oxidant.

实验证明，这是一个连续进行的多步反应：2-羰基吡啶鎓盐在反应中先生成1-羟基或3-羟基喹嗪叶立德，然后与烯烃起1，3—偶极加成反应，最后在氧化剂作用下脱氢芳构化而生成Cycl[3，3，2]azinone。

Two series of polyurethane acrylate grafted acrylic resins (Acr-g-TPU-PETA and Acr-gPPU-PETA) self-emulsifying systems are obtained by grafting -NCO group modified polyurethane acrylates with acrylic copolymer prepared from n-butyl acrylate, styrene,βhydroxyethyl methacrylate and acrylic acid The self-emulsifying systems showed Newtonian fluidity with viscosity closed to that of water, the solid contents were around 30% The T〓 of 15～4℃ for dried film before photocuring favored film formation at room temperature DSC and DMA results showed that PU-PETA is compatible with acrylic resin in the grafted resin The TG and dTG curves for Acr-g-PU-PETA samples were substantially different from the corresponding blends, and the brodened dTG peaks for photocured grafted resin suggest that there might be multiple interactions among chain segments The photocued film of the grafted resins self-emulsifying system exhibited good overall properties with polyurethane acrylate grafts ranging from 30% to 50%, and Acr-g-TPU-PETA series showed better properties than Acr-gPPU-PETA series The adhesion of the photocured film was 1～2 grade, impact strength was 50kg-cm and flexibility was 1mm The Shore hardness and the adhesion of the film decreased markedly if PETA was replaced by HEMA as photoactive group due to the lower C=C double bond content in the grafted resin The polyhydroxy amine-linked thioxanthones photoinitiators can be evenly dispersed in self-emulsifying system without color spot appearing in the dried film The films photocured with IV〓～IV〓 generally exhibited higher Shore hardness, gloss and solventresistance than that cured with Irgacure 2959 and did not induce the rusting of the iron substrate Pigmenting with titanium oxide had no effect on the photocuring The polyhydroxy amine-linked thioxanthone IV〓 and IV〓 can be new candidates for the formulation of titanium oxide pigmented photocurable water-borne coatings for their pale-yellow appearance and slight interference with the color of the coatings WB 4759 with high water-solubility coalesced and separated from the dried resin film, and even induced the rusting of iron substrate.

以丙烯酸丁酯，甲基丙烯酸-β-羟乙酯，丙烯酸及苯乙烯合成厂丙烯酸共聚树脂，并与含-NCO端基的聚氨酯丙烯酸酯接枝反应，经水性化后，得到两个系列（Acr-g-TPU-PETA和Acr-g-PPU-PETA）各5个不同配比的丙烯酸树脂接枝聚氨酯丙烯酸酯自乳化体系，粘度与水相近，为牛顿流体，固含量30％左右。光固化前干燥涂膜的玻璃化转变温度在-15℃～4℃之间，有利于室温下成膜。DSC及DMA谱表明两种树脂基本相容。Acr-g-PU-PETA的热失重行为明显不同于共混材料，接枝样dTG峰明显宽化，表明接枝样中链段之间的相互作刚有多重性，丙烯酸树脂与聚氨酯之间有一定的相容性。接枝树脂自乳化体系光固化涂层的综合性能以聚氨酯丙烯酸酯成分为50％～30％者相对较好，且以Acr-g-TPU-PETA系列更理想。光固化膜的附着力为1～2级，冲击强度为50kg·cm，柔软性多为1mm。以HEMA代替PETA作为接枝树脂的活性基团，碳—碳双键密度太低，光固化膜交联点太少，硬度和附着力均较差。多羟基胺连硫杂蒽酮光引发剂能均匀分散于树脂自乳化体系和接枝树脂干膜中，不出现色斑，光固化膜肖氏硬度一般高于以Irgacure 2959为光引发剂的光固化膜，光泽度及耐丁酮溶剂性能均有所提高，不会诱导铁基生锈，钛白着色对光固化结果几乎没有影响。本论文所合成的多羟基胺连硫杂蒽酮光引发剂IV〓与IV〓为浅黄色，对光固化涂层的颜色干扰较小，为配制钛白着色光固化水性涂料提供了新的光引发剂。水溶性太强的WB 4759在干膜中易聚结析出，且对所附着的铁基有诱导锈蚀作用。

To evaluate the allelopathy effects of benzoic acid and ρ-hydroxybenzoic acid on watermelon, this paper studied the effects of benzoic acid and ρ-hydroxybenzoic acid on watermelon seed germination and seedling growth by seed soaking, seed-bud soaking and seedling irrigation.

为探明苯甲酸、对-羟基苯甲酸对西瓜的化感作用，采用浸种、浸芽和浇灌幼苗的方法分别研究了苯甲酸、对-羟基苯甲酸对西瓜种子发芽和幼苗生长的影响。

The reaction catalyzed by DAK converts DHA into dihydroxyacetone phosphate which is no toxic and can be ustilized by yeast cells. DAK presents in most organisms. DAK genes in the Saccharmyces cerevisiae and P. pastoris were cloned and characterized by a combined genetic and biochemical approach and the proteins encoded by these DAK genes are homodimer.

二羟基丙酮对酵母细胞来说是种有毒的化合物，在酵母菌中二羟基丙酮激酶参与二羟基丙酮的脱毒作用，DAK催化的反应使二羟基丙酮磷酸化，形成无毒性的磷酸二羟丙酮，可为酵母细胞所利用。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。