羟基化

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。

In some cases, its epimer 4 was also obtained. 22 compounds were synthesized, among them 18 were new.3. Using the intramolecular Pictet-Spengler reaction to form the pentacyclic skeleton of Et-743, the byproducts 25 were obtained under various conditions. The structures of them were determined to be 1, 2-dihydro-isoquinoline compounds, and the mechanism of the reaction was proposed.B. The synthesis of the analogs of Et-743Because of the failure of removing the protective groups in compounds 14, the synthetic strategy was adjusted.

对于苄基保护的羟基化合物13a，顺利得到化合物30，然后与不同的羧酸反应得到18个酯化合物33-50；对于苄氧羰基保护的氨基化合物13b，由于脱除保护基的化合物31在空气中不稳定，所以我们采取不经分离纯化，直接与羧酸反应得到酰胺化合物53-62，然后再分别对其C-21位的羰基进行还原氰基化，得到10个酰胺目标化合物63-72，另外，我们还对羟基转化为氨基的反应进行了探索。3。

The pigment in colored cotton fibers was extracted by methanol at room temperature. The results of color reactions HCl-Mg reaction, NaBH4 reaction, NaOH reaction, FeCl3 reaction and Pb(Ac2 reaction of the pigment extractive showed that the pigment extracted by methanol was flavone or flavonol with two adjacent hydroxide groups (Table 2, Fig. 1). The results of UV spectral analysis further proved that the pigment extracted by methanol from brown fiber belonged to flavone with two adjacent hydroxide groups in B ring, and that from the green fiber contained not only flavone but also flavonols with two adjacent hydroxide groups both in A ring and B ring and indican replaced a hydroxide group at 3-site of A ring Fig.

通过盐酸－镁粉反应、四氢硼钠还原反应、碱反应、醋酸铅反应、氯化铁反应和紫外光谱吸收的分析表明，甲醇室温提取的棕色棉纤维色素可能是黄酮类化合物，B环上带有邻二酚羟基；甲醇室温提取的绿色棉纤维色素除黄酮类化合物外，还含有3-位羟基被糖甙化的黄酮醇类化合物，A、B环上都带有邻二酚羟基。

The basic structural motive of alkali lignin is similar with phenol, containing phenol-carbonyl, alcohol-carbonyl, metonym and other active groups, and it can set off a reaction of carbonyl modification.

碱木素基本结构单元分子类似于苯酚，含有酚羟基，醇羟基，甲氧基等活性基团，可以发生羟甲基化等改性反应。

It includes the following steps: polymerizing 2, 4-dihydroxyl metaphenylene diamine hydrochloride, diamine monomer and dipic acid anhydride to gain the polyimide that contains hydroxy on the molecule chain, making the hydroxyl take esterification reacting with acyl chloride and acrylic acid to gain polyimide photosensitive material that has negative photonasty.

该聚酰亚胺光敏材料以2，4-二羟基间苯二胺盐酸盐，二胺单体和二酸酐为原料进行聚合，得到分子链上含羟基的聚酰亚胺，然后使羟基与丙烯酸及其衍生物的酰氯发生酯化反应，得到具有负性感光性能的聚酰亚胺光敏材料。

The smooth surface of nano-HA prothesis fails to take advantage of the benefit of nano-HA.

光滑表面的纳米羟基磷灰石假体未能发挥纳米级羟基磷灰石的优势；在影响骨整合方面就羟基磷灰石涂层来说，涂层表面改性可能比单纯涂层材料纳米化更重要。

Prophenoloxidase is a key enzyme for mediating melanotic encapsulation of oocysts,which may be transformed into active phenoloxidase by limiting proteolysis.

而前酚氧化酶(Prophenoloxidase，PPO)是介导卵囊黑化包被反应的一种关键酶，活化后可催化酪氨酸羟基化为二羟基苯基丙氨酸，二羟基苯基丙氨酸和多巴胺可进一步氧化为具有活性的苯醌活性，苯醌即可介导蛋白交联并聚合成黑色素层固定、隔离或杀死入侵的病原体。

Methods 4-Hydroxy- benzonitrile was treated with sodium hydrogen sulfide and anhydrous magnesium chloride in dimethyl formamide to give thioamide, which was then directly cyclized with ethyl 2-chloroacetoacetate without separation to give ethyl 2-(4-hydroxyphenyl)-4-methylthiazole-5-carboxylate(2) in one-pot; then 2 was formylated with Duff reaction adopting hexamethylenetetramine in trifluoroacetic acid to give ethyl 2-(3-formyl-4-hydroxyphenyl)-4-methylthiazole-5-carboxylate(3); finally, the target compound was obtained by the treatment of 3 with hydroxylamine hydrochloride and sodium formate in formic acid.

采用&一勺烩&方法，以4-羟基苯甲腈为起始原料，首先与硫氢化钠和无水氯化镁在N，N-二甲基甲酰胺中反应，所得中间体不经分离，直接加入2-氯乙酰乙酸乙酯进行环合反应，得到2-(4-羟基)苯基-4-甲基-5-噻唑甲酸乙酯（2）；然后通过六亚甲基四胺/三氟乙酸进行Duff反应，得到2-(3-甲酰基-4-羟基)苯基-4-甲基-5-噻唑甲酸乙酯（3）；再经盐酸羟胺/甲酸/甲酸钠体系脱水得到目标化合物。

According to the invention, the natural substances in question are selected from: hydroxy-cinnamic acids and the esters and depsides thereof; plant phenols which can be derived from hydroxy-cinnamic acids; polymers of hydroxy-cinnamic alcohols; other natural substances of plant origin which have anti-mutagenic and aromatising properties and are combined with anti-oxydant vitamins or with the precursors and/or derivatives thereof; and other anti-oxidant vitamins which are made to form complexes with eucaryotic cell cultures.

按照本发明，这些天然物质选自羟基肉桂酸及其酯和缩酚酸、可以由羟基肉桂酸衍生得到的植物酚、羟基肉桂醇的聚合物、具有抗诱变性和芳化性质的并且与维生素合用的其他植物源天然物质、以及与真核细胞培养物络合的其他抗氧化性维生素。

The separation behavior of o hydroxybenzoic acid, m hydroxybenzoic acid and p hydroxybenzoic acid in high performance capillary zone electrophoresis was investigated using cetyltrimethylammonium bromide as reversed reagent for electroosmotic flow The effects of pH of buffer solution and volume fraction of methanol on the separation, peak shape and elution order were studie

采用十六烷基三甲基溴化铵为电渗流改性剂，考察了邻羟基苯甲酸、间羟基苯甲酸和对羟基苯甲酸在高效毛细管区带电泳模式下的分离行为，研究了缓冲液的pH和添加剂甲醇的用量对这 3种同分异构体的分离、峰形和出峰顺序的影响，并据此优化了这 3种异构体的分离条件。

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。