羟基酸

In this reaction a lag period was discovered which may be resulted from isomerism of enol and ketone.

结果表明，2-羟基吡啶、4-羟基吡啶不能被酪氨酸酶氧化，也不是酪氨酸酶的抑制剂。

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。

Therefore it is very necessary and of great importance in environmental protection and economy to study the industrially production method of 3-hydroxybutyric acid.

生物降解塑料的开发是解决"白色污染"的有效途径，3-羟基丁酸是制备生物降解塑料的重要原料之一，且目前尚无规模化的工业生产，故研究3-羟基丁酸的工业化合成方法具有重要的环境意义和经济意义。

OBJECTIVE: This study is designed to investigate the feasibility of poly (hydroxybutyrate-hydroxyvalerate) membrane for guiding bone regeneration.

目的： 探讨聚羟基丁酸/羟基戊酸共聚酯构建引导骨组织再生膜的可行性。

Silicon phthalocyanine dihydroxide was prepared from silicon phthalocyanine dichloride through two methods. The first was alkali treating that meaned silicon phthalocyanine dihydroxide was treated in the ethanol solution containing sodium methylate .The second was acid treating meaned precipitating its solution in concentrated sulfuric acid into ice water. The product yield of the second method was 77.0％, which was higher than the method of alkali treating.

此外将合成的二氯酞菁硅采用两种方法转化为二羟基酞菁硅，第一种方法是碱处理法即将二氯酞菁硅在甲醇钠的乙醇溶液中回流得到，最高收率为53％第二种方法是酸处理法即采用二氯酞菁硅的硫酸溶液在冰水析出的方法转化为二羟基酞菁硅，其中酸溶析出法收率为77.0％。

Blending PHB with the random copolymer poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) made use of the moldability of the former and the toughness of the latter, which provided an effective method for PHA modification.

提出了PHB和聚（3—羟基丁酸酯—共聚—3—羟基己酸酯）共混的PHA改性方法，同时兼顾了材料的韧性和加工成型性。

Blends of P(3-hydroxylbutyrate-co-4-hydroxylbutyrate) [P(3HB-co-4HB)] plasticized by triethyl citrate, soybean oil and glycerin triacetate have been prepared by a solvent casting film method. The effects of varying the type and content of plasticizer on the properties of the polymer blends have been studied.

采用溶剂成膜法制备了柠檬酸三乙酯、大豆油和甘油三乙酸酯增塑的聚（3-羟基丁酸酯－co-4-羟基丁酸酯）共混物，考察了增塑剂的种类及其用量对共混物热学和力学性能的影响。

The viscometry is used to determine average number molecular weights of polyhydroxyalkanoates taking chloroform as solvent.

以氯仿作溶剂，用黏度法测定了多聚羟基烷酸的分子量，摸索了检测的最佳温度与溶液浓度，比较了黏度外推法与黏度单点法测验结果，建立了黏度法测定多聚羟基烷酸平均分子量的操作方法。

However, the unique exception isthat PHB is able to be aerobically degraded to carbon dioxide and water by a numberof different soil-bacteria and fungi. As a result, PHB has gained much attention in theplastic industry. 3-Hydroxybutyrac acid and ethyl 3-hydroxybutyrate are the mainmonomers for producing PHB, an important biodegradable plastic.

这主要原因是PHB不但具有与通用塑料类似的物理性质，而且它还可被土壤中的细菌和真菌降解为二氧化碳和水。3-羟基丁酸和3-羟基丁酸乙酯是合成PHB的主要单体，目前尚未工业化生产。

In accordance with the present invention, optically pure-hydroxycarboxylic acid can be prepared by culturing E. coli transformed with a recombinant plasmid which expresses intracellular PHA depolymerase of Ralstonia eutropha and PHA biosynthesis enzyme of Alcaligenes latus to give-hydroxycarboxylic acid.

根据本发明，光学纯的-羟基羧酸可通过培养用重组质粒转化的E.coli制备，所述重组质粒表达真养产碱杆菌的胞内PHA解聚酶和广泛产碱菌的PHA生物合成酶从而生成-羟基羧酸。

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。