羟基酸

Dihydroxyacetone; formamidine acetate; imidazole-4,5-dicarboxylic acid; optimizing process; ethyl imidazole-4-carboxylate; reductive reaction; 4(5)-hydroxymethylimidazole

关键字或关键词组： 1，3-二羟基丙酮；醋酸甲脒；4，5-二羧酸咪唑；工艺优化；4(5)-羧酸咪唑乙酯；还原反应；4(5)-羟甲基咪唑

Ethoxy-4-hydroxy mandelic acid was synthesized from glyoxylic acid and o-ethoxyphenol in alkaline solution.

在碱性条件下由乙醛酸和邻乙氧基苯酚合成了3-乙氧基-4-羟基苯乙醇酸。

As an intermediate for preparing vanillin derived from glyoxylic acid, 3, 4-dihydroxymandelic acid is synthesized based on condensation of catechol and glyoxylic acid in alkaline aqueous solution.

以邻苯二酚和乙醛酸为原料，在碱性条件下发生缩合反应，合成了3， 4-二羟基扁桃酸，此物质是多种香料和药物合成的重要中间体。

Glycolic acid (Hydroxyacetic acid, 2-hydroxyethanoic acid) is a chemical industry material. It is applied in a lot of fields including organic synthesis, cleanout, plating, spinning, leather and sterilization, etc.

羟基乙酸又称乙醇酸、甘醇酸，是一种重要的有机合成中间体和化工产品，广泛应用于有机合成、清洗、电镀、纺织、皮革、灭菌等行业。

It was found that the more easily systhesized and stable N, N-acetal or N, Ohemiacetal can replace N-tosyl imino ester to react with phenols in the presence of TiCl〓, and α-arylglycine derivatives were also obtained in high yields and high regioselectivity.

进一步研究发现，更易合成的N，N-或N，O-缩醛可以作为亚胺酯的替代物和酚类化合物发生傅克反应。路易酸TiCl〓能有效地促进酚类化合物和亚胺酯的傅克反应较高产率、较高区域选择性的得到2-羟基α-芳香甘氨酸衍生物。

In ternary system of PGA/POH and HDI isocyanurate, there are twomain reactions: one forms urethane at 30-50℃, the other producesoxazolidone at 140-165℃.

聚丙烯酸环氧丙酯（PGA、聚丙烯酸羟丙酯（POH和HDI三聚体的三元反应体系中，醇羟基与异氰酸酯在30-50℃下反应可生成氨酯，环氧基团与异氰酸酯在140-165℃下反应生成噁唑烷酮。

In this analogue, the hydrogen of amide group could still form a hydrogen bond with the oxygen of ester bond and the ester bond was isosteric with peptide bond.

我们合成了甜味肽的类似物L-天冬酰氨酰-L-α-羟基苯丙酸甲酯，将甜味肽的天冬氨酸替换为天冬酰胺，肽键替换为酯键。

Bone marrow mesenchymal stem cells could differentiate into osteoblasts, adipocytes and neural like cells with osteoblast inductor (β-sodium glycerophosphate, dexamethasone, vitamin C), lipoblast inductor (dexamethasone, 3-isobutyl-1-methylxanthine, bovine insulin, indometacin) and serum-free medium inductor (dimethyl sulphoxide, butylated hydroxyanisole) respectively. Osteoblast marker (alkaline phosphatase, osteocalcin mRNA, calcium node), adipocyte marker (lipid droplet, PPAR γ-2mRNA) and neural cell-like marker (nissl body, neuron specific enolase, neurofilament protein) were respectively determined by the immunohistochemical method, polymerase chain reaction and immunocytochemical method.

分别采用成骨细胞诱导剂（β-甘油磷酸钠，地塞米松，维生素C）、成脂肪细胞诱导液（地塞米松，甲基异丁酸黄嘌呤，牛胰岛素，吲哚美辛）及二甲基亚砜和羟基丁酸苯甲醚无血清培养基诱导剂干预细胞向成骨、脂肪、神经细胞分化，经免疫组织化学染色、PCR、免疫细胞染色方法检测成骨标志物（碱性磷酸酶、骨钙素mRNA、钙结节）、脂肪标志物（脂滴、PPARγ-2mRNA）、以及类神经标志物（尼克氏体、神经烯醇化酶、神经丝蛋白）。

A series of 3 - aryl - 3 -( 5,5 - dimethyl - 3 - hydroxy - 2 - cyclohexene - 1 - one - 2 - yl) propanoic ester s were synthesized by reaction between aromatic aldehydes ,5,5- dimethyl -1,3-cyclohexanedione and isopropylidene malonate catalyzed by KF - Al2O3 in alcohols.

在KF-Al_2O_3催化下，将芳香醛3，5-二甲基-1，3-环己二酮及丙二酸亚异丙酯在醇中反应，一锅式合成了一系列的3-芳基-3-(5，5-二甲基-3-羟基-2-环己烯-1-酮-2-基)丙酸酯。

The present invention discloses a polycarboxylic acid copolymer which is obtained by copolymerization of monomer components comprising a polyalkyleneimine unsaturated monomer (A2) and an unsaturated carboxylic acid monomer, the polyalkylene glycol unsaturated monomer (A2) having an oxyalkylene group bonded to a polyhydric alcohol residue, and the monomer component containing an unsaturated monocarboxylic acid monomer.

公开了一种多元羧酸共聚物，它是通过单体组分共聚制得的，所述单体组分包括聚二醇不饱和单体(A2)和不饱和一元羧酸单体，所述聚二醇不饱和单体(A2)具有使氧化烯基结合到多元醇残基上的结构，所述多元醇残基平均每个分子具有不少于3个羟基。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。