羟基酸

It can be used for the quality control of ferulic acid and hydroxysafflor yellow A simultaneously in extracts of medicinal material.

该法快速、简便、准确，可为评价提取物中阿魏酸和羟基红花黄色素A的质量提供依据。

To study the changes of the contents of ferulic acid and hydroxysafflor yellow A in the single and mixed decoction of Radix Angelicae Sinensis and Flos Carthami, and to explore the characteristics of Chinese herbs compatibility.

目的 研究和探讨当归－红花单煎及共煎液中有效成分阿魏酸和羟基红花黄色素A含量的变化，初步探索两味中药配伍应用的变化规律。

Reaction of L-tyrosine with benzyl bromide in the presence of copper sulfate led to the protection of phenol group on the side chain of L-tyrosine to give H-Tyr-OH in 45% yield via a copper complex intermediate.

酪氨酸与溴化苄在硫酸铜存在下反应，选择性地在其侧链酚羟基上引入苄基保护基，通过反应条件的优化，反应产率达到45%。

The bioactivity of titania coatings before and after modification were investigated by simulated body fluidtests in vitro.X-ray diffraction,Scanning electron microscope,Fourier transform infrared spectroscope and Energy diffraction spectroscope were used to investigate the microstr...

结果表明：氧化钛涂层和钛合金基体的结合强度较高，其值高达40MPa，涂层的耐模拟体液腐蚀性优于钛合金。酸和碱溶液表面改性后的氧化钛涂层经模拟体液浸泡可在其表面生成含有碳酸根的羟基磷灰石，显示良好的生物活性。

Optically active ethyl-3-hydroxybutyrate,a useful chiral synthon,was prepared by stereoselective reduction of ethyl acetoacetate of the bread yeast in organic solvent.

利用面包酵母在非水相中不对称还原乙酰乙酸乙酯，制备了光学活性的手性化合物S-3-羟基丁酸乙酯。

7-Hydroxy-4-methylcoumarin was synthesized from ethyl acetoacetate and m-dihydroxybenzene by the Pechmann condensation using phenyl sulfonic acid as catalyst under solvent-free conditions.

摘 要：以苯磺酸作催化剂，乙酰乙酸乙酯和间苯二酚为原料，通过Pechmann缩合反应合成7-羟基-4-甲基香豆素。

A novel method for synthesis of-4-cyano-3-hydroxybutyric acid ethyl ester (1), a key intermediate of statins, was reported.

研究了一条新的路线用于他汀类药物的重要中间体-4-氰基-3-羟基丁酸乙酯的合成。

Treatment of sucrose alkyl 4,6-orthoacetate hexaacetates I with water or alcohol in the presence of an acid catalyst afforded derivatives of sucrose acetates by selectively blocking specific hydroxyl group in sucrose and acetyl migration.

4，6-原乙酸蔗糖六乙酸酯在酸催化下水解和醇解，选择性地保护了蔗糖分子中的某些羟基，并通过乙酰基由C~4→C~6迁移的异构化反应合成了一系列蔗糖乙酸酯。

METHODS: The bone marrow stem cells at the fifth passage were cocultured with nano-hydroxyapatite/collagen/calcium alginate in vitro.

选取生长良好的第5代兔骨髓基质干细胞与海藻酸钙纳米羟基磷灰石胶原复合材料体外复合培养。

Among it wrap up surface auxiliary that cover,-COOH,-OH, sulphur base S032~ sour hydroxyl carboxyl , etc. group last the not facilitating last aluminium the buoyancy of floatings of the powders, and C-C chain , alkyl phenyl R-C6HU fatty alcohol base fatty acid base R-COO, R-0- long in structure, etc. base group kiss not oily, base these group add , facilitate aluminium powder water build rise of area.

表面包覆的助剂中，羧基-COOH、羟基-OH、磺酸基SO_3~(2-)等集团是亲水性的有助于提高铝粉的漂浮力，而C-C结构长链、烷基苯基R-C_6H_(14)脂肪醇基R-O-、脂肪酸基R-COO~-等基团是亲油性的，这些基团的加入有助于铝粉水盖面积的提高。

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。