羟基化作用

Meanwhile, when the supported ionic liquid is used in asymmetric dihydroxylation reaction, there was no catalystic activity of osmium catalyst.

离子液体固载于改性后BMMs在不对称双羟基化反应中由于分子筛改性引入的氨基与锇催化剂的配位作用使其失去活性。

The experiments also show that adding NaHSO3 into the reaction liquid of hydroxylation reaction can inhibit the catalytic effect of benzoquinone and residual catalyst on the phenolic tars formation caused by oxo-condensation of the diphenols and therefore reduce the tars formation of the diphenols in the reaction solution.

在羟基化反应液中加入亚硫酸氢钠可以抑制对苯醌和残留催化剂对苯二酚氧化缩合生成焦油的催化作用，从而减少了反应液中苯二酚的生焦反应。

At present,the synthesis of lignin that is not only a means,but Phenylalanine AmmoniaLyaseand Cinnamic acid 4-Hydroxylase(C4H),such as enzyme in the synthesis played a very important role.

目前认为木质素的合成途径不只一条，但苯丙氨酸解氨酶和肉桂酸4-羟基化酶(C4H)等酶在合成中起到了十分重要的作用。

The bacterial, mammalian and plant cytochrome P450s involved in metabolism of herbicides are reviewed in this paper. The action modes of cytochrome P450s on herbicides including dealkylation, ring-methyl hydroxylation and aromatic ring hydroxylation etc are summarized.

本文综述了代谢除草剂的细菌、哺乳动物和植物细胞色素P450酶系，概述了细胞色素P450酶系参与除草剂代谢的作用方式：脱烷基化作用、环甲基化羟基化作用和芳环的羟基化作用等。

The results indicated that the water or 50% ethanol extracts from peonies petals could reduce light absorption of DPPH and OH initiated hydroxylation of salicylate, and inhibit O2(superscript -) mediated light chemical reduction of nitroblue tetrazolium effectively, and lipid peroxidation of polyunsaturated fatty from yolk lipoprotein, in which DPPH scavenging activities of 6 peonies water extracts were hinger than that of 200 μg/mL BHT, but lower than 80 μg/mL Vc. In 4 kinds of detecting systems of antioxidation, the peroxidation activity of deep colored flowers of peonies was higher than that of light colored flowers of peonies.

牡丹花瓣提取液能明显抑制卵黄组织匀浆的脂质过氧化作用，降低DPPH的吸光值、抑制O2介导的NBT光化学还原及OH作用下的水杨酸羟基化作用，其中牡丹花瓣提取液清除DPPH自由基的活性高于200μg/mL BHT，但低于80μg/mL Vc.6个品种的牡丹花瓣提取液，在4种测定系统中均具有一定程度的抗氧化能力，且水提取液的抗氧化活性略高于体积分数50%乙醇提取液，深色花瓣提取液对不同自由基的清除能力较强。

One of the potential advantages of the hypoxia-induced factor prolyl hydroxylase inhibitor approach to anemia therapy over ESA is improved regulation of iron absorption and iron recycling to improve the efficiency of iron utilization, partially via a mechanism of hepcidin suppression, to overcome functional iron deficiency.

用作贫血治疗的缺氧诱导因子脯氨酰羟基化酶抑制剂相对于红细胞生成作用刺激剂的一个优势是铁吸收和铁再利用的调节得到改善，提高了铁利用的效率，尤其是通过铁调节蛋白抑制机制，克服功能性铁缺乏。

Itamin D from the skin and diet is metabolized in the lier to 25-hydroxyitamin D (Figure 1), which is used to determine a patient's itamin D status1,2,3,4; 25-hydroxyitamin D is metabolized in the kidneys by the enzyme 25-hydroxyitamin D-1-hydroxylase (CYP27B1) to its actie form, 1,25-dihydroxyitamin D.1,2,3,4 The renal production of 1,25-dihydroxyitamin D is tightly regulated by plasma parathyroid hormone leels and serum calcium and phosphorus leels.1,2,3,4 Fibroblast growth factor 23, secreted from the bone, causes the sodium–phosphate cotransporter to be internalized by the cells of the kidney and small intestine and also suppresses 1,25-dihydroxyitamin D synthesis.5 The efficiency of the absorption of renal calcium and of intestinal calcium and phosphorus is increased in the presence of 1,25-dihydroxyitamin D (Figure 1).2,3,6 It also induces the expression of the enzyme 25-hydroxyitamin D-24-hydroxylase (CYP24), which catabolizes both 25-hydroxyitamin D and 1,25-dihydroxyitamin D into biologically inactie, water-soluble calcitroic acid.2,3,4

从皮肤和食物来的维生素D在肝中代谢为25-羟基维生素D（图1），被用来决定病人体内维生素D情况的1，2，3，4；25-羟基维生素D在肾中被25-羟基维生素D1羟化酶（CYP27B1）转变为有活性的1，25-二羟基维生素D 。1，2，3，4由肾产生1，25-二羟基维生素D是被血浆甲状旁腺激素和血清钙，磷水平紧密调节。1，2，3，4由骨分泌的成纤维细胞生长因子23使钠磷协同转运蛋白被肾和小肠细胞内化及抑制1，25-二羟维生素D合成。5 在1，25-二羟基维生素D作用下肾和小肠吸收钙及磷的效率增高(图1)。2，3，6 它也包括25-羟四- 24 -羟化酶的表达(CYP24)，且将1，25二羟基维生素D和25羟基维生素D异化成无生物活性，水溶性的维生素D3-23羧酸。2，3，4

The characterization and tribological properties of samples were conducted by contact angle measuring meter, atomic force microscopy and microtribometer, and the hydroxylation of titanium surfaces by different methods was explored. The effects of load, sliding velocity and ultraviolet radiation on the tribological properties of samples were analyzed.

利用接触角测量仪、原子力显微镜和微摩擦磨损试验机对制备的试样进行表征和摩擦学特性测试，探讨不同方法进行钛金属表面羟基化的作用效果，并分析载荷、滑动速度以及紫外照射对试样摩擦学特性的影响。

We found that the iodohydroxylation of 1-2-allenyl selenides with I〓 and water can smoothly proceed in aqueous MeCN at 0℃.

我们发现在乙腈水溶液中，1，2-联烯基硒醚可以和碘发生羟碘化作用，碘和羟基高度区域和立体选择性加成到1，2-联烯基硒醚的β，γ-位。

In this article the mechanism, synthesis process , application and development of the synthetic technology of nicotinic acid are introduced.

综述了烟酸的作用机理、合成工艺、应用及研究进展，从合成方法上看，一般分为试剂氧化法、氨氧化法、气相氧化法、电化学氧化法、生物氧化法和吡啶羟基化法等。

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。