羟基化

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 reaction mechanism for the formation of ultimate carcinogens diazohydroxide, diazonium and oxoniumions by α-hydroxylation-NPYR and the alkylation process of C and guanine were investigated including solvent effects at the B3LYP/6-31G(superscript **) level.

采用密度泛函理论，在B3LYP/6-31G水平上，研究了气相和水溶剂中，α-羟基化吡咯烷亚硝胺(-αhydroxylation-NPYR， A)代谢为终致癌物重氮氢氧化物、重氮烷阳离子和氧离子，以及C与鸟嘌呤碱基相互作用的反应机理。

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。

Aim To identify the hydroxylate metabolites and its sulfate conjugates of daidzein in rat urine.

目的 鉴定大豆黄素在大鼠体内的羟基化及其结合形代谢产物。

Results Several new hydroxylate metabolites and its sulfate conjugates were found and identified in rat urine.

结果 在大鼠尿中检测到几种尚未在国内外报道过的羟基化代谢产物及其硫酸酯轭合物。

LC-ESI/MS is proved to be a simple, rapid, sensitive and specific technique for identification of the hydroxylate metabolites and its sulfate conjugates of daidzein in rat urine.

LC-ESI/MS法可以快速、简捷、准确地鉴定大豆黄素在大鼠体内羟基化及其结合形代谢产物。

Kinetic parameters, three dimensional structures and homogenous sequence alignment of evolved P450 BM3 E435T,D168H,D168NA225VK440N that can hydroxylate indole into indigo were compared to illustrate the molecular structural changes and mechanisms that improve catalytic properties.

通过动力学参数测定、同源序列比较以及三维结构的模建，对三个能够羟基化吲哚生成靛蓝的高活力P450BM3进化酶E435T，D168H，D168NA225VK440N所导致的酶分子结构变化和可能的活力提高机制进行了初步分析。

To our knowledge, reverse phase of high performance liquid chromatography was firstly developed to analyze the metabolites of 7-tocopherol with ideal results. Meanwhile, Gas chromatography/Mass chromatography were used to analyze the structures of unknown metabolites of 7-tocopherol and a main unknown metabolite was identified as a side chain ω- hydroxylate of 7-tocopherol.The kinetic results of of 7-tocopherol reacted in the S9 of male SD-rat liver showed that the optimal time was 45 min; the optimal concentration of S9 5 mg/ml; the optimal concentration of NADPH 1 mM; and the optimal concentration of 7-tocopherol 8 μg/ml. The result of γ-tocopherol metabolized in the S9 of male SD-rat was the best; male Brazil turtle better; and male cobia worst.

本试验首次确立了γ-生育酚代谢物的RP-HPLC分析方法，结果理想且重现性好；用GC／MS对γ-生育酚的未知代谢物结构进行分析，判断其中一种主要的代谢物为γ-生育酚侧链初级羟基化代谢物；γ-生育酚在雄性SD-大鼠肝S9的代谢动力学表明，本实验条件下代谢反应的最佳时间为45min，S9浓度为5mg／ml，NADPH浓度为1mM，γ-生育酚浓度为8μg／ml；发现γ-生育酚在雄性SD-大鼠肝S9中代谢最高，雄性巴西龟次之，雄性军曹鱼最低。

Mutant libraries created by saturation mutagenesis of each single amino acid site D168, A225, K434 and E435 were screened to further improve the capability of cytochrome P450 BM-3(A74G/F87V/L188Q) mutant from Bacillus Megaterium which can hydroxylate indole into indigo. Results showed that D168, K434 and E435 are located at the functional domain of P450 BM-3 protein while A225 is sited at the unfunctional domain.

为了进一步获得具有更高活力的细胞色素P450 BM-3(F87V/A74G/L188Q)突变酶，利用饱和突变技术对该突变酶的4个氨基酸位点D168、A225、K434、E435分别进行单一的随机突变，通过对其羟基化吲哚生成靛蓝的催化性能表征，发现P450 BM-3氨基酸残基的168、434和435位均位于蛋白功能区域，而225位则位于非功能区域。

Two coordination polymers composed of in situ synthesized ligand deriving from isophthalic acid through the hydroxylation on the 2-position have been synthesized under hydrothermal conditions.

利用铜离子的氧化还原性质，以铜离子和间苯二甲酸在水热条件下反应使配体发生羟基化衍生成2，6-二羧基苯酚，并组装出2个含衍生配体的配位聚合物。

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。