差向异构体

Sitafloxacin epimers were separated by capillary zone electrophoresis using γ-cyclodextrin and D-phenylalanine as chiral selector.

以γ-环糊精和D-苯丙氨酸为手性选择剂，采用毛细管区带电泳成功地分离了新型抗菌素西他沙星差向异构体。

Its main active component is glycyrrhizic acid. GL hastwo epimers, namelyα-GL andβ-GL.

甘草酸具有两种差向异构体，分别为α-GL和β-GL。

A baseline separation of Sitafloxacin epimers was achieved with a background electrolyte of 10 mmol/L KH2PO4-K2HPO4 (pH 4.5), 10 mmol/L CuSO4, 20 mmol/L γ-CD and 10 mmol/L D-Phe. The linear range for Sitafloxacin was 32-400 mg/L (0.996). The relative standard deviations of migration time and peak area were less than 1.9% and 3.8% respectively.

实验结果表明，添加剂的种类和浓度是影响西他沙星手性分离的重要因素，只有当D-苯丙氨酸、铜离子和γ-环糊精同时存在并达到一定浓度时，西他沙星差向异构体在毛细管电泳中才具有良好的分离效果。

Two approaches for the asymmetric syntheses of naturally occuring eudesmane-type triol kudtriol and 5-epi-kudtriol as well as their C-11 epimers were achieved starting from-dihydrocarvone through six and seven steps, respectively.

以-二氢香芹酮为原料，用两条合成路线分别经六、七步反应完成了三羟基桉烷类天然产物Kudtriol、5-epi-Kudtriol及它们的C-11位差向异构体的不对称全合成。

High performance liquid chromatography, carbon-13 nuclea magnetic resonance, chemical ionization mass spectrometry and gas chromatography with flame ionization detection have been employed for the identification and quantitative deter mlnation of the epimers of amygdalin.

登录后回答可以获得经验值奖励，并可以查看和管理所有的回答。登录|高效液相色谱法、carbon-13 nuclea 磁场共振电离质谱、化学品与气相层析法，以氢火焰离子化检测被用来识别和定量的威慑 mlnation差向异构体的苦的。

This Sm-catalyzed reaction firstly efficiently realized the catalytic cycle in the tandem rearrangement/reduction reaction of α-hydroxy epoxides, and moreover the diastereoselective amplification could be distinctly observed when two C1 epimers in substrate were subjected to this catalytic tandem reaction.

该催化的多功能串联反应，高度非对映选择性地一步控制了含有季碳的三个相邻立体中心，有效地构建了&2-季碳1，3-二醇&结构单元，首次实现了此类重排—还原过程的催化循环，其中对于两个C1位的差向异构体底物，此反应具有明显的非对映选择性放大特点。

Determination of Tyrosine in Urine Spectrophotometric Method;2. For chemical pre-extraction, MSTFA/TMSL derivatization reaction, GC/MS analysis, it is confirmed that two main metabolites (19-no-randrosterone and 19-noretiocholanolone) were found in nandrolone urine.

本文对合成的19-去甲雄烷醇酮的四个差向异构体混合物进行气相色谱分离，对诺龙和炔诺酮用药后，留取的人尿样通过化学预处理，MSTFA/TMSI衍生化反应，GC/MS分析，确证了尿样中诺龙的两个主要代谢产物为19-去甲雄酮和19-去甲原胆烷醇酮，炔诺酮的两个主要代谢物是四氢炔诺酮的两个形式，可能是3α-OH-5α-THINE和3α-OH-5β-THINE，在炔诺酮代谢前期，还发现有诺龙的上述两个代谢物存在。

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。