高速逆流色谱分离制备椭圆叶花锚中的2种口山酮苷元

椭圆叶花锚的主要活性成分为口山酮类化合物,这类化合物具有利胆、抗炎、抗菌及抗病毒活性。应用高速逆流色谱法建立了2种高纯度口山酮苷元的分离制备方法。对椭圆叶花锚氯仿萃取部位运用高速逆流色谱分离纯化,以正己烷-乙酸乙酯-甲醇-水(5:5:7:5, v/v/v/v)为两相溶剂系统,上相为固定相,下相为流动相。在主机转速800 r/min,流动相流速1.5 mL/min,检测波长254 nm条件下进行分离制备。所得产物经高效液相色谱分析检测,其化学结构由核磁共振氢谱(1H NMR)和核磁共振碳谱(13C NMR)鉴定。在此条件下,从100 mg粗样品中一步分离得到18 mg 1-羟基-2,3,5-三甲氧基口山酮,14 mg 1-羟基-2,3,4,5-四甲氧基口山酮。经高效液相色谱分析,其纯度均达98%以上。该方法简便、快速,所得产物纯度高,适合于椭圆叶花锚口山酮苷元的制备分离。     

Determination of Sotalol in Tablets and Serum by CZE

A validated capillary zone electrophoretic method for analysis of sotalol is described. Analysis was performed in a fused-silica capillary with 20 mM phosphate buffer (pH 4.20) containing 10% (v/v) acetonitrile as background electrolyte. The applied potential was +20 kV, the injection time 0.08 min, signal detection was at 200 nm, and 3,4-dihydoxybenzylamine was used as internal standard. The method was validated over the concentration range 1.98 × 10⁻⁵ to 9.90 × 10⁻⁵ M; repeatability was good and there was no interference. Highly satisfactory results were obtained from analysis of tablets and serum, indicating the method is specific, accurate, and precise, and suitable for routine analysis of sotalol in pharmaceutical tablets and in pharmacokinetic studies.

     

Determination of pathogenic bacteria by CZE with surface-modified capillaries

The importance of electromigration techniques in molecular biology and medicine is increasing rapidly, especially in systematic studies on proteomes and metabolomes. Staphylococcus aureus and Escherichia coli are bacterial species most frequently encountered in human infections, and many serious illnesses can be observed in the hospital environment. In this contribution we proposed a CE method with different modification of internal capillary surface and with monolithic beds as a selective material for determination of bacteria in clinical samples. The electrophoretic separation depends on the differential mobility of bacteria in the capillary and selective interactions between bacterial cells and stationary phases (modified surface, monolithic beads). Proposed procedures could become an effective tool for diagnosis of certain diseases caused by S. aureus and E. coli as well as Proteus vulgaris.     

CZE Determination of Quinolinic Acid in Rat Brain Tissue and Plasma

In this paper, a capillary zone electrophoretic method for the determination of the excitotoxic quinolinic acid in rat brain tissue (cerebellum, cortex, hippocampus, striatum) and plasma samples is described. Optimum separation of the excitotoxic quinolinic acid was achieved with a 14.4 mM boric acid/5.6 mM sodium tetraborate electrolyte solution at pH 8.84. The applied voltage was 30 kV and the capillary temperature was kept constant at 25 °C. The regression equations revealed a good linear correlation between the peak area and the concentration. The method was linear over the concentration range of 0.50 to 600 nM. All correlation coefficients were higher or equal to 0.9998. To optimize the analysis conditions, the effects of electrolyte solution pH, the concentration, and the use of methanol as an organic modifier were systematically studied. The amount of quinolinic acid in the rat brain tissue and plasma under control conditions were found to be: cerebellum 30.2 ± 1.7 nM (mean ± standard deviation); cortex 5.6 ± 0.7 nM; hippocampus 64.2 ± 9.4 nM; striatum 4.3 ± 0.6 nM, and plasma 40.1 ± 2.3 nM. The limits of detection and quantification were 0.47 nM (signal/noise = 3) and 1.58 nM, respectively. The method was successfully applied to quantify quinolinic acid in the rat brain striata under two neurotoxicity models with good repeatability (RSD < 10%) and recovery (98–102%). The proposed analytical method could be useful to clarify the role of quinolinic acid in neurodegenerative entities such as Alzheimer’s and Huntington’s diseases.     

Determination of phosphate in seawater by CZE with on-line transient ITP

We developed CZE with indirect UV detection for the determination of phosphate in seawater using transient ITP as an on-line concentration procedure. The following optimum conditions were established: BGE, 5 mM 2,6-pyridinedicarboxylic acid (PDC) containing 0.01% hydroxypropylmethylcellulose (HPMC) adjusted to pH 3.5; detection wavelength, 200 nm; vacuum injection period of sample, 3 s (45 nL); terminating ion solution, 500 mM MES adjusted to pH 4.0; vacuum injection period of the terminating ion solution, 30 s (450 nL); applied voltage, 30 kV with the sample inlet side as the cathode. The LOD for phosphate was 16 microg/L (PO(3-)(4) -P) at S/N of 3. The respective values of the RSD of the peak area, peak height, and migration time for phosphate were 2.6, 2.3, and 0.34%. The proposed method was applied to the determination of phosphate in a seawater certified reference material for nutrients, MOOS-1, distributed by the National Research Council of Canada (NRC). The results were very similar to certified values. The method was also applied to the determination of phosphate in coastal seawaters. The results agreed with those obtained using a conventional spectrophotometric method.     

Interactions Between Thrombin with Flavonoids from Abelmoschus manihot (L.) Medicus by CZE

A capillary zone electrophoretic method was applied to determine the interactions between flavonoids from Abelmoschus manihot (L.) Medicus and thrombin. Samples containing flavonoids and thrombin at various ratios were incubated at 25 °C and then were separated by CZE with tris-acetate buffer at pH 7.2. Each run could be accomplished within 10 min. In CZE, the peak width broadened due to the affinity interactions between flavonoids and thrombin. Compared with positive and negative control, hirudin interacted with thrombin but heparin had no binding to thrombin, we concluded that the total flavone LXY1 and flavonoids LXY3, LXY4, LXY5 and LXY7 from Abelmoschus manihot (L.) Medicus interacted with thrombin; the aqueous extract LXY2 and flavonoid LXY6 had no binding to thrombin. Both qualification and quantification characterizations of the binding were determined. The experimental results showed that the reported method by capillary zone electrophoresis for the determination of flavonoids and thrombin interactions is powerful, sensitive and fast, requires less amounts of reagents, and further, it can be employed as a reliable alternative to other methods.     

Isolation,purification and structural characterization of a water-soluble polysaccharide HM41 from Halenia elliptica D. Don

A water-soluble polysaccharide, HM_(41), was obtained from Halenia elliptica D. Don by acidic ethanol fractionation and gel filtration. Its homogeneity was confirmed by chromatography using multiple systems. HM_(41) was composed of rhamnose(Rha), arabinose(Ara), xylose(Xyl), mannose(Man),galactose(Gal), glucose(Glc) with a molar ratio of 1.0:5.5:1.8:3.0:9.4:21. The average molecular weight of HM_(41) was approximately 1.17 * 10~4. Periodate oxidation, Smith degradation, methylation and GC, IR,NMR, XRD, GC–MS analysis were used for the structural analysis of HM_(41). Its main chain was composed mainly of β-(1→4)Gal, β-(1→4)Glc and β-(1→6)Glc. β-(1 →4)Gal were substituted at 6-O and on average there were 14 branches among 23 main chain residues;(1→ 4)Glc had no branch;(1→6)Glc were substituted at 3-O and on average there were 9 branches among 14 main chain residues. The side chain was composed of(1→3,6)-Rha,(1→4)/(1→5)-Ara,(1 →4)/(1→5)-Xyl,(1→4,6)-Man and(1→2)-Glc. The terminal residue was composed of Ara, Xyl, Man, Gal, and Glc. Then, we demonstrated that HM and HM_(41) had strong scavenging activities in vitro hydroxyl. Overall, HM and HM_(41) may have potential applications in the antioxidants for medical and food industry.     

CZE-ESI-MS联用测定小肽混合物的研究

研究肽的分离行为、测定方法及测定条件对蛋白质组学研究具有重要意义 .毛细管电泳 ( CE)作为一种高效、快速的分离方法 ,样品用量少 ,已被广泛应用于生物领域中 ,尤其是小肽和蛋白质的分离分析 .质谱 ( MS)能够进行微量鉴定 ,并提供精确的分子量和结构信息 ,使其成为小肽和蛋白质检测和序列测定的强有力的支撑技术之一 [1～ 3] .其中 ,电喷雾 ( ESI)质谱作为一种软电离技术 ,易与常规的高分辨率分离方法如高效液相色谱、毛细管电泳等实现在线联用 ,具有分离效率高、检测灵敏度高和样品定性方便等特点 ,因而在小肽和蛋白质的测定中得到广…     

Determination of neutral carbohydrates by CZE with direct UV detection

A new CZE method relying on in-capillary reaction and direct UV detection at the wavelength 270 nm is presented for the simultaneous separation of the neutral carbohydrates xylitol, D-(-)-mannitol, sucrose, D-(+)-fucose, D-(+)-cellobiose, D-(+)-galactose, D-(+)-glucose, L-rhamnose, D-(+)-mannose, D-(-)-arabinose, D-(+)-xylose, and D-(-)-ribose. The alkaline electrolyte solution was prepared of 130 mM sodium hydroxide and 36 mM disodium hydrogen phosphate dihydrate. Separation of the sample mixture was achieved within 35 min. Calibration plots were linear in the range of 0.05-3 mM. Reproducibility of migration times was between 0.3 and 1.1%, and the detection limits for the analytes were 0.02 and 0.05 mM. The optimized method was applied for the determination of neutral monosaccharides in lemon, pineapple, and orange juices and a cognac sample. The methodology is fast since no other sample preparation except dilution is required.     

Determination of Melamine in Food by SPE and CZE with UV Detection

A novel method for the determination of melamine residue in food was developed using solid-phase extraction and capillary zone electrophoresis with UV detection. Spiked samples were extracted with 1% trichloroacetic acid while 0.03 g sodium deoxycholate was used to precipitate protein in the real samples. After centrifuging and clean-up by solid-phase extraction cartridge, the extract was directly analyzed by CZE–UV. The method was validated and good results were obtained with respect to precision, repeatability and spiked recovery. The limit of detection for melamine varied between 0.25 and 0.5 mg kg^?1. The proposed method was successfully applied for the analysis of melamine in food with total recoveries ranging from 94 to 102% in the spiked range of 0.5–5 mg kg^?1, and the relative standard deviations were between 1.5 and 4.1%.     

Determination of tetracycline residues in honey by CZE with ultraviolet absorbance detection

We have developed a sensitive CE method to determine eight tetracyclines (TCs) (chlortetracycline, demeclocycline, doxycycline, methacycline, minocycline, oxytetracycline, TC, and rolitetracycline (RTC)) in honey samples. The running buffer was 150 mM sodium borate (pH 9.8) and 2.5% 2-propanol with 15 s hydrodynamic injection at 25 kV. We have also developed an SPE procedure with a C18 cartridge as a clean-up step. Analytes were detected at 360 nm in less than 16 min. LODs ranged in honey from 23.9 microg/kg for TC to 49.3 microg/kg for RTC. Seven samples of Spanish honey of different floral origins were examined. None of them showed contamination with these antibiotics using the proposed method.     

CZE法鉴别测定苦豆草药材中多种生物碱成分

建立了一种同时在苦参药材中鉴别9种生物碱并测定其中6种生物碱含量的毛细管区带电泳法.即用未涂渍熔融石英毛细管柱50μm×41.5cm(有效长度33cm),以0.3mol/L Tris水溶液一正丙醇(ⅥV=60/40,pH=7.0)为运行缓冲液,氯丙那林为内标,在检测波长210nm、运行电压30kV、50mbar压力下进样10s、运行温度25℃和分析时间40min进行毛细管区带电泳.结果表明,宁夏市售苦豆草中含有野靛碱、莱蔓碱、槐安碱、苦参碱、槐定碱、槐果碱、苦豆碱、氧化槐果碱和氧化苦参碱,其中苦参碱、槐果碱、苦豆碱、氧化槐果碱和氧化苦参碱的含量接近,槐定碱的含量明显高于它们.本法灵敏、准确、专属性好,适用于苦豆草药材中生物碱成分的鉴别和含量测定.     

Interaction effects on cytochrome P450 both in vitro and in vivo studies by two major bioactive xanthones from Halenia elliptica D. Don

The major components, 1‐hydroxy‐2,3,5‐trimethoxy‐xanthone (HM‐1) and 1,5‐dihydroxy‐2,3‐dimethoxy‐xanthone (HM‐5) isolated from Halenia elliptica D. Don (Gentianaceae), could cause vasodilatation in rat coronary artery with different mechanisms. In this work, high‐performance liquid chromatography coupled to ion trap time‐of‐flight mass spectrometry (LCMS‐IT‐TOF) was used to clarify the metabolic pathways, and CYP450 isoform involvement of HM‐1 and HM‐5 were also studied in rat. At the same time, in vivo inhibition effects of HM‐1 and ethyl acetate extracts from origin herb were studied. Three metabolites of HM‐5 were found in rat liver microsomes (RLMs); demethylation and hydroxylation were the major phase I metabolic reactions for HM‐5. Multiple CYP450s were involved in metabolism of HM‐1 and HM‐5. The inhibition study showed that HM‐5 inhibited Cyp1a2, 2c6 and 2d2 in RLMs. HM‐1 inhibited activities of Cyp1a2, Cyp2c6 and Cyp3a2. In vivo experiment demonstrated that both HM‐1 and ethyl acetate extracts could inhibit Cyp3a2 in rats. In conclusion, the metabolism of xanthones from the origin herb involved multiple CYP450 isoforms; in vitro, metabolism of HM‐5 was similar to that of its parent drug HM‐1, but their inhibition effects upon CYP450s were different; in vivo, Cyp3a2 could be inhibited by HM‐1 and ethyl acetate extracts.     

Development of a CZE Method for the Determination of Olmesartan Medoxomil in Tablets

A CZE method was developed and validated for the analysis of Olmesartan medoxomil (OLMD) in tablets. The influences of pH, buffer concentration, applied voltage and capillary temperature on the migration time of OLMD were investigated. About 50 mM pH 6.5 phosphate buffer were used as background electrolyte. The optimum instrument parameters were found to be 30 °C temperature with 30 kV applied voltage and diode array detection was carried out at 210 nm. OLMD was hydrodynamically injected (P _inj  = 50 mbar, t _inj  = 3 s) and an internal standard, diflunisal (IS), was used to improve the precision and repeatability. Under these conditions, the migration time of OLMD was 2.32 min and the total analysis time was shorter than 5 min. Linearity range for the developed method was found to be 2.0–50.0 μg mL⁻¹ and the limit of detection was 0.5 μg mL⁻¹. The developed method was applied for the analysis of OLMD in pharmaceutical tablet formulations.

     

Development of a CZE Method for the Determination of Olmesartan Medoxomil in Tablets

A CZE method was developed and validated for the analysis of Olmesartan medoxomil (OLMD) in tablets. The influences of pH, buffer concentration, applied voltage and capillary temperature on the migration time of OLMD were investigated. About 50 mM pH 6.5 phosphate buffer were used as background electrolyte. The optimum instrument parameters were found to be 30 °C temperature with 30 kV applied voltage and diode array detection was carried out at 210 nm. OLMD was hydrodynamically injected (P _inj  = 50 mbar, t _inj  = 3 s) and an internal standard, diflunisal (IS), was used to improve the precision and repeatability. Under these conditions, the migration time of OLMD was 2.32 min and the total analysis time was shorter than 5 min. Linearity range for the developed method was found to be 2.0–50.0 μg mL^?1 and the limit of detection was 0.5 μg mL^?1. The developed method was applied for the analysis of OLMD in pharmaceutical tablet formulations.     

CZE Determination of Calixarenes and Related Derivatives Using Acetonitrile as a Modifier

The applications of third-generation host compound calixarenes have been restricted due to their high price and shortage of supply. To obtain high pure calixarenes with high yield, synthesis strategy and analytical method investigations are necessary. The present work describes capillary zone electrophoresis (CZE) for the separation and determination of calixarene derivatives under the optimized CZE conditions within 20 min. The CZE method was evaluated with linear ranges, detection limits, recoveries and repeatability. The results indicated that the method was accurate and reproducible. As expected, it could be utilized to separate and evaluate calixarene derivatives during their synthesis and purification.     

水飞蓟素中活性黄酮的测定

采用高效液相色谱梯度淋洗法,使水飞蓟素中的７种主要成分得到完全分离。方法简便、快速,能单独测得水飞滨的含量,与紫外分光光度法相比,具有较好的重复性,变异系数在２％以下。     

光度法测定杜仲藤中总黄酮

石油醚索氏提取除杂,甲醇索氏提取杜仲藤中各部位的总黄酮含量,所得提取液用甲醇定量稀释至100mL,分取1．0mL于10mL容量瓶中,并在碱性溶液中与铝（Ⅲ）反应后在510nm波长处测定所生成络合物的吸光度。用芦丁作标准制作校准曲线,其回归方程为C=0．09669A-0．000763,相关系数为0．9993。按此方法分析了杜仲藤样品,测得茎中总黄酮量为93．0mg&#183;g^-1（n=6,相对标准偏差为1．62％）,叶中为96．4mg&#183;g^-1（n=6,相对标准偏差为0．44％）。     

Simultaneous Determination of Neuroactive Amino Acids in Serum by CZE Coupled with Amperometric Detection

A quantitative determination of six neuroactive amino acids (NAAs) was performed by capillary zone electrophoresis with amperometric detection (CZE-AD). This CZE-AD method utilized two electrolytes: the borate solution flowing in a capillary has the NAAs-separation effects, and the sodium hydroxide (NaOH) solution filled in the detection reservoir for the amperometric analysis of NAAs. The following experimental parameters were optimized: the working electrode potential, the pH value, the component, and the concentration of running buffer, the separation voltage, and the injection time on CZE-AD. Then, under the optimum conditions, the six NAAs could be completely separated in 30 min and had well-shaped AD responses at 0.75 V (versus SCE) on a copper electrode. The linear calibration range of NAAs was from 5 × 10^?4 to 5 × 10^?6 mol L^?1 with the limits of detection (LODs) ranging from 10^?6 to 10^?7 mol L^?1 (signal-to-noise ratio = 3), and the relative standard deviations (RSDs) of the migration time and peak area were 0.45–0.55 and 3.8–6.3 %, respectively. Moreover, this method has succeeded in human serum analysis, and the determined contents of the six NAAs in human serum were in an average recovery range of 85.3–117.9 %, which confirmed the validity and practicability of this method.