Interactions Between Thrombin and Natural Proudcts of Coreopsis tinctoria Nuttt. and Cistanche deserticola Ma. in Capillary Zone Electrophoresis

Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubated at 25 ℃ and then were separated by CZE with Tris-acetate buffer at pH 7.2. Each run could be accomplished within 5 min. Results In CZE, the peak width broadened due to the affinity interaction between natural products and thrombin. Compared with positive and negative control, the natural products （CB-1, CB-2） from Coreopsis tinctoria Nuttt. interacted with thrombin; CB-3 from Coreopsis tinctoria Nuttt. and HC-1, HC-2, HC-3 from Cistanche deserticola Ma. did not bind to thrombin. Both qualification and quantification characterizations of the binding were determined. Conclusion The established method is capable of sensitive and fast determination of natural products and thrombin interactions, it can be employed as an alternative method.

A Peptides Migration Model in capillary Zone Electrophoresis

A peptides migration model based on the principle of mechanics is presented in capillary zone electrophoresis (CZE). It is shown that the migration that the (tr) is a function of electric (Q), relative molecular mass (Mr), conformation parameter (Rc) of peptides and electrophoretic condition parameter(A). The conformation parameter is introduced to characterize multifarious shapes owing to the complex conlormation and the various kinds of macromolecules, where Rc≥1/3. The parameters A and Rc can be obtained from experimental data. The times of migration of the nine standard peptides were measured in pH 2.5buffer on different electrophoretic conditions in CZE. The experimental results agreed well with the theoretical prediction.

Separation of Nucleotides in Swine Tissues Using Capillary Zone Electrophoresis

Capillary zone electrophoresis has been applied to the analysis of nucleotides. The effects of buffer concentration. pH and other operating conditions on the separation were investigated and optimized. By using the method, separation and identification of nuclotides in swine tissues were completed.

p-Hydrazinobenzenesulfonic Acid Derivatives of Carbohydrates andTheir Capillary Zone Electrophoresis

p-Hydrazinobenzenesulfonic acid is explored as a novel ultraviolet labeling reagent for capillary electrophoresis (CE) of mono- and disaccharides. The labeling reaction takes less than 10 minutes and introduces both of absorption and charge groups into the sugars.

Separation of chiral drugs with sulfobutylether-β-cyclodextrin bycapillary zone electrophoresis

Sulfobutylether－β－cyclodextrin（SBE－β－CD）was used as a chiral selector tor separatingten chlral drugs with resolution 1．2 by capillary zone electrophoresls（CZE）， The backgroundelectrolylc solution comprised of 120 mmol／L Britton－Robinson buffer（BRB） containing1 ～10mmol／L SBE－β－CD with the pH value adjusted from 5．0－6．8． Five of the drugs were better resolvedthan those previously reported with neutral CDs．

Ionic Liquid and HP-β-CD Modified Capillary Zone Electrophoresis to Separate Hyperoside, Luteolin and Chlorogenic Acid

Ionic liquid （1-ethyl-3-methylimidazolium tetrafluoroborate, 1E-3MI-TFB） and HP-β- CD as modifier was added to the buffer to separate hyperoside, luteolin and chlorogenic acid. Experiments explored the effect of concentration of 1E-3MI-TFB and HP-β-CD on separation. The results indicated that 1.0 mmol/L HP-β-CD and 1%0 （v/v） 1E-3MI-TFB added to the buffer simultaneously could achieve a good compromise of resolution and analysis time. Capillary experiments and UV spectra indicated that there was interaction between 1E-3MI-TFB and analytes.

Capillary Zone Electrophoresis Investigation of Interactions between Granulocyte-colony Stimulating Factor and Dextran Sulfate/Carrageenan Oligosaccharide

The interactions between granulocyte-colony stimulating factor (G-CSF) and dextran sulfate / κ-carrageenan oligosaccharide were studied by capillary zone electrophoresis. Dextran sulfate could strongly interact with G-CSF and the complex was detected. The binding constant and stoichiometry were determined to be 1.2×106 (mol/L)-1 and 3:1, respectively. However, the interaction between κ-carrageenan oligosaccharide and G-CSF was not found.

Studies of Active Ingredients in Cough Syrup by Capillary Zone Electrophoresis with Amperometric Detection

The present paper covers a simple, reliable and reproducible method, based on capillary zone electrophoresis(CZE) with amperometric detection(AD), for the separation and the determination of ephedrine hydrochloride, promethazine hydrochloride and codeine phosphate. Under the optimal conditions, the three analytes were base-line separated completely within 16 min. Good linear relationships between the peak heights and the concentrations of the three analytes were obtained with the correlation coefficients better than 0 9993. The method was directly applied to the determination of the active ingredients in pharmaceutical preparations and the assay results were satisfactory.

Screening of chemokine receptor CCR4 antagonists by capillary zone electrophoresis

CC chemokine receptor 4(CCR4)is a kind of G-protein-coupled receptor,which plays a pivotal role in allergic inflammation.The interaction between 2-(2-(4-chloro-phenyl)-5-{[(naphthalen-1-ylmethyl)-carbamlyl]-methyl-4-oxo-thiazolidin-3-yl)-N-(3-morpholin-4-yl-propyi)-acetamide(S009)and the N-terminal extracellular tail(ML40)of CCR4 has been validated to be high affinity by capillary zone electrophoresis(CZE).The S009 is a known CCR4 antagonist.Now,a series of new thiourea derivatives have been synthesized.Compared with positive control S009,they were screened using ML40 as target by CZE to find some new drugs for allergic inflammation diseases.The synthesized compounds XJH-5,XJH-4,XJH-17 and XJH-1 displayed the interaction with ML40,but XJH-9,XJH-10,XJH-I 1,XJH-12,XJH-13,XJH-14,XJH-3,XJH-8,XJH-6,XJH-7,XJH-15,XJH-16 and XJH-2 did not bind to ML40.Both qualification and quantification characterizations of the binding were determined.The affinity of the four compounds was valued by the binding constant,which was similar with the results of chemotactic experiments.The established CEZ method is capable of sensitive and fast screening for a series of lactam analogs in the drug discovery for allergic inflammation diseases.

Study of Interaction between Red-tide Toxin, Domoic Acid and Double stranded DNA by Capillary Zone Electrophoresis

The interactions between amnesic red-tide toxin, domoic acid (DA) and 14mer double-stranded DNA (dsDNA with three kinds of sequences) were studied by capillary zone electrophoresis (CZE). For the dsDNA with a sequence of 5'-CCCCCTATACCCGC-3', the amount of free dsDNA decreases with the increase of added DA; and the signal of DA-dsDNA complex was observed. Meanwhile, the other two dsDNAs, 5'-(C)12GC-3' and 5'-(AT)7-3', the existence of DA could not lead to the change of dsDNA signal and indicated that there is no interaction between DA and these two dsDNAs.

Evaluation of The Interaction between Netropsin and Double Stranded DNA by Capillary Zone Electrophoresis

Capillary zone electrophoresis (CZE) was applied to study the interaction between netropsin and a 14mer double stranded DNA (dsDNA). The binding constant of this interaction calculated from Scatchard plot was (1.070.10)×105 (mol/L)-1. The binding stoichiometry was 1:1. The use of polyacrylamide coated capillary showed better effect in the analysis of DNA than noncoated capillary.

A Novel Method for Quantification of Circulating DNA in Serum by Capillary Zone Electrophoresis

In this paper, we first presented a novel method for quantification of circulating DNA in human serum based on capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). The serum was digested by proteinase to release free DNA, and then CZE-LIF system was used for the quantification of total circulating DNA. This method was successfully used to quantify the circulating DNA levels in sera from healthy individuals and certain cancer patients. We found the significantly elevated circulating DNA levels in certain prostate cancer patients. Our results demonstrated that CZE-LIF system has good linearity, excellent sensitivity (0.5 ng/mL DNA), satisfactory reproducibility (RSDs in one day and between days were both less than 5%) and reliability, and is well suitable to the quantification of the circulating DNA in human serum or plasma.

Determination of Size Distribution of Nano-particles by Capillary Zone Electrophoresis

A new method was developed for the determination of the size distribution of nano-particles by capillary zone electrophoresis (CZE). Scattering effect of nanoparticles was studied . This method for the determination of size distribution was statistical.

CAPILLARY ZONE ELECTROPHORESIS OF NONOSACCHARIDES

A method for the analysis of monosaccharides derived from glycoproteins and glycolipids was described using the newly developed technique of capillary zone electrophoresis(CZE).It is found that,at ca.0.5-5 nL in- jection,CZE can offer a high resolution of most monoses from glycoprotein and glycolipids.A mixture of amino-and non-aminomonosaccharides,which is difficult to separate with chromatographic methods,was separated complet- ely by CZE in borate buffer after the monosaccharides were derivatized with 1-naphthylamine.

Separation of Purine and Its Derivatives by Capillary Zone Electrophoresis

The separation of a group of 17 purine and its derivatives by capillary zone electrophoresis is presented. A systematic approach was used to study the effect of pH, buffer type, organic modifiers, applied potential, sodium dodecyl sulfate (SDS) and cyclodextrins on the separation of these purine derivatives. An ideal condition was found for their separation, which was 30 mmol/L sodium borate buffer (pH 9–9.5), 10%(V/V) methanol buffer modifier and 20 kV. Under this condition, the 17 purine derivatives were baseline separated and the linear correlation coefficient for adenine, uric acid and 2-thioxanthine was 0. 99 over two orders of magnitude. The variation of peak areas was less than 4. 6%(n=5) and that of migration times was in the range of 0%–3%, while the samples were injected hydrodynamically at a height of 15 cm and an injection time of 8–10 s. In addition, alcohol, 1-propanol, 1-butanol and acetonitrile were also effective additives in the separation. However, SDS and various β-cyclodextrin (β-CDs) were found to do no good to their separation.

Enhancement of Selectivity in Capillary Zone Electrophoresis by Adding Ethanolamines or Ethylamines in the Running Buffer

Mono-, di-, tri-ethanolamines and di-, tri-ethylamines were used to prepare phosphate buffer at pH 2.5 and shown to be capable of enhancing the separation selectivity of chiral drug pinacidil and melittin in bee venom in capillary zone electrophoresis. The reason is due to the reduction of the average apparent mobilities of the analytes.

Application of Simultaneous Technique of Capillary Zone Electrophoresis Photothermal Interference Spectrometry for Monitoring Chelating Reaction of Light Rare Earth with Tribromoarsenazo

A novel high sensihtity, small-volume photothermal intheence detector has beenintroduced for capillap zone electrophoresis separation analysis. The utility of thes sdriulboconstecheque for momtomp chelating reachon of light rare earth with tribromoarsenazo has beenreported.

Chiral Separation of Esmolol and Terazosin by Cyclodextrinmodified Capillary Zone Electrophoresis

Cyclodextrin-modified CZE was applied to the chiral separation of two basic drugs, i.e., esmolol and terazosin. Selector screening and concentration optimization experiments were performed. Resolution 3.1 for esmolol, 1.2 for terazosin were achieved when using 60 mmol/L gamma-CD and 60 mmoL/L DM-P-CD, respectively, in 50 mmol/L pH 2.5 sodium phosphate buffer.

A simple capillary zone electrophoresis method for the determination of mycophenolic acid in human plasma

Mycophenolic acid （MPA）, an immunosuppressive drug, was determined in human plasma by a simple capillary zone electrophoresis （CZE） method. A bare fused-silica capillary with an internal diameter （i.d.） of 75/am and an effective length of 50 cm was used for the separation. A 200 }aL plasma sample was deproteinized with 400 μL acetonitrile, and the supematant was directly injected into the capillary after a water plug at a pressure of 0.5 psi for 10 s. Boric acid （H3BO3, 200 mmol/L） solution adjusted to a pH of 8.60 with 1 mol/L sodium hydroxide （NaOH） solution was selected as the background electrolyte （BGE） through a uniform design. Calibration curve established on each day was linear over the MPA concentration range of 0.625-30.0 Bg/mL in human plasma with the correlation coefficient （r） larger than 0.9997. The limit of detection （LOD） was 0.200 ~tg/mL. Intra- and inter-day precisions at three concentrations within the calibration range were less than 4.45%. Plasma samples collected from 14 renal transplant recipients treated with the prodrug mycophenolate mofetil （MMF） were analyzed successfully by both the developed CZE technique and a validated high-performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS） technique. The mean absolute and relative differences between the concentrations measured by the two methods were -0.17 and -0.20%, respectively. In conclusion, the CZE method described here was validated to be accurate, precise, and economical for the clinical quantification of MPA.