Abstract：
:Michaelis constant of enzymatic reaction was evaluated by affinity capillary electrophoresis using beta-galactosidase as a model enzyme and o- and p-isomers of nitrophenyl-beta-galactoside as substrates. The enzyme was immobilized on the inner surface of a fused-silica capillary by the covalent bonding through a bridging group, and the substrates were introduced into the capillary. The reaction products migrated electrophoretically toward the detection side (anodic side), while the unreacted substrates moved toward the injection side (cathodic side) on a slow electroosmotic flow generated by the weak negative charge of the immobilized enzyme. The initial velocity of the enzymatic reaction was estimated from the peak height of the product, and the Michaelis constant was calculated according to Lineweaver-Burk equation. The results (Km, 2.34 mM for o-isomer and 1.09 mM for p-isomer) were reproducible (RSD < 11.8%, n = 5). Although the estimated Michaelis constants were larger than the reported values measured in homogeneous solution, the ratio of the Michaelis constants of o-/p-isomers was in good agreement with the literature value. The present method required as low as a few microgram amount of enzyme and nanogram amount of substrate which is far smaller than those required in a conventional affinity HPLC.
journal_name
J Pharm Biomed Analjournal_title
Journal of pharmaceutical and biomedical analysisauthors
Yoshimoto Y,Shibukawa A,Sasagawa H,Nitta S,Nakagawa Tdoi
10.1016/0731-7085(95)01337-ksubject
Has Abstractpub_date
1995-04-01 00:00:00pages
483-8issue
4-5eissn
0731-7085issn
1873-264Xpii
0731-7085(95)01337-Kjournal_volume
13pub_type
杂志文章abstract：:Xanthine oxidase (XO) is a key enzyme that can catalyze the conversion of xanthine to uric acid, causing various diseases in humans. We have developed a high-throughput chip-based assay that uses a photodiode array (PDA) microchip system to explore the inhibitory effects of drug analogs on XO. Inhibitory activities of...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2009.07.020
更新日期：2010-01-05 00:00:00
abstract：:The deuterohemin-peptide conjugate (DhHP-6) is a microperoxidase mimetic, which has demonstrated substantial benefits in vivo as a scavenger of reactive oxygen species. This paper reports the development of a sensitive and rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method for the determination of ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2014.06.026
更新日期：2014-09-01 00:00:00
abstract：:Using the regression model building the relationships between the concentration of 37 fatty acids of blood plasma phospholipids of 41 patients with coronary artery disease after coronary stent implantation, the inflammatory response and oxidative stress markers were estimated. The dynamics of the inflammatory response...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2017.10.033
更新日期：2018-02-05 00:00:00
abstract：:Studies on molecular interactions between cellular receptors of herpes simplex virus (HSV) and the viral glycoproteins showing receptor-binding activity are of great relevance for understanding the molecular basis of virus entry. Information on such interactions further provides the basis for a rational design of anti...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(03)00177-8
更新日期：2003-08-08 00:00:00
abstract：:An LC procedure was developed to separate diatrizoate sodium from three known impurities. These impurities are 2,4- and 2,6-diiodo-3,5-diacetamidobenzoic acid (DDZA), and the free amine (5-acetamido-3-amino-2,4,6-triiodobenzoic acid). The separation was achieved using a Hamilton, PRP-X100, anion exchange column. The r...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(97)00007-1
更新日期：1997-09-01 00:00:00
abstract：:An analytical GC-MS method based on nonpolar fused silica capillary column was developed to analyze the lipophilic constituents, mainly alkamides, from the root extracts of Echinacea purpurea (L.) Moench. In particular, the proposed method was applied to evaluate the phytochemical impacts of cucumber mosaic cucumoviru...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(02)00146-2
更新日期：2002-08-01 00:00:00
abstract：:A method for the separation of a mixture of terbutaline and non-steroidal anti-inflammatory drugs was developed using capillary electrophoresis with a new hemispherodextrin, ad hoc designed, the lysine - bridged hemispherodextrin (THLYSH). The use of lysine residues to bridge the trehalose capping unit moiety to the c...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2017.07.041
更新日期：2017-10-25 00:00:00
abstract：:A PVC membrane electrode, without inner reference solution, based on an ion association extraction system responding to methadone (MD) is described. It incorporates a methadone-tetrakis(4-chlorophenyl)borate ion-pair complex in 2-nitrophenyloctyl ether. The prepared electrode exhibits a near Nernstian response (59.5 m...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(02)00694-5
更新日期：2003-03-10 00:00:00
abstract：:A refined toxic fraction, Fr-2, from the ethanol extract of Aster tataricus roots was obtained by a toxic tracing isolation. The hepatotoxic effects of Fr-2 were proved by the level elevation of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) in mice serum and further co...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2012.04.034
更新日期：2012-08-01 00:00:00
abstract：:Three configurations based on the principles behind flow injection analysis (FIA) are proposed for the automatic determination of enzymatic activity. The proposed approaches are normal, stopped-flow and open-closed FIA. The comparative study of the methods developed from these approaches allows the establishment of th...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(89)80096-2
更新日期：1989-01-01 00:00:00
abstract：:An automated electronic tongue consisting of an array of potentiometric sensors and an artificial neural network (ANN) has been developed to resolve mixtures of anionic surfactants. The sensor array was formed by five different flow-through sensors for anionic surfactants, based on poly(vinyl chloride) membranes havin...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2007.09.013
更新日期：2008-01-22 00:00:00
abstract：:Ginseng saponins isolated from ginseng, have been regarded as the principal constituents responsible for the biological activities. The aim of this study was to set up a liquid chromatography-mass spectrometry (LC-MS) method for simultaneously determine the concentration of Ginsenoside Rg1 and its secondary glycoside ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2004.12.007
更新日期：2005-06-01 00:00:00
abstract：:This study reports the first ever development and validation of a quantification method for a lantibiotic in plasma. This method was developed for the quantification of total MU1140 in Sprague Dawley rat plasma. The procedure involved acidification of plasma samples with formic acid followed by precipitation of plasma...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2008.12.022
更新日期：2009-05-01 00:00:00
abstract：:A first-derivative spectrophotometric method for the determination of irbesartan (IRB) alone and in the presence of hydrochlorothiazide (HCT) is described. Measurements are made at the zero-crossing wavelength at 263.0 nm for IRB. The calibration graph was linear over the range 1.0-12.0 mg l(-1) of IRB, detection limi...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(02)00073-0
更新日期：2002-06-20 00:00:00
abstract：:Spectrophotometric procedures for the determination of two irriversible proton pump inhibitors, omeprazole (OMZ) and pantoprazole (PNZ) sodium have been developed, the procedures are based on the formation of 2:1 chelates of both drugs with different metal ions. Pantoprazole sodium is quantified by a stability-indicat...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(03)00233-4
更新日期：2003-10-15 00:00:00
abstract：:The aim of this work was to obtain the direct optical resolution of a new glutamate receptor antagonist ((p-chloro)1-aryl-6,7,-dimethoxy-1,2,3,4-tetrahydroisoquinoline, PS3), by liquid chromatography on Chiralcel OD column. A response surface methodology (RSM) was employed to optimize the enantiomeric separation of th...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2006.05.023
更新日期：2006-11-16 00:00:00
abstract：:Under positive-ion fast atom bombardment (FAB) mass spectrometric conditions, benzalkonium chloride (BAK) afforded intense peaks at m/z 304 and 332, corresponding to the intact cations [M--Cl]+ of C12 and C14 homologues, respectively. The use of benzethonium chloride as an internal standard and thioglycerol as a FAB m...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(89)80172-4
更新日期：1989-01-01 00:00:00
abstract：:Fluoxetine hydrochloride has been prepared using two similar synthetic routes, both of which rely upon an ether formation reaction mediated by a base. The base used can affect the impurity profile of this reaction. It was proposed that the synthesis of fluoxetine carried out using potassium t-butoxide as base and 4-ch...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(02)00605-2
更新日期：2003-02-05 00:00:00
abstract：:This paper presents a facile and selective method for the determination of the pharmaceutical compound nafronyl using heavy atom induced room temperature phosphorimetry (HAI-RTP) as analytical technique. The determination was performed in potassium iodide 1.6 M and sodium sulphite 0.002 M at a measurement temperature ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(00)00391-5
更新日期：2000-10-01 00:00:00
abstract：:Propofol concentration in human plasma can be quantified by liquid chromatography coupled mass spectrometry. Sample preparation usually requires solid phase extraction to remove matrix components and enrich the analyte. To facilitate user-independent measurements and speed extraction, we developed and validated a full...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2017.12.043
更新日期：2018-02-20 00:00:00
abstract：:The binding of carbamazepine (CBZ) to human serum albumin (HSA) was investigated under simulative physiological conditions. In this study, intrinsic fluorescence of tryptophan-214 in HSA was monitored upon the addition of CBZ. Binding constant of CBZ-HSA was calculated by the remarkable static quenching effect of CBZ ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2010.05.025
更新日期：2010-11-02 00:00:00
abstract：:Two monoglucuronides (CA1G1 and CA1G2) of the catecholic cis-stilbene Combretastatin A1 (CA1, OXi4500), have been identified in a clinical trial of the bisphosphate prodrug of OXi4500, OXi4503. A validated assay for the two glucuronides in human plasma using HPLC with fluorescence detection after post-column photolysi...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2011.12.022
更新日期：2012-03-25 00:00:00
abstract：:An automated solid-phase extraction workstation was used to develop, characterize and validate two separate HPLC methods for quantifying drugs in plasma. Method development was facilitated by workstation functions which allowed wash solvents of varying organic composition to be mixed and tested automatically. The prec...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(97)00278-1
更新日期：1998-08-01 00:00:00
abstract：:An analytical method to study the bioavailability of newly developed pentoxifylline sustained-release tablets has been developed and assessed in experiments on dogs. For the isolation of pentoxifylline and its metabolites from serum solid-liquid extraction was applied by involving the internal standard probe. HPTLC pl...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(91)80153-z
更新日期：1991-01-01 00:00:00
abstract：:An antibiotic-affinity method was developed for analyzing Staphylococcus on the basis of the strong binding capability of daptomycin towards Gram-positive bacteria cellular membrane, as well as the selective lytic action of lysostaphin towards Staphylococcus. Daptomycin-modified magnetic beads were adopted to enrich S...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2019.112785
更新日期：2019-10-25 00:00:00
abstract：:The clinical effect of glucosamine, the most widely used supplement in patients with osteoarthritis, on joint pain and function improvement, is reported to be inconsistent. Inter-patient variability in the pharmacokinetics of glucosamine, especially its oral absorption, could contribute to the inconsistent clinical ou...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2019.112954
更新日期：2020-01-30 00:00:00
abstract：:In a multicentre study involving six laboratories, a microbiological assay was performed on three neomycin samples containing respectively, 0.12, 2.1 and 11% (m/m) of neomycin C, as well on a pure neomycin C sample. The potency was determined according to the European Pharmacopoeia method but using a neomycin B base s...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(97)00247-1
更新日期：1998-08-01 00:00:00
abstract：:A new tadalafil analogue was identified along with homotadalafil during routine screening of an adulterated dietary supplement using HPLC-DAD. The UV spectrum of this analogue was almost identical with that of tadalafil. This compound was isolated from the supplement by using semi-preparative HPLC and its structure wa...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2015.07.023
更新日期：2015-11-10 00:00:00
abstract：:The equivalent response of evaporative light scattering detector (ELSD) for compounds of similar structure is exploited to develop an LC/ELSD method for the simultaneous quantitation of the four main components of gentamicin sulfate, using as external standard the one main component kanamycin. A C18 column was used al...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2004.05.018
更新日期：2004-09-21 00:00:00
abstract：:A simple, rapid and reproducible method for identification and quantification of iodopropynyl butylcarbamate (IPBC) in different cosmetic formulations is presented. The determination was carried out using a high-performance liquid chromatography (HPLC) procedure on a reversed phase column coupled to a single quadrupol...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(01)00356-9
更新日期：2001-07-01 00:00:00
