Abstract：
:The mixture of creatinine, activated charcoal and water was stirred. As a result the conversion of creatinine into two products was observed. (1)H, (13)C NMR and HMBC spectra were recorded and the chemical shifts assigned. Two uremic toxins: creatol and N-methylguanidine were identified. To interpret the NMR data obtained, the optimum structure of creatol, which can exist in the forms of seven tautomers, has been calculated using the DFT B3LYP/6-311G(2d,p) method. The influence of the solvent was described by the polarizable continuum model (PCM). The calculated energy of the most energetically stable tautomeric form A is lower by 12.2, 16.9, 33.8, 81.5, 106.3, 130.4kJ/mol in water than that of the tautomers B-G, respectively, which suggests that the A form of creatol should prevail in solution. In DMSO, the calculated energy of the most energetically stable tautomeric form A is lower than that of both D and B and the remaining tautomeric forms (C, E-G) are less energetically stable. Subsequently, we sought the correlations between the experimental and the calculated chemical shifts of protons and carbons-13 for the forms -A, B (in water) and A, B, D (in DMSO) - of creatol. The population of the A tautomer is predominant in both H(2)O and DMSO. We have also recorded the spectra of creatol and N-methylguanidine at different pH. Our data are complete enough to be used in the analysis of body fluids.
journal_name
J Pharm Biomed Analjournal_title
Journal of pharmaceutical and biomedical analysisauthors
Krawczyk Hdoi
10.1016/j.jpba.2009.02.012subject
Has Abstractpub_date
2009-05-01 00:00:00pages
945-9issue
4eissn
0731-7085issn
1873-264Xpii
S0731-7085(09)00113-7journal_volume
49pub_type
杂志文章abstract：:The development of biosensor technologies for the investigation of biomolecular interactions has markedly advanced over the last years. One promising biosensor platform, the Bio-Layer Interferometry (BLI), was developed by ForteBio with the main focus to qualify and quantify protein/protein interactions in research an...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2012.10.008
更新日期：2013-01-01 00:00:00
abstract：:The electrochemical reduction of meloxicam has been studied at a mercury electrode using various electrochemical methods in aqueous solutions over a wide pH range. The reduction of the drug produced a single reduction step in acidic media, whereas in slightly acidic and neutral media two reduction steps were observed....
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(01)00528-3
更新日期：2002-02-01 00:00:00
abstract：:A method of analysis of SC-560 (5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole) in biological fluids is necessary to study the kinetics of in vitro and in vivo metabolism. A simple high-performance liquid chromatographic method was developed for simultaneous determination of SC-560 and other pr...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2004.03.013
更新日期：2004-09-03 00:00:00
abstract：:Medroxyprogesterone acetate (MPA) injectable products are a key commodity for reproductive health and are available in the global market from a variety of manufacturing sources. Depending on the climatic zone conditions of the destination country for product use, MPA injectables are at risk of exposure to adverse tran...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2020.113352
更新日期：2020-08-05 00:00:00
abstract：:The elevated cardiovascular morbidity and mortality in chronic kidney disease (CKD) is linked with endothelial dysfunction secondary to the pro-inflammatory and pro-oxidative state typical of this pathology. In consideration of the well-known pleiotropic effect of statins, we investigated the effect of cholesterol low...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2016.07.025
更新日期：2016-09-10 00:00:00
abstract：:A reversed-phase high-performance liquid chromatographic (HPLC) method was developed and validated for evaluating the chiral discrimination ability of CYCLOBOND I 2000 DM chiral stationary phase (CSP) towards sertraline and its related enantiomers. The effect of pH, buffer concentration as well as nature of organic mo...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2009.04.038
更新日期：2009-10-15 00:00:00
abstract：:The use of Near-infrared spectroscopy (NIRS) as a fast and non-destructive technique was employed for moisture content (MC) determination in Antibody-drug conjugates (ADCs) in replacement to Karl Fischer (KF) method. The lab analysis of ADCs, high potent medicines, should be performed in conditions ensuring the operat...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2016.09.014
更新日期：2016-11-30 00:00:00
abstract：:A sensitive enantioselective liquid chromatography-mass spectrometry (LC-MS) assay using a manual solid-phase extraction (SPE) procedure, a non-deuterated internal standard and an ion trap LC-MS was developed to measure (R)- and (S)-albuterol in plasma. Sample extraction from plasma was achieved by a manual SPE extrac...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(02)00734-3
更新日期：2003-04-10 00:00:00
abstract：:Medicinal plant materials are not usually analysed for condensed tannins (CT). Thirty commercially available European medicinal plants and herbal products were screened for CT and fourteen CT samples were analysed in detail. This is also the first comprehensive CT analysis of pine buds, walnut leaves, heather flowers ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2015.12.034
更新日期：2016-03-20 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：:This study addresses the lack of data on the stability of carfilzomib, a newly approved proteasome-inhibiting anticancer drug. A new stability-indicating UHPLC-UV method for analysis of carfilzomib was developed and validated within the concentrations of 10-250 μg/mL. The aforementioned method was utilized to evaluate...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2016.03.015
更新日期：2016-05-30 00:00:00
abstract：:A novel stability-indicating reversed phase high performance liquid chromatographic (RP-HPLC) method for the simultaneous assay of betamethasone-17-valerate, fusidic acid and potassium sorbate as well as methyl- and propylparaben in a topical cream preparation has been developed. A 100mm×3.0mm ID. Ascentis Express C18...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2014.03.005
更新日期：2014-08-05 00:00:00
abstract：:The principles of multivariate calibration (MC) are presented, with reference to the main objectives of this chellometrics technique: the reduction of the variance in the prediction of a response variable (generally, a chemical quantity) and the possibility of the determination of the response in complex matrices with...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章,评审
doi：10.1016/s0731-7085(98)00153-8
更新日期：1998-10-01 00:00:00
abstract：:Capillary zone electrophoresis (CZE) with carboxyethyl-beta-cyclodextrin (CE-beta-CD) dissolved in the operating buffer was used for the separation and determination of enantiomers of phenothiazine antihistaminic, dioxopromethazine, in commercial pharmaceutical preparation, eye drops. This chiral selector, negatively ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/s0731-7085(03)00254-1
更新日期：2003-09-19 00:00:00
abstract：:The optimization of the HPLC procedures and the investigation of the predictive models are generally seen as distinct tasks although they could be both approached by very similar chemometric methods. In this work we used chemometric approaches to both optimize the separation of a non-steroidal anti-inflammatory drugs ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2009.08.001
更新日期：2010-01-05 00:00:00
abstract：:The contamination of commonly used supplements by unknown steroids as well as their metabolites (parent compounds) become a challenge for the analytical laboratories. Although the determination of steroids profile is not trivial because of the complex matrix and low concentration of single compound, one of the most di...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2014.11.017
更新日期：2015-03-15 00:00:00
abstract：:Lipid nanoparticles, especially liposomes and lipid/nucleic acid complexed nanoparticles have shown great success in the pharmaceutical industry. Their success is attributed to stable drug loading, extended pharmacokinetics, reduced off-target side effects, and enhanced delivery efficiency to disease targets with form...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章,评审
doi：10.1016/j.jpba.2020.113642
更新日期：2021-01-05 00:00:00
abstract：:Guest-host interactions of sildenafil (Sild) with cyclodextrins (CyDs) have been investigated using several techniques including phase solubility diagrams (PSD), differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), proton nuclear magnetic resonance (1H NMR) and molecular mechanical modeling (MM...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2006.01.055
更新日期：2006-06-07 00:00:00
abstract：:A stability study for amodiaquine (AQ) and desethylamodiaquine (AQm) in whole blood and plasma is reported. AQ, AQm and chloroquine (CQ) were simultaneously analysed and the ratios AQ/CQ and AQm/CQ were used to ensure correct interpretation of the stability results. CQ was stable in whole blood and plasma at all teste...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2005.10.018
更新日期：2006-04-11 00:00:00
abstract：:In traditional Chinese medicine practice, crude herbs are often subjected to traditional processing (Paozhi in Chinese) for a special medicinal purpose. Bran-frying is one of processing methods for Paeoniae Radix Alba (PRA). Previous studies found that paeoniflorin and paeoniflorin sulfonate, a principle bioactive com...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2018.07.003
更新日期：2018-09-10 00:00:00
abstract：:Near-infrared (NIR) spectroscopy is one of the most successful pharmaceutical process analytical tools. For botanical drug products (BDPs), many studies have applied NIR spectroscopy for rapid analysis of botanical raw materials, extracts and formulations. However, the real-time process analysis reported for BDPs was ...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2019.06.046
更新日期：2019-09-10 00:00:00
abstract：:A pure β-D-Glucopyranosiduronic acid metabolite (≥98.0 % purity and a single impurity ≤0.50 %) was requested for biological studies. Due to its unusual instability, the purification of the glucuronide metabolite was extremely challenging. Initially, the crude sample (89 % HPLC area purity) was purified on a Waters S...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2020.113651
更新日期：2021-01-05 00:00:00
abstract：:The purpose of this study was to investigate whole-dosage form UV-vis imaging as a potential tool for functional characterization of excipients used in solid oral dosage forms. To this end, tablets (average mass 260.0 mg, 224.5 mg and 222.1 mg) containing theophylline anhydrate (20 % w/w), 1% (w/w) magnesium stearate,...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2020.113789
更新日期：2021-02-05 00:00:00
abstract：:Statistical modelling and experimental design (SMED) are essential tools for the development and understanding of complicated products and processes. SMED allows efficient experimentation in which all or a large subset of factors are together varied over a set of experiments, in contrast to the traditional approach of...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(91)80185-c
更新日期：1991-01-01 00:00:00
abstract：:A main challenge in the development of biosensing devices for the identification and quantification of nucleic acids is to avoid the amplification of the genetic material from the sample by polymerase chain reaction (PCR), which is at present necessary to enhance sensitivity and selectivity of assays. PCR has undoubte...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章,评审
doi：10.1016/j.jpba.2020.113645
更新日期：2021-01-05 00:00:00
abstract：:3-Quinuclidinyl benzilate (QNB) is an anticholinergic compound that affects the nervous system. Its hallucinogenic action has led to its potential utility as an incapacitating warfare agent, and it is listed in Schedule 2 by the Organization for the Prohibition of Chemical Weapons. Although this compound has been know...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2020.113519
更新日期：2020-10-25 00:00:00
abstract：:A rapid, sensitive and specific high-performance liquid chromatographic (HPLC) assay is reported for the determination of 4-amino-1-hydroxybutane-1, 1-diphosphonic acid (AHBuDP) monosodium salt trihydrate, a new inhibitor of bone resorption. The compound does not demonstrate any intrinsic UV properties and thus pre-co...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/0731-7085(89)80186-4
更新日期：1989-01-01 00:00:00
abstract：:Inulin-type fructooligosaccharides (FOS) purified from Morinda Officinalis, with degrees of polymerization (DP) from 3 to 9, have been approved in China as an oral prescribed drug for mild and moderate depression episode, while the stability and oral absorption of this FOS mixtures are largely unknown. As the main act...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2018.04.028
更新日期：2018-07-15 00:00:00
abstract：:A sensitive and specific method for the determination of bifendate in human plasma was developed, based on high-performance liquid chromatography (HPLC)-mass spectrometry (MS). The samples were extracted from plasma with diethyl ether, followed by separation and evaporation after addition of internal standard diazepam...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 临床试验,杂志文章
doi：10.1016/j.jpba.2005.08.007
更新日期：2006-03-03 00:00:00
abstract：:This paper describes a new LC-MS/TOF method for the degradation products determination when Etifoxine (ETI) is submitted to different stress conditions. Chromatography is performed by using Kromasil C18 column (250mm×4.6mm, 5μm particle size). The selected mobile phase consists of formate buffer 0.02M, pH 3 and methan...
journal_title：Journal of pharmaceutical and biomedical analysis
pub_type： 杂志文章
doi：10.1016/j.jpba.2014.07.017
更新日期：2014-11-01 00:00:00
