Abstract:
:The methyl- and ethylsulphoxide diastereoisomers (V and VI) of the corticosteroid tipredane (INN, I) have been shown to undergo further stereoselective S-oxidation to yield diastereoisomeric disulphoxides (II). Interactive computer optimisation software was employed to develop semi-preparative chromatography conditions for the isolation of the disulphoxide diastereoisomers (II) and to develop a multiselective gradient HPLC analysis of tipredane (I), the four monosulphoxide diastereoisomeric pairs (V, VI, IX and X), the four disulphoxide diastereoisomers (II), the vinyl methyl and ethyl derivatives (XI and XII) and the methylsulphone of tipredane (VII). The four diastereoisomeric disulphoxides (II) have been isolated by semi-preparative HPLC and their structures unambiguously confirmed by high resolution multinuclear NMR and mass spectrometry. The stereochemical assignment of the four disulphoxide diastereoisomers (II), the ethylsulphoxide diastereoisomeric pair (VI), and the vinyl methyl and ethylsulphoxide diastereoisomeric pairs (IX and X) was determined by degradation/synthesis and relation to the S/R-disulphoxide (II) whose stereochemistry was determined by X-ray crystallography. The monosulphoxides (V and VI) showed a high degree of site and stereoselectivity towards further S-oxidation. S-Oxidation on the C-17 beta-substituent of tipredane occurred at a rate approximately 50-fold faster than that on the alpha-substituent. The disulphoxides (II) have been shown to be susceptible to thermolysis yielding the vinyl methylsulphoxide diastereoisomers (IX) preferentially. The loss of the ethylsulphenic acid from the disulphoxide diastereoisomers (II) could be rationalised in terms of the preferred rotamers of the C-17 substituents.
journal_name
J Pharm Biomed Analjournal_title
Journal of pharmaceutical and biomedical analysisauthors
Euerby MR,Graham JA,Johnson CM,Lewis RJ,Wallace DBdoi
10.1016/s0731-7085(96)01860-2subject
Has Abstractpub_date
1996-12-01 00:00:00pages
299-313issue
3eissn
0731-7085issn
1873-264Xpii
S0731708596018602journal_volume
15pub_type
杂志文章abstract::Popularity of natural-based preparations supporting the sexual potency significantly increased in recent years, which also led to the increase of illegal use of phosphodiesterase type 5 inhibitor (PDE-5) in sexual performance enhancement products. In this study, a rapid U-HPLC‒HRMS/MS method has been developed to simu...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2018.11.007
更新日期:2019-02-05 00:00:00
abstract::The pharmaceutical industry is under stringent regulations on quality control of their products because is critical for both, productive process and consumer safety. According to the framework of "process analytical technology" (PAT), a complete understanding of the process and a stepwise monitoring of manufacturing a...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2015.05.002
更新日期:2015-10-10 00:00:00
abstract::Radix Dipsaci (RD), the dried root of Dipsacus asper, is commonly used as a traditional Chinese medicine for the treatment of bone diseases and functions in strengthening bone and healing bone fractures. Nevertheless, the high polarity, non chromophores and low abundance of multiple compounds in this plant bring diffi...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2014.05.006
更新日期:2014-09-01 00:00:00
abstract::Macrocyclic antibiotics are present in an increasing number of chiral separation applications. In this study, erythromycin and some derivatives, belonging to the group of macrolide antibiotics, were investigated for their potential as chiral selector. Erythromycin A itself and five related substances namely erythromyc...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2003.11.004
更新日期:2004-03-10 00:00:00
abstract::Ligustici Rhizoma et Radix (LR), known as Gaoben (GB) in Chinese, has been used in traditional Chinese medicine for more than 2000 years. However, the varieties of LR are not well characterized at present, and traditional recognition methods have encountered increasing difficulties. This research attempts to distingui...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2018.02.053
更新日期:2018-05-30 00:00:00
abstract::The lipophilicity of a compound is a fundamental property related to pharmaceutical and biomedical activity. As many approaches are mixed together in every-day published studies, the subject needs some standardization. The paper presents a comparative study on several approaches of TLC lipophilicity determination: a s...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2010.06.024
更新日期:2010-12-01 00:00:00
abstract::The incubation of 14C-furosemide at high specific activity with intact red blood cells at 37 degrees C, pH 7.4, has enabled the furosemide binding sites to be characterized with respect to time course, affinity and specificity. The binding reaction was rapid, reversible and close to thermodynamic equilibrium. Binding ...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/0731-7085(89)80151-7
更新日期:1989-01-01 00:00:00
abstract::An ion mobility spectrometry (IMS) method was developed to screen for the presence of undeclared synthetic erectile dysfunction (ED) drugs or drug analogues in herbal dietary supplements claiming to enhance male sexual performance. Ion mobility spectra of authenticated reference materials including three FDA approved ...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2008.12.002
更新日期:2009-04-05 00:00:00
abstract::Protandim is an over-the-counter herbal dietary supplement. The key components of Protandim, i.e., epigallocatechin-3-gallate (EGCG), silibinin (SIL), and curcumin (CUR) were simultaneously analyzed through a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method in plasma and different tissues after admini...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2019.03.024
更新日期:2019-06-05 00:00:00
abstract::Covalent binding of reactive metabolites (RMs) to proteins is thought to play an important role in the processes leading to adverse drug reactions. Therefore, there is great interest in methodologies that enable the characterization of covalent binding of drugs to proteins. To facilitate the study of drug-protein addu...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2012.04.035
更新日期:2012-08-01 00:00:00
abstract::Over 100 chromatographic procedures for the separation of beta-blocker enantiomers are reviewed including a large number for the analysis of biological samples. All the principal chiral chromatographic procedures have found use, namely Chiral Mobile Phase Additives (CMPA), Chiral Derivatization Agents (CDA) and Chiral...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章,评审
doi:10.1016/0731-7085(92)80057-t
更新日期:1992-06-01 00:00:00
abstract::High-molecular-weight hyaluronan (HA) samples were exposed to free-radical chain-degradation reactions induced by ascorbate in the presence of Cu(II) ions - the so-called Weissberger's oxidative system. The concentrations of both reactants [ascorbate, Cu(II)] were comparable to those that may occur during an early sta...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2011.06.015
更新日期:2011-11-01 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::Quantitative whole-body autoradiography (QWBA) and liquid scintillation counting (LSC) have been conducted to determine the metabolic profiles and tissue distribution of [(14)C] labeled artesunate (AS) injection in rats. The QWBA technique showed more accurate results in the quantification of radioactivity in 40 organ...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2008.07.015
更新日期:2008-11-04 00:00:00
abstract::A comprehensive review with 276 references for the analysis of members of an important class of drugs, cephalosporin antibiotics, is presented. The review covers most of the methods described for the analysis of these drugs in pure forms, in different pharmaceutical dosage forms and in biological fluids. ...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章,评审
doi:10.1016/j.jpba.2007.06.002
更新日期:2007-09-21 00:00:00
abstract::A novel sensor based on a modification of glassy carbon electrode (GCE) with NH2-functionalized multi-walled carbon nano-tubes (NH2fMWCNTs) is reported and its applicability to the electrochemical sensing of Propafenone (PPF) demonstrated. The electrochemical catalytic activity was also utilized as a sensitive detecti...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2019.06.026
更新日期:2019-09-10 00:00:00
abstract::General multistep methods are described for the screening of the chemical and the physical stability and/or reactivity of new drug candidates. The chemical reactivity is studied in aqueous buffer solutions; the rate of degradation is measured as a function of pH. The products of the reaction mixture are evaluated at s...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/0731-7085(90)80094-6
更新日期:1990-01-01 00:00:00
abstract::An extracellular thermostable antibacterial peptide designated as MFAP9 was purified from marine Aspergillus fumigatus BTMF9 by ammonium sulfate precipitation followed by ion exchange chromatography on a DEAE-sepharose column. The molecular weight of MFAP9 was found to be∼3 kDa in SDS-PAGE gel corresponding a single i...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2020.113808
更新日期:2021-02-05 00:00:00
abstract::The relationship of glutamate acid decarboxylase (GAD) activity with the reaction products was developed. It was based on incubating sodium glutamate substrate (S) with GAD enzyme (E) when the enzyme-substrate-complex (ES) product was obtained along with gamma aminobutyric acid (GABA) and unreacted sodium glutamate. T...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/s0731-7085(98)00140-x
更新日期:1999-05-01 00:00:00
abstract::DuP 937, an anthrapyrazole antitumour agent that is chemically unstable in aqueous solution, was shown, by absorption spectroscopy, to form an inclusion complex with heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DM beta CD) in aqueous solution. Proton nuclear magnetic resonance spectroscopy was used to determine the st...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/0731-7085(94)00063-8
更新日期:1994-10-01 00:00:00
abstract::A combined pH/organic solvent linear gradient mode in high performance liquid chromatography (HPLC) is presented as a new approach to determination of low concentrations of ionogenic analytes in biological material. The approach consists in simultaneous development of linear gradients of pH and organic modifier in the...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2004.06.031
更新日期:2005-04-29 00:00:00
abstract::Ethylphenidate is a new potent synthetic psychoactive drug, structurally related to methylphenidate. Using human liver microsomes and cytosol, we have investigated for the first time the Phase-I and Phase-II in vitro metabolism of ethylphenidate. The structure of the metabolites was elucidated by hybrid quadrupole tim...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2015.09.029
更新日期:2016-01-05 00:00:00
abstract::This study is based on a plan of collecting different matrices (hair, eye, muscle, liver and kidney) in order to define a strategy for the control of the illegal use of clenbuterol in bovine production. Of all matrices utilised, hair is recommended for the analytical control of clenbuterol in living animals, due to it...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/s0731-7085(03)00073-6
更新日期:2003-06-01 00:00:00
abstract::Two HPLC systems have been developed for the investigation of flumecinol (3-trifluoromethyl-alpha-ethyl-benzhydrol). The reversed-phase system (LiChrosorb RP-18; methanol-water, 7:3, v/v) enables the isolation and identification of the impurities. The chiral system (Chiralcel OD; hexane-2-propanol, 98:2, v/v) separate...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/0731-7085(91)80088-q
更新日期:1992-10-01 00:00:00
abstract::The aim of this study was to evaluate the relationship between serum levels of beta-trace protein (BTP), a low molecular weight (MW) protein, and glomerular filtration rate (GFR). GFR and serum levels of BTP, and for comparison creatinine (Creat), cystatin C (Cys) and beta 2-microglobulin (beta 2M), were measured in 6...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/s0731-7085(03)00215-2
更新日期:2003-08-08 00:00:00
abstract::l-asparagine is a non-essential amino acid being used for a variety of pharmaceutical applications. The compound may be produced following synthetic or fermentative pathways leading to the formation of distinct impurities such as organic acids, other amino acids, dipeptides, or cyclic amino acid derivatives. Analysis ...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2016.08.035
更新日期:2016-11-30 00:00:00
abstract::Different therapeutically active ingredients, from plants, animals, and mineral sources, are prescribed as traditional Chinese medicines (TCM). TCMs, from animal sources, are rich in proteins and peptides. Different advanced proteomics technologies, such as two-dimensional gel electrophoresis (2-DE), multi-dimensional...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章,评审
doi:10.1016/j.jpba.2020.113609
更新日期:2020-11-30 00:00:00
abstract::The human Dialyzed Leukocyte Extract (DLE) is a heterogeneous mix of oligopeptides of <10kDa, extracted from leukocytes of healthy donors. There is significant clinical evidence of improvement using DLE during treatment of allergies, cancer,immunodeficiencies, and in mycotic and viral infections. Nevertheless, the DLE...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2017.01.052
更新日期:2017-05-10 00:00:00
abstract::This study aimed to reveal chemical profiles and biological activities of ethyl acetate (EA), methanol (MeOH), and water extracts of Lotus corniculatus. Ethnobotanical reports have indicated the importance of phytochemical properties of the genus Lotus. In this study, the effects of medicinal plant extracts on antioxi...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2019.05.068
更新日期:2019-09-10 00:00:00
abstract::A sensitive, selective and rapid liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-MS/MS) method has been developed for the quantification of the novel transforming growth factor-β (TGF-β) inhibitor SB-505124 in rat plasma and then validated. Plasma samples were prepared by simple protein prec...
journal_title:Journal of pharmaceutical and biomedical analysis
pub_type: 杂志文章
doi:10.1016/j.jpba.2015.09.002
更新日期:2016-01-05 00:00:00