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At least 451 records · Page 25Linked to original sources
PubMed2005

High performance liquid chromatographic determination of N-butyryl glucosamine in rat plasma.

PURPOSE: A high performance liquid chromatography (HPLC) method for determination in plasma of N-butyryl glucosamine (GLBU), a highly water-soluble compound with no chromophore was developed. METHOD: To 100 muL of plasma containing GLBU was added fucose as internal standard. GLBU and fucose were derivatized using 1-phenyl-3-methyl-5-pyrazolone in the presence of sodium hydroxide at 70 degrees C for 30 min. The solution was neutralized with hydrochloric acid and the excess derivatizing reagent was extracted with chloroform. The aqueous layer was injected into an isocratic HPLC system consisting of an autoinjector, a single pump and a UV detector set at 245 nm. Two different 25 cm reversed phase columns were used, a 4 and a 10 microm C(18) columns. The mobile phase was a mixture of phosphate buffer (pH 7) and acetonitrile (80:20), which was run through a pump at a flow rate of 1.0 mL/min at ambient temperature. RESULTS: Derivatized fucose and GLBU appeared 24 and 28 min, and at 34 and 37 min using 4 and 10 microm columns, respectively. The assay was linear over the range of 0.2-200 microg/mL with a limit of quantification of 0.2 and 1 microg/mL for the 4 and 10 microm columns, respectively. The method was applied to the determination of GLBU in rat plasma after oral administration of 233 mg/kg of GLBU. CONCLUSION: The present assay is precise, and accurate with sufficient sensitivity for pharmacokinetic studies following therapeutically relevant doses.

Administration, Oral↗
PubMed2006

Cloud point extraction and graphite furnace atomic absorption spectrometry determination of manganese(II) and iron(III) in water samples.

Cloud point extraction (CPE) was applied as a preconcentration step prior to graphite furnace atomic absorption spectrometry (GFAAS) determination of manganese(II) and iron(III) in water samples. After complexation with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP), the analytes could be quantitatively extracted to the phase rich in the surfactant p-octylpolyethyleneglycolphenylether (Triton X-100) and be concentrated, then determined by GFAAS. The parameters affecting the extraction efficiency, such as solution pH, concentration of PMBP and Triton X-100, equilibration temperature and time, were investigated in detail. Under the optimum conditions, preconcentration of 10 ml of sample solution permitted the detection of 0.02 ng ml(-1) of Mn(II) and 0.08 ng ml(-1) of Fe(III) with enrichment factors of 31 and 25 for Mn(II) and Fe(III), respectively. The proposed method was applied to determination of trace manganese(II) and iron(III) in water samples with satisfactory results.

Iron↗
PubMed2006

Determination of trace nickel in water samples by cloud point extraction preconcentration coupled with graphite furnace atomic absorption spectrometry.

A new method based on the cloud point extraction (CPE) preconcentration and graphite furnace atomic absorption spectrometry (GFAAS) detection was proposed for the determination of trace nickel in water samples. When the micelle solution temperature is higher than the cloud point of surfactant p-octylpolyethyleneglycolphenyether (Triton X-100), the complex of Ni2+ with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) could enter surfactant-rich phase and be concentrated, then determined by GFAAS. The main factors affecting the cloud point extraction were investigated in detail. An enrichment factor of 27 was obtained for the preconcentration of Ni2+ with 10 mL solution. Under the optimal conditions, the detection limit of Ni2+ is 0.12 ng mL(-1) with R.S.D. of 4.3% (n = 10, c = 100 ng mL(-1)). The proposed method was applied to determination of trace nickel in water samples with satisfactory results.

Nickel↗
PubMed2006

The action of urocortins on body temperature in rats.

The actions of individual urocortins on colon temperature were studied in rats. Urocortin 1, urocortin 2 or urocortin 3 was injected into the lateral brain ventricle in conscious rats and the colon temperature was measured at different times following injection, for up to 6 h. In order to study the possible role of prostaglandins, the animals were treated with either a urocortin together with the pyrazolone derivative noraminophenazone to inhibit the action of cyclooxygenase in initiating hyperthermia, or with noraminophenazone 30 min following urocortin administration to act on existing hyperthermia. Noraminophenazone was administered intramuscularly in a dose of 50 mg/kg. Urocortin 1 caused a dose-related increase in colon temperature, maximal action being observed at a dose of 2 microg with the maximal increase in body temperature at 4 h. Noraminophenazone prevented the urocortin-induced increase in colon temperature and attenuated the already existing elevated body temperature. Somewhat similar action was observed with urocortin 2. However, following treatment with 0.5 or 1.0 microg urocortin 2, the action was already over at 2 h, whereas 2 microg increased the colon temperature steadily, with a maximum at 4 h. Noraminophenazone blocked or diminished the action of urocortin 2. Urocortin 3 in a dose of 1 microg was the most effective in increasing the colon temperature; the maximal effect was observed at 2 h. Noraminophenazone blocked the development of urocortin 3-induced hyperthermia, or attenuated it when the hyperthermia was already present. The results demonstrated that urocortin 1, 2 or 3 caused increases in body temperature when injected into the lateral brain ventricle, though the optimal dose and the duration of hyperthermia differed for the individual urocortins. The cyclooxygenase inhibitor blocked or diminished the action of these urocortins, indicating the involvement of prostaglandins in urocortin-induced hyperthermia.

Animals↗
PubMed2005

Structural model of dioxouranium(VI) with hydrazono ligands.

Synthesis and characterization of several new coordination compounds of dioxouranium(VI) heterochelates with bidentate hydrazono compounds derived from 1-phenyl-3-methyl-5-pyrazolone are described. The ligands and uranayl complexes have been characterized by various physico-chemical techniques. The bond lengths and the force constant have been calculated from asymmetric stretching frequency of OUO groups. The infrared spectral studies showed a monobasic bidentate behaviour with the oxygen and hydrazo nitrogen donor system. The effect of Hammett's constant on the bond distances and the force constants were also discussed and drawn. Wilson's matrix method, Badger's formula, Jones and El-Sonbati equations were used to determine the stretching and interaction force constant from which the UO bond distances were calculated. The bond distances of these complexes were also investigated.

Hydrazones↗
PubMed2005

Identification of a novel conjugate in human urine: bile acid acyl galactosides.

We report a novel conjugate, bile acid acyl galactosides, which exist in the urine of healthy volunteers. To identify the two unknown peaks obtained in urine specimens from healthy subjects, the specimens were subjected to solid phase extraction and then to liquid chromatographic separation. The eluate corresponding to the unknown peaks on the chromatogram was collected. Following alkaline hydrolysis and liquid chromatography (LC)/electrospray ionization (ESI)-mass spectrometric (MS) analysis, cholic acid (CA) and deoxycholic acid (DCA) were identified as liberated bile acids. When a portion of the alkaline hydrolyzate was subjected to a derivatization reaction with 1-phenyl-3-methyl-5-pyrazolone, a derivative of galactose was detected by LC/ESI-MS. Finally, the liquid chromatographic and mass spectrometric properties of these unknown compounds in urine specimens were compared to those of authentic specimens and the structures were confirmed as CA 24-galactoside and DCA 24-galactoside. These results strongly imply that bile acid 24-galactosides, a novel conjugate, were synthesized in the human body.

Adult↗
PubMed2005

Oxidation of pharmaceuticals during water treatment with chlorine dioxide.

The potential of chlorine dioxide (ClO2) for the oxidation of pharmaceuticals during water treatment was assessed by determining second-order rate constants for the reaction with selected environmentally relevant pharmaceuticals. Out of 9 pharmaceuticals only the 4 following compounds showed an appreciable reactivity with ClO2 (in brackets apparent second-order rate constants at pH 7 and T = 20 degrees C): the sulfonamide antibiotic sulfamethoxazole (6.7 x 10(3) M(-1) s(-1)), the macrolide antibiotic roxithromycin (2.2 x 10(2) M(-1) s(-1)), the estrogen 17alpha-ethinylestradiol (approximately 2 x 10(5) M(-1) s(-1)), and the antiphlogistic diclofenac (1.05 x 10(4) M(-1) s(-1)). Experiments performed using natural water showed that ClO2 also reacted fast with other sulfonamides and macrolides, the natural hormones estrone and 17beta-estradiol as well as 3 pyrazolone derivatives (phenazone, propylphenazone, and dimethylaminophenazone). However, many compounds in the study were ClO2 refractive. Experiments with lake water and groundwater that were partly performed at microgram/L to nanogram/L levels proved that the rate constants determined in pure water could be applied to predict the oxidation of pharmaceuticals in natural waters. Compared to ozone, ClO2 reacted more slowly and with fewer compounds. However, it reacted faster with the investigated compounds than chlorine. Overall, the results indicate that ClO2 will only be effective to oxidize certain compound classes such as the investigated classes of sulfonamide and macrolide antibiotics, and estrogens.

Anti-Bacterial Agents↗
PubMed1977

The synthesis of D-ribofuranosyl derivatives of methyl propiolate and a study of the activating influence of the ester group in cycloaddition reactions.

2,3,5-Tri-O-benzyl-D-ribofuranosyl bromide (17) has been converted into methyl 3-(2,3,5-tri-O-benzyl-beta-D-ribofuranosyl) propiolate (8) and its alpha anomer 10 in 21 and 42% yields, respectively, by reaction with the silver salt of methyl propiolate. Attempts to prepare 8 from (beta-D-ribofuranosyl)ethyne (1) by standard methods were unsuccessful. The reactions of the esters 8 and 10 and the ethyne 1 with several 1,3-dipoles have been examined. With diazomethane, 8 and 10 gave the pyrazole esters 20 and 28, respectively, whereast the ethyne 1 reacted more slowly to give a mixture of 23 (37%) and 26 (31%). The ester 10 was converted into the triazoles 32 (51%) and 36 (34%) by reaction with benzyl azide. Treatment of the ester 10 with phenylhydrazine gave the pyrazolone 38 in 71% yield. A number of the products of dipolar addition have been converted into new D-ribofuranosyl-pyrazoles and -triazoles by hydrogenolysis.

Chemical Phenomena↗
PubMed1979

Characteristics of lithium iodide-containing poly(ethylene glycol) as a gas chromatographic stationary phase, and its application to analysis of amidic drugs.

The characteristics of lithium iodide-containing poly(ethylene glycol) as a gas chromatographic stationary phase have been evaluated in terms of partial free energy of transfer (delta G t0) from poly(ethylene glycol) to the lithium iodide-poly(ethylene glycol) system for a variaty of amides (n-fatty acid amides, lactams, benzamides, anilides, nicotinamides, isonicotinamides, barbiturates, pyrazolones) and several amines. The changes in relative retention and resolution of two solute peaks caused by the addition of lithium iodide to poly)ethylene glycol) are correlated with the difference in their delta Gt0 values. The application to the specific separation of some amidic drugs is demonstrated.

Amides↗
PubMed1987

Determination of p-cresidine in FD&C red no. 40 by the diazotization and coupling procedure followed by reversed-phase high-performance liquid chromatography.

The free aromatic amine p-cresidine is determined at low ppb (10(9] levels in the regulated color additive FD&C Red No. 40. The determination involves chloroform extraction of p-cresidine and other unsulfonated impurities from the color additive, followed by diazotization of the aromatic amines and coupling with the disodium salt of 3-hydroxy-2,7-naphthalenedisulfonic acid (R-salt). The coupling products are then determined by reversed-phase high-performance liquid chromatography. Calibration is performed in the presence of the color additive by using the external standard method. The identity of the p-cresidine coupling product is confirmed by obtaining a UV-VIS spectrum of the eluting solute. The presence of aniline in commercial batches is also confirmed in this manner by using 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid (pyrazolone-T) as an alternative coupling agent.

Aniline Compounds↗
PubMed1998

Characterization of carbohydrates using a combination of derivatization, high-performance liquid chromatography and mass spectrometry.

A combination of derivatization methods, chromatographic techniques and mass spectrometric ionization modes have been explored for the characterization of small sugars and medium-size oligosaccharides. Derivatization using 1-phenyl-3-methyl-5-pyrazolone (PMP) was preferred over pyridylamination (PA) owing to the simplicity of the reaction method, and also to enhanced ionization efficiency of the PMP derivatives relative to aminopyridyl sugars. The good quality and ease of separation of PMP derivatives by high-performance liquid chromatography were also advantages of using PMP derivatization rather than pyridylamination. PMP- and PA-monosaccharides produced abundant ions by either fast atom bombardment (FAB), electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI). The PA and PMP derivatives of lactose, fucosyllactose and sialyllactose yielded FAB spectra with low S/N ratios, whereas ESI and MALDI produced better spectra with a hundredth of the material used for FAB. In general, PMP derivatives of these di- and trisaccharides gave rise to stronger signals than PA analogs. For Oligosaccharides containing more than three sugar rings, only PMP was used for derivatization, FAB was dropped and only ESI and MALDI were utilized.

Carbohydrates↗
PubMed2000

Preparation of various silica-based columns for capillary electrochromatography by in-column derivatization.

Chemically bonded silica gels were prepared in a capillary by pumping an ethanolic solution of a silylating reagent, such as octadecyltrimethoxysilane, 3-aminopropyltrimethoxysilane and dimethyloctadecyltrimethoxysilylpropylammonium chloride into a heated capillary packed with bare silica particles. The silylation reactions were completed in a short time and thus-prepared columns showed high column efficiency and high reproducibility. Examples are shown for the separation of 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatives of aldopentoses on a 3-aminopropylated silica column and benzoate homologues as well as PMP derivatives of the component monosaccharides of glycoproteins on an octadecylammonium column. Since the presence of frit filters hampers high efficiency separation, an attempt was made to fix the bed of modified silica gel particles to the capillary inner wall by a cross-linking technique. The results indicated that this technique is promising.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed1999

Rapid structural characterisation of a murine monoclonal IgA alpha chain: heterogeneity in the oligosaccharide structures at a specific site in samples produced in different bioreactor systems.

A murine hybridoma cell line which secretes a monoclonal IgA antibody, directed against the LPS antigen of Vibrio cholerae, was grown in either a continuous stirred tank reactor, a fluidised bed reactor or a hollow fibre reactor. Different methods were used for the structural characterisation of the IgA alpha chains. A classical approach consisted of Edman sequencing and mass determination of peptides separated by reversed phase HPLC. Alternatively, peptides and glycopeptides from a tryptic digest of each alpha chain were identified directly by MALDI-TOF mass spectrometry. A detailed analysis of the oligosaccharide structures at an unique site on the alpha chain was made by labelling the oligosaccharides released by N-glycosidase F with 1-(p-methoxy)phenyl-3-methyl-5-pyrazolone. After separation by HPLC, mass measurements were made using matrix-assisted laser desorption time of flight mass spectrometry before and after digestion with specific exoglycosidases. The primary structure of the alpha chain of IgA was not affected by different cell culture conditions; in contrast, significant variations could be detected in the pattern of N-linked oligosaccharide structures, most prominently in the degree of sialylation. The efficiency of the analytical techniques in providing quality control of the identity, integrity and consistency of the glycoprotein is shown and discussed.

Amino Acid Sequence↗
PubMed1984

Observations on drug-induced toxic epidermal necrolysis in Singapore.

Fifteen patients with toxic epidermal necrolysis (TEN) were studied. In all of them the TEN was related to drug ingestion and believed to be drug-induced. The drugs implicated include pyrazolone derivatives, allopurinol, barbiturates, tetracycline, phenytoin, and penicillamine. Possible etiologic co-factors are infections, cancer, and the systemic lupus erythematosus diathesis. The extent of skin loss varied from 25% to almost 100% involvement of the total body surface. Seven of the fifteen patients had more than 75% epidermal loss. Three deaths were recorded (20%). From observations on these fifteen patients it was found that a single drug can cause two "reaction" patterns, namely, Stevens-Johnson syndrome (or erythema multiforme) and TEN, at the same time or at different times in one and the same patient. It is stressed that from the prognostic and therapeutic viewpoints patients with TEN may be equated to patients with extensive partial-thickness burns and should be treated in a burn unit.

Adult↗
PubMed1986

Histological studies into rat liver following long-term application of aminophenazone, phenazone, and propyphenazone.

Morphological studies by means of light microscopy are important for toxicological drug testing. More complete information on potential damage can be obtained only by combination of pharmacological, biochemical, hepatofunctional, and morphological tests and studies. No systematic tests had been applied to rats, in the past. Therefore, aminophenazone, phenazone, and propyphenazone were tested for periods up to 16 weeks. Long-term application of the three pyrazolone derivatives resulted in the following dose-dependent and time-dependent alterations: hepatocyte enlargement, fatty degeneration and reactive-inflammatory changes along with single-cell necrosis, round cellular infiltration of periportal fields, and Kupffer cell activation. The alterations differed in intensity by the following order: aminophenazone greater than phenazone greater than propyphenazone.

Aminopyrine↗
PubMedDate not supplied

Metamizole intolerance and bronchial asthma.

BACKGROUND: Metamizole is one of the pyrazolone drugs used widely in Turkey. The aim of this survey was to determine the clinical features of metamizole intolerant patients and to find out if there was any difference between the ones with or without bronchial asthma. METHODS: A total of 264 patients with metamizole intolerance were enrolled in the survey. Patients having bronchial asthma were accepted as group I (n = 133) and the ones without bronchial asthma as group II (n = 131). A standard questionnaire was used to collect the data. RESULTS: The mean age of the patients were 41.8 11.8 and 39.2 12.2 for groups I and II respectively and 99 (79.4 %) and 99 (75.6 %) were females in the same order. There was no significant difference between groups I and II when the rates of personal atopy, familial atopy and familial analgesic intolerance were compared. The most common reactions appearing after metamizole ingestion was bronchospasm (75.9 and 9 %) and urticaria (25.6 and 64.9 %) (for groups I and II, respectively and p < 0.05). Aspirin cross-reactivity was significantly more common in group I. At least one safe alternative analgesic was determined for all the patients who have not been able to use any analgesic. CONCLUSIONS: Metamizole intolerance seems to be as important as aspirin intolerance in Turkey. The clinical features in general appear to be similar for metamizole and aspirin intolerant asthmatics.

Adult↗
PubMed1997

Quantitative uronic acid analysis of the otoconial membrane of the guinea pig.

Histochemical and biochemical studies have shown that the otoconial membrane, as well as the tectorial membrane and the cupula, contains glycoproteins and proteoglycans. However, uronic acids, which are essential elements of glycosaminoglycans (GAGs), have not so far been directly detected or quantitatively measured in inner ear samples. In the present study, we quantitatively analyzed the glucuronic acid (GlcA) content of the otoconial membrane of the guinea pig by methanolysis combined with reversed-phase high-performance liquid chromatography (RP-HPLC). The utricular otoconial membrane was treated with thermolysin to separate the supernatant (OM-sup; gelatinous layer) and precipitate (OM-ppt; otoconia). The samples were then subjected to methanolysis followed by brief TFA hydrolysis, incubated with 1-phenyl-3-methyl-5-pyrazolone for labeling, and then analyzed by RP-HPLC coupled with the detection of UV absorbance at 245 nm. The GlcA contents of OM-sup and OM-ppt were 2.1 and 5.8 pmol/100 ng protein, respectively. Based on this result, GlcA-containing GAGs estimated as (GlcA+monosulfo-N-acetylhexosamine)n would be 1.0% of protein in OM-sup and 2.61% of protein in OM-ppt, indicating that this type of glycoconjugate is a minor component in both fractions. It is, accordingly, presumed that both the gelatinous layer and otoconia of the otoconial membrane have totally different properties from those of the tectorial membrane and cartilaginous matrix, which contain abundant GAGs.

Animals↗
PubMed2000

Toxic epidermal necrolysis.

Toxic epidermal necrolysis (TEN) is a rare but life-threatening adverse drug reaction. Implicated drugs are sulfonamides, anticonvulsants, allopurinol, and pyrazolone derivatives. Recently, advances in pathogenesis have been made in two directions. It is now known that (1) most patients with TEN have an abnormal metabolism to the culprit drug; and (2) the mechanism leading to epidermal necrolysis seems to be a cell-mediated cytotoxic reaction. The treatment remains symptomatic.

Humans↗