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PubMed2003

Quantitative analysis of aglycone quercetin in mulberry leaves (Morus alba L.) by capillary zone electrophoresis.

A capillary zone electrophoresis method was established for analysis of aglycone quercetin in mulberry leaves (Morus alba L.). The influence of, e.g., background electrolyte concentrations and pH, surfactant concentrations, organic solvents, temperature, and voltage on the separation of aglycone quercetin, rutin, quercitrin, kaempferol, catechin, and gallic acid was systematically investigated. The optimum condition providing baseline separation of all compounds within 16.5 min was obtained in 150 mM boric acid (pH 10.0) using a fused-silica capillary with an effective length of 42.5 cm (50 microm inner diameter), temperature of 32 degrees C, and voltage of 15 kV. Method assessment was performed by standard addition method using rutin as an internal standard. Linearity of the method was excellent (r(2) > 0.999) over the concentration tested (40-160 microg/mL). The relative standard deviations (%RSDs) from injection, intraday, and interday precision were less than 2.5%. Recoveries were good (asymptotically equal to 100.0%,%RSD = 0.8%) with a limit of detection (LOD) and limit of quantitation (LOQ) of 0.86 and 3.16 microg/mL (%RSD = 1.8%), respectively. The aglycone quercetin found in the mulberry leaves was 0.452 g/100 g (%RSD = 0.6%) on dry weight.

Electrophoresis, Capillary↗

PubMed1992

Formation of beta-galactosyl compounds of pyridoxine in growing culture of Sporobolomyces singularis.

Several pyridoxine compounds were found to be formed in a high yield in a growing culture of Sporobolomyces singularis containing lactose and pyridoxine. Three compounds, I, II and III, were isolated from cultured broth by Dowex 50W-X8 column chromatography, paper chromatography, lyophilization, and then obtained as needle crystals (m.p. (decomp.): I, 204-206 degrees C; II, 192-194 degrees C; III, 222-223 degrees C. [alpha]D16: I, -27.7 degrees (c = 3.82, H2O); II, -1.6 degrees (c = 2.52, H2O); III, +8.3 degrees (c = 3.98, H2O)). Compounds I, II and III were identified as 5'-O-(beta-D-galactopyranosyl)-pyridoxine, 4'-O-(beta-D-galactopyranosyl)-pyridoxine, and 4'-O-(beta-D-galactopyranosyl-(1----4)-beta-D-galactopyranosyl)-pyrid oxi ne, respectively, on the basis of the various experimental results, viz., ultraviolet, infra-red, 1H-NMR, and 13C-NMR spectra, products by hydrolysis with acid and with alpha- and beta-galactosidases, migration on paper electrophoresis, and Gibbs reaction in the presence and absence of boric acid. Also, the yeast produced a remarkable amount of beta-glucosyl compounds of pyridoxine in cultured broth, when grown on cellobiose and pyridoxine.

Carbohydrate Sequence↗

PubMed1997

Determination of imipenem in plasma by high-performance liquid chromatography for pharmacokinetic studies in patients.

A rapid and simple HPLC method is described for the determination of imipenem in human plasma. After blood collection, plasma was separated by centrifugation and immediately stabilized with 3-morpholinopropanesulfonic acid (MOPS) and ethylene glycol solution (1:1). The sample preparation, before injection into HPLC, was ultrafiltration. The mobile phase was boric acid buffer. The imipenem was detected at 300 nm and cilastatin sodium, coadministered, did not interfere. Calibration curves in human plasma were linear from 0.1 to 100 microg/ml. The limit of detection was 0.030 microg/ml. Inter-day precision at 0.1 microg/ml, determined as the coefficient of variation, was 6.26%. Only 250 microl of plasma was required in our assay. Due to the limited stability of imipenem [G.B. Smith et al., J. Pharm. Sci., 79 (1990) 732], stability studies in plasma were done to establish appropriate storage conditions. The assay was applied to pharmacokinetic studies in patients.

Chromatography, High Pressure Liquid↗

PubMed2002

Capillary zone electrophoresis of humic acids from the American continent.

A multicomponent background electrolyte (BGE) was developed and its composition optimized using artificial neural networks (ANN). The optimal BGE composition was found to be 90 mM boric acid, 115 mM Tris, and 0.75 mM EDTA (pH 8.4). A separation voltage of 20 kV, 20 degrees C and detection at 210 nm were used. The method was applied to characterize several humic acids originating from various countries of the American continent: soil (Argentina), peat (Brazil), leonardite (Guatemala and Mexico) and coal (United States). Comparison with humic acids of International Humic Substances Society (IHSS) standard samples was also done. Well reproducible electropherograms showing a relatively high number of peaks were obtained. Characterization of the samples by elemental analysis and UV spectrophotometry was also done. In spite of the very different origins, the similarities between humic acids are high and by matrix assisted desorption/ionization-time of flight (MALDI-TOF)-mass spectrometry it was shown that most of the m/z patterns are the same in all humic acids. This means that humic acids of different origin have the same structural units or that they contain the same components.

Americas↗

PubMed2005

Jack bean (Canavalia ensiformis) urease. Probing acid-base groups of the active site by pH variation.

A pH-variation study of jack bean (Canavalia ensiformis) urease steady-state kinetic parameters and of the inhibition constant of boric acid, a urease competitive inhibitor, was performed using both noninhibitory organic (MES, HEPES and CHES) and inhibitory inorganic (phosphate) buffers, in an effort to elucidate the functions exercised in the catalysis by the ionizable groups of the enzyme active site. The results obtained are consistent with the requirement for three groups utilized by urease with pK(a)s equal to 5.3+/-0.2, 6.6+/-0.2 and 9.1+/-0.4. Based on the appearance of the ionization step with pK(a)=5.3 in v(max)-pH, K(M)-pH and K(i)-pH profiles, we assigned this group as participating both in the substrate binding and catalytic reaction. As shown by its presence in v(max)-pH and K(M)-pH curves, the obvious role of the group with pK(a)=9.1 is the participation in the catalytic reaction. One function of the group featuring pK(a)=6.6, which was derived from a two-maxima v(max)-pH profile obtained upon increasing phosphate buffer concentration, an effect the first time observed for urease-phosphate systems, is the substrate binding, another possible function being modulation of the active site structure controlled by the ionic strength. It is also possible that the pK(a)=6.6 is a merger of two pK(a)s close in value. The study establishes that regular bell-shaped activity-pH profiles, commonly reported for urease, entail more complex pH-dependent behavior of the urease active site ionizable groups, which could be experimentally derived using species interacting with the enzyme, in addition to changing solution pH and ionic strength.

Canavalia↗

PubMed1988

Isolation and structural elucidation of three new pyridoxine-glycosides in rice bran.

Three new pyridoxine-glycosides were isolated from rice bran (10 kg) as colorless powder by various chromatographic techniques: compound A, 53 mg; compound B, 7.8 mg; compound C, 5.8 mg. Compound A was shown to consist of pyridoxine and glucose in a 1:2 molar ratio by beta-glucosidase hydrolysis, and by 1H-NMR and secondary ion mass spectrometry (SI-MS) data. On partial acid hydrolysis of the compound, cellobiose was liberated. Compound A showed the positive Gibbs color reaction, but the reaction was negative in the presence of boric acid. Thus, compound A was identified as 5'-O-(beta-cellobiosyl)pyridoxine. The 13C-NMR spectral data were compatible with this structure. Compounds B and C were proven to be triglucosides of pyridoxine by enzymic hydrolysis and SI-MS data. From the results of the Gibbs color reaction and partial hydrolyses which yielded compound A, compound B was concluded to be 4'-O-(beta-D-glucosyl)-5'-O-(beta-cellobiosyl)pyridoxine, and compound C to be 5'-O-(beta-glucotriosyl)pyridoxine in which a glucose molecule was bound to the cellobiosyl moiety of compound A through beta-glycosidic linkage.

Chromatography↗

PubMed1975

Radiochromatography of 5-3H-uridine derivatives found in trichloracetic and soluble fractions of mouse brain, liver, muscle and blood.

Trichloracetic acid soluble fractions from the mouse brain, liver, muscle and blood were chromatographed in three solvent systems after a subcutaneous injection of 5-3H-uridine (boric acid -- ethanol -- water -- ammonium hydroxide; n-butanol -- acetic acid -- water; IM ammonium acetate -- 95% ethanol). The amount of uridine converted to uracil in the brain and blood highly prevailed over that phosphorylated to UMP. On the contrary, the amount of 3H-;uracil was small in the LIVER AND MUSCLe, the majority of 3H-uridine being converted to UMP.

Animals↗

PubMed2000

[Study on the separation of proteins in human serum by high performance capillary zone electrophoresis].

A high performance capillary zone electrophoretic method has been developed for the separation of proteins in human serum. Sera were diluted with a buffer (0.05 mol/L boric acid, pH 8.80), and then introduced hydrodynamically into a 37 cm (32 cm to detector) x 50 microns i.d. fused-silica capillary, electrophoresed for 12 min using a boric buffer solution (0.10 mol/L, pH 9.35; containing 4 g/L of polyethylene glycol 8000), and detected at the wavelength of 200 nm. The method is simple, rapid and repeatable.

Alpha-Globulins↗

PubMed2003

The separation and synthesis of lipidic 1,2- and 1,3-diols from natural phenolic lipids for the complexation and recovery of boron.

A study has been made of the semi-synthesis of 1,3-diols (anacardic alcohols) from natural phenolic lipid resources from Anacardium occidentale and Anacardium giganteum which have given C15 and C11 derivatives, respectively. An isomeric 1,3-diol (isoanacardic alcohol) has been obtained from cardanol separated from technical cashew nut-shell liquid. Homologous 1,3-diols have been synthesised from a range of synthetic 2-alkyl-, 3-alkyl- and 4-alkylphenols and from 6-alkylsalicylic acids. The natural 1,2-diol, urushiol, from Rhus vernicifera has been purified. All these lipidic compounds have been studied for their complexation and the potential recovery of boron as boric acid.

Anacardium↗

PubMed1986

[Identification of 3-acetamidino-2-acetamido-2,3-dideoxy-L-guluronic acid in lipopolysaccharide from Pseudomonas aeruginosa immunotype 7].

O-Specific polysaccharide chain of Pseudomonas aeruginosa immunotype 7 lipopolysaccharide is composed of 3-acetamidino-2-acetamido-2,3-dideoxy-L-guluronic acid (GulNAcAmA), 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid (ManN2Ac2A), and N-acetyl-D-fucosamine (FucNAc). On solvolysis with anhydrous hydrogen fluoride, the polysaccharide afforded a trisaccharide containing all its components. Borohydride reduction of the trisaccharide in boric acid solution resulted in conversion of reducing fucosamine into fucosaminitol, whereas in water the reduction was accompanied by reductive deamination of acetamidino function into ethylamino group. On hydrolysis with aqueous triethylamine, acetamidino group gave acetamido group. Analysis of the trisaccharides thus obtained by 1H NMR spectroscopy (including nuclear Overhauser effect), 13C NMR spectroscopy, and fast-atom bombardment mass spectrometry allowed the determination of the structure of the unusual uronic acid derivative and the following structure of the polysaccharide repeating unit: -4)-alpha-L-GulNAcAmA-(1-4)-beta-D-ManN2Ac2A-(1-3)-alpha-D-+ ++FucNAc-(1-.

Antigens, Bacterial↗

PubMed1985

Estimation of catecholamines by ion-exchange chromatography on Asahipak ES-502C, using glycylglycine as the post-derivatizing agent.

The estimation of catecholamines in human urine was carried out by ion-exchange chromatography on a column of a weakly acidic ion exchanger with an hydrophilic matrix. The catecholamines were first adsorbed onto Amberlite CG-50 (buffered at pH 6.5 with 0.4 M phosphate buffer) and selectively eluted by 0.66 M boric acid solution. They were then separated from impurities that responded to fluorometric detection by isocratic elution from a column of Asahipak ES-502C, a cross-linked vinyl alcohol copolymer with carboxymethyl groups, at 60 degrees C. The mobile phase was 0.05 M sodium succinate buffer pH 5.25 containing 0.015 M borate and 0.5 mM ethylenediaminetetraacetate. Isoproterenol was used as the internal standard; epinephrine, norepinephrine, isoproterenol and dopamine were eluted in this order. One sample could be analyzed every 35 min. The detection limits were 0.2 ng for epinephrine and norepinephrine, 0.6 ng for dopamine. The elution pattern was quite reproducible; the elution volumes of the catecholamines had not changed after 500 determinations.

Catecholamines↗

PubMed1996

Two Chains of Rhamnogalacturonan II Are Cross-Linked by Borate-Diol Ester Bonds in Higher Plant Cell Walls.

Polysaccharide moiety of the boron-polysaccharide complex (T. Matoh, K. Ishigaki, K. Ohno, J. Azuma [1993] Plant Cell Physiol 34: 639-642) isolated from radish (Raphanus sativus) roots has been shown to be rhamnogalacturonan II by glycosyl-linkage analysis and the presence of diagnostic monosaccharides, including apiose, aceric acid, 2-O-methylfucose, and 3-deoxy-D-manno-2-octulosonic acid. Removal of boron from the complex reduced the molecular weight by one-half without causing a significant increase in the number of reducing end groups, indicating that boron, as boric acid, links two rhamnogalacturonan II chains together to form the boron-polysaccharide complex.

Journal Article↗

PubMed1988

Determination of salsolinol by ion-exchange chromatography with glycylglycine as the post-derivatizing agent.

The determination of salsolinol in human urine was carried out by ion-exchange chromatography on two coupled columns of a weakly acidic ion exchanger with a hydrophilic matrix (Asahipak ES-502C). Salsolinol was first isolated from urine by adsorption on Amberlite CG-50. It was eluted together with catecholamines by 2/3 M boric acid solution. The amines were then separated by isocratic elution from the first column of Asahipak with 0.05 M sodium succinate buffer (pH 5.5) containing 0.015 M borate and 0.5 mM ethylenediaminetetraacetate. Epinephrine, norepinephrine, dopamine and salsolinol were eluted in that order. The salsolinol-containing fraction was then transferred, by column switching, to a second Asahipak column and eluted with the same mobile phase. Salsolinol was determined fluorimetrically by reaction with glycylglycine in the presence of hexacyanoferrate(III) at pH 7.5-8 and 65 degrees C. Samples could be analysed every 47 min. The detection limit for salsolinol was 2 pmol/ml.

Chromatography, Ion Exchange↗

PubMed1991

Determination of boron in tissues and cells using direct-current plasma atomic emission spectroscopy.

We have developed a safe, simple, and efficient method for boron determination by means of direct-current plasma atomic emission spectroscopy. Tissues were solubilized by using concentrated sulfuric acid and 70% hydrogen peroxide to digest the samples without the need of high temperatures and pressures. Boron cluster compounds could be measured with sensitivity, precision, and accuracy similar to those of boric acid standards. Results obtained with [(C2H5)3NH]2B12H12, Cs2B12H11SH.H2O, and C15H32B10O6 show that this analytical method is applicable to a variety of compounds with different chemical structures. A sensitivity of 0.1 ppm has been obtained with known standards alone and in a variety of tissue matrices including tumor, blood, liver, skin, and cell suspensions. The measurement of total boron by direct-current plasma atomic emission spectroscopy (DCP-AES) has been achieved with as little as 50 mg of tissue or as few as 5 x 10(7) cells. The procedure is applicable to the analysis of boron in the ppm range with a high degree of precision and accuracy.

Animals↗

PubMed1992

Influence of the transport on the outcome of the bacteriological analysis of dog urine comparison of three transport tubes.

A sterile plastic tube, a boric acid-glycerol-sodium formate tube and a dip-slide tube were compared for transport of dog urine for bacteriological examination under practice conditions, at ambient temperature. In a first part, 50 dog urine samples were cultured on agar plates and on a dip-slide kit within 2 h after collection and after storage at 20 degrees C in a sterile tube and in a boric acid tube for 24 h and 48 h. Culture of the samples stored in the boric acid tube and culture on the dip-slide yielded results which correlated very well with those of the culture of fresh urine. However, culture of the samples stored in the sterile tube yielded up to 65% false positive results. In a second part, a comparison was drawn with culture results of 100 dog urine specimens collected by different practitioners and simultaneously mailed to our laboratory in a sterile tube, in a boric acid tube and in a dip-slide kit. Samples sent in the boric acid and in the dip-slide tube showed comparable culture results. Culture of the samples sent in the plastic tube yielded 53% false positive results in comparison with those of the samples preserved in boric acid.

Animals↗

PubMed1989

Automated analysis of 2,3-diamino-2,3-dideoxy-D-glucuronic acid by cation exchange chromatography with fluorometric postcolumn derivatization.

2,3-Diamino-2,3-dideoxy-D-glucuronic acid (diaminoglucuronic acid) occurs as its di-N-acetyl derivative as a unique constituent of some bacterial cell walls. A sensitive chromatographic method for its determination is described. Diaminoglucuronic acid was well separated from glucosamine and galactosamine in about 80 min on a Dionex DC-6A cation exchange column (0.9 x 18 cm, 50 degrees C) with a sodium citrate buffer (pH 5.28) containing boric acid (0.2 M). The amino sugars in the eluate were monitored fluorometrically by postcolumn derivatization with orthophthalaldehyde detection reagent. This method allowed the automated determination of 50-100 pmol of glucosamine, galactosamine, and diaminoglucuronic acid and was applied successfully to the analysis of diaminoglucuronic acid in Propionibacterium acnes cells.

Amino Acids↗

PubMed1995

Occupational allergic contact dermatitis from alkanolamineborates in metalworking fluids.

Alkanolamineborates are extensively used in coolants as corrosion inhibitors. In this paper, 3 machinists with contact allergy to alkanolamineborates are reported. To avoid false-positive test reactions due to the alkalinity of the alkanolamineborates, they should be tested when dissolved in an acidic buffer. When various alkanolamineborates were tested in dilution series in the 3 patients, 2 types of reactivity patterns emerged, indicating the existence of at least 2 separate sensitizers in alkanolamineborates. The raw materials, ethanolamines and boric acid, did not yield any positive patch test reactions. Thin-layer chromatography investigations demonstrated that each alkanolamineborate consists of many substances, which differed in part between different alkanolamineborates. The present study shows that it is not possible to use 1 particular alkanolamineborate for tracing contact allergy to alkanolamineborates in general.

Adult↗

PubMed1991

Direct monitoring by carbon-13 nuclear magnetic resonance spectroscopy of the metabolism and metabolic rate of 13C-labeled compounds in vivo.

Carbon-13 nuclear magnetic resonance spectroscopy has been used to observe the transformations of [1-13C]-D-glucose to [1,1'-13C2]-D-trehalose, and [3-13C]-L-alanine to [2-13C]-L-glutamic acid in the living body of Gryllodes sigillatus. [3-13C]-D-Alanine was not metabolized. The metabolic rate of [1-13C]-D-glucose was found to be altered by prior injection of boric acid.

Alanine↗