Concentration Of Glucuronic Acid Research Articles

Precolumn derivatization LC-MS/MS method to simultaneous quantitation of 10 monosaccharides in rat plasma

Monosaccharides are essential for maintaining the normal physiological functions of living organisms. Under disease states, metabolic disorders in vivo will inevitably affect the levels of monosaccharides, which brings the possibility of monosaccharides as a biomarker of some diseases. In this study, a method was developed and validated for simultaneously determining 10 monosaccharides (glucose, galactose, mannose, rhamnose, fucose, xylose, iduronic acid, glucuronic acid, N-acetylgalactosamine and N-acetylglucosamine) in SD rat plasma using liquid chromatography-tandem mass spectrometry. The method employed 1-phenyl-3-methyl-5-pyrazolone (PMP) as a derivatization reagent, considerably improved the chromatographic retention and ionization efficiency of monosaccharides. After protein precipitation of plasma samples, monosaccharides and isotope internal standards were derivatized and liquid-liquid extraction was performed to remove excess PMP. To achieve the baseline separation of several isomers, the resulting derivatives were chromatographed on a Bridged ethyl hybrid (BEH) Phenyl column using gradient elution with a total run time of 8 min. The method was linear within the range of 0.0100–5.00 μg/mL for rhamnose, 0.0500–25.0 μg/mL for fucose, xylose, iduronic acid, glucuronic acid, N-acetylgalactosamine and N-acetylglucosamine, 1.00–500 μg/mL for galactose, 10.0–5000 μg/mL for mannose, and 50.0–25,000 μg/mL for glucose. And the accuracy and precision verification of surrogate matrix samples and plasma samples met the required criteria. The method has been used successfully to study the effect of hepatic insufficiency on monosaccharide levels in rats. It was found that the concentration of glucuronic acid in SD rat plasma was abnormally increased in rats with liver injury.

Cell Wall Polysaccharide Composition of Grafted 'Liberty' Watermelon With Reduced Incidence of Hollow Heart Defect.

Grafting watermelon scions to interspecific squash hybrids has been found to increase fruit firmness. Triploid (seedless) watermelon are prone to hollow heart (HH), an internal fruit disorder characterized by a crack in the placental tissue expanding to a cavity. Although watermelon with lower tissue firmness tend to have a higher HH incidence, associated differences in cell wall polysaccharide composition are unknown. Grafting “Liberty” watermelon to “Carnivor” (interspecific hybrid rootstock, C. moschata × C. maxima) reduced HH 39% and increased tissue firmness by 3 N. Fruit with and without severe HH from both grafted and non-grafted plants were analyzed to determine differences in cell wall polysaccharides associated with grafting and HH. Alcohol insoluble residues (AIR) were sequentially extracted from placental tissue to yield water soluble (WSF), carbonate soluble (CSF), alkali soluble (ASF), or unextractable (UNX) pectic fractions. The CSF was lower in fruit with HH (24.5%) compared to those without HH (27.1%). AIRs were also reduced, hydrolyzed, and acetylated for GC-MS analysis of monosaccharide composition, and a portion of each AIR was methylated prior to hydrolysis and acetylation to produce partially methylated alditol acetates for polysaccharide linkage assembly. No differences in degree of methylation or galacturonic and glucuronic acid concentrations were found. Glucose and galactose were in highest abundance at 75.9 and 82.4 μg⋅mg–1 AIR, respectively, followed by xylose and arabinose (29.3 and 22.0 μg⋅mg–1). Mannose was higher in fruit with HH (p < 0.05) and xylose was highest in fruit from grafted plants (p < 0.05). Mannose is primarily found in heteromannan and rhamnogalacturonan I side chains, while xylose is found in xylogalacturonan or heteroxylan. In watermelon, 34 carbohydrate linkages were identified with galactose, glucose, and arabinose linkages in highest abundance. This represents the most comprehensive polysaccharide linkage analysis to date for watermelon, including the identification of several new linkages. However, total pectin and cell wall composition data could not explain the increased tissue firmness observed in fruit from grafted plants. Nonetheless, grafting onto the interspecific hybrid rootstock decreased the incidence of HH and can be a useful method for growers using HH susceptible cultivars.

Effect of Organic Fe-Ligands, Released by Emiliania huxleyi, on Fe(II) Oxidation Rate in Seawater Under Simulated Ocean Acidification Conditions: A Modeling Approach

The potential effect of ocean acidification on the exudation of organic matter by phytoplankton and, consequently, on the iron redox chemistry is largely unknown. In this study, the cocccolithophorid Emiliania huxleyi was exposed to different pCO2 conditions (225-900 μatm), in order to determine the role of natural organic ligands on the Fe(II) oxidation rate. Oxidation kinetics of Fe(II) were studied as a function of pH (7.75-8.25) and dissolved organic carbon levels produced (0-141.11 μmol C L-1) during the different growth stages. The Fe(II) oxidation rate always decreased in the presence of exudates as compared to that in the exudates-free seawater. The organic ligands present in the coccolithophorid exudates were responsible for this decrease. The oxidation of Fe(II) in artificial seawater was also investigated at nanomolar levels over a range of pH (7.75–8.25) at 25 oC in the presence of different glucuronic acid concentrations. Dissolved uronic acids (DUA) slightly increased the experimental rate compared to control artificial seawater (ASW) which can be ascribed to the stabilization of the oxidized form by chelation. This behavior was a function of the Fe(II):DUA ratio and was a pH dependent process. A kinetic model in ASW, with a single organic ligand, was applied for computing the equilibrium constant (log KFeCHO+ = 3.68 ± 0.81 M-1) and the oxidation rate (log kFeCHO+ = 3.28 ± 0.41 M-1 min-1) for the Fe(II)-DUA complex (FeCHO+), providing an excellent description of data obtained over a wide range of DUA concentrations and pH conditions. Considering the Marcus theory the Fe(III) complexing constant with DUA was limited to between 1013-1016. For the seawater enriched with exudates of E. huxleyi a second kinetic modelling approach was carried out for fitting the Fe(II) speciation, and the contribution of each Fe(II) species to the overall oxidation rate as a function of the pH/pCO2 conditions. The influence of organic ligands in the Fe(II) speciation diminished as pH decreased in solution. During the stationary growth phase, the FeCHO+ complex became the most important contributor to the overall oxidation rate when pH was lower than 7.95. Because CO2 levels modify the composition of excreted organic ligands, the

Composition and properties of pectin polysaccharides of St. John’s wort Hypericum Perforatum L.

Three fractions of acidic water-soluble polysaccharides (concentration of glucuronic acid 10–65%) were obtained from the above-ground part of St. Johns wort Hypericum perforatum L. by serial extraction with water and 0.7% aqueous solution of ammonium oxalate. Enzymatic hydrolysis of these polysaccharides using endo-polygalacturonase indicates that their carbohydrate chains contain the units of galacturone formed by 1,4-α-linked residues of non-substituted D-galacturonic acid. The extracted polysaccharides have been purified by means of gel filtration. It has been shown that water-soluble polysaccharides obtained by extraction with water manly contain the residues of galactose, mannose, glucose, and arabinose (the concentration of glucuronic acid being 10–27%) while the polysaccharide fraction extracted using 0.7% aqueous solution of ammonium oxalate is presented by pectin polysaccharides. Only the residues of galacturonic acid (55–72%) have been identified among glucuronic acids in its composition using chromatography/mass spectrometry of trimethylsilyl derivatives. In addition, this fraction contains the residues of the neutral monosaccharides which are typical for pectins: arabinoses, galactoses, rhamnoses, and glucose; there are also minor concentrations of residues of xylose and mannose. IR spectra of pectin polysaccharides of St. John’s wort have absorption bands in the ranges 1740, 1640–1620, 1236–1200, and 1200–1000 cm−1 which are typical for pectins. It has been demonstrated that aqueous solutions of pectin polysaccharides of St. John’s wort (2 mg/mL) have pronounced antioxidant activity (44% of the activity of trolox taken for 100%).

Production of Glucaric Acid from a Synthetic Pathway in Recombinant Escherichia coli

A synthetic pathway has been constructed for the production of glucuronic and glucaric acids from glucose in Escherichia coli. Coexpression of the genes encoding myo-inositol-1-phosphate synthase (Ino1) from Saccharomyces cerevisiae and myo-inositol oxygenase (MIOX) from mice led to production of glucuronic acid through the intermediate myo-inositol. Glucuronic acid concentrations up to 0.3 g/liter were measured in the culture broth. The activity of MIOX was rate limiting, resulting in the accumulation of both myo-inositol and glucuronic acid as final products, in approximately equal concentrations. Inclusion of a third enzyme, uronate dehydrogenase (Udh) from Pseudomonas syringae, facilitated the conversion of glucuronic acid to glucaric acid. The activity of this recombinant enzyme was more than 2 orders of magnitude higher than that of Ino1 and MIOX and increased overall flux through the pathway such that glucaric acid concentrations in excess of 1 g/liter were observed. This represents a novel microbial system for the biological production of glucaric acid, a "top value-added chemical" from biomass.

A new family of genetic algorithms for wavelength interval selection in multivariate analytical spectroscopy

AbstractA new procedure is presented for wavelength interval selection with a genetic algorithm in order to improve the predictive ability of partial least squares multivariate calibration. It involves separately labelling each of the selected sensor ranges with an appropriate inclusion ranking. The new approach intends to alleviate overfitting without the need of preparing an independent monitoring sample set. A theoretical example is worked out in order to compare the performance of the new approach with previous implementations of genetic algorithms. Two experimental data sets are also studied: target parameters are the concentration of glucuronic acid in complex mixtures studied by Fourier transform mid‐infrared spectroscopy and the octane number in gasolines monitored by near‐infrared spectroscopy. Copyright © 2003 John Wiley &amp; Sons, Ltd.

Uptake of Acidic and Basic Sugar Derivatives in Lemna gibba G1

The uptake of acidic and basic sugar derivatives in Lemna gibba L. was studied. Uronic acids applied to the experimental solution (50 millimolar) induced a small decrease of the membrane potential (10 +/- 1 millivolt galacturonic acid, and 20 +/- 4 millivolt glucuronic acid). After incubation of the plants in a 0.1 millimolar solution of these substrates, no decrease in the concentration of reducing groups in the external solution was detected. Respiration increased by 31% with 50 millimolar galacturonic acid, whereas no effect was found with the same concentration of glucuronic acid. Glucosamine caused a considerable concentration-dependent membrane depolarization. ((14)C)glucosamine uptake followed Michaelis-Menten kinetics together with a linear component. Influx of this substrate was inhibited by glucose but the type of competition could not be clearly distinguished. Glucosamine, 50 millimolar, inhibited the respiration rate by 30%. The glucosamine uptake was pH-dependent, with maximum uptake at around pH 7. Lack of enhancement of uptake by low pH as well as the permanent membrane depolarization suggest a uniport mechanism for the charged species of the substrate and an electroneutral diffusion of the uncharged species.

Glucuronoconjugates in chronic renal failure. Comparative determination with values in healthy adult.

We have isolated substances of molecular weight ranging between 350 and 2,000 daltons from ultrafiltrates of patients traited by maintenance haemodialysis for chronic renal failure (CRF). Such substances might have a role in the genesis of uremic toxicity. They were found to be glucuronoconjugates. We have studied 22 patients with CRF and 16 with end stage renal failure, 8 of them were traited by peritoneal dialysis, 8 by haemodialysis. We have evaluated the concentration of glucuronic acid in the serum, the urine and dialysis fluid. The patients with chronic renal failure have plasma levels of free and conjugate glucuronic acid higher than normal subjects. Urinary elimination is very lower in patient with CRF. Nevertheless the glucuronoconjugates are removed to a large extend by haemodialysis and peritoneal dialysis.

Urinary excretion of free and conjugated glucuronic acid in jaundiced newborn.

SummaryFree and conjugated components of the total urinary glucuronic acid were analyzed daily during the first 4 days of life in 62 newborn male infants. The newborn were divided into two groups: “jaundiced” 37 infants in whom the serum bilirubin level on the fourth day of life was either the same or higher than the level on the third day; and “non‐jaundiced” 25 infants, in whom the serum bilirubin level showed a fall on the fourth day after an initial rise during the first 3 days. The percentage of free glucuronic acid excreted was found significantly higher in the jaundiced infants.Premature infants studied for comparison demonstrated an even higher percentage of free glucuronic acid excreted in the urine than the jaundiced infants. On the other hand, in healthy adult males the percentage of free glucuronic acid excreted was found to be the lowest.No significant difference was found in the total glucuronic acid concentrations of the jaundiced and non‐jaundiced infants.It could be concluded, therefore, that when a high percentage of free glucuronic acid is excreted in the urine this probably indicates impaired conjugating capacity of the liver.

Measurement of uridine diphosphate glucuronic acid concentrations and synthesis in animal tissues

1. A method for the isolation from animal tissues of UDP-glucuronic acid by one-dimensional paper chromatography is described and its concentrations in some tissues of several species of vertebrates are reported; the incorporation of [(32)P]-phosphate into UDP-glucuronic acid in vivo was also investigated. 2. The concentration of UDP-glucuronic acid was higher in the liver of rats, rabbits and guinea pigs than in the same tissue of some species of birds, amphibia and fishes; also, the concentration of UDP-glucuronic acid in rat liver, kidney and small intestine was several times lower than that of the same tissues of guinea pigs. 3. The rate of [(32)P]-phosphate incorporation into UDP-glucuronic acid was very high in rat liver and kidney and almost reached equilibrium with the radioactivity of UDP-glucose 30min after the administration of the [(32)P]phosphate.

泌尿器科領域に於けるグルクロン酸の消長

1. The glucuronic acid in blood, urine and tissue of the rabbits, followed by an experimental tuberculosis and treating with use of Streptomycin and Kanamycine, was measured. Comparing with the normal rabbits, the concentration of glucuronic acid in blood, the urinary excretion of glucuronic acid and the intrarenal or intrahepatic amount of glucuronic acid, in the rabbits of renal tuberculosis, tended to decrease. The urinary excretory amount of glucuronic acid decreased more remarkably in the treatment by Kanamycine than in the treatment by Streptomycin, however, this amount gradually increased in both cases when these treatments were interrupted.2. When the ureter of rabbit was ligated, the blood level of glucuronic acid markedly raised, but this rise was not so considerably 48 hours after. This experiment shows one style of the fact reported in a preceding paper which indicated the increase of glucuronic acid in blood in the urinary excretion disturbance such as a prostatic hypertrophy. The intrahepatic or intrarenal amount of glucuronic acid, 72hr after the ligation, was lower than that in normal state.3. In Brown-Pearce carcinoma of rabbits, the elevation of glucuronic acid concentration in blood, the increase of urinary excretion of glucuronic acid and the decrease of intrahepatic and intrarenal glucuronic acid were observed.These results can be summarized as follows. In the experimental renal tuberculosis, the glucuronic acid concentration in blood and the urinary excretion were decreased considerably. In the case of urinary excretory disorder due to the ureter ligation the significant elevation of the blood concentration of glucuronic acid was seen. In the experimental carcinoma, both the blood level and the urinary excretion of glucuronic acid were increased. In various diseases, the intrarenal or intrahepatic glucuronic acid were decreased. These clinical results of glucuronic acid metabolism in various diseases are similar to the experimental results. Moreover, the intrahepatic or intrarenal glucuronic acid amount in various diseases, except the renal tuberculosis, tends to shift reversely proportional to the blood level. Even in various urological diseases, it can be supposed that the conjngate metabolism of glucuronic acid is evidently remarkable and has the close relation to the hepatic and renal functions.

グルクロン酸の定量法の研究 (第1報)

In order to study the determination method for glucuronic acid, coloration of 20 kinds of aromatic amines and glucuronic acid was examined. It was thereby found that coloration with 4, 4′-diaminodiphenyl sulfone was comparatively good. Various conditions for its use in the determination were examined and the following procedure was found to be satisfactory. To 1 cc. of the sample, 5 cc. of 1% solution of 4, 4′-di-aminodiphenyl sulfone in 3.5% hydrochloric acid and 3cc. of conc. hydrochloric acid are added, and the whole volume is brought to 10cc. with water. After warming this on a boiling water bath for 30 minutes, it is cooled, allowed to stand for 35 minutes, and filtered. The absorbence at 500mμ is determined with the Beckman photoelectric spectrophotometer and the concentration of glucuronic acid is obtained from the detection curve preliminarily calculated. The accuracy is within 10%. This method is not so satisfactory for the determination of glucuronic acid but is advantageous in that it is not hinderd by the presence of other neutral sugars.