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At least 19 recordsLinked to original sources
PubMed1978

Synthesis and biological activities of some uronic acids, uronates, uronamides, and urononitriles of pyrimidine nucleosides.

The 5'-hydroxymethylene function of several uracil and cytosine nucleosides has been modified to produce a variety of uronic acids, uronates, uronamides, and urononitriles of 2'-deoxy-beta-D-erythro-pentofuranosyl- and beta-D-arabino-pentofuranosylpyrimidines. In addition, the 5 position in many of these nucleosides has been substituted by a halogen atom. Twenty-one of the 35 compounds synthesized and examined for biological activity have not been previously reported. The purity of the products was measured by a high-pressure liquid chromatographic method. They were then evaluated as potential growth inhibitors of murine Sarcoma 180 cells in culture, of herpes simplex virus type 1 in vitro, and of Streptococcus faecium, a folic acid or deoxythymidine dependent bacterial strain. The ability of these nucleoside analogues to inhibit the phosphorylation of deoxythymidine by herpes simplex virus type 1 encoded pyrimidine deoxyribonucleoside kinase was also investigated and a structure-activity relationship examined.

Animals↗
PubMed1978

Effects of the teratogenic folic acid antagonist, 9-methyl pteroylglutamic acid on uronic acid levels in fetal rat limbs.

Experimental pregnant rats were placed on a transitory folic acid-deficient regimen, i.e. dietary restriction of folic acid plus the teratogen and folic acid antagonist, 9-methyl pteroylglutamic acid; a regimen resulting in multiple congenital skeletal malformations. Controls received a folic acid-supplemented regimen. Accumulation of a primary component of the extracellular matrix, glycosaminoglycans (GAG), was quantitatively evaluated by measuring uronic acid concentrations in fetal limbs. On days 16 and 18 of gestation, fetal limbs were removed, pooled from each litter, and prepared for uronic acid, protein, and DNA quantitation. The treatment results in (1) a decreased rate of protein and DNA accumulation prior to day 16 of gestation, the rate not being affected from day 16 to day 18 of gestation; (2) a trend toward an increased rate of uronic acid accumulation prior to day 16 of gestation, and (3) a decreased rate of uronic acid accumulation from day 16 to day 18 of gestation. Furthermore, our observations confirm our earlier suggestion that there is a decreased rate of accumulation of some nonprotein component(s) in fetal limbs obtained from folic acid-deficient mothers from day 16 to day 18 of gestation.

Animals↗
PubMed1976

Uronic acid dehydrogenase from Pseudomonas syringae. Purification and properties.

1. Uronic acid dehydrogenase was purified to homogeneity. After a 338-fold purification a yield of 16% was achieved with a specific activity of 81 mumol NADH formed min-1 mg protein-1. 2. The purity of the enzyme was controlled by disc electrophoresis, sodium dodecylsulfate electrophoresis and ultracentrifugation. 3. A molecular weight of 60 000 was determined by gel chromatography and by ultracentrifugation. 4. The native enzyme is composed of two subunits, their molecular weight being 30 000 as estimated by sodium dodecylsulfate electrophoresis. The subunits as such are inactive. 5. The absorption spectrum with a maximum at 278 nm shows no evidence for a prosthetic group. 6. For catalytic activity no SH groups and no metals seem to be necessary. 7. The Michaelis constants determined with the pure enzyme are for glucuronic acid Km = 0.37 mM, galacturonic acid Km = 54 muM and NAD+ (with glucuronic acid) Km = 80 muM. 8. A weak reverse reaction could be observed with glucaric acid lactones at acidic pH. 9. NADH is competitive with NAD+. The inhibitor constant is Ki = 60 muM. 10. The NAD+ binding site seems to be of lower specificity than the uronic acid binding site.

Aldehyde Oxidoreductases↗
PubMed1975

The distribution of sulfated uronic acid and hexosamine residues in heparin and heparan sulfate.

Heparins from various sources and heparan sulfate from umbilical cords have been subjected to Smith-degradation and reaction with nitrites. These procedures were effective for providing data relating to the distribution of sulfated iduronic acid residues in the molecule. Results indicated that heparins may have, as a prominent structural feature of the molecule, non-sulfated uronic acid distributed in single sequences, much as had been shown previously for N-acetylglucosamine residues. Sulfated uronic acid, however, may occur in multiple sequences of up to 5 or 6 residues. Heparan sulfate was found to have a major proportion of its ester sulfate on iduronic acid rather than hexosamine units, thereby having sections similar to those in heparins, though in considerably lower proportion.

Amino Acids↗
PubMed1978

Mass spectrometry of uronic acid derivatives. XI--Structure elucidation by mass spectrometry of aldobiouronic and pseudoaldobiouronic acids and their beta-elimination products as per-o-methyl derivatives.

Electron impact mass spectra of a series of aldobiouronic and pseudoaldobiouronic acid per-O-methyl derivatives and of the corresponding 4,5-unsaturated analogues, found normally among the products of methylation of uronic acid containing disaccharides as a result of methylation accompanying beta-elimination, have been studied. Using labelling experiments, metastable transition measurements and high resolution mass spectrometry, the fragmentation mechanisms of substances of this class have been deduced. Application of the information to the structure elucidation of this type of compound is discussed. It is concluded that from the mass spectra alone it is possible to determine the molecular weight, the cycle masses as well as the mode of linkage between the monomeric units. The appearance potentials of ions formed by cleavage of the glycosidic linkages have also been determined and the energetic differences encountered in the fission of the glycosidic linkages of various types of uronic acid containing oligosaccharides are discussed.

Hexuronic Acids↗
PubMed1978

Automatic column chromatographic analysis of saccharides and uronic acids.

Using n-proponal/water as the eluting solvent, a flow rate of 50 ml/h and a 90 degrees C column temperature, the separation of a complex mixture of 11 monosaccharides could be much improved over the procedure described by v. Wilm and Sordé using isopropanol/water, 70--100 ml/h flow rate and temperatures of 83--90 degrees C. With a small total error of 3%, the saccharide analysis lies in the region of reproducibility that has also been reached in amino acid analysis. The limit of detection for saccharides lies at 1 x 10(-9) mole/ml.

Autoanalysis↗
PubMed1976

[Analysis of polysaccharides used as food additives. V. Gaschromatographic identification of hydrolysis products in uronic acids containing polysaccharides].

Alduronic acids can be found among the monomeric units of polysaccharides, which are used as stabilisators in the food industry. Gaschromatographically they cannot be separated directly by the way of their aldonitrilacetates but it is possible by the procedure described. The 1-0-methylalduronic-acidmethylesters, obtained by the methanolysis of the polysaccharides, are reduced with boronhydrid to the corresponding methyl glycosides; there are split with acid to the aldoses, which are converted in pyridine with hydroxylamine to the aldoximes and than with acetic anhydride to the aldonitrilacetates, which can be separated by gaschromatography without difficulty.

Chromatography, Gas↗
PubMed1979

Convenient method for the gas chromatographic analysis of hexosamines in the presence of neutral monosaccharides and uronic acids.

A convenient gas chromatographic method has been devised for the analysis of hexosamines in the presence of neutral and acidic sugars, which involves sequential derivatization reactions of nitrous acid deamination, mercaptalation, and trimethylsilylation. This method allows rapid, simultaneous determination of 0.1-1 micromole samples of hexosamines with coefficients of variation of less than 3%.

Adult↗
PubMed1976

Alaskan malamute chondrodysplasia. II. Urinary excretion of hydroxyproline, uronic acid and acid mucopolysaccharides.

The urinary excretion of free, total and non-dialyzable hydroxyproline appeared to be similar in both chondrodysplastic and non-chondrodysplastic Alaskan Malamutes of ages six and twenty-six weeks suggesting the metabolic defect was probably not related to a gross disturbance in collagen metabolism. Urinary hexuronic acids also appeared to be similar in levels for both populations. A four-fold increase in urinary mucopolysaccharide levels observed at age twenty-six weeks in the chondrodysplastic Alaskan Malamute suggested a deviation from normal. The magnitude and variability of deviation were not sufficient to indicate that this condition could serve as a model for the mucopolysaccharidosis of man but probably indicated a delayed maturation process.

Animals↗
PubMed1978

Pharmacological studies on experimental nephritic rats (3). Changes in the connective tissue components of renal cortex in the modified type of Masugi's nephritis.

Using a modified type of Masugi's nephritis, quantitative changes in several connective tissue components of renal cortex during the process of nephritis were compared with those of the contents of urinary protein and serum cholesterol. Levels of urinary protein and serum cholesterol were highest 10 days after anti-kidney serum injection and nearly normal levels were reverted to on the 30th day. The levels of sialic acid, uronic acid and hydroxyproline in the renal cortex of the nephritic group significantly increased from the 1st, 5th and 10th days, respectively compared with the normal group. The sialic acid content reached a peak with an increase of approx. 40% on the 15th day, reverting to almost the normal level on the 30th day, while the uronic acid and hydroxyproline levels continued to increase slowly after the 15th day, reaching rates of approx. 70% and 40%, respectively on the 30th day. The hexosamine content reached a maximum of 20% on the 20th day. Quantitative changes in connective tissue components of the renal cortex due to nephritis appear to reflect the degree of the repair of injured renal tissue.

Animals↗