Glucosiduronate

IC with bovine enzyme which is very similar to the human one. Inhibitor concentration for 50% inhibition. K of substrate (phenyl a-D-mannopyranoside). K of substrate (4-nitrophenyl a-D-manno-pyranoside). K of substrate (4-nitrophenyl D-glucosiduronic acid). K of substrate (4-nitrophenyl 2-acetamido-2-deoxy- o-glueoside). Inhibitors were chitotetraono-1,5-lactone and chitotetraose, respectively. 

Methanolysis of standard uronic acids has been studied by Inoue and Miyawaki in regard to the depolymerization of chondroitin sulfate and dermatan sulfate. These workers found the glucosiduronic linkage to ga-lactosamine to be rather resistant to methanolysis, but that it is more efficiently cleaved after deamination of the amino galactoside, with its conversion into 2,5-anhydrotalose. For iduronic, glucuronic, and man-nuronic acids released from a polymer, it was found that the peaks monitored for these acids, relative to an internal standard, increase during the first 8 h of methanolysis (M hydrogen chloride, 100°) and remain constant for up to 20 h of methanolysis. This indicated that 8 h is required for complete methanolysis, and that the monosaccharides liberated are stable to the conditions of methanolysis. 

Unlike in calves, the nature of the major liver metabolites was identified in steers the -o-glucopyranoside of estradiol-17 was found to be a major metabolite, whereas the 3- -o-glucosiduronate of estradiol-17 and other 17-glucosides of estradiol-17 and estradiol-17 were found to be minor ones (3). Residue depletion studies in steers implanted for 70-180 days with controlled-release implants containing 24 mg estradiol-17 showed that 24 h after implant removal the concentrations of residual estradiol-17 and estrone were 4.0 and 4.0 ppt in muscle, 5.0 and 4.7 ppt in liver, 7.5 and 7.1 ppt in kidney, and 7.1 and 14.3 ppt in the fat, respectively. These concentrations of residual estradiol-17 and estrone in the incurred samples were very close to those in the control tissues, which accounted for 5.8 and 4.8 ppt in muscle, 4.0 and 6.5 ppt in liver,... 

The primary form of pregnanediol excreted into the urine is that of the conjugate, and the major conjugate present is the glucosiduronate. Very little work has been done on the gas chromatographic separation of glucosiduronates, either directly... 

Pregnanetriol is formed by the reduction of 17-a-hydroxyprogest-erone, which is formed by hydroxylation at the 17- a-position of progesterone. Progesterone is produced by the corpus luteum of the ovary, the placenta, and the adrenal gland. Under normal circumstances, very little pregnanetriol appears to accumulate rather it is secreted as the glucosiduronate in the urine. 

Mass-spectrometric analysis has been used to detect isosorbide and its 5-nitrate in human urine and plasma probes.34 An assay for the quantitative determination of isosorbide 5-nitrate and its D-glucosiduronic ester, and that of isosorbide itself, using g.l.c.-m.s. techniques with a triple-stage, quadra-pole mass spectrometer, has been reported.36 A combination of g.l.c. and... 

Tri-O-methyl-D-glucose-(4— 1) 2,3,4-tri-O-methyl-D-glucosiduronic acid Pneumococcus Type III specific polysaccharide B 0 64a... 

D-Xylose-(2 —> 1) 4-O-methyl-D-glucosiduronic acid Aspen wood A a 67 See 70d, 70e... 

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