Blood group substances hydrolysis

Other oligosaccharides obtained from ovarian-cyst blood-group substances indicate that these macromolecules have many features in common (items 17-19) between the various types but, as they have been isolated after partial hydrolysis with acid, it is, in general, not possible, from this information alone, to assign a position to them within the carbohydrate moieties. Those items represented by 13,... 

Chapters 17 through 21 deal with carbohydrate-enzyme systems. Hehre presents some new ideas on the action of amylases. Kabat presents some new immunochemical studies on the carbohydrate moiety of certain water-soluble blood-group substances and their precursor antigens. Hassid reviews the role of sugar phosphates in the biosynthesis of complex saccharides. Pazur and co-workers present information obtained by isotopic techniques on the nature of enzyme-substrate complexes in the hydrolysis of polysaccharides. Gabriel presents a common mechanism for the production of 6-deoxyhexoses. An intermediate nucleoside-5 -(6-deoxyhexose-4-ulose pyrophosphate) is formed in each of the syntheses. 

These bacterial antigens (in their susceptibility to hydrolysis, which separates polysaccharide from the rest of the molecular complex) differ markedly from the blood-group substances, where amino acids and sugars cannot be separated from one another as polypeptide and polysaccharide. ... 

Structural details of various blood group substances were revealed by partial hydrolysis, chromatography, and results of periodate oxidation, treatment with various enzymes such as ficin (M50), and acetolysis (Mil, M12, M15-M17, M19-M21, Y4, Y5). They are well described in various reviews on carbohydrates (K16, S39) and blood group substances (Kl, M49, M50). 

By the catalytic reduction of the phenylosazone from lactose, Kuhn and Kirschenlohr obtained both /3-n-gaIactopyranosyl-(l— 4)-l-amino-l-deoxy-D-fructose and /S-n-galactopyranosyl- (1- -4) -2-amino-2-deoxy-D-glu-cose. The A -acetyl derivative of the latter was found to be identical with a disaccharide obtained from the partial hydrolysis of a blood-group substance. The structure of a disaccharide obtained from the partial hydrolysis of heparin was likewise confirmed by comparison of the disaccharide with a synthetic product obtained by catalytic hydrogenation of the osazone from maltose. - Here, too, both the 1-amino-l-deoxy and the 2-amino-2-deoxy compounds were obtained. 

Mild hydrolysis breaks down blood group substances only partially their specificity is lost, but the cross reaction with antiserum to the pneumococcal strain XIV increases. The degradation product consists of galactose, glucosamine, galactosamine in the ratio of 2 1 1. The cross reaction... 

This approach was used qualitatively by Kotchetkov et al. (71), who showed that the blood-group A substance from pig stomach linings after treatment with alkali and subsequent acid hydrolysis was cleaved into smaller fragments which still carried the carbohydrate side chains. 

Blood Groups XXIV. Some Oligosaccharides Isolated from Dialysates after Mild Acid Hydrolysis of Human Blood Group B Substances from Ovarian Cyst Fluid, J. Amer. Chem. Soc. (I960) 82, 1122. 

C14H25NO11 383.352 Repeating unit in mucopolysaccharides isol. from partial acid hydrolysates or acetolysates of human-blood group A substance and other sources. Structural unit in higher oligosaccharides present in human milk. Hydrolysis prod, of human plasma glycoprotein and of fetuin, a glycoprotein from calf foetal plasma. Cryst. (2-propanol/MeOH). 

In general, esters and amides are hydrolyzed by enzymes In the blood, liver microsomes, kidneys, and other tissues. Esters and certain amides are hydrolyzed rapidly by a group of enzymes termed carboxylesterases." The more lipophilic the amide, the more favorabie it is as a substrate for this ehzyme. In most cases, the hydrolysis of an ester or amide bond in a toxic substance results in bioinactivation to hydrophilic metabolites that are readily excreted. Some of these metabolites may yield cohjugated metabolites (i.e., glucuronides). 

The plasma volume expanders are the substances that are transfused to maintain fluid volume of the blood in event of great necessity, supplemental to the use of whole blood and plasma. Some starch derivatives like hydroxyethyl starch and acetyl starch, which are a group of coUoids, are used to provide sustained intravascular volume expansion. Hydroxyethyl starches are high-polymeric compounds obtained via hydrolysis and subsequent hydroxyl ethylation of glucose units substituted at carbon number 2, 3, and 6 of starch. Recently some waxy starches were also evaluated for plasma volume expander, but more research is needed to establish them as a good substitute for the synthetic polymers. 

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