Carbohydrates identifying

Sell, S. (1990) Cancer-associated carbohydrates identified by monoclonal antibodies. Hum. Pathol. 21(10), 1003-1019. 

Blood group carbohydrates identified by monoclonal antibodies that have been used as markers of cancers are listed in Table 23-11. These include CA 19-9 (sialylated Le ), CA 50 (sialylated Le k afucosyl forms), CA 72-4 (sialyl Tn), and CA 242 (sialylated carbohydrate coexpressed with CA 50). 

The nonstructural carbohydrates in SB can be divided based on their chemical properties (See section Carbohydrates in Soybeans and Soybean Meal), but also on their value as nutrients. The different categories of SB carbohydrates identified based on chemistry are profoundly different in their rate of digestion and their physiological behavior. 

Students arc strongly advised not to attempt identification of the soluble carbohydrates by taste—quite apart from the fact that other compounds (c.g., saccharin] also have a sweet taste, the tasting of an imperfectly identified organic compound u too dangerous an operation. 

Periodic acid cleavage of vicinal diols is often used for analytical purposes as an aid m structure determination By identifying the carbonyl compounds produced the con stitution of the starting diol may be deduced This technique finds its widest application with carbohydrates and will be discussed more fully in Chapter 25... 

Periodic acid oxidation (Section 15 12) finds extensive use as an analytical method m carbohydrate chemistry Structural information is obtained by measuring the number of equivalents of periodic acid that react with a given compound and by identifying the reaction products A vicinal diol consumes one equivalent of penodate and is cleaved to two carbonyl compounds... 

Analysis of coatings is simplified if the coating can be removed from the paper in a water bath by ultrasonic cleaning. If fibers are not present, a carbohydrate deterrnination can be used to identify gums and other carbohydrate polymers in the coating. 

Nicotinic acid is found in plants associated with both peptides and polysaccharides. For example in wheat bran, two forms are described a peptide with a molecular weight of approximately 12,000 and a carbohydrate complex that is called niacytin. Polysaccharides isolated from wheat bran have been found to contain 1.05% nicotinic acid in bound form. Hydrolysis yielded a fragment identified as P-3-O-nicotinoyl-D-glucose (25). 

Identify the chiral carbon atoms in a carbohydrate or n-amino acid. 

The ketone group can be reduced to an alcohol that can then be silylated. This procedure has been used to identify the keto group in carbohydrates. 

This is an extracellular deposition of an insoluble protein, which has adopted a (3-sheet structure due to an unknown event that induced misfolding of unstable proteins. The name amyloid has been given according to the amyloid staining properties, which are similar to carbohydrate deposits, e.g., amyloid can be identified with Congo red and seen under polarized light (birefringence test). 

Several dozens of aldolases have been identified so far in nature [23,24], and many of these enzymes are commercially available at a scale sufficient for preparative applications. Enzyme catalysis is more attractive for the synthesis and modification of biologically relevant classes of organic compounds that are typically complex, multifunctional, and water soluble. Typical examples are those structurally related to amino acids [5-10] or carbohydrates [25-28], which are difficult to prepare and to handle by conventional methods of chemical synthesis and mandate the laborious manipulation of protective groups. 

One limitation of serum-specific IgE is that given the cross-reactivity between different Hymenoptera venoms, and also due to the presence of anti-carbohydrate antibodies, it is frequent to find several simultaneous positive results in patients with non-identified insect stings, a situation which makes diagnosis of the same difficult. In these cases, RAST inhibition and the release of histamine occasionally provide data on the venom involved and when this is not the case, it is advisable to administer immunotherapy against both [44]. 

Monascus pigments have been used in Asian countries for centuries as food colorants and spices and in traditional medicine. These pigments are produced by the fungi of Monascus genus cultivated on carbohydrate-rich substrates such as rice, wheat, com, potatoes, and soybeans. Three species of Monascus identified are pilosus. 

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