Carbon monosaccharides

Sialic acids are nine-carbon monosaccharides involved in a wide range of biological phenomena. Their unique structure is characterized by the presence of a carboxylic... 

A 5-carbon monosaccharide (either D-ribose [in RNA] or 2-deoxy-D-ribose [in DNA])... 

C.-H. Lin, T. Sugai, R. L. Halcomb, Y. Ichikawa, and C. H. Wong, Unusual stereoselectivity in sialic acid aldolase-catalyzed aldol condensations Synthesis of both enantiomers of high-carbon monosaccharides, J. Am. Chem. Soc. 774 10138 (1992). 

Jarosz, S, Salanski, P, Mach, M, Application of stabilized sugar-derived phosphoranes in the synthesis of higher carbon monosaccharides. First synthesis of a C-21-dialdose, Tetrahedron, 54, 2583-2594, 1998. 

In Chapters 7-13, the focus shifts to the biochemistry of carbohydrates and the exploration of fundamental principles related to cell signaling and protein-carbohydrate interactions on a molecular level. Sialic acids are a class of nine-carbon monosaccharides found at the termini of oligosaccharides in many mammalian cellular systems. Randall Halcomb and Mark Chappell (Chapter 7) summarize the most current sialylation technology. Both chemical and enzymatic methodologies for coupling sialic acid to various carbohydrate moieties are examined while providing the reader with chemical detail that one requires to work in this field. 

Glyceraldehyde is a three-carbon monosaccharide containing an aldehyde group. D-Glyceraldehyde is formed by action of aldolase B on fmctose-1-phosphate. 

Monosaccharides are classified as aldoses or ketoses, respectively, depending on whether the carbonyl group is an aldehyde or a ketone. Classification into trioses, tetroses, pentoses, and hexoses, respectively, is used to indicate there are three, four, five, and six carbon atoms in the monosaccharide. Both types of prefixes are also used together, e.g., aldohexose for a six-carbon monosaccharide with an aldehyde group. 

There are two series of simple monosaccharides aldoses, which contain an aldehyde group, and ketoses, which contain a ketone group. Simple monosaccharides are also classified by the munber of carbon atoms which they contain e.g., trioses (3 C), tetroses (4 C), pentoses (5 C), and hexoses (6 C). The two naming systems are combined e.g., glucose is an aldohexose as it is a six-carbon monosaccharide with an aldehyde group. 

Hexokinase, in all cells, can phosphorylate other 6-carbon monosaccharides such as fructose and galactose, whereas glucokinase is specific for glucose and is only found in the liver. Hexokinase is inhibited by its product, glucose... 

Among the higher-carbon monosaccharides, the most important examples are the nine-carbon amino sugar A-acetylneuraminic acid (5-acetamido-3,5-dideoxy-D-g/ycero-a-D-gfl/flcto-non-2-ulopyranosonic acid, Neu5Ac Scheme 11), the parent member of the family of sialic acids, and the eight-carbon sugar... 

Based on the number of carbons, monosaccharides can be called trioses (three carbons), tetroses (four carbons), pentoses (five carbons), hexoses (six carbons), heptoses (seven carbons), octoses (eight carbons), and so on. 

New drugs to treat influenza were developed based on an understanding of the oligosaccharide structure on the surface of the virus. The key player is A -acetylneuraminic acid which is the A -acetyl derivative of a nine-carbon monosaccharide. A -Acetylneuraminic acid is part of the cell-surface glycoprotein that is recognized by an invading influenza virus (Figure 23.14). 

Fig. 8 0 C vs F C ratio for a range of carbohydrate-derived chcanicals and derivatives thereof. Feedstocks highlighted in green box. Cx resp. x-carbon monosaccharide...

Fig. 11 Atom economy vs F C plot for common biomass primary products and srane dtaivatives, calculated directly from the pentose or glucose biomass. Cx resp. x-carbon monosaccharide Data ...

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