Monosaccharides common names

Most sugars have their own specific common names, such as glucose, fructose, galactose, and mannose. These names are not systematic, although there are simple ways to remember the common structures. We simplify the study of monosaccharides by grouping similar structures together. Three criteria guide the classification of monosaccharides ... 

All carbohydrates have common names. The simplest aldehyde, glyceraldehyde, and the simplest ketone, dihydroxyacetone, are the only monosaccharides whose names do not end in the suffix -ose. ( The prefix D- is explained in Section 27.2C.)... 

The common name of each monosaccharide indicates both the number of atoms it contains and the configuration at each of the stereogenic centers. Because the common names are firmiy entrenched in the chemicai literature, no systematic method has ever been estabiished to name these compounds. 

Figure 2 Mammalian monosaccharides and nucleotide sugars. (A) Chemical structures, common names, and abbreviations of the 11 monosaccharides found in mammalian glycans as well as ManNAc, the precursor for sialic acids. (B) Examples of the three classes of nucleotide sugars are provided by UDP-GIcNAc (Glc, GIcA, Gal, GalNAc, and Xyl also use UDP), GDP-Man (Fuc also is linked to GDP), and CMP-Neu5Ac/Gc (IdoA is produced by postsynthetic epimerization of GIcA and therefore does not require a nucleotide sugar).

The nomenclature of carbohydrates usually includes the suffix -ose. Monosaccharides may also be identified according to the nature of the carbonyl functional group (aldose or ketose), the number of carbons in the molecule (tri-, tetr-, pent- ose) or a combination of these two. Monosaccharides also have common names such as ribose, glucose, galactose, and fructose (four of the most common monosaccharides found in nature). 

Table 9.4 shows abbreviations for the common monosaccharides. The naming rules for oligosaccharides based on these abbreviations are as follows ... 

The common name of the monosaccharide, together with the d or l designation, completely defines its stmcture because the relative configurations of all the asymmetric carbons are implicit in the common name. 

Carbohydrates exist as sugars, starches, and cellulose. The simplest of these are the sugars. The common names for sugars end in -ose (e.g., glucose, sucrose, maltose). Carbohydrates are classified as monosaccharides, disaccharides, oligosaccharides, and polysaccharides according to the number of monosaccharide units linked in a molecule. 

For polysaccharides, even the shorthand notation is unwieldy. Most of these compounds are given common names and, because they are usually polymeric, the repeating monosaccharide or disaccharide units are often shown. Many of these are homopolymers that is, the poly(saccharide) is formed by coupling only one monosaccharide unit. Cellulose, for example, is a linear poly(glucopyranose) coupled in a (l- 4) P-d manner as shown in 66, it is a major constituent of plant cell walls. Amylose (a constituent of starch) is a linear poly(glucopyranose) coupled (1 4)-a-d (see 67), and inulin (found in dandelions) is a linear fructofuranose coupled (2— l)-P-d (see 68). 

Glyceraldehyde is a common name the lUPAC name for this monosaccharide is 2,3-dihydroxypropanal. Similarly, dihydroxyacetone is a common name its lUPAC name is 1,3-dihydroxypropanone. The common names for these and other monosaccharides, however, are so firmly rooted in the literature of organic chemistry and biochemistry that they are used almost exclusively to refer to these compounds. Therefore, throughout our discussions of the chemistry and biochemistry of carbohydrates, we use the names most common in the literature of chemistry and biochemistry. 

The nomenclature of monosaccharides is dominated by common names. Even though lUPAC names can be derived for each different monosaccharide, the common names are much simpler and are used almost exclusively. 

Monosaccharides consist of only one sugar unit. Oligosaccharides consist of between two and ten of the same or different monosaccharides connected to each other by glycosidic (semiacetal) bonds. Monosaccharides and oligosaccharides are sometimes referred to collectively by the name sugars, as they share many common properties and often have a sweet taste. Polysaccharides are composed of more than ten of the same or different monosaccharides commonly they consist of multiple molecules of monosaccharides, which are often precisely determined. Complex carbohydrates also contain compounds other than saccharides, such as, for example, peptides, proteins and lipids. 

Arabinoxylans Heteropolysaccharides consisting predominantly of arabinose and xylose residues. The d-xylopyranose molecules are generally linked by p-1,4 bonds, while the bonds with 1-arabinofuran to carbon 3 or less frequently to carbon 2. They are commonly named pentosans because the polysaccharides are mainly made up of five carbon monosaccharides. 

An intramolecular ether (commonly called an intramolecular anhydride), formally arising by elimination of water from two hydroxy groups of a single molecule of a monosaccharide (aldose or ketose) or monosaccharide derivative, is named by attaching the (detachable) prefix anhydro- preceded by a pair of locants identifying the two hydroxy groups involved. 

The cyclic product of condensation of two monosaccharide molecules with the elimination of two molecules of water (commonly called an intermolecular anhydride), is named by placing the word dianhydride after the names of the two parent monosaccharides. When the two parent monosaccharides are different, the one preferred according to the order of preference given in 2-Carb-2.1 is cited first. The position of each anhydride link is indicated by a pair of locants showing the positions of the two hydroxy groups involved the locants relating to one monosaccharide (in a mixed dianhydride, the second monosaccharide named) are primed. Both pairs of locants immediately precede the word dianhydride . 

Symbols for the common monosaccharide residues and derivatives are listed in Table 2. They are generally derived from the corresponding trivial names. Abbreviations for substituents (see 2-Carb-1.16.2), preceded by locants, follow the monosaccharide abbreviations directly. 

The partially methylated monosaccharides obtained on depolymerization of the permethylated sample are preferably analyzed as acetates by g.l.c.-m.s., as shown by Bjomdal and coworkers.41,42 The neutral sugars and the amino sugars obtained in acetolysis-acid hydrolysis are reduced, and acetylated for the analysis, and the amino-hexitol and the neuraminic acid residues are acetylated after methanolysis. Identification with the aid of g.l.c.-m.s. has been described for all of the common components of protein- and lipid-linked glycans and oligosaccharides from animal cells, namely, the neutral sugars,41-43 hexitols,44 hexosamines,29,43,45,46 aminohexitols,31,32 and neuraminic acids.33,34,47... 

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