Monosaccharides nomenclature system

These two nomenclature systems, the only ones which allow the position of the substituents on the constituent monsaccharides to be clearly indicated, are found particularly in articles on synthetic chemistry. They are awkward but can be simplified for free oligosaccharides. Each monosaccharide is represented by the following symbols Glc for glucose. Gal for galactose, Man for mannose. 

The term carbohydrate includes a wide range of molecules which in many cases are quite complex structures. In chemical terms a carbohydrate is either a polyhydroxy aldehyde, a polyhydroxy ketone or, alternatively, it is a compound that can be hydrolysed to such a structure. The smallest unit that cannot be hydrolysed any further is called a monosaccharide. Glucose (Fig. 11.4.1) is the most abundant monosaccharide known and is by far the most important. Other examples include fructose and mannose. A carbohydrate which has been hydrolysed to two monosaccharide units is cabled a disaccharide and the best known example is sucrose, which is composed of a unit of glucose covalently linked to a unit of fructose. The nomenclature system continues in a logical fashion until one can refer to an ohgosaccharide as being a chain composed of several monosaccharide units. Depending upon whether a monosaccharide is an aldehyde or a... 

A further complication that may be encountered in the nomenclature of branched-chain monosaccharides is in the numbering of the carbon atoms of the molecule. There is some precedent for numbering the carbon atoms of the branched moiety continuously with the carbon atoms of the main chain. However, this can result in confusion and ambiguity, especially when there are further substituents on the branched carbon atoms. In this connection, the Geneva system of nomenclature11 provides a reasonable solution, which is illustrated in the naming of compounds XII10 and XIII. 

Using the condensed system of carbohydrate nomenclature (ref. 2, section 3.7 ref. 4, 2-Carb-38.5), positions of glycosidic linkages and anomeric configurations are expressed in parentheses between the monosaccharide residues that are thus linked. This principle should be adhered to with full names as well as with the abbreviated structures. A short form for repre-... 

According to the traditional system of carbohydrate nomenclature, the configuration of any monosaccharide having up to six carbon atoms is completely defined by a prefix D or L followed by a syllable glue- , mann- etc. This latter specifies both the number of carbon atoms in the sugar and the relative stereochemistry of all chiral centres, while the D or L prefix designates the enantiomeric series to which the compound belongs. 

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