Definition sugars

Amino-5-hydroxymethyl-2-methylpyrimidine, 268-269 Amino sugars definition, 51... 

Glucolin a-D-Glucopyranose D-Glucose Grape sugar Definition Sugar obtained from the hydrolysis of starch commercial prod. 

In general, the dyes occur as glycosides, the most common sugar being glucose. Some flavones contain more than one sugar. Their role as dyes in the plant is not definitely known a common suggestion is that they protect the plant from harm fill uv radiation. 

By far the majority of carbohydrate material in nature occurs in the form of polysaccharides. By our definition, polysaccharides include not only those substances composed only of glycosidically linked sugar residues but also molecules that contain polymeric saccharide structures linked via covalent bonds to amino acids, peptides, proteins, lipids, and other structures. 

Nucleosides are compounds formed when a base is linked to a sugar via a gly-cosidic bond (Figure 11.10). Glycosidic bonds by definition involve the carbonyl carbon atom of the sugar, which in cyclic structures is joined to the ring... 

Because of the somewhat ambiguous definitions of D and L, another system of nomendature was devised for asymmetric compounds, and it has largely replaced the old D, L-system since the 1960s. However, the D, L-nomendature is still used for amino adds and sugars. 

Manley-Harris and Richards (Missoula, Montana) have compiled a comprehensive account of the dianhydrides of D-fructose and related compounds, more than 30 in all. These compounds, several of which are of importance in the sugar industry, have in the past presented significant problems in their chemical characterization. Their chemistry was surveyed as early as 1945 by McDonald in Volume 2 of this series, and discussed again in Volume 22 by Verstraeten. The current article furnishes detailed NMR data for each of the anhydrides, providing definitive reference data for accurate identification and correlation with earlier literature, where erroneous structural attributions are rather frequent. 

Matrix Components The term matrix component refers to the constituents in the material aside from those being determined, which are denoted as analyte. Clearly, what is a matrix component to one analyst may be an analyte to another. Thus, in one hand for the case of analyses for elemental content, components such as dietary fibre, ash, protein, fat, and carbohydrate are classified as matrix components and are used to define the nature of the material. On the other hand, reference values are required to monitor the quality of determinations of these nutritionally significant matrix components. Hence, there is a challenging immediate need for certified values for dietary fibre, ash, protein, fat, and carbohydrate. Concomitantly, these values must be accompanied by scientifically sound definitions (e.g. total soluble dietary fibre, total sulpha-ted ash, total unsaturated fat, polyunsaturated fat, individual lipids, simple sugars, and complex carbohydrates). 

Solutions are mixtures, and therefore do not have definite compositions. For example, in a glass of water it is possible to dissolve 1 teaspoonful of sugar or 2 or 3 or more. However, for most solutions there is a limit to how much solute will dissolve in a given quantity of solvent at a given temperature. The maximum concentration of solute that will dissolve in contact with excess solute is called the solubility of the solute. Solubility depends on temperature. Most solids dissolve in liquids more at higher temperatures than at lower temperatures, while gases dissolve in cold liquids better than in hot liquids. 

Our present knowledge of the second type of hydrofuranol anhydro sugars, the 2,5-anhydro hexoses, is less extensive and definite than is the case with the 3,6-anhydro type. The credit for most of the information we have belongs to Levene and coworkers and results from the comprehensive study of hexosamines made by them. A good summary of this work was provided by Levene in 1921.49... 

Carbohydrates are characterized by the presence of polyhydroxylic aldehyde or polyhydroxy-lic ketone structures or polymers made of such units. Sugars and polysaccharides have definite... 

The carbohydrate nomenclature jointly established by the American and British Committees4 does not specifically refer to the branched-chain sugars nevertheless, the application and extension of its Rules can provide definitive names to augment or to replace the trivial or unsystematic terms which have been conferred on naturally occurring, branched-chain sugars and related synthetic products, including the branched-chain saccharinic acids.6 9... 

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