Simple sugar

The conversion of the compounds under investigation into coloured derivatives (e.g., the separation of carbonyl compounds by conversion into their 2 4-dinitrophenylhydrazones, etc. of hydrocarbons through their picrates of alcohols through their 3 5-dinitrobenzoates of glucose, fructose and other simple sugars through their p-phenylazobenzoyl esters). 

The simple sugars or monosaccharides are polyhydroxy aldehydes or ketones, and belong to Solubility Group II. They are termed tetroses, pentoses, hexoses. etc. according to the number of carbon atoms in the long chain constituting the molecule, and aldoses or ketoses if they are aldehydes or ketones. Most of the monosaccharides that occur in nature are pentoses and hexoses. 

MaillardReaction (Nonenzymatic Glycation), Browned reaction products ate formed by heating amino acid and simple sugar. This reaction is important in food science relating to coloring, taste, and flavor enhancement (79), and is iUustrated as follows ... 

Carbohydrates. Carbohydrates are the principal components of the cell wall, comprising 65—75% by weight of the dry wood. Total hydrolysis yields simple sugars, primarily glucose and xylose in hardwoods and glucose and mannose in softwoods. Minor amounts of galactose, arabinose, and rhamnose are present. 

Although the hydrolysis of wood to produce simple sugars has not proved to be economically feasible, by-product sugars from sulfite pulping are used to produce ethanol and to feed yeast (107). Furthermore, a hemiceUulose molasses, obtained as a by-product in hardboard manufacture, can be used in catde feeds instead of blackstrap molasses (108). Furfural can be produced from a variety of wood processing byproducts, such as spent sulfite Hquor, bquors from the prehydrolysis of wood for kraft pulping, hardboard plants, and hardwood wastes (109). 

The net result of photosynthesis is reduction of carbon dioxide to form carbohydrates. A key intermediate is phosphoglyceric acid, from which various simple sugars are produced and disproportionated to form other carbohydrates. 

The Jordi polyamine column is a polar column for simple sugar and polysaccharide applications. The amine groups are bonded to the DVB backbone and are stable in aqueous mobile phases. This material does not self-hydrolyze as do many silica-based amino packings (Fig. 13.14). 

A variety of chemical and enzymatic reactions produce derivatives of the simple sugars. These modifications produce a diverse array of saccharide derivatives. Some of the most common derivations are discussed here. 

Another simple sugar that enters glycolysis at the same point as fructose is mannose, which occurs in many glycoproteins, glycolipids, and polysaccharides (Chapter 7). Mannose is also phosphorylated from ATP by hexokinase, and the mannose-6-phosphate thus produced is converted to fructose-6-phosphate by phosphomannoisomerase. 

Simple sugars undergo reaction with phenylhydrazine, PhNHNH2, to yield crystalline derivatives called osazones. The reaction is a bit complex, however, as shown by the fact that glucose and fructose yield the same osazone. 

Carbohydrate (Section 25.1) A polyhydroxy aldehyde or ketone. Carbohydrates can be either simple sugars, such as glucose, or complex sugars, such as cellulose. 

Complex carbohydrate (Section 25.1) A carbohydrate that is made of two or more simple sugars linked together. 

Digestion (Section 29.1) The first stage of catabolism, in which food is broken down by hydrolysis of ester, glycoside (acetal), and peptide (amide) bonds to yield fatty acids, simple sugars, and amino acids. 

Disaccharide (Section 25.8) A carbohydrate formed by linking two simple sugars through an acetal bond. 

Furanose (Section 25.5) The five-membered-ring form of a simple sugar. 

Although glucose can exist as a simple sugar, it is most often found in nature in combined form, as a disaccharide or polysaccharide. Several glucose-containing disaccharides are known. We will consider two of these, maltose and sucrose. 

There is another aspect of the structure of glucose and fructose. They, like other simple sugars, can exist as a straight chain but this form is in equilibrium with a cyclic structure. In solutions the latter form prevails. Reaction (2) shows both forms of glucose. 

The two sugars we have discussed are monosaccharides—they have a single, simple sugar unit in each molecule. The sugar on your table is a disaccharide—it has two units. One molecule of sucrose contains one molecule of glucose and one of fructose hooked together (losing a... 

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