Two Monosaccharide Units

Thermal Condensations, Two moles of sugar may condense when heated in vacuo. Maltose is said to be produced in this manner from jS-D-glucose and a-D-glucose and from jS-D-glucose and 1,6-anhydro-jS-D-glucose. The 

Most of the isomers theoretically possible by the condensation of two glucose units have been isolated 26a). (See also under Isomaltose.) 

In many cases the synthesis of oligosaccharides under natural conditions 

The methylation method has been the principal means for determining the type of ring of the monosaccharide constituents and their points of attachment to one another in the oligosaccharide molecule. The usual procedure involves (1) complete methylation of the disaccharide (2) hydrolysis of the methylated disaccharide to partially methylated monosaccharide units, and their identification by comparison of their properties with those of known methylated compounds (3) determination of the unmethylated positions in each unit, these being the positions which were available for ring formation and for linkage between units and (4) determination of the ring type (pyranose or furanose) by supplementary evidence, such as determination of the rate of hydrolysis of the partially methylated lactone (31). 

These figures presumably represent the hydrolysis of the sucrose linkage in these trisaccharides. 

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Disaccharide (Sections 25 1 and 25 14) A carbohydrate that yields two monosaccharide units (which may be the same or different) on hydrolysis... 

If d carbohydrate already contains a nitro group, the nitro-bearing carbon atom can become the nucleophilic center for the conphng of two monosaccharide units fsee Section 3 2 2 Snami and coworkers have used this method for the synthesis of andbiodcs bearing sugars " A typical example is presented in Eq 3 63 "... 

Disaccharides, which are dimers farmed when two monosaccharide units combine with the elimination of H20. The monosaccharides may be the same (two glucose units in maltose) or different (a glucose and fructose unit in sucrose). 

A disaccharide is a compound in which two monosaccharide units are joined by a... 

Disaccharides are condensation products of two monosaccharide units. Examples are maltose and sucrose. 

Carbohydrates are classified based upon the products formed when they are hydrolyzed. Monosaccharides are simple sugars that cannot be broken down into simpler sugars upon hydrolysis. Examples of monosaccharides are glucose, ribose, deoxyribose, and fructose. Disaccharides contain two monosaccharide units and yield two monosaccharides upon hydrolysis. Examples of disaccharides are lactose, maltose, and sucrose. Polysaccharides are polymers of monosaccharide units and yield many individual monosaccharides upon hydrolysis. Examples of polysaccharides are starch, glycogen, and cellulose. 

Oligo means a few or some. It follows that oligosaccharides contain a few monosaccharide units. The simplest oligosaccharides are the disaccharides, which contain two monosaccharide units. These are followed by the trisaccharides, which contain three and so forth. The most common disaccharide is sucrose, common table sugar. 

FIGURE 10.1 Anthocyanidins (An) and anthocyanins grouped according to their content of monosaccharide units and acylation. The vertical axis represents the number of pigments. The upper dark part of each bar represents the anthocyanins reported later than 1992. IM, one monosaccharide unit IMA, one monosaccharide unit plus acylation 2M, two monosaccharide units 2MA, two monosaccharide plus acylation 3M, three monosaccharide units 3MA, three monosaccharide units plus acylation >3M, more than three monosaccharide units >3MA, more than three monosaccharide units plus acylation. 

Glycosaminoglycans are extracellular heteropolysaccharides in which one of the two monosaccharide units is a uronic acid and the... 

Monosaccharides are the building blocks of disaccharides, which are carbohydrate molecules containing two monosaccharide units. Figure 13.3 shows table sugar—sucrose—the most well-known disaccharide. In the digestive tract, sucrose is readily cleaved into its monosaccharide units, glucose and fructose. 

Monosaccharides and disaccharides are classified as simple carbohydrates, where the word simple is used because these food molecules consist of only one or two monosaccharide units. Most simple carbohydrates have some degree of sweetness and are also known as sugars. 

Was this your answer Simple carbohydrates are simple in the sense that they consist of only one or two monosaccharide units per molecule. Complex carbohydrates are complex in the sense of consisting of high numbers of monosaccharide units per molecule. 

Disaccharides are formed from two monosaccharide units that are connected by a gly-cosidic bond. Different disaccharides result from the combination of different monosaccharides, from the formation of the glycosidic bond using different hydroxy groups on the monosaccharides, or from different stereochemistries of the glycosidic bond. A few of the more important disaccharides are described in the following paragraph. 

Dipole moment (/i) (Section 1.9) The product of the amount of charge separation in a molecule times the distance of the charge separation. Disaccharide (Section 25.6) A carbohydrate formed from two monosaccharide units tliat are connected by a glycosidic bond. 

A general term for an acetal bond from an anomeric carbon joining two monosaccharide units, (pp. 1120, 1132)... 

Disaccharide (Section 27.12) A carbohydrate containing two monosaccharide units joined together by a glycosidic linkage. 

A disaccharide is a compound that is formed from two monosaccharide units by elimination of one molecule of water. At least one carbon atom involved in the acetal bridge (called glycosidic linkage)... 

Disaccharides are carbohydrates that are made up of two monosaccharide units. On hydrolysis a molecule of disaccharide yields two molecules of monosaccharide. 

Stichoposide A (26), C (27), D (28) E (29) affect survival of Ehrlich tumor cells. Minimal effective doses of glycosides ranged from 3.1 to 12 jj,g/ml. Stichoposide A, with two monosaccharide units, and stichoposide E, with the xylose residue as second monosaccharide unit, were less active [60]. 

Molecular model of sucrose. Sucrose is a disaccharide, consisting of two monosaccharide units linked together. One of the units in sucrose is a glucose ring (6-member) and the other is a fructose ring (5-member). Sucrose is common table sugar. 

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