Disaccharides Cellobiose, Lactose, Maltose, Sucrose

Directing effects of substituents. See Electrophilic aromatic substitution Disaccharide, 973, 991-993, 1008. See also Cellobiose Lactose Maltose Sucrose Disparlure, 239... 

C. beijerinckii (formerly C. acetohutylicum) NCIMB 8052 prefers glucose as substrate but also ferments glucitol, galactose, and the disaccharides cellobiose, lactose, maltose, and sucrose [25]. C. beijerinckii NCIMB 8052 is a grampositive, rod-shaped, obligately anaerobic, mesophylic bacterium and possesses peritrichous flagella. 

Some common disaccharides are maltose, cellobiose, lactose, and sucrose. 

In principle, any of the hydroxyl groups of the aglycone could provide the linkage between the two monosaccharides, and in fact, every possible linkage has been found in naturally occurring disaccharides. We will consider four disaccharides maltose, cellobiose, lactose, and sucrose. 

Two sugars can link to each other by losing water from OHs to form disaccharides. Figure 4.6 shows the Haworth projection formulas of four important disaccharides sucrose, lactose, maltose, and cellobiose, which all have the same molecular formulas, C12H22011. Sucrose and lactose are the most abundant and most important disaccharides of natural origin. Maltose and cellobiose are repeating units of polymeric starch and cellulose, respectively. Disaccharides may hydrolyze to form two monosaccharide molecules. 

Disaccharides are formed by the union of two monosaccharides with the loss of one molecule of water. Disaccharides include lactose, cellobiose, maltose, and sucrose. The molecular formula for sucrose is as follows ... 

Disaccharides are complex carbohydrates in which two simple sugars are linked by a glycoside bond between the anomeric carbon of one unit and a hydroxyl of the second unit. The two sugars can be the same, as in maltose and cellobiose, or different, as in lactose and sucrose. The gly-cosidic bond can be either a (maltose) or j3 (cellobiose, lactose) and can involve any hydroxyl of the second sugar. A 1,4 link is most common (cellobiose, maltose), but others such as 1,2 (sucrose) are also known. 

Glycosidic bonds between monosaccharides give rise to oligosaccharides and polysaccharides. The simplest oligosaccharides, the disaccharides, include compounds such as sucrose and lactose, which are referred to as sugars (like the monosaccharides). Other common disaccharides include trehalose, maltose, gentiobiose, and cellobiose. 

The most common naturally occurring disaccharides are sucrose (table sugar) and lactose (milk sugar). While sucrose is derived from plants and is prepared commercially from sugar cane and sugar beet, lactose is found in the milk of animals. Other common disaccharides that are produced by breaking down polysaccharides include maltose (obtained from starch) and cellobiose (obtained from cellulose). 

Among the more important disaccharides are sucrose, 24, maltose, 25, cellobiose, 26, and lactose, 27 ... 

We shall study four disaccharides (-f )-maltose (malt sugar), ( +) -cellobiose, (-p )-lactose (milk sugar), and ( + )-sucrose (cane or beet sugar). As with the monosaccharides, we shall focus our attention on the structure of these molecules on which monosaccharides make up the disaccharide, and how they are attached to each other. In doing this, we shall also learn something about the properties of these disaccharides. 

Fig. 3-112. Gradient elution of various disaccharides. - Separator column IonPac AS6A eluent (A) water, (B) 0.05 mol/L NaOH + 0.0015 mol/L acetic acid gradient 20% B for 5 min iso-cratically, then linearly to 100% B in 15 min flow rate 0.8 mL/min detection and injection volume see Fig. 3-110 solute concentrations 10 ppm trehalose (1), 25 ppm sucrose (2), lactose (3), isomaltose (4), melibiose (5), gentiobiose (6), cellobiose (7), 50 ppm turanose (8), and maltose (9).

Disaccharides are glycosides composed to two monosaccharide units. Examples of disaccharides are maltose, lactose, cellobiose, and sucrose. Oligosaccharides contain two to ten monosaccharide units. 

A disaccharide is a saccharide containing two monosaccharide residues. Common examples include sucrose, maltose, lactose, trehalose, cellobiose, and gentiobiose. 

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