Carbohydrates/sugar maltose

Many other simple carbohydrates occur in nature. These include fructose (fruit sugar), maltose (malt sugar), and lactose (milk sugar). 

The interest attaching to the [carbohydrates] may be said to centre around glucose, this carbohydrate being the first to arise in the plant and the unit group from which substances such as cane sugar, maltose, starch and cellulose are derived it is also of primary importance in animal metabolism, as the main bulk of the carbohydrate in our food materials enters the circulation in the form of glucose. ... 

By taking advantage of the remarkable abihty of subtihsia [9014-01-1] to remain catalyticahy active ia anhydrous dimethylformamide, a number of carbohydrates and other sugar-related compounds have been regioselectively acylated with trichloroethyl butyrate (100). In the case of maltose [69-79-4] (76) and sahcia [138-52-3] (77), for example, acylation occurs exclusively at the C-6 positions. 

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. 

Complexes of maltose with urea, thiourea, imidazole, methanol, 2-oxazolidinone, N,N-dimethylformamide, and hexamethylphosphoric triamide have been described.131 These complexes were noncrystalline and hygroscopic. Such complex-forming reactions could be valuable in the preservation of food flavors during the dehydration process. Sugars have been shown to complex with ethylenediamine.133,133 The nature of the complex has been suggested to be that of a proton-transfer type, in which the carbohydrate moiety is the proton donor and the amine is the proton acceptor. 

Complexes of alkali metals and alkaline-earth metals with carbohydrates have been reviewed in this Series,134 and the interaction of alkaline-earth metals with maltose has been described.135 Standard procedures for the preparation of adducts of D-glucose and maltose with the hydroxides of barium, calcium, and strontium have been established. The medium most suitable for the preparation of the adduct was found to be 80% methanol. It is of interest that the composition of the adducts, from D-glucose, maltose, sucrose, and a,a-trehalose was the same, namely, 1 1, in all cases. The value of such complex-forming reactions in the recovery of metals from industrial wastes has been recognized. Metal hydroxide-sugar complexes may also play an important biological role in the transport of metal hydroxides across cell membranes. 

Carbohydrates other than glucose, fructose, and sucrose have been found in the above common fruits. However, these sugars are usually found in trace amounts and are quite variable. Trace sugars in these fruits have included mannose, galactose, arabinose, xylose, maltose, and sorbitol (36, 39, 41). 

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