Monosaccharide complexes

Monosaccharide complexes Enzymes Transporters Receptors Metabolic engineering Monosaccharide mimetics Diagnosis of malignant diseases Cancer therapy... 

Stanca-Kaposta EC, farfabal P, Cocinero EJ, Hurtado P, Simons JP (2013) Carbohydrate-aromatic interactions vibrational spectroscopy and structural assignment of isolated monosaccharide complexes with p-hydroxy toluene and N-acetyl L-tyrosine Methylamide. J Phys ChemB 117 8135... 

These interactions are being investigated in a rapidly increasing range of monosaccharide complexes, via gas-phase spectroscopy [44, 48,49,59-63, 65, 66] with their partners judiciously selected to probe specific types of interaction and to determine the minimum ingredients involved in CBH-protein interactions. 

Lithium tetrahydridoaluminate-monosaccharide complex Sec. alcohols from ketones Asym. reduction... 

Acarbose is a nonabsorbable a-glucosidase inhibitor which blocks the digestion of starch, sucrose, and maltose. The digestion of complex carbohydrates is delayed and occurs throughout the small intestine rather than in the upper part of the jejunum. Absorption of glucose and other monosaccharides is not affected. Acarbose is adrninistered orally three times a day and chewed with the first mouthful of food. 

Antibiotic A201A. Antibiotic A201A (23), produced by S. capreolus is an /V -dimethyladenine nucleoside stmcturaHy similar to puromycin (19). Compound (23) which contains an aromatic acid and monosaccharide residues (1,4), inhibits the incorporation of amino acids into proteins but has no effect on RNA or DNA synthesis. Compound (23) does not accept polypeptides as does (19), and does appear to block formation of the initiation complex of the SOS subunit. It may block formation of a puromycin-reactive ribosome. 

Deoxy sugars, as we saw in Section 25.7, have an oxygen atom "missing." That is, an —OH group is replaced by an -H. The most common deoxy sugar is 2-deoxyribose, a monosaccharide found in DNA (deoxyribonucleic acid). Note that 2-deoxyribose exists in water solution as a complex equilibrium mixture of both furanose and pyranose forms. 

In contrast with the monotonous monosaccharide repeat and the same type of linkage in the polysaccharide structures (1 to 21) described in Sections IV and V, this section deals with rather more complex polymers (23 to 39), which are composed of disaccharide repeats. Further, combining two types of linkages enhances the formation of exotic morphologies not amenable to the former set. The sequence listed in Table II is referred to as -A-B- in Table V while listing... 

Besides water, the diet must provide metabolic fuels (mainly carbohydrates and lipids), protein (for growth and turnover of tissue proteins), fiber (for roughage), minerals (elements with specific metabolic functions), and vitamins and essential fatty acids (organic compounds needed in small amounts for essential metabolic and physiologic functions). The polysaccharides, tri-acylglycerols, and proteins that make up the bulk of the diet must be hydrolyzed to their constituent monosaccharides, fatty acids, and amino acids, respectively, before absorption and utilization. Minerals and vitamins must be released from the complex matrix of food before they can be absorbed and utifized. 

Rhamnogalacturonan 11 (RG-11) is a structurally complex, pectic polysaccharide that is present in the primary cell-walls of higher plants. It is composed of 60 glycosyl residues, and is a very complex molecule indeed. For example, on acid hydrolysis, at least ten different monosaccharides are formed, including the novel aceric acid (30), which is the only branched-... 

The pyranoid monosaccharides provide a wide range of asymmetric molecules for study by the c.d. spectroscopist. However, these compounds are not without their difficulties. In aqueous solution, these compounds exist in a complex equilibrium involving the two possible chair conformers of the pyranoses, the furanoses, a and p anomers, and the acyclic form, as well as septanoses for aldohexoses and higher sugars. 

Peelen, G. O. H., de Jong, J. G. N., and Wevers, R. A., High-performance liquid chromatography of monosaccharides and oligosaccharides in a complex biological matrix, Anal. Biochem., 198, 334, 1991. 

Proteins, the main constituents of the animals body, are polypeptides, biopolymers consisting of many amino acid molecules (the monomers) combined together (see Chapter 11) collagen, for example, the main component of animal skin, is a complex protein consisting of many molecules of amino acids combined together into polypeptide chains (see Fig. 71). Polysaccharides, the essential constituents of plants, also consist of many monosaccharide molecules combined together. Cellulose, the most abundant biological material on earth, which makes up most of the structural... 

The most well known and most widely used compounds mentioned in the chapter are the doubly protected monosaccharide derivatives (cf. Schemes 16-18 and 27-29), which serve as building blocks for the regio- and stereospecific synthesis of a host of more complex carbohydrates. A number of newly discovered alkaloids contain fused 5 6 6-triheterocyclic systems these compounds may come from not only traditional (plant) sources, for example, compounds 96, 292-294, 446, and 447, but also insects (compounds 531-533), marine animals of various kinds, for example, sponges (compounds 58 R = H or OH) and ascidians (compound 289), and amphibians (compound 535). Although the majority of these alkaloids are known to be toxic in sufficient quantity, any possible therapeutic applications have apparently not yet been disclosed. 

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