Biological roles of carbohydrates

Therefore the view that carbohydrates are of limited importance within biological systems has been challenged and renewed interest into the science of Glycobiology has emerged. 

An alternative approach for treating bacterial infections has seen the development of carbohydrate based antibiotics to target carbohydrate receptors and carbohydrate modifying enzymes [6]. 

Represents one-third to one-half of the total milk oligosaccharides. 

An alternative approach has concentrated on aborting the synthesis of disease associated carbohydrates, and this again requires access to carbohydrate 

It has been demonstrated that carbohydrate analogues are capable of inhibiting specific enzymes involved in the carbohydrate biosynthesis, offering the potential to engineer the synthesis of different carbohydrates. This has proved of use for aborting the synthesis of disease associated carbohydrates that are central to the infection pathway [13]. 

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The chemistry and biochemistry of carbohydrates in general is detailed in a four-volume series (31), and a comprehensive treatment of polysaccharides can be found in the three volumes edited by AspinaU (32). A multiauthored treatise on polysaccharides published in 2005 (33) covers a wide range of aspects of the structural diversity, biological relevance, and technological apphcations of polysaccharides. A volume in the series Comprehensive Natural Product Chemistry edited by Pinto (34) provides extensive detail on the biosynthesis and biological role of carbohydrates. 

In order to fully explore the biological roles of carbohydrates and exploit the therapeutic opportunities divulged above, it is essential to develop efficient regio- and stereoselective methods for the synthesis of carbohydrates. Whilst carbohydrates can sometimes be isolated from natural sources, synthetic strategies... 

To examine the biological role of carbohydrates of the binding protein, it was... 

A coirplete understanding of the role of carbohydrates in biological systems requires knowledge of the distribution at equilibrium of the various conformers in aqueous solution. The conformational behavior of carbohydrates in solution can be examined from different vantage points (1,), but the most relevant approach is, no doubt, study of dilute solutions themselves. At present, high resolution NMR spectroscopy is the primary tool for determination of three-dimensional structure of oligosaccharides in solution. Optical rotation is also very sensitive to conformation (2) and there is a new, semi-enqpirical theory of optical rotation of oligosaccharides ( ). 

Three published papers (110-112) and the chapter of a Ph.D. thesis (46) have reported VCD results in carbohydrates. The significance of these studies derives from the important biological roles that carbohydrates play in living systems. All three contributions are concerned with either sugars or their derivatives. From a structural point of view these molecules are quite interesting due to the presence of several adjacent stereogenic centers and the availability of different... 

Due to the biological roles of glycolipids, many papers have been devoted to their syntheses over the last ten years. The coupling of a fully protected carbohydrate donor to a lipid acceptor requires efficient and highly stereoselective glycosylation methods because lipid derivatives often have low reactivity. A few examples of glycosphingolipids syntheses will be discussed below as well as multistep preparations of other amphiphilic carbohydrates designed as biochemical mimetics, surfactants or liquid crystals. 

A review of applications of chemical synthesis of carbohydrates to an understanding of the biological roles of oligosaccharides. 

The role of carbohydrates in biological communication is well illustrated by the human blood types.a b According to the ABO system first described by Landsteiner in 1900, individuals are classified into types A, B, AB, and O. Blood of individuals of the same type can be mixed without clumping of cells, but serum from a type O individual contains antibodies that agglutinate erythrocytes of persons of types A and B. Serum of persons of type B causes type A cells to clump and vice versa. Individuals of none of the four types have antibodies against type O erythrocytes. For this reason, persons with type O blood are sometimes inaccurately described as "universal donors."... 

The biological roles of phosphorus include (1) anabolic and catabolic reactions, as exemplified by its essentiality in high-energy bond formation, e.g., ATP (adenosine triphosphate), ADP (adenosine diphosphate), etc., and the formation of phosphorylated intermediates in carbohydrate metabolism ... 

Weymouth-Wilson AC (1997) The role of carbohydrates in biologically active natural products. Nat Prod Rep 14, 99-110. 

Abstract Carbohydrates have been investigated and developed as delivery vehicles for shuttling nucleic acids into cells. In this review, we present the state of the art in carbohydrate-based polymeric vehicles for nucleic acid delivery, with the focus on the recent successes in preclinical models, both in vitro and in vivo. Polymeric scaffolds based on the natural polysaccharides chitosan, hyaluronan, pullulan, dextran, and schizophyllan each have unique properties and potential for modification, and these results are discussed with the focus on facile synthetic routes and favorable performance in biological systems. Many of these carbohydrates have been used to develop alternative types of biomaterials for nucleic acid delivery to typical polyplexes, and these novel materials are discussed. Also presented are polymeric vehicles that incorporate copolymerized carbohydrates into polymer backbones based on polyethylenimine and polylysine and their effect on transfection and biocompatibility. Unique scaffolds, such as clusters and polymers based on cyclodextrin (CD), are also discussed, with the focus on recent successes in vivo and in the clinic. These results are presented with the emphasis on the role of carbohydrate and charge on transfection. Use of carbohydrates as molecular recognition ligands for cell-type specific dehvery is also briefly... 

This volume contains the papers presented in a symposium on carbohydrate-protein interaction. The symposium was devoted to an exploration of protein-glycoconjugate interaction in a wide range of biological phenomena the interaction of enzymes, antibodies, and lectins with complementary carbohydrate molecules the recognition of carbohydrate-containing structures by chemoreceptors such as taste and other plasma membrane proteins and the role of carbohydrates in the organization of connective tissue. 

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