Structures carbohydrates

This chapter is divided into two parts The first and major portion is devoted to carbohydrate structure You will see how the principles of stereochemistry and confer matronal analysis combine to aid our understanding of this complex subject The remain der of the chapter describes chemical reactions of carbohydrates Most of these reactions are simply extensions of what you have already learned concerning alcohols aldehydes ketones and acetals... 

A commonplace variation on the general pattern seen m carbohydrate structure is the replacement of one or more of the hydroxyl substituents by some other atom or group In deoxy sugars the hydroxyl group is replaced by hydrogen Two examples of deoxy sugars are 2 deoxy d nbose and l rhamnose... 

Lehman J (editor) (translated by Haines A.) Carbohydrates Structure and BioUgy. Thieme, 1998. 

Carbohydrate Structure and Amino Acid-Sequence Data for Glycophorin A,... 

Cellulose and starch are macromolecules with empirical formulas that resemble hydrated carbon, CX (H2 0)y, where x and y are integers. The monomers from which these macromolecules are consfructed are sugars such as glucose and fructose. These monomers and macromolecules are the carbohydrates. Structurally, carbohydrates are very different from simple combinations of carbon and water. Even the smallest carbohydrates contain carbon chains with hydrogen atoms, OH groups, and occasional ether linkages. 

Separation of the Nortriterpenes with Carbohydrate Structure of B. carterii... 

The GC-MS data (Figure 16.11) of the violet zone of B. carterii revealed that the unchanged diterpenes (verticillatriene, cembrene A, and cembrene C) and the nortriterpenes with carbohydrate structure originated from the pyrolyzed triterpenes (Figure 16.12) of the a- and (3-boswellic acids, named 24-norursa-3,12-diene (compound 7), 24-norursa-3,9(ll),12-triene (compound 8), 24-noroleana-3,12-diene (compound 9), and 24-noroleana-3,9(ll),12-triene (compound 10). 

In order to investigate, and deduce, the complex carbohydrate structures of glycoproteins, it must be possible to release, and isolate, the oligosaccharide chain(s) from the glycoprotein. Following this, the structure is usually deduced by a combination of enzymic, chemical, and instrumental methods.34-36... 

The asterisks indicate the point of glycosylation by the following carbohydrate structures. 

The make-up of this volume of Advances deviates somewhat from the accustomed format, even though the major themes of advances in carbohydrate structural methodology, synthetic methods related to important biomolecules, and structural characterization of key natural carbohydrates are all represented. 

Hoffmann, A., et al. (1994). Carbohydrate structures of beta-trace protein from human cerebrospinal fluid evidence for brain-type N-glycosylation. J. Neurochem. 63, 2185-96. 

A. Dondoni, M. Kleban, and A. Marra, The assembly of Carbon-linked calix-arene-carbohydrate structures (C-calixsugars) by multiple Wittig olefination, Tetrahedron Lett., 38 (1997) 7801-7804. 

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