Diversity carbohydrate molecular

Sofia, M.J., Chemical strategies for introducing carbohydrate molecular diversity into the drug discovery process, Network Sci. 1996, http //www.netsci.org/Science/Combichem/featurel2.html, accessed on September 22, 2003. 

The ability to explore carbohydrate molecular diversity has taken great strides in recent years. Viable solid phase and solution phase methods now exist for rapidly accessing some of the broad universe of carbohydrate-based molecular structures. It is now the job of chemists to exploit these methods for the discovery of novel medicinal, agricultural and industrial agents. 

The chemical composition of the natural resins is very diverse, and their molecular structure may be highly complex most resins of vegetable origin, however, are chemically related to the carbohydrates. Dry vegetable resins... 

Carbohydrates are diverse with respect to occurrence and size. Familiar mono and disaccharides include glucose, fructose, sucrose (table sugar), cellobiose, and mannose. Familiar polysaccharides are listed in Table 9.1 along with their source, purity, and molecular weight range. 

Carbohydrates are configurationally stable, easily available in enantiopure forms from the chiral pool, and they show a high density of chiral information per molecular unit. Their polyfunctionality and structural diversity fadhtate their tailor-made modification, derivatization, and structural optimization for a broad spectrum of synthetic applications. While derivatives of various saccharides have already been utilized as versatile starting materials and building blocks for chiral auxiliaries, ligands, and reagents [330] their obvious role as precursors for the... 

P R E CONTENTS Preface. Stable-Isotope Assisted Protein NMR Spectroscopy in Solution, Brian J. Stockman and John L. Mar-kley. 31P and 1H Two-Dimensional NMR and NOESY-Dis-tance Restrained Molecular Dynamics Methodologies for Defining Sequence-Specific Variations in Duplex Oligonucleotides, David G. Gorenstein, Robert P. Meadows, James T. Metz, Edward Nikonowcz and Carol Beth Post. NMR Study of B- and Z-DNA Hairpins of d[(CG) 3T4(CG)3] in Solution, Sa-toshi Ikuta and Yu-Sen Wang. Molecular Dynamics Simulations of Carbohydrate Molecules, J.W. Brady. Diversity in the Structure of Hemes, Russell Timkovich and Laureano L. Bon-doc. Index. Volume 2,1991, 180 pp. 112.50/E72.50 ISBN 1-55938-396-8... 

The unique feature of the Diels-Alder reaction — generating up to four new stereogenic centers in one step — combined with the variety of useful reactants, has made this reaction a favorite methodology for constructing molecular diversity [54]. Therefore, asymmetric versions of this reaction represent an attractive tool for the diastereoselective synthesis of optically active compounds [55,56]. Various carbohydrate auxiliaries, either attached to the diene or to the dienophUe component, have been successfully used to produce stereochemically pure cycloadducts [57]. 

Carbohydrates include a large variety of different molecules and materials, different in composition, size, and function. The chemistry of Cx (H20)x-molecules (i. e., carbohydrates) is extremely complex in terms of its molecular and stereo-chemical diversity. This complexity has been the subject of numerous texts [2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17, 18,19,20,21,22,23,24,25]. 

For carbohydrates to meet these requirements, diversity is needed on both the molecular and the size-level. Only large carbohydrate molecules, polysaccharides, can provide the wide spectrum of storage, structural, and gel-forming abilities required by nature. Meeting these requirements has made it necessary for plants to produce polysaccharides that can be classified as linear, branched, and crosslinked polymers, as well as homo- and heteropolymers in accordance with terminology in common use in the polymer community (O Fig. 1) [26]. Nature has found need to adopt all different kinds of macromolecular architectures in pursuit of the three different functions of carbohydrates. 

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