Oligosaccharides naturally occurring

Note. These representations do not follow the recommendations for choice of main chain given in 2-Carb-37.3. Such deviations are common in depicting series of naturally occurring oligosaccharides where it is desirable to show homomorphic relationships. 

Sucrose, maltose, and lactose were included in model glycoprotein systems,34 and retention times for a wide range of naturally occurring oligosaccharides, up to pentasaccharides, were listed by Clamp and coworkers.67... 

Naturally occurring oligosaccharides have also been isolated by gel chromatography. Ohman and Hygstedt94 have reported the isolation, from colostrum, of sialic acid oligosaccharides, including di-O-sialoyl-lactose [0-A/-acetylneuraminoyl-(2 — 8)-0-(N-acetylneur-... 

Naturally occurring oligosaccharides including disaccharides and trisaccharides have attracted enormous attention in the last few years. Multidisciplinary efforts of biochemists and medicinal chemists have led to new developments [1,2,3,4,5] in the field, which are based primarily on the phenomenal physical properties such as stability, crystallinity, and solubility. Chemical properties include selective reactivity towards various reagents such as oxidative and reducing agents and this has opened up new possibilities for functionalization and derivatization of value-added oligo- and polysaccharides. 

While in the synthesis of naturally occurring oligosaccharides the use of enzymes (glycosyl transferases) proved very useful due to their substrate specificity and stereospecificity and the possibility to work without protective groups, the synthesis of unnatural oligosaccharides still relies on synthetic methods. ... 

Most of the naturally occurring oligosaccharides have 1,4-glycosidic linkages. In case of the model compounds so far synthesized by solid-phase methods, 1,6-glycosidic bonds have always been made. It appears that the polymer support increases the selectivity of reaction for the less hindered 6-0 position of a hexopyranose over that at the 4-0 position. 

Oligosaccharides of animal origin (a) Naturally occurring oligosaccharides of human milk... 

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