Carbohydrate conjugates

The following method for carbohydrate conjugation to dendrimers may be used to couple a variety of reducing sugars to amine-dendrimers, including saccharides, longer-chain carbohydrates, and even complex glycans after release from a protein (see Chapter 1, Section 4.6). 

This chapter, therefore, ends the monograph with a potpourri of reactions all of which occur without a change in oxidation state. In many cases, the reaction is one of nucleophilic attack at an electrophilic C-atom. The result is often hydrolytic bond cleavage (e.g., in carbohydrate conjugates, disubstitut-ed methylene and methine groups, imines, oximes, isocyanates, and nitriles, and various ring systems) or a nucleophilic substitution (e.g., hydrolytic de-halogenation of halocarbons and chloroplatin derivatives, and cyclization reactions). The formation of multiple bonds by dehydration is a special case to be discussed separately. 

S. D. Chamberlain, A. R. Moorman, T. C. Burnette, P. de Miranda, T. A. Krenitsky, Novel Carbohydrate Conjugates as Potential Prodrugs of Acyclovir , Antiviral Chem. 

Several combinatorial approaches for the synthesis of glyco-amino acids have been developed, due to the complexity of carbohydrate conjugates. The synthetic challenge is to get access to these building blocks by automated synthesis in order to generate glycopeptides library, to fully understand their biological roles and to widen their use in medicinal chemistry. 

In addition, carbohydrate conjugates can be utilized to develop carbohydrate-based vaccines for treatment of diseases in which carbohydrate toxins or antigens, respectively, are involved. Thus, fully synthetic glycoconjugates might be developed into vaccines for malaria, and other parasites such as different bacteria, tuberculosis, tropical diseases, leishmaniasis and the Influenzae virus. 

Asayama, S. Kawakami, H. Nagaoka, S. Design of a poly(L-histidine)-carbohydrate conjugate for a new pH-sensitive drug carrier. Polym. Adv. Technol. 2004, 15, 439 44. 

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