Carbohydrate moieties

In some analogues of MDP, only the N-acetyl-muramyl portion has been modified. 

The muramic acid moiety is important for the expression of the biological activity of MDP, since NaBH reduction leads to the inactive muraminitol derivative (33) and P-elimination gives the lactyl-dipeptide (34) which is inactive or even seems to inhibit adjuvant activity ). 

Some analogues in which N-acetyl-muramic acid is replaced by another carbohydrate have been reported. 

The 2-deacetamido-MDP (3 is obtained by the procedure described for MDP via benzyl-4,6-0-benzylidene-3-0-(D-l-carboxyethyl)-2-deoxy-ot-D-glucopyranoside (47). More recently, the D-manno-analogue (36) has been prepared via benzyl-2-acetamido-5,6-0-isopropylidene-3-0-(D-1 -carboxyethyl)-2-deoxy-ot-D-manno-furanoside (20). 

The preparation of benzyl-2,3,6-0-benzyl-4-0-(D-l-carboxyethyl)-P-D-glucopyranoside (67) allowed the synthesis of 4-0-(D-2-propionyl-L-alanyl-D-isoglutamine)-D-glucopyranose (37) (47). 

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Many proteins found in nature are glycoproteins because they contain covalently linked oligo- and polysaccharide groups. The list of known glycoproteins includes structural proteins, enzymes, membrane receptors, transport proteins, and immunoglobulins, among others. In most cases, the precise function of the bound carbohydrate moiety is not understood. 

Vancomycin, ristocetin A and teicoplanin are produced as fermentation products of Streptomyces orientalis, Nocardia lurida and Actinoplanes teichomyceticus, respectively. All three of these related compounds consist of an aglycone basket made up of fused macrocyclic rings and pendant carbohydrate moieties (Fig. 2-1). The macrocycles contain both ether and peptide linkages. The aglycones of vancomycin and teicoplanin contain two chloro-substituted aromatic rings, while the analogous portion of ristocetin A contains no chloro substituents. 

The need to produce the carbohydrate moiety from alkane. 

The Fine Structure of the Carbohydrate Moiety of Urinary Orosomucoid, S. A. Barker, G. I. Paidoe, M. Stacey, and J. W. Hopton, in H. Peeters (Ed.) Prolides of the Biological Fluids, Elsevier Publishing Co Amsterdam, 11 (1963) 284-287. 

Scheme 4. Antibody dendrimers prepared by the combination of IgM with IgG attached hapten to the carbohydrate moiety in the Fc fragment... 

Shapiro L. and Halpem M. (1995). Lectin histochemical identification of carbohydrate moieties in opossum chemosensory systems during development, with special emphasis on VVA-identified subdivisions in the accessory olfactory bulb. J Morphol 224, 331-349. 

C Chemical-shift Data" for the Disaccharide Moiety of Bleomycin Af, and Some Related Carbohydrate Moieties... 

These carbohydrate moieties have several important functions, including ... 

Maras, M., Saelens, X., Laroy, W. et al. (1997) In vitro conversion of the carbohydrate moiety of fungal glycoproteins to mammalian-type oligosaccharides - evidence for JV-acetylglucosaminyltransferase-I-accepting glycans from Trichoderma reesei. European Journal of Biochemistry, 249 (3), 701-707. 

Premier, C., Mach, L., Glossl, J. and Marz, L. (1992) The antigenicity of the carbohydrate moiety of an insect glycoprotein, honey-bee (Apis mellifera) venom phospholipase A2. The role of al,3-fucosylation of the asparagine-bound IV-acetylglucosamine. Bio chemicalJournal 284, 377-380. 

S. G. Gouin, L. Bultel, C. Falentin, and J. Kovensky, Simple procedure for connecting two carbohydrate moieties by click chemistry techniques, Eur. J. Org. Chem. (2007) 1160-1167. 

Alternative strategies utilizing the initial introduction of suitable chemical functionality onto the fullerene have been adopted by several research groups, allowing conjugation of the saccharides with complementary functions in the final synthetic steps. This approach has led to improved flexibility with the chemical functions on the carbohydrate moieties, especially the anchoring ones, and a better control on the number of attached saccharide residues. 

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