Pyranosyl sugar amino acids

Gervay-Hague, J. Weathers, T. M., Pyranosyl Sugar Amino Acid Conjugates Their Biological Origins, Synthetic Preparations, and Structural Characterization, Marcel Dekker New York, (2001). 

Pyranosyl Sugar Amino Acid Conjugates Their Biological Origins, Synthetic Preparations, and Structural Characterization... 

In the late 1960s and into the mid-1970s new synthetic reports appeared in the literature. Most of these focused on the total synthesis of naturally occurring pyranosyl sugar amino acid conjugates. Then, in 1976, Fuchs and Lehmann published the first synthesis of sugar amino acids amidically linked in a fashion similar to a-amino acids. Surprisingly, this disclosure received little attention for nearly 20 years. 

In the past 5 years, the chemistry of pyranosyl sugar amino acids has evolved into a new science at the forefront of chemical design, synthesis, and structural characterization. Parallel work by Fleet and coworkers has elegantly exploited fur-anosyl sugar amino acids. At the same time, the sugar amino acids are only a small part of a larger science encompassing the use of unnatural amino acids in the synthesis of new materials with defined secondary structures. 

II. NATURALLY OCCURRING PYRANOSYL SUGAR AMINO ACIDS... 

III. SYNTHETIC STUDIES OF PYRANOSYL SUGAR AMINO ACIDS A. Syntheses of Natural Amino Hexuronic Acids... 

Kim and Hollingsworth prepared a C-glycoside of A-acetylglucosamine by alkylation of a pyranosyl bromide with malonate anion, giving an A-acetyl y-sugar amino acid after decarboxylation (Fig. 13) [30]. 

The structure (5) of the lipid-A component of the lipopolysaccharide from Chromobacterium violaceum has been elucidated by chemical and enzymic degradations, although the site of attachment of the 4-amino-4-deoxy-L-arabino-pyranosyl phosphate residue and the distribution of the fatty-acid residues on the central disaccharide unit have still to be determined. This lipid-A component differs from most others in that non-acylated amino-sugars are joined, by phosphoric diester linkages, to the central disaccharide unit. 

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