2- amino-2-deoxy acid

Epimerization at C-5 of hexuronic acids is a reaction that proceeds both on the polymer and on the sugar nucleotide level. In addition to the three pairs of parent acids, namely, the u-glucolL-ido-, D manno/L-gulo-, and D-ga-lacto/L-altro-he uron c acids, the 2-amino-2-deoxy acids belonging to the last two and the 2,3-diamino-2,3-dideoxy acids belonging to the middle pair have been found. 

Peroxyacids are the most widely used class of oxidant for aromatic amino to nitro group conversion and include peroxydisulfuric, peroxymonosulfuric, peroxyacetic, peroxytrifluo-roacetic and peroxymaleic acids. The oxidizing potential of the peroxyacid is, as a rule, proportional to the strength of the parent deoxy-acid. Dimethyldioxirane (DMDO) and ozone have also found use for amino to nitro group conversion. 

The chemical shifts observed in the 13C-n.m.r. spectra of amino-deoxy sugars are strongly dependent on the pH of the sample solution, and the spectra of such compounds should, therefore, be measured with control of the pH. Comparison of, 3C-n.m.r. spectra, measured at low or high pH, that is, for compounds having protonated or free amino groups, may be used for the assignment of carbons a and /3 to the amino groups.11,16,81 82 Similar, but smaller, effects are.observed in the spectra of other ionizable compounds, such as aldonic or uronic acids.60,83... 

Acetamido-2-deoxy-D-galacturonic acid, a major immunogenic component of Salmonella typhosa [2], was the first naturally occurring amino hexuronic acid identified [3]. In 1962 Perkins reported that the cell wall of Micrococcus lysodeikticus... 

Very recently, amino deoxyglucmonic acids were used in the construction of disaccharide libraries [45]. In the report, methyl 3-azido-3-deoxy-4-0-methyl-j8-D-glucmonic acid was prepared and glycosidically linked to a protected glucosamine, yielding a disaccharide with both amino and carboxamide fimctionalities. The azide was subsequently reduced and reacted with several isocyanates, providing libraries of j8-linked disaccharides (Fig. 24). 

Hetero-Diels-Alder reactions have been used in the construction of amino-sugars, asymmetry being induced by the use of either a chiral Lewis acid catalyst or a chiral auxiliary. Thus, the 3-amino-hexuronic acid derivatives 61 were obtained with high de and ee using a copper(II) triflate catalyst with a chiral bisoxazoline ligand. 4-Amino-4-deoxy-D-erythrose and 4-amino-4,5-dideoxy-L-lyxose (63), the latter a potent inhibitor of a-L-fucosidase, were obtained from the D-pyroglutamic add-containing diene 62 (Scheme 19). ... 

Cellulose is converted to chlorine deoxy cellulose whieh is reacted with an amino acid to form a carboxy-subslituted amino deoxy cellulose. Show the reactions involved. 

Sugars Unusual sugars (amino, deoxy and methyl sugars, and sugars with branched chains). Reduction products (sugar alcohols, cyclitols, streptidine). Oxidation products (uronic acids, aldonic acids, sugar dicarboxylic acids). 

L 2 aminobutyric acid can substitute for L-alanine (CyV). N-Methyl-L-leucine in position 4 may be replaced by N-methyl-L isoleucine (Cy29) or by L-valine in CyQ and CyS. Regarding possible biosynthetic pathways, variations at position 1 are of special interest CyF and CyK contain deoxy-MeBmt, whereas N-methyl-L-Z-amino-octanoic acid is found in CyZ, Both building units probably stem from a common precursor of the genuine amino acid (4R) 4 l E) 2 butenyI] 4 fnethYl L-threonine (Bmt). A full exchange of this characteristic structural unit by N-methyl-L-leucine is observed in CyO. At present, positions 3 and 8 containing sarcosine and D-alanine, respectively, are the only conserved building units. 

Amino-5 -deoxy-2, 3 -0-isopropylideneadenosine was acylated at N-5 with an activated derivative of the 6-carboxy-2-naphthyl ester of Kemp s acid imide. The resulting molecule possesses self-complementary binding sites, the key feature of replicating molecules that act as templates for their own reproduction. The dimer of this molecule is, however, not very stable K = 630 L mol ). When the two initially mentioned educts are added, a small proportion of the ternary complex is also formed and undergoes a fast, template-catalysed... 

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