Of amino sugars

Ruonnated carboxylic anhydrides and acyl halides as common acylating reagents to convert amines to amides and to acy late suitable heterocyclic nitiogen atoms have already been described in the first edition [10] Like in the acylation at oxygen, much synthetic activity was concentrated m the past few years on the denvatization of biomolecules by fluoroacylation reactions, that is, tnfluoroacetylation of amino sugars,... 

Several approaches based on nitro-aldol for the synthesis of amino sugars have been reported Alumina-catalyzed reaction of methyl 3- nitropropanoate with O-benzyl-o-lactaldehyde gives the o-ribo-nitro-aldol fanti, and isomeri in 63% yield, which is converted into L-dannosamine fsee Secdon 3 3 Jager and coworkers have reported a short synthesis of L-acosamine based on the stereoselective nitro-aldol reaction of 2-O-benzyl-L-lactaldehyde with 3-nitropropanal dimethyl acetal as shovm in Scheme 3 10 The stereoselecdve nitro-aldol reacdon is carried ont by the silyl nitronate approach as discussed in Secdon 3 3... 

Fragmentation The TMS derivatives of amino sugars have their base peak at mass 131.0765. 

For polysaccharides containing a substantial proportion of amino sugar residues, the term polysaccharide is adequate, although the term glycosaminoglycan may be used where particular emphasis is desired. 

A polysaccharide composed entirely of amino sugar residues is named by appropriate modification of the systematic amino sugar name. 

Figure 20-7. Summary of the interrelationships in metabolism of amino sugars. (At asterisk Analogous to UDPGIc.) Other purine or pyrimidine nucleotides may be similarly linked to sugars or amino sugars. Examples are thymidine diphosphate (TDP)-glucosamine and TDP-N-acetylglucosamine.

A second main subject of research by Garci a Gonzalez, mainly with the collaboration of A. Gomez-Sanchez, was the reaction of amino sugars with... 

Stoffyn, P. J., and R. W. Jeanloz Identification of Amino Sugars by Paper... 

Nitroacetaldehyde diethyl acetal is prepared by the reaction of nitromethane with triethyl orthoformate in the presence of ZnCl2 (Eq. 5.8).17 Jager and coworkers have used this reagent for the synthesis of amino sugars via nitro-aldol reaction.18 Preparation of this useful reagent is now described in volume 74 of Organic Synthesis.19... 

The reduction of nitro sugars with H2 in the presence of Raney Ni is one of the standard methods for the preparation of amino sugars (Eq. 6.47).93... 

The death on October 8, 2009 of Antonio Gomez Sanchez is noted with regret. He was one of the successors of the Seville carbohydrate school built up by Francisco Garcia Gonzalez, with whom he coauthored in Volume 20 a chapter on the reaction of amino sugars with 1,3-dicarbonyl compounds, a subject that was a major theme of Gomez Sanchez s research. 

In carbohydrate chemistry, the most described method for the preparation of saccharidic thionocarbamates involves preliminary introduction of the amine function on a partially or non-protected saccharidic template. The condensation of amino sugars with carbon disulfide or thiophosgene leads to cyclization in 1,3-oxazolidine- or l,3-oxazine-2-thiones. This reaction involves the formation of an intermediate isothiocyanate, which reacts further with a 3- or y-located hydroxyl group. The viability and facility of this process depends on the saccharidic ring size and the inherent strain. Some major rules can be put into light from the cases studied 30... 

Derivatization with phenyl isothiocyanate (97, R = Ph) followed by HPLC was compared with IEC followed by the ninhydrin reaction for over ninety compounds. The former method was favored for speed, sensitivity and equipment versatility257. Phenylth-iocarbamyl derivatives of amino sugars and amino sugar alcohols (reaction 10) were... 

Kaiser, K., and R. Benner. 2000. Determination of amino sugars in environmental samples with high salt content by high performance anion exchange chromatography and pulsed amperometric detection. Analytical Chemistry 72(ll) 2566-2572. 

Novatchev, N., and Holzgrabe, U. (2002). Evaluation of amino sugar, low molecular peptide and amino acid impurities of biotechnologically produced amino acids by means of capillary electrophoresis./. Pharm. Biomed. Anal. 28, 475—486. 

Figure 22.11. Cellulose is a structural and rather chemically inert component of terrestrial plants. Alginic acid is synthesized by marine algae and has medicinal properties. Some polysaccharides contain nitrogen in the form of amino sugars. The primary example of this is chitin, which composes the exoskeletons of Crustacea. An amino sugar contains an amine in place of a hydroxyl group. In other polysaccharides, sugars combine with lipids and proteins. These form glycoUpids and glycoproteins, respectively.

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