Acylated glucosamine

P. Lerouge, P. Roche, C. Faucher, F. Maillet, G. Truchet, J. C. Prome, and J. Denarie, Symbiotic host-specificity of Rhizohium meliloti is determined by a sulphated and acylated glucosamine oligosaccharide signal. Nature 344 781 (1990). 

This enzyme catalyzes the epimerization at the 2-position of A-acetylglucosamine 6-phosphate. See also N-Acyl-glucosamine-6-phosphate 2-Epimerase... 

Saccharolipidsm, where fatty acids are linked in ester and amide linkages directly to sugar molecules. This is a relatively small class of molecules, best described in bacteria and plants. The most well known of these are the acylated glucosamine precursors of the lipid A component of the endotoxin thought to be responsible for the toxicity of Gram-negative bacteria. A simple monosaccharide precursor. Lipid X, is shown in Table 3.1. 

Lerouge, P. 1990. Symbiotic host-specificity of Rhizobiim meliloti is determined by a sulfated and acylated glucosamine oligosaccharides signal. IVafttrc 344 781-784. 

Fig. 3. The stmcture of the nodulation (Nod) factors of i bium meliloti 2011 (44), where is 2 or 3, R is —H or—COCH, and R is C 2 as shown, C gT, or ie, a fatty acid chain having from 1 to 3 double bonds. The A/-acetyl glucosamine residues and an acyl moiety, R, are present ia all...

Tabelle 4. Vergleich einiger anomerer N-Acyl-o-glucosamine. 

Tetraacetyl-/ -D-glucosamine with Acyl Amino Acid Azides. J. Amer. chem. Soc. 75, 3469 (1953). 

Polyamides derived from o-glucose and o-glucosamine by interfacial and solution polycondensations of the sugar diamino derivatives with aromatic and aliphatic acyl chlorides have also been described [83]. 

Finally, Kren and coworkers have proposed the use of selectively acylated glycosides to be used as acceptors in a bi-enzymatic approach to the synthesis of di- and trisaccharides exploiting lipases/proteases and glycosidases (for instance, 6-0-acetyl-N-acetyl-D-glucosamine, 14, to give the corresponding chitobiose derivative 15) [44]. 

Two differently JV-acyl protected derivatives of (S)-serinal 197, readily available from D-glucosamine, have been subjected to aldolizations with DHAP aldolases to furnish the corresponding 5-aminoketoses 196/198 [220,235], The latter compounds are interesting in their own right or as further potential precursors for pyrrolidine-type azasugars. 

Therefore, of the 2 moles of ester-bound 3-OH-14 0 one is 3-0-acylated by tetradecanoic acid the other should carry a free 3-hydroxyl group. This latter assumption was proven to be correct by the following experiment. Lipid A was treated with t-butyldimethylsilylchloride, ester-bound fatty acids were trans-esterified by NaOCH3 and analysed by gas-liquid chromatography. Besides the other expected fatty acid methyl esters (12 0, 16 0, 3-OCH3-14 0) approximately 1 mole (per 2 moles glucosamine) of the t-butyldimethylsilylether of 3-hydroxytetradecanoic acid me-thylester could be identified (26). 

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