Sugar amino group

The problem was solved using a more traditional chemo-enzymatic approach in which the sugar amino group was preliminarily protected by reacting 8 with... 

Transferases Transfer acyl, phosphoryl, sugar, amino groups, etc. transaminases kinases... 

Numerous reports describe the modification of natural amino-glycoside antibiotics or products derived from them by conventional methods. 1-/ -Alkylated kanamycins can be prepared very efficiently by utilizing an O N acyl migration to protect the sugar amino-groups selectively, leaving the deoxy-streptamine amino-groups free-, a formylation-deformylation sequence then... 

Fig. 9 Electropherograms showing the change in enantioselectivity obtained before and after blocking of the sugar amino groups. Conditions buffer, 40 mM sodium phosphate buffer pH 6.0 with 2 mM chiral selector. Analyte dansyl-norleucine. The selector is indicated on each electropherograms. Reprinted by permission of the American Chemical Society [29]...

A major trend in organic synthesis, however, is the move towards complex systems. It may happen that one needs to combine a steroid and a sugar molecule, a porphyrin and a carotenoid, a penicillin and a peptide. Also the specialists in a field have developed reactions and concepts that may, with or without modifications, be applied in other fields. If one needs to protect an amino group in a steroid, it is advisable not only to search the steroid literature but also to look into publications on peptide synthesis. In the synthesis of corrin chromophores with chiral centres, special knowledge of steroid, porphyrin, and alkaloid chemistry has been very helpful (R.B. Woodward, 1967 A. Eschenmoser, 1970). 

Amino sugar (Section 25.11) Carbohydrate in which one of the hydroxyl groups has been replaced by an amino group. 

Preparation of the TMS derivative Add 0.5 ml of TRI-SIL Z reagent (trimethylsilylimidazole in pyridine) to 1-5 mg of the sample. (This derivatizing preparation does not react with amino groups and tolerates the presence of water.) Heat in a sealed vial at 60° until the sample is dissolved. An alternate method is to let the reaction mixture stand at room temperature for at least 30 minutes (or overnight). This procedure is not appropriate for amino sugars. 

The dominant interactions that take place with this novel phase are not clear. There will obviously be dispersive interactions with the propyl chain and some polar interactions with the amino group. Whether there are ionic interactions taking place as well is uncertain but, nevertheless, the material affects an excellent separation of glucose and fructose and this remains a baseline separation even when the two sugars are both present at about the 5% level. 

In tandem with his studies of polysaccharides, Stacey had a research group investigating the chemistry of the unusual sugars found as components of carbohydrate macromolecules. In this context, derivatives of simple sugars, di- and trisaccharides, uronic acids, deoxy sugars, amino sugars, sugar sulfates, and phosphates were studied. 

Monosaccharides in which an alcoholic hydroxy group has been replaced by an amino group are called amino sugars (see 2-Carb-14). When the hemiacetal hydroxy group is replaced, the compounds are called glycosylamines. 

Among other carba-sugar derivatives, the most important compounds are amino carba-sugars having an amino group at C-1. They are known as validamine, valiolamine, hydroxyvalidamine, and valienamine, and are found in validamycin antibiotics as unique components they have been synthesized in dl forms and also in optically active forms. 

Amino carba-sugars having an amino group other than at C-1 have never been discovered in Nature, but the eighteen compounds have been prepared in DL forms, and four enantiomers were synthesized during the course of the studies. 

Listowsky and coworkers showed that the c.d. of this sugar derivative is due entirely to lactic acid, and confirmed that this chromophore is in the D configuration for muramic acid. N-Acetylmuramic acid, in which the amino group is replaced by an amido group at C-2, has a c.d. spectrum that is roughly a linear combination of the lactic acid in muramic acid and the amide in 2-acetamido-2-deoxy-D-glucose. This indicates that the amide chromophore and the lactic acid chromophore in N-acetylmuramic acid behave independently. 

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