Sugars branched-chain amino

Debono, M. and Molloy, R.M., Isolation and structure of the novel branched-chain amino sugar derived from antibiotic A35512B, J. Org. Chem., 45, 4685, 1980. 

Nitroolefins are good Michael acceptors and have been used as such in the carbohydrate series. One advantage of this approach would be the subsequent transformation into branched-chain amino sugars after reduction of the nitro group. Baer has reported the... 

J. S. Brimacombe, J. A. Miller, and U. Zakir, An approach to the synthesis of branched chain amino sugars from C-methylene sugars, Carbohydr. Res. 49 233 (1976). 

R. J. Alves, S. Castillon, A. Dessinges, P. Herczegh, J. C. Lopez, G. Lukaes, A. Olesker, and T. T. Thang, A route to functionalized branched-chain amino sugars via nitrous acid promoted spiroaziridine formation, J. Org. Chem. 53 4616 (1988). 

For example, alkaponuria is characterized by homogentisic acid in urine phenylketonuria, which results in mental retardation, is characterized by quantities of phenylpyruvic acid in the urine. It is diagnosed in a suspected patient by determining the amount of this acid in the urine and the increased levels of phenylalanine in the plasma. Maple sugar disease is diagnosed the presence of large amounts of the branched chain amino acids, such as valine, leucine, and isoleucine in the blood and urine. 

Yeast-derived saturated short-medium chain and branched-chain aldehydes are formed from sugar metabolism, fatty acid metabolism and branched-chain amino acid metabolism (Fig 8D.7). In addition, hexanal, as well as hexenal isomers, are formed during the pre-fermentative stages of winemaking by the sequential action of grape lipoxygenase and hydroperoxide cleavage enzyme on linoleic and linolenic acid, respectively (Crouzet 1986). 

Jordaan, J H, Smedley, S, S3mthesis of branched-chain amino sugars via a spiro-epoxide derivative of 2-amino-2-deoxy-D-glucose, Carbohydr. Res., 16, 177-183, 1971. 

Rosenthal, A., and Baker, D.A., New route to branched-chain amino sugars by application of modified Wittig reaction to ketoses. Tetrahedron Lett., 10, 397, 1969. 

Primary amine formation is equally well promoted in alkaline medium, e.g., aqueous ethanolic NaOH solution, that selectively poisons the catalyst for hydrogenolysis reactions. However, saturated NH3/alcohol solutions best afford almost quantitative yields of primary amines from catalytic reduction of nitriles. Ammonia adds to imine 1 to give a 1,1-diamine, which is hydrogenolyzed to the primary amine. In the presence of NHj, finely divided Ni can be used, platinized finely divided Ni for the hydrogenation of hindered nitriles, and rhodium-on-alumina for sensitive compounds. Mild reduction of 3-indoleacetonitrile to tryptamine [equation (c)] is effected at RT over 5% rhodium-on-alumina in 10% ethanolic NH3 with little side reaction , and branched chain amino sugars are conveniently prepared using this selective hydrogenation [equation (d)] . 

In maple syrup urine disease, the branched-chain a-keto acid dehydrogenase that oxidatively decar-bo xylates the branched-chain amino acids is defective. As a result, the branched-chain amino acids and their a-keto analogs (produced by transamination) accumulate. They appear in the urine, giving it the odor of maple syrup or burnt sugar. The accumulation of a-keto analogs leads to neurologic complications. This condition is difficult to treat by dietary restriction, because abnormalities in the metabolism of three essential amino acids contribute to the disease. 

Analysis of Labeled Acyl Groups. Deuterated branched chain amino acids were all incorporated at extremely high rates into sugar ester acyl groups, an indication of the active nature of this pathway. In some instances the amount of deuterium labeled fatty acids exceeded (146%) that of the unlabeled material remaining on the leaf surface (10-20% of the original amount of glucose ester). GC/MS data for labeled 3-methylbutyrate from the incubation of [dio] Leu are shown in Fig. 2. As... 

References to branched-chain amino-sugars and to amino-sugar nucleosides can be found in Chapters 19 and 20 respectively. 

The formation of branched-chain amino-sugars from enaminals and from branched-chain glycosiduloses is referred to in Chapter 9. 

Simple Sugars—Secondary Metabolites Nomenclature 2-Deoxyhexoses 6-Deoxyhexoses Methoxy Sugars Branched-Chain Sugars Sugar Carboxylic Acids Amino Sugars... 

Syntheses of disaccharides containing amino-sugar residues, of aminoglycoside antibiotics, and of branched-chain amino-sugars are dealt with in Chapters 3, 18, and 13, respectively. 

The synthesis of D-evernitrose utilizing branched-chain amino-sugar intermediates is mentioned in Chapter 13. Some amine-containing acid compounds are reported in Chapter 15. 

Carbohydrate a-nitroepoxides react with methylmagnesium iodide to yield branched-chain amino-sugars as outlined in Scheme 8, but the stereochemistry of the process has not been elucidated. ... 

The branched-chain amino-sugar derivative (32) has been prepared from the unsaturated branched-chain sugar (33) by the sequence shown in Scheme 9 these were then used to prepare analogues of the nucleoside moiety of the polyoxins which are referred to in Chapter 19. 

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