Sugars names

Derivatives of 6-deoxy-hex-5-enopyranosides are important intermediates in the synthesis of dicarbonyl sugars, namely hexos-5-uloses. For... 

Problem 25.10 > The following model is that of an aldopentose. Draw a Fischer projection of the sugar, name it, and identify it as a n sugar or an ). sugar. 

A general term for a polysaccharide (glycan) composed of a single type of monosaccharide residue is obtained by replacing the ending -ose of the sugar name by -an . 

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

On Ca +-form columns, some separation of monosaccharides is possible and, for the separation of galactose and glucose in dairy products, this is the column of choice. The separation of several disaccharides, such as sucrose plus maltose plus lactose, in sweetened dairy products cannot be accomplished on single-resin columns, however, and separation on amine-modified silica gel or on dual-resin columns " is recommended. These columns are capable of separating the five major food sugars, namely, D-glucose, D-fructose, sucrose, maltose, and lactose, but are subject to rapid degradation if proper precautions are not used (see Section II,2,a). 

Uridine 5 -(2-acetamido-2-deoxy-a-n-gIucopyranosyluronic acid pyrophosphate) (36) was isolated from extracts of Achromobacter georgiopolitanum14Sa and Micrococcus lysodeikticus.149b The ester of uridine 5 -pyrophosphate with an unusual amino sugar, namely, a 2-acetamido-2,4,6-trideoxyhexose of unknown configuration, has... 

The crystal structure of the hydrochloride and hydrobromide of isoquinocycline A was elucidated by the method of single, isomor-phous replacement.67 The glycosyl group, which constitutes about 20% of the molecule, is that of a branched-chain, eight-carbon sugar, namely, 2,6-dideoxy-4-(L-glycero-l-hydroxyethyl)-a-L-xylo-hexopyranose-IC (17). 

The reactivity of the 2,5-anhydrides of aldoses is determined by two essential structural features that do not exist in the sugars, namely, the presence of an oxolane ring and of a carbonyl group (most frequently, free) a to the ring-oxygen atom. These two characteristics make the 2,5-anhydroaldoses closer to tetrahydro-2-furaldehyde than to the aldoses, where only in exceptional cases is the carbonyl group not masked by the formation of an intramolecular, five- or six-membered, hemiacetal ring. 

Unsaturated sugars, namely glycals, such as 3,4,6-tri-Oacetyl-l, 5-anhydro-2-dcoxy-D-r//v/-/w7o-hex-1-enetol and the d-/v.yo epimer react with xenon difluoride in the presence of a boron trifluoride-diethyl ether complex to give a mixture of C2 epimeric fluorides.45,46 Tri-O-acctyl-D-galactal treated with xenon difluoride in trichlorofluoromcthane below 5 C forms after hydrolysis (0.5 M HC1) 2-deoxy-2-fluoro-D-galactose in 63% overall yield.47... 

In all these d isomers, the chiral carbon most distant from the carbonyl carbon has the same configuration as the chiral carbon in D-glyceraldehyde. The sugars named in boxes are the most common in nature you will encounter these again in this and later chapters. 

Formic and oxalic acids and their salts in the presence of mineral acid reduce arsenic acid and arsenates the reaction is accelerated by boiling.10 Tartaric acid does not appear to form complexes with arsenic acid 11 such as are formed with arsenious acid. Certain sugars, namely fructose and less rapidly sucrose, but not glucose, maltose or lactose, form labile esters of arsenic acid during fermentation in the presence of this acid the reaction is purely a chemical one and not biochemical.12... 

Two substituted sugars, namely 2,3-0-isopropylidene-D-lyxofuranose,8to and 2,3,5-tri-O-methyl-D-lyxofuranose,l0ab undergo polymerization during slow distillation under diminished pressure the latter formed a nonreducing dimer of the trehalose type. 

Besides these major glycolipids, minor glycosphingolipid components were isolated from the spermatozoa of Hyriopsis schlegelii. These are oligosylceramides264 having a shorter carbohydrate chain, and lacking any amino sugars, namely, the ceramide disaccharides /3-Gal-(l - 4)-Glc-Cer... 

Numerous derivatives of 2-amino-2-deoxy-D-glucosyl halides have been reported recently, especially by Micheel and coworkers.112 113 150 163 168 Methods of synthesis are similar to those for the analogous non-nitrogeneous sugars, namely, treatment of acylated derivatives with acyl halides,169 hydrogen halides,106 1U-112 147 149 or titanic halide.106... 

The discovery of enzyme systems by which D-glucose could be isomerized directly to D-fructose was a key factor in the development of commercial-scale isomerization-processes. These direct systems were developed from fundamental studies of carbohydrate metabolism, in which was identified for the first time an enzyme that catalyzes the isomerization of an unsubstituted sugar, namely, the isomerization of D-erythrose to D-g/ycero-tetrulose.31... 

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