L- -Glucose

Jl exists in this form only in solution, though stable derivatives of the aldehyde structure are known. The optical antipode of D-glucose in which the positions of every H and OH are transposed is L-glucose. 

Similarly l gluconomtrile has been reduced to l glucose its yield was 26% from L arabinose)... 

Chain extension of the aldopentose ( —)-arabinose by way of the derived cyanohydrin gave a mixture of (-l-)-glucose and (-l-)-mannose. 

There is another sugar, (-l-)-gulose, that gives the same aldaric acid on oxidation as does (-l-)-glucose. 

A mixture of methyl 3-deoxy-3-C-methyl-3-nitro-ct-D- and fi-L-glucopyranosides d l is formed by the reaction of nitroethane with the sugar thaldehyde obtained from L-glucose The products are separated and converted into branched-chain fluoro nitro l- and L-sugars fEq 361 ... 

Examples of rare sugars which have been found in some microbial polysaccharides are L-glucose ... 

The conformational symbols for enantiomers are different. It is therefore important to state in the context whether the d or the L form is under consideration. Enantiomers have the same reference plane (see 2-Caib-7.3), and it should be noted that the mirror image of a-D-glucose-4Ci is a-L-glucose-C4. 

Three 3-amino-3,6-dideoxyhexoses, having the d- and L gluco and D-ga-lacto configurations, have been found. The two D-sugars are not very common, but occur in some 0-antigens for example, those from E. coli 0114 (Ref. 60) and E. coli 02 (Ref 61), respectively. The D-galacto isomer has also been found in the cell-wall polysaccharide from Eubacterium saburreum strain L13.3-Amino-3,6-dideoxy-L-glucose has been found in the core part of the Aeromonas hydrophila chemotype 111 LPS. 

Polymeric carbohydrates are usually encountered as distributions, so high resolution is rarely important. Of all biological macromolecules, carbohydrates are particularly amenable to analysis by GPC because hydrophobic interactions are typically weak. A section below is devoted to the analyses of carboxymethylcellulose and xanthan. Other examples of polysaccharides of interest are hyaluronic acid,62 polymers of (l-glucose,121125 heparin,126127 cellulose and chitin,128 and Mucorales extracellular polysaccharides.129... 

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