Glucose nucleotide sugars from

Fig. 9. Outline of the formation of nucleotide sugars from glucose.

Tenhaken, R., and Thulke, O., 1996, Cloning of an enzyme that synthesizes a key nucleotide-sugar precursor of hemicellulose biosynthesis from soybean UDP-glucose dehydrogenase. Plant Physiol. 112 1127-1134. 

Carbohydrates, commonly referred to as sugars and starches, are polyhydroxy aldehydes and ketones, or compounds that can be hydrolyzed to them. The cellulose in plant stems and tree trunks and the chitin in the exoskeletons of arthropods and mollusks are all complex carbohydrates. Four examples are shown in Figure 27.1. They include not only glucose and cellulose, but also doxorubicin (an anticancer drug) and 2 -deoxyadenosine 5 -monophosphate (a nucleotide base from DNA), both of which have a carbohydrate moiety as part of a larger molecule. 

The enzyme CMP-Neu5Ac synthase, which is also known as Neu5Ac cytidylyltransferase (EC 2.7.7.43), is ubiquitous in pro- and eukaryotic cells synthesizing sialic acids from glucose [5,33]. In contrast to other nucleotide-sugar-synthesizing enzymes, it is located... 

Sucrose synthetase. The fructose derivatives 1-azido-l-deoxy-, 1-fluoro-l-deoxy-, 6-deoxy-, 6-fluoro-6-deoxy-, and 4-fluoro-4-deoxy-fructose have been used as glycosyl acceptors in the sucrose synthetase-catalyzed synthesis of sucrose analogs12031. 6-Deoxy- and 6-fluoro-6-deoxy-fructose were generated in situ from the corresponding glucose derivatives under catalysis by glucose isomerase[2031. Sucrose synthetase has also been extensively employed in the synthesis of nucleotide sugars[2041. 

Figure 17 Some examples of alternative nucleotide sugar donors that have been produced chemoenzymatically. Differences from a natural nucleotide sugar donor structure, UDP-glucose, are highlighted in red.

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