Deoxyhexose

For most of the sugar components, little or nothing is known about their biosynthesis. Nucleoside hexosyl-4-ulose diphosphates are, however, almost certainly key intermediates in the biosynthesis of several of these sugars, as discussed in Ref 7. The biosynthesis of the 6-deoxyheptoses is probably analogous to that of the 6-deoxyhexoses, and proceeds by way of nucleoside heptosyl-4-ulose diphosphates. 

As a corollary to this work, oxidation with periodate constitutes the basis of analytical procedures for the determination of 6-deoxyhexoses ( methylpentoses ),88 calcium gluconate89 and gluconic acid,90 hexitols,91 94... 

Carbohydrates such as 6-deoxyhexoses [210] and aldopentose [211] have been oxidized electrochemically by using manganese mediators. Manganese mediators are also useful for the oxidation of a-amino acids [212]. Sorbic acid precursors... 

Myo-Inositol and 6-Deoxyhexose-Based AGAs STR-Related AGAs 22... 

Not much has been added to the biochemistry of STRs in the recent years. Therefore, we will only briefly treat the biosynthetic pathway here. Biosynthesis of the aminocyclitol (streptidine) and 6-deoxyhexose (streptose) moieties are well understood, with some remaining gaps in the enzymology. Much less is known about the residual biosynthetic phases, the formation of A-methyl-L-glucosamine, the condensation of subunits, and the late modification steps potentially coupled with export. ... 

Schlorke O, Zeeck A, Orsellides A-E an example for 6-deoxyhexose derivatives produced by fungi, Europ] Org Chem, 1043—1049, 2006. 

A large number of sugars in natural products belong to the 6-deoxyhexose (6DOH) family, of which more than 70 different variants have been reported in plants, fungi and bacteria (Figure 8.1) [4b, 4c, 5]. These sugars are linked to the... 

I Modifying the Glycosflation Pattern in Aainomycetes by Combinatorial Biosynthesis 6-deoxyhexoses... 

The results of Ikawa and Niemann,78 who used 79% sulfuric acid for 15 minutes at 100°, of Bath,220 who used 90% sulfuric acid for 5 minutes at 100°, and others221 indicated that, when so treated, hexoses, 6-deoxyhexoses, and D-xylose give rise to the appropriate 2-furalde-hyde as the principal ultraviolet-absorbing product, but that other pentoses, as well as hexuronic acids, afford mixtures of compounds in which 2-furaldehyde is the major, but not the sole, product. 

The yellow color that develops serves also as a qualitative test for the presence of 6-deoxyhexoses, including fucose, in samples. 

The oligosaccharide components of glycoproteins are generally branched heteropolymers composed primarily of D-hexoses, with the addition in seme cases of neuraminic acid, and of L-fucose—a 6-deoxyhexose. 

As expected, the spectrum of the 6-deoxyhexose (23) contains no peaks of the E series however, the B series appears (m/e 176, 131), the peaks of the F, G, H, and J series have the same intensities and positions as with permethylated methyl hexosides, and the peaks of fragments involving C-5 and C-6 are shifted 30 mass units to lower m/e values compared with the peaks of permethylated methyl hexosides (Di, m/e 119 C2, m/e 129, and so on). 

Detailed investigation of the mass spectra of permethylated methyl glycosides of the pentose,1617 27 hexose,13-16 6-deoxyhexose,16 and 2-amino-2-deoxyhexose30 series, using compounds specifically labeled with trideuterio-methyl groupings in all of the positions, served as a basis for elucidating... 

Hence, the mass spectra of diethyl dithioacetal acetates may serve to distinguish between aldopentoses, aldohexoses, ketohexoses, 2-deoxy-hexoses, and 6-deoxyhexoses. 

The 6-deoxyhexoses are conveniently separated from their aglycons after... 

This interesting transformation from a readily available 6-deoxyhexose forms the basis for the synthesis231 of 6-deoxy-2,3-di-0-methyl-D-allose (mycinose),168 one of the carbohydrate moieties of the antibiotic chalco-mycin. The synthesis merely involves the protection of the C-5 hydroxyl group in (41) by benzylation, followed by partial hydrolysis with acid, methylation of the product at the C-2 and C-3 hydroxyl groups, and debenzylation. 

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