6- deoxy-L-Galactose

Deoxy-L-galactose (L-fucose) is common, and has only been found as the a- or )3-pyranoside. The rare D-fucose has, however, been found both as a-pyranoside, in the LPS frorn Pseudomonas cepacia serotypes B and E, and as a-furanoside, in the cell-wall antigen from Eubacterium saburreum L 452 and the O-antigens from different strains of Psuedomonas syrin-gae The a-furanoside, as in 3, has a cis relationship between the aglycon and OH-2. The corresponding P form has not yet been found. 6-Deoxy-o-and -L-talose are components of the extracellular polysaccharides from some strains of Butyrivibrio fibrisolvens and of the LPS from some strains of E. coli respectively. 

Deoxy-L-galactose (L-fucose) HO H H HO HaC—C—C—C—C-—CHO H HO HO H plant gums seaweeds blood polysaccharides sea-urchin eggs frog-spawn mucin... 

In addition, the isolation of 4(5)-ethylimidazole (23) from the reactions of L-rhamnose (see Table VI), L-fucose (6-deoxy-L-galactose), and 3-deoxy-L-glyceraldehyde (see Table IX) with aqueous ammonia, led Komoto and Tsuchida39 to believe that the 2-oxobutanal forming the 4(5)-ethylimidazole (23) arose from an aldol reaction of the 3-deoxy-L-glyceraldehyde (formed by dealdolization in the cases of L-rhamnose and L-fucose) with formaldehyde, with subsequent loss of water from the 4-deoxytetrose so formed. 

G DP-6-deoxy-L-galactose (L-Fucose) (1, 6) UDP-6-deoxy-L-mannose (L-Rhamnose) (7) TDP-6-deoxy-L-mannose (L-Rhamnose) (3, /+, 5, 8) GDP-6-deoxy-D-mannose... 

D-galactose, and then transform it to its mirror image, L-galactose. Transform the C-6 CH2OH group to CH3 to produce 6-deoxy-L-galactose. 

Several deoxy sugars, notably 2-deoxy-D-mY/ o-pentose (2-deoxy-D-ribose) the sugar component of DNA, 6-deoxy-L-mannose (L-rhamnose), 6-deoxy-L-galactose (L-fucose), 6-deoxy-D-glucose (quinovose), and their derivatives, occur very widely in natural products. Also relevant are dideoxy and trideoxy sugars, such as 3,6-dideoxyhexoses, components of the antigenic determinants bacterial... 

Deoxy-L-galactose (L-fucose) and 6-deoxy-L-mannose (L-rhamnose). 

Keratan sulfate consists of the disaccharide, iV-acetyl-lactosamine, linked /3-(1 3) to the D-galactopyranose residue of the next iV-acetyl-lactosamine unit. Keratan sulfate is the most heterogeneous of the glycosaminoglycans, with variable sulfate content linked to C-4 or C-6 of the D-galactop)Tanose residue in lactosamine, and small amounts of L-fucose (6-deoxy-L-galactose), D-mannose, and iV-acetyl-neuraminic acid residues [93] (also see Sects. 10.2 and O 14 on the occurrence of iV-acetyl-D-neuraminic acid and L-fucose in other systems). Keratan sulfate is found in the cornea, on the surfaces of erythrocytes, in cartilage, and in bone. 

MGl and MG2 account for the smooth surface of the oral mucosa and the viscosity of whole saliva. There are four monosaccharides associated with these mucins, of which three are illustrated in Fig. 12.5 W-acetyl galactosamine, L-fucose (6-deoxy-L-galactose),... 

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