ISSN:
1434-193X
Keywords:
Carbohydrates
;
Cyclitols
;
Carbohydrate mimetics
;
Disaccharides, 5a′-carba-
;
N-Acetyl-5a′-carbalactosaminides
;
Fucosyltransferase
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
-Synthesis of ether-linked octyl 5a′-carba-β-lactosaminide 3 and -isolactosaminide 5 was carried out in seven steps, starting from the coupling products of 1,2-anhydro-5a-carba-β-D-mannopyranose derivative 7, and the oxide anions generated from the octyl N-acetyl-β-D-glucosaminide derivatives 13 and 16, respectively, under basic conditions. The 5a-carba-α-D-mannopyranose residues of the coupling products 17 and 26 were transformed into the β-D-gluco configuration through epimerization of the respective 2′-oxo derivatives 19 and 28, and selective reduction, and then into the β-D-galacto configuration by direct nucleophilic substitution of their 4′,6′-dimesylates 23 and 31 with an acetate ion. Biological assay has shown that 3 is an acceptor substrate for human-milk α-(1→3/4)-fucosyltransferase and, interestingly, 5 is not. In addition, the imino-linked congeners 4 and 6 have been synthesized by coupling of the 4-amino-4-deoxy- and 3-amino-3-deoxy derivatives 37 and 41 of octyl N-acetyl-β-D-glucosaminide, and the carba-sugar epoxide 8, respectively, and subsequent deprotection. Compound 4 is a substrate while 6 is neither a substrate nor an inhibitor for fucosyltransferase. Small-scale enzymatic synthesis was carried out by treatment of 3 and 4 with GDP-fucose and milk fucosyltransferase, which resulted in conversion into the corresponding trisaccharides 47 and 48, respectively.
Type of Medium:
Electronic Resource
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