Fucitol

Abstract: 1-Deoxy- d -tagatose was produced by the hydrogenation of 6-deoxy- l -galactose ( l -fucose) to l -fucitol followed by oxidation with Enterobacter agglomerans 221e; a similar sequence on d -fucose afforded 6-deoxy- d -tagatose. Thus, the polylol dehydrogenase recognizes the d -galacto-configuration of both d -fucitol and l -fucitol. The procedures were conducted in water and show the power of green, environmentally friendly biotechnology in the preparation of new monosaccharides with a potential for novel bioactive properties. 6-Deoxy- d -tagatose was also synthesized from d -tagatose via the efficient formation of 1,2:3,4-di-O-isopropylidene-α- d -tagatofuranose; a difficult final removal of protecting groups by acid makes the biotechnological route more attractive.

Abstract: The only protection required in a five-step synthesis of the α-L-fucosidase inhibitor, deoxyfuconojirimycin [1,5-dideoxy-1,5-imino-L-fucitol] from D-lyxonolactone, a readily available chiral pool material, is a single isopropylidene group.

Abstract: 1,5-Dideoxy-1,5-imino-L-fucitol (1), synthesised from methyl α-D-glucopyranoside, is a potent competitive inhibitor of the hydrolysis of p-nitrophenyl α-L-fucopyranoside catalysed by α-L-fucosidase (ex. bovine epididymis) causing 50% inhibition of enzymic activity at 2.5 × 10–8M.

Abstract: We report our discovery that many glycoproteins synthesized by Chinese hamster ovary (CHO) cells contain fucose in O-glycosidic linkage to polypeptide. To enrich for the possible presence of O-linked fucose, we studied the lectin-resistant mutant of CHO cells known as Lec1. Lec1 cells lack N-acetylglucosaminyltransferase I and are therefore unable to synthesize complex-type N-linked oligosaccharides. Lec1 cells were metabolically radiolabelled with [6-3H]fucose and total glycoproteins were isolated. Glycopeptides were prepared by proteolysis and fractionated by chromatography on a column of concanavalin A (Con A)-Sepharose. The sets of fractionated glycopeptides were treated with mild base/borohydride to effect the beta-elimination reaction and release potential O-linked fucosyl residues. The beta-elimination produced [3H]fucitol quantitatively from [3H]fucose-labelled glycopeptides not bound by Con A-Sepharose, whereas none was generated by treatment of glycopeptides bound by the lectin. The total [3H]fucose-labelled glycoproteins from Lec1 cells were separated by SDS-PAGE and detected by fluorography. Treatment of selected bands of detectable glycoproteins with mild base/borohydride quantitatively generated [3H]fucitol. Pretreatment of the glycoproteins with N-glycanase prior to the SDS-PAGE method of analysis caused an enrichment in the percentage of radioactivity recovered as [3H]fucitol. Trypsin treatment of [3H]fucose-labelled intact CHO cells released glycopeptides that contained O-linked fucose, indicating that it is present in surface glycoproteins. These findings demonstrate that many glycoproteins from CHO cells contain O-linked fucosyl residues and raise new questions about its biosynthesis and possible function.