The synthesis and characterization of α- and (β-L-fucopyranosyl phosphates and GDP fucose

Abstract

Guanosine diphosphate fucose (GDPFuc) has been synthesized chemically in an overall yield of 40% from fucose. This synthesis was made possible by increasing the yield of the key intermediate, β-L-fucopyranosyl phosphate, five-fold over that previously reported (Prihar and Behrman. Biochemistry, 12, 997 (1973)), by utilizing guanosine 5′-phosphoric di-n-butylphosphinothioic anhydride (Furusawa et al. J. Chem. Soc. Perkin Trans I, 171 (1976)) or GMP morpholdate for the synthesis of GDPFuc, and by improving the method of isolating intermediates and the final product. At pH 3, GDPFuc is degraded to GDP with a half-life of 7 h at 37 °C and 52 h at 4 °C. At pH values between 5 and 8, less than 10% is degraded after 7 days. Neither 20 mM Mn2+ nor Mg2+ in 0.2 M PIPES buffer at pH 7.5 stimulate the hydrolysis of GDPFuc. Heteronuclear, C–P and H–P coupling constants indicate that the preferential position of the phosphate moiety in both β-L-fucopyranosyl phosphate and GDPFuc is trans to C-2. In the ribose moiety of GDPFuc, the 5′-phosphate is trans to C-4. The 1Hand 13C nmr parameters of intermediates and products are reported.