Conformational differences between Fuc(α1–3)GlcNAc and its thioglycoside analogue

NOE measurements and molecular mechanics calculations have been performed to study the conformational behaviour of Fuc(α1–3)GlcNAc and its thioglycoside analogue in solution. Experimental data show that, in contrast with the natural O-disaccharide, which is basically monoconformational, the S-analogue shows two conformational families, namely syn and anti.