TABLE 1.

Possible conformers of an α2,3-sialoglycan in solution, represented by 3′SLN (Neu5Acα2-3Galβ1-4GlcNAc). These three conformers differ in the φ dihedral angle (C1-C2-O-C3′), which can adopt values of 180°, -60°, and 60° (t, -g, and g conformers, respectively), whereas the ψ dihedral angle (C2-O-C3′-H3′) remains stable at around −11°. The t and -g conformers are the most populated in solution. The information about each conformer and the corresponding NMR evidence proving their existence was retrieved from Forgione et al. (2020a) and Forgione et al. (2020b). The representative structures were generated using the carbohydrate builder tool from GLYCAM-web (Woods, 2005), and the images were created using PyMOL 2.4.1 (Schrödinger, 2010).

Φ(C1-C2-O-C3′)	180° (t conformer)	−60° (-g conformer)	60° (g conformer)
NMR Evidence	H3axNeu5Ac-H3 Gal (Strong NOE)	H8 Neu5Ac-H3 Gal (Medium NOE)	H3eq Neu5Ac-H3 Gal H3eq/H3ax Neu5Ac-H4 Gal (Strong NOEs)
Representative structure