Fig. 5: 2D 1H-STD-1H,13C-HSQC NMR experiments probing the interaction of compounds 3 to 5 with different HA proteins.

a Off-resonance reference (left) and associated 1H-STD-1H,13C-HSQC spectra for the indicated three HA proteins in complex with compound 3. b, c Sum of all 1H[13C]-STD signals of the 13C labeled Gal (orange) and GlcNAc (cyan) moieties in compounds 4 (b) and 5 (c) in complex with the three HA proteins.