The name/synonym for ligand SIA (curated from ChEBI, PubChem, and PDB databases):

1N-ACETYLNEURAMINIC ACID
25-ACETAMIDO-3,5-DIDEOXY-D-GLYCERO-D-GALACTO-NON-2-ULOPYRANOSONIC ACID
3NEUAC
4O-SIALIC ACID
5ACENEURAMIC ACID
6NEU5AC
75-ACETAMIDO-3,5-DIDEOXY-D-GLYCERO-D-GALACTO-2-NONULOSONIC ACID