alpha-D-Neup5Ac-(2->3/6)-beta-D-Galp-(1->4)-beta-D-GlcpNAc-(1->3)[alpha-D-Neup5Ac-(2->3/6)-beta-D-Galp-(1->4)-beta-D-GlcpNAc-(1->6)]-?-D-Gal
