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