?-D-Galp-(1->?)[?-D-NeupAc-(2->?)]-?-D-GlcpNAc-(1->?)[?-D-NeupAc-(2->?)]-?-D-Galp-(1->?)-?-D-GlcpNAc-(1->?)[?-D-NeupAc-(2->?)]-?-D-GalpNAc-(1->
