?-6-deoxy-HexNAc-(?->?),?-6-deoxy-HexNAc-(?->?),?-6-deoxy-HexNAc-(?->?),?-6-deoxy-HexN-(?->?),?-6-deoxy-HexNAc4N-(?->?),?-3-deoxy-Non2ulo-onic-(?->?)