?-D-GlcpA-(1→?)-?-D-GlcpNAc-(1→?)-?-D-GlcpA-(1→?)-?-D-GlcpNAc-(1→?)-?-D-GlcpA-(1→?)-?-D-GlcpNAc-(1→?)-?-D-GlcA
