?-D-GlcpA-(1->?)-?-D-GlcpNAc-(1->?)-?-D-GlcpA-(1->?)-?-D-GlcpNAc-(1->?)-?-D-GlcpA-(1->?)-?-D-GlcpNAc-(1->?)-?-D-GlcpA-(1->?)-?-D-GlcpNAc-(1->?)-?-D-GlcpA(1->