alpha-D-GlcpN2S-(1->4)-beta-D-GlcpA-(1->4)-alpha-D-GlcpN2S-(1->4)-beta-D-GlcpA2S-(1->4)-alpha-D-GlcpN2S-(1->4)-beta-D-GlcpA2S-(1->4)-alpha-D-GlcpN2S-(1->4)-?-D-GlcpA(1->