?-D-GlcpN-(1->?)-?-D-GlcpN-(1->?)-?-D-GlcpN-(1->?)-?-D-GlcpN-(1->?)-?-D-GlcpN-(1->?)-?-D-GlcpN-(1->?)-?-D-GlcpN-(1->?)-?-D-GlcpN-(1->?)-D-GlcN(?->