[4)-D-GlcpN-(1->](1+) residue
[4)-d-glcpn-(1->](1+) residue
An organic cationic group obtained by protonation of the amino group of [4)-<small>D</small>-GlcpN-(1→] residue. The major structure at pH 7.3 of <small>D</small>-glucosamine residue.