can't read?
Carboxymethyl cellulose (CMC) or cellulose gum[1] is a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers that make up the cellulose backbone.
C 1634 (OTTO) Carboxymethylcellulose sodium salt, medium viscosity Cas 9004-32-4 - used as its sodium salt, sodium carboxymethyl cellulose.