Biochemistry

I н-с-он 1 соон (acyclic form) (cyclic form) D -galacturonic acid Pectin substances are heterogeneous and are found in the form of protopectin, pectin and pectic acid. Pectic acid is polygalacturonic acid. This is a linear polysaccharide from the residues of D -galacturonic acid connected by a- 1,4 bonds. H OH COOH H OH O — COOH H OH COOH Pectic acid (polygalacturonic acid) Pectin is a derivative of pectic acid, in which part of the carboxyl groups forms esters with methyl alcohol, in other words: pectin is an ester of methyl alcohol and pectic acid. H OH COOH H OH COOCHj H OH COOCHj Pectin 151