Calcium sodium a-D-galacturonate

C8H90T]3CaNa,6H20 Calcium sodium a-D-galacturonate hexahy-drate11... 

Pectin belongs to a family of plant polysaccharides in which the polymer backbone consists of (1— 4)-linked a-D-galacturonic acid repeating-units. Often, (1— 2)-linked a-L-rhamnose residues interrupt the regular polygalacturonate sequence. The high viscosity and gelling properties of pectins are exploited by the food and pharmaceutical industries. X-Ray studies on sodium pectate, calcium pectate, pectic acid, and pectinic acid (methyl ester of pectic acid) have disclosed their structural details. 

A series of crystalline salts of D-galacturonic acid has recently been prepared by Isbell and Frush.62 Some of these, e. g., calcium sodium D-galacturonate, are suitable for the separation of D-galacturonic acid from plant materials. 

Pectins " are high molecular weight polysaccharides with at least 65 wt% of a-(1 4)-linked d-galacturonic acid-based units, which may exist as free acid, salt (calcium, sodium, potassium, ammonium, etc.), naturally esterified with methanol, or as acid amide in ami-dated pectins. 

---