28144-27-6 4-O-alpha-D-Galactopyranuronosyl-alpha-D-galactopyranuronic acid Digalacturonate Digalacturonic acid O-(alpha-D-Galactopyranosyluronic acid)-(1-4)-alpha-D-galactopyranuronic acid Sodium digalacturonate alpha-D-Galactopyranuronic acid, 4-O-alpha-D-galactopyranuronosyl-