[{"from": "human", "value": "Provide a description of this molecule. [C@@H1][Branch2][Ring2][#C][C@H1][Branch2][Ring2][#Branch2][C@H1][Branch2][Ring1][P][O][C@@H1][Branch1][Branch1][C@@H1][Ring1][=Branch1][O][O][C@@H1][C@@H1][Branch2][Ring1][C][C@H1][Branch1][=C][C][Branch1][#Branch2][O][C@@H1][Ring1][=Branch1][C][=Branch1][C][=O][O][O][O][O][C][=Branch1][C][=O][O][O][O]"}, {"from": "gpt", "value": "The molecule is a digalacturonic acid in which an alpha-D-galactopyranuronic acid unit is joined to a D-galactopyranuronic acid unit via an alpha-(1->4)-linkage. It is a conjugate acid of an alpha-D-galacturonosyl-(1->4)-D-galacturonate(2-)."}]