[{"from": "human", "value": "Describe this molecule. [C][C@H1][C@@H1][Branch2][#Branch1][P][C@H1][Branch2][Ring2][#Branch2][C@@H1][Branch2][Ring1][S][C@@H1][Branch1][Ring2][O][Ring1][=Branch1][O][C@@H1][C@H1][Branch1][#C][C@@H1][Branch1][O][O][C@@H1][Branch1][Branch1][C@H1][Ring1][=Branch1][O][C][O][O][N][C][=Branch1][C][=O][C][N][C][=Branch1][C][=O][C][O][C@@H1][C@@H1][Branch2][Ring2][Branch2][C@H1][Branch2][Ring2][Ring1][C@@H1][Branch2][Ring1][=C][C@H1][Branch1][Ring2][O][Ring1][=Branch1][C][O][C@H1][C@@H1][Branch1][P][C@H1][Branch1][=N][C@@H1][Branch1][=Branch2][C@H1][Branch1][Ring2][O][Ring1][=Branch1][C][O][O][O][O][O][O][N][C][=Branch1][C][=O][C][O]"}, {"from": "gpt", "value": "The molecule is a linear tetrasaccharide derivative consisting of beta-D-glucose, N-acetyl-alpha-D-fucosamine, N-acetyl-alpha-L-quinovosamine and N-acetyl-beta-D-glucosamine residues linked sequentially (1->6), (1->3) and (1->3). It forms an important epitope of the Proteus vulgaris O-specific polysaccharide. It has a role as an epitope."}]