[{"from": "human", "value": "What can you tell me about this molecule? [C][C][=Branch1][C][=O][N][C@@H1][C@H1][Branch2][Ring1][#Branch2][C@H1][Branch2][Ring1][Branch1][C@H1][Branch1][S][O][C@@H1][Ring1][=Branch1][O][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O][N][C][O][O][O]"}, {"from": "gpt", "value": "The molecule is a non-proteinogenic L-amino acid that is N-acetyl-alpha-D-galactosamine linked via an alpha glycosidic bond to the O at position 3 of L-serine. It has a role as a tumour antigen. It is a L-serine derivative and a non-proteinogenic L-alpha-amino acid."}]