[{"from": "human", "value": "Describe this molecule. [C][C][S][C][C][C@H1][Branch1][=Branch1][C][=Branch1][C][=O][O][N]"}, {"from": "gpt", "value": "The molecule is an S-ethylhomocysteine that has R-configuration at the chiral centre. It is an enantiomer of a L-ethionine."}]