[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is the least plentiful of all 22 amino acids and an essential amino acid in humans (provided by food), Tryptophan is found in most proteins and a precursor of serotonin. Tryptophan is converted to 5-hydroxy-tryptophan (5-HTP), converted in turn to serotonin, a neurotransmitter essential in regulating appetite, sleep, mood, and pain. Tryptophan is a natural sedative and present in dairy products, meats, brown rice, fish, and soybeans. (NCI04)"}, {"from": "gpt", "value": "[C][=C][C][=C][C][=Branch1][Ring2][=C][Ring1][=Branch1][C][=Branch1][Branch1][=C][N][Ring1][=Branch1][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O][N]"}]