[{"from": "human", "value": "Based on the given information, design a molecule that meets the desired specifications. The molecule is a 2,5-diketopiperazine where the substituents are methylidene and (S)-isopropyl at positions 3 and 6 respectively. It has a role as a metabolite."}, {"from": "gpt", "value": "[C][C][Branch1][C][C][C@H1][C][=Branch1][C][=O][N][C][=Branch1][C][=C][C][=Branch1][C][=O][N][Ring1][=Branch2]"}]