[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is the meso-diastereomer of 1,4-dimercaptobutane-2,3-diol; a sulfur-containing sugar derived from the monosaccharide erythrose; and an epimer of dithiothreitol. It has a role as a reducing agent."}, {"from": "gpt", "value": "[C][Branch1][O][C@H1][Branch1][#Branch1][C@H1][Branch1][Ring1][C][S][O][O][S]"}]