[{"from": "human", "value": "Synthesize a molecule that matches the given characteristics. The molecule is a S-alkyl-L-cysteine zwitterion resulting from the transfer of a proton from the carboxy group to the amino group of felinine. Major microspecies at pH 7.3. It is a tautomer of a felinine."}, {"from": "gpt", "value": "[C][C][Branch1][C][C][Branch1][Ring2][C][C][O][S][C][C@@H1][Branch1][=Branch1][C][=Branch1][C][=O][O-1][NH3+1]"}]