SEARCH Articles Figures Tables 2- Amino-5-[(2 -carboxy-6 -hydroxy 2- Carboxy-5-hydroxy-4-pyrone 2-Carboxy-3-hydroxy-5,6-dimethylpyrazine 2-Carboxy-3-hydroxy-5,6-diphenylpyrazine 3- Carboxy-2-hydroxy pyrazine 3- Carboxy-4-hydroxy-4 -sulfo Carboxy-hydroxy-elimination