[Studies on the metabolites of tetramethylpyrazine in rabbits]

The metabolites of tetramethylpyrazine (TMPz) in rabbit have been separated by HPLC and solvent extraction. Their structures were identified by means of UV, IR, MS and NMR spectroscopy. The possible metabolic ways of TMPz are oxidzation of one of the four methyl groups to hydroxymethyl and carboxyl group forming 2-hydroxymethyl-3, 5, 6-trimethylpyrazine (TMPz D1) and 3, 5, 6-trimethylpyrazine-2-carboxylic acid (TMPz D2). These were further confirmed by the identity of HPLC data and all the above spectral parameters of the metabolites in vivo and the compounds objectively synthesized from TMPz.