Identification and elucidation of the structure of in vivo metabolites of diaveridine in chicken

• This novel study investigated in vivo diaveridine metabolism in chickens.
• Nine phase I and six phase II metabolites were identified in total.
• Ten new metabolites were identified compared to previous in vitro studies in pigs.
• The major phase I metabolites were O-demethylation and N-oxidation derivatives.
• The major phase II metabolites were glucuronide conjugates.

Diaveridine (DVD) is a popular antibacterial synergist that is widely used in combination with sulfonamide. It has been reported to be genotoxic to mammalian cells, but more studies are required to clarify this. Moreover, there is very little information on its pharmacokinetics, metabolic elimination and mechanism of toxicity. Therefore, in order to gain a better understanding of the metabolism of DVD, we performed high-performance liquid chromatography linear ion trapped orbitrap mass spectrometer (LC-LTQ-Orbitrap). With this approach, we identified 15 metabolites of DVD in chicken after a single oral administration of DVD; 10 of these metabolites have been identified in vivo for the first time. Nine phase I and five phase II metabolites were detected in the plasma, and eight phase I and six phase II metabolites were found in feces. The major phase I metabolites were formed via the O-demethylation and N-oxidation pathways, and the major phase II metabolites were glucuronide conjugates. These results are essential for understanding this compound more clearly and lay the basis for further studies about the metabolism of DVD. Therefore, using this approach, we were able to identify and characterize metabolites of DVD with high sensitivity and resolution. We were able to detect a broad range of metabolites, even some trace ones and some so far unknown metabolites.