o-Nitroanilines as major metabolic products of anti-Trypanosoma cruzi 5-phenylethenylbenzofuroxans in microsomal and cytosolic fractions of rat hepatocytes and in whole parasitic cells

Abstract

1. The metabolism of six anti-Trypanosoma cruzi 5-phenylethenylbenzofuroxans (PhEBfx) was studied in vitro using rat hepatic microsomal and cytosolic fractions as a mammalian model and whole cells of T. cruzi as a parasitic model.

2. Some of the expected metabolites were synthesized to provide authentic chromatographic standards.

3. The metabolites were identified using high-performance liquid chromatography (HPLC) in comparison with the authentic standards and their proportions were determined. Their structures were confirmed using mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy.

4. The behaviour of the six PhEBfx in the three different systems was similar. The main metabolites, formed by reductive processes, were the corresponding o-nitroanilines.

5. Two of the test compounds were studied for extended time periods in the rat liver preparations and their terminal metabolites were identified as o-phenylendiamine derivatives.

Keywords::

• Chagas disease
• benzofuroxan
• metabolism
• rat hepatocytes microsomes
• rat hepatocytes cytosolic fraction
• Trypanosoma cruzi

Acknowledgements

This investigation was performed as part of the project ‘Clinical Development of Arylethenylbenzofuroxan Derivatives as Drugs for Chagas Disease’ supported by the Drugs for Neglected Diseases initiative. Mass spectrometry facilities at the Polo Tecnologico-FQ were supported by UE Grant Proyecto Enlaces-UE URY- 2003-5906.

Declaration of interest: The authors report no conflicts of interest.