Aim: To study phase II metabolites of etofesalamide in filamentous fungi.
Methods: Seven fungi were screened to transform etofesalamide. The metabolites of etofesalamide were assayed using liquid chromatography coupled to mass spectrometry. The major metabolite was subject to enzymatic hydrolysis to confirm its structure.
Results: Etofesalamide was converted into two phase II metabolites: glucoside and riboside conjugates. Glucoside conjugate was the major product with a yield greater than 90%; no phase I metabolites were detected.
Conclusion: Glucoside and riboside conjugations of etofesalamide in filamentous fungi differ from the phase II metabolism of glucuronidation in mammals.