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