The diuretic furosemide (Lasix) was metabolized by the fungus Cunninghamella elegans (ATCC 36112) to the phase II conjugate, furosemide acyl glucoside. This metabolite was isolated following semipreparative scale incubations of C. elegans involving glucose nutrient dosing, and was characterized by NMR spectroscopy (1H and 1H/1H correlated), MS (FAB), UV, HPLC with fluorescence detection, and enzymatic treatments. The aglycone fragment of the conjugate was characterized as furosemide by treatment of the metabolite with sodium hydroxide, whereas the sugar part was identified as glucose by cleavage of the conjugate, derivatization of the released sugar, and GC/MS analysis.