Table 1.

List of main peaks for FLU biotransformation samples detected by UHPLC-MS/MS with their retention times, theoretical values of [M+H]⁺ ions in ESI positive-ion mode, elemental composition, product ions, and description of present metabolites.

tR [min]	Theoretical m/z values of [M+H]+ ions	Elemental composition	Description of metabolite formation		Product ions of [M+H]+, m/z	Metabolite designation
			Phase I	Phase II
3.22	418.14	C20H20FN3O6	Hydrolysis	N-glycosidation	256, 123	M1FLU
3.31	478.16	C22H24FN3O8	Carbonyl reduction	N-glycosidation	316, 284	M2FLU
3.42	478.16	C22H24FN3O8	Carbonyl reduction	O-glycosidation	298, 266	M3FLU
3.58	478.16	C22H24FN3O8	Carbonyl reduction	O-glycosidation	298, 266	M4FLU
3.7	418.14	C20H20FN3O6	Hydrolysis	N-glycosidation	256	M5FLU
3.82	478.16	C22H24FN3O8	Carbonyl reduction	O-glycosidation	298, 266	M6FLU
4.04	478.16	C22H24FN3O8	Carbonyl reduction	N-glycosidation	316, 284	M7FLU
4.8	316.10	C16H14FN3O3	Carbonyl reduction	–	284, 238	M8FLU
5.33	476.14	C22H22FN3O8	–	N-glycosidation	314, 282, 123	M9FLU
5.44	330.12	C17H16FN3O3	Carbonyl reduction	Methylation	298, 174	M10FLU
5.52	476.14	C22H22FN3O8	Hydrolysis, hydroxylation	Glycosidation, O-acetylation	256	M11FLU
5.62	476.14	C22H22FN3O8	–	N-glycosidation	314, 282, 123	M12FLU
8.27	314.09	C16H12FN3O3		–	282, 123	FLU (parent drug)