The detection and identifi cation of metabolites is a critical step in the early drug

discovery phase. The identifi cation of metabolites from complex biological samples

is often challenging, as they may be present at trace levels. This Application Note

describes the seamless integration of a high sensitivity Agilent LC/Q

-

TOF

instrument

with software tools (Mass MetaSite software) for the identifi cation of

drug metabolites. Mass MetaSite can predict metabolic transformations, estimate

the primary site of metabolism, and assign the structures of metabolites from

accurate mass MS/MS dat

a. The workfl ow is demonstrated by predicting and

identifying primary metabolites from rat hepatocyte incubation of warfarin for

24 hours.