Fig 4.

Fragmentation spectra of RPV (top) and glucuronidated metabolites M5 (top) and M6 and M7 (bottom). Proposed modes of fragmentation are indicated by the fragment ion corresponding to the appropriate mass-to-charge ratio. Human liver microsomes (2 mg/ml) were incubated with 20 μM RPV for 60 min at 37°C in the presence of an NADPH-regenerating system and UDPGA. Metabolites were detected in MS/MS mode using parent masses of 367, 543, 559, and 575 m/z for RPV, M5, M6, and M7, respectively. Spectra are representative of three individual experiments.