Fig. 8.

Glucuronidation of monohydroxylated ETR using cDNA-expressed UGTs. The proposed origins of fragment ions (A) and MS/MS spectra (B) of the O-glucuronide product M7 are shown. CYP3A4 (10 pmol) was incubated with cDNA-expressed UGT isozymes, 20 μM ETR, an NADPH-regenerating system, UDPGA, and UGT reaction mix at 37°C for 60 min. Formation of M7 was detected using UPLC-MS/MS in product ion mode (C). Data are presented as relative peak intensities and represent the means ± S.D. of three individual experiments.