Inhibitory effects of DiPP, DiBP, DCHP, DBP, BBZP, BBOP, DMEP, DPP and DHP on UGT1A9 activity in human cDNA-expressed UGT1A9 supersomes. IC50 values of DiPP, DiBP, DCHP, DBP, BBZP, BBOP, DMEP, DPP and DHP on UGT1A9 were calculated to be 14.70, 7.03, 1.46, 17.6, 5.54, 28.3, 18.2, 18.5 and 25.4 mM, respectively. Data were presented as the mean value plus S.D..