TABLE 1

Experimental conditions for measuring UGT activity for enzyme inhibition studies in human liver microsomes and recombinant enzymes

EnzymeSubstrate ConcentrationProteinIncubation TimeIonization ModeMass Transition of MetaboliteMetabolite Monitored (Internal Standard)
HLMrUGTHLMrUGTHLMrUGT
µMmg/mlmin
UGT1A1990.10.155Negative447 / 27117β-Estradiol-3-glucuronide (17β-Estradiol 3-glucuronide-d5)
UGT1A320200.10.1105Negative567 / 391Chenodeoxycholic acid 24-O-glucuronide (chenodeoxycholic acid 24-O-glucuronide-d5)
UGT1A412120.10.155Positive584 / 408Trifluoperazine N-glucuronide (prochlorperazine N-glucuronide)
UGT1A6110.0050.00555Negative319 / 1431-Naphthol O-glucuronide (1-naphthol O-glucuronide-d7)
UGT1A92050.10.155Negative353 / 177Propofol O-glucuronide (propofol O-glucuronide-d17)
UGT2B74004000.10.155Positive462 / 286Morphine 3-O-glucuronide (morphine 3-O-glucuronide-d3)
UGT2B10330.10.1105Positive377 / 201Levomedetomidine N-glucuronide (1ʹ-hydroxymidazolam-d4)
UGT2B1550200.10.1105Positive463 / 286S-Oxazepam O-glucuronide (S-oxazepam O-glucuronide-d5)
UGT2B1752.50.10.1105Positive465 / 289Testosterone 17β-O-glucuronide (testosterone 17β-O-glucuronide-d5)
UGT1A7NA14NA0.1NA5Positive353 / 1774-Methylumbelliferone glucuronide (7-hydroxycoumarin-d5)
UGT1A87300.15
UGT1A10310.130
UGT2B412000.2515
  • HLM, human liver microsomes; rUGT, recombinant UDP-glucuronosyltransferase; NA, not applicable.