List of inhibitors and substrates of UGT isoforms

UGT IsoformSpecific SubstrateReported HLM Unbound Km or S50 in µM (Vmax - pmol/min per mg)InhibitorReported IC50 (µM)Inhibitor Reference
1A1SN-38 (active metabolite of irinotecan), a bit of 1A71.4 (820) without 2% BSAAtazanavir1.9(Zhang et al., 2005; Liu et al., 2010)
β-Estradiola,*6.6 (1400) with 2% BSA (β-estradiol-3-glucuronide)Erlotinib1.2 (Ki = 0.64)
1A3Zolarsartan (Alonen et al., 2008), fulvestrant (Chouinard et al., 2006), hexafluoro-1α, 25−dihydroxyvitamin D3 (Kasai et al., 2005)Buprenorphine40–50(Oechsler and Skopp, 2010)
1A4Imipramine (Uchaipichat et al., 2006a)11 (1500) without 2% BSAHecogenin1.5(Uchaipichat et al., 2006a)
Trifluorperazinea,*4.1 (870) with 2% BSA (trifluoperazine-N-glucuronide)
1A6Serotonin (Krishnaswamy et al., 2004)390 (66,000) without 2% BSATroglitazone20(Ito et al., 2001)
5-Hydroxytryptophola,*300 (47,000) with 2% BSA (5HTOL-O-glucuronide)
1A7 (extrahepatic)OctylgallatePhenylbutazone(nonselective)3.9(Uchaipichat et al., 2006a)
1A8 (extrahepatic)Dihydroxytestosterone metabolized to a diglucuronide (Murai et al., 2006)Emodinb15.6(Watanabe et al., 2002)
1A9Propofola,*98 (1400) without 2% BSANiflumic acid0.0275(Mano et al., 2006)
7.8 (780) with 2% BSA (propofol-O-glucuronide)
1A10 (extrahepatic)Dopamine (Itaaho et al., 2009)Tacrolimus0.034(Zucker et al., 1999)
2B73′-Azido-3′deoythymidine (AZT)a,*420 (2100) without 2% BSAFluconazolec146 (Ki = 73)(Uchaipichat et al., 2006b)
100 (4700) with 2% BSA (AZT-5′-glucuronide)
2B15(S)-Oxazepamd,*54 (303) without BSA [(S)-oxazepam glucuronide]Ibuprofen120(Sten et al., 2009)
  • SN-38, N-[(2′-dimethylamino)ethyl]acridine-4-carboxamide.

  • a Substrate and data acquired from Walsky et al. (2012a).

  • b 1A10 interaction may influence specificity assessment.

  • c Plus BSA in incubation.

  • d Substrate and data acquired from Court et al. (2002).

  • * Indicates the substrates which have been shown to be specific for each isoform, hence are the preferred tool compounds for UGT phenotyping.