TABLE 2

Rates of glucuronidation and O-methylation of catechols catalyzed by human recombinant UDP-glucuronosyltransferases and soluble catechol O-methyltransferase a

Compound
UGT1A1
UGT1A6
UGT1A9
UGT2B7
UGT2B15
S-COMT
nmol/mg/min
Endogenous Compounds
    1 Dopamine -b - - - - 28.4
    2 6-Hydroxydopamine - - 0.030 - - 14.2
    3 5-Hydroxydopamine - - - - - 33.1
    4 Adrenaline - - - - - 20.6
    5 Noradrenaline - - - - - 17.8
    6 Salsoline - - - - - 28.7
    7 Salsoline-1-carboxylic acid - - - - - 29.6
    8 l-Dopa - - - - - 13.5
    9 6-Hydroxydopa - - 0.060 - - 2.9
10 3,4-Dihydroxyphenylacetic acid - - - - - 26.3
11 3,4-Dihydroxymandelic acid - - - - - 22.5
12 3,4-Dihydroxyphenylglycol - - - - 0.13 29.7
13 2-Hydroxyestradiol - - 0.020 - - 40
14 4-Hydroxyestradiol - - 0.110 - - 24.7
15 4-Hydroxyestrone - - 0.230 0.34 -
Drugs and Pharmacological Tools
16 Apomorphine 0.03 - 0.240 0.06 0.04 -
17 Dihydrexidine 0.20 - 0.530 - 0.06 11.4
18 Dobutamine - 0.03 0.150 - - 26.5
19 SKF38393 0.08 - 0.140 - - 7.9
20 Carbidopa - - - - - 8
21 Tyrphostin A23 - 0.04 0.250 0.11 0.01 -
22 Ethyl-3,4-dihydroxybenzylcyanoacetate 1.30 - 2.300 0.04 0.09 3.6
23 2-(1-Thienyl)ethyl-3,4-dihydroxybicinchoninic acid 0.96 - 1.800 - - 1
24 Entacapone 0.06 - 1.310 0.07 0.05 -
25 Tolcapone - - 0.730 0.03 - -
26 3,5-Dinitrocatechol - - 0.250 - - -
Natural Compounds
27 Gallic acid - - - - - 11.7
28 Methyl gallate - - 1.260 0.03 0.08 10.2
29 Catechin - - - 0.06 - 22.1
30 Epicatechin - - - - - 28.3
31 Epigallocatechin - - - - - 7.7
32 Epicatechin gallate - - 0.470 - - 0.4
33 Epigallocatechin gallate - - - - - 0.5
34 Rosmarinic acid - - - - - 7.1
35 Chlorogenic acid - - - - - 20.1
Various Chemicals
36 Catechol - - 0.150 - 0.02 32.2
37 Pyrogallol - 0.11 0.530 0.22 - 20.9
38 3-Methoxycatechol - 0.96 0.610 - - 37.4
39 2,3-Dihydroxybenzoic acid - - - - - -
40 2,3-Dihydroxybenzaldehyde - - 0.110 - - 3
41 3-Fluorocatechol - 0.77 0.640 0.06 0.14 25
42 3-Chlorocatechol - 1.05 1.070 0.12 0.13
43 4-Methylcatechol - 0.19 0.910 - 0.07 31.2
44 4-Isopropylcatechol - 0.48 1.620 0.17 0.22 32.5
45 4-tert-Butylcatechol - 0.34 1.760 0.19 0.21 39.3
46 4-Chlorocatechol 0.11 2.32 1.600 0.11 0.29 29.7
47 4-Nitrocatechol 0.32 0.27 0.600 - 0.06 1.6
48 3,4-Dihydroxyacetophenone 0.03 0.72 0.510 - 0.11 8
49 3,4-Dihydroxybenzoic acid ethyl ester 0.29 0.09 1.730 0.14 0.16 10.5
50 4-tert-Butyl-5-methoxycatechol - 0.08 0.500 0.03 0.10 25.2
51 3-Methoxy-5-bromocatechol 0.32 3.50 1.020 - 0.17 17.8
52 Tetrachlorocatechol 1.14 1.55 1.460 2.97 0.12 0.6
53 2,3-Dihydroxynaphthalene
0.18
1.77
1.930
0.08
0.22
29.7

  • ↵ a The enzyme activities were determined as described under Materials and Methods

  • ↵ b -, no activity could be determined (the limits of determination were 0.01 ng/mg/min for glucuronidation and 0.2 ng/mg/min for O-methylation, respectively)