Kinetic constants for glucuronidation of 4-substituted phenols catalysed by UGT1A9
| Substrate | Control AdjustedVmax | Km | Vmax/Km | Correlation Coefficient (R) |
|---|---|---|---|---|
| nmol/min/mg | μM | ml/min/mg | ||
| 4-Methylphenol | 0.47 ± 0.026 | 75 ± 13 | 6.20 | 0.965 |
| 4-Ethylphenol | 0.38 ± 0.016 | 34 ± 6 | 11.24 | 0.981 |
| 4-n Propylphenol | 0.56 ± 0.036 | 53 ± 13 | 10.53 | 0.973 |
| 4-iso Propylphenol | 0.78 ± 0.087 | 51 ± 15 | 15.29 | 0.973 |
| 4-nButylphenol | 0.57 ± 0.036 | 154 ± 38 | 3.69 | 0.991 |
| 4-sec Butylphenol | 0.91 ± 0.039 | 99 ± 13 | 9.20 | 0.993 |
| 4-tert Butylphenol | 1.26 ± 0.12 | 75 ± 16 | 16.80 | 0.989 |
| 4-Cyclopentylphenol | 1.02 ± 0.03 | 160 ± 13 | 6.38 | 0.997 |
| 4-Phenylphenol | 0.36 ± 0.03 | 67 ± 21 | 5.43 | 0.945 |
| Methyl 4-hydroxybenzoate | 1.11 ± 0.05 | 82 ± 11 | 13.54 | 0.993 |
| Ethyl 4-hydroxybenzoate | 0.96 ± 0.05 | 94 ± 16 | 10.23 | 0.988 |
| Propyl 4-hydroxybenzoate | 0.90 ± 0.04 | 120 ± 16 | 7.53 | 0.993 |
| Butyl 4-hydroxybenzoate | 0.91 ± 0.03 | 113 ± 12 | 8.03 | 0.993 |
| 4-Hydroxybenzophenone | 0.97 ± 0.06 | 57 ± 12 | 17.02 | 0.983 |
| 4-Hydroxyacetophenone | 1.07 ± 0.05 | 298 ± 36 | 3.59 | 0.994 |
| 4-Fluorophenol | 0.81 ± 0.03 | 213 ± 51 | 3.78 | 0.993 |
| 4-Chlorophenol | 1.02 ± 0.07 | 43 ± 9 | 23.72 | 0.986 |
| 4-Bromophenol | 0.94 ± 0.09 | 41 ± 11 | 22.90 | 0.974 |
| 4-Iodophenol | 0.78 ± 0.05 | 21 ± 6 | 37.10 | 0.962 |
| 4-Phenylazophenol | 0.28 ± 0.01 | 79 ± 15 | 3.54 | 0.989 |
| 4-Nitrophenol | 0.93 ± 0.07 | 88 ± 19 | 10.58 | 0.979 |
| 4-Methoxyphenol | 0.90 ± 0.06 | 236 ± 35 | 3.80 | 0.994 |
| 4-Ethoxyphenol | 1.12 ± 0.08 | 271 ± 38 | 4.13 | 0.995 |
| 4-Propoxyphenol | 0.53 ± 0.05 | 211 ± 49 | 2.53 | 0.984 |
Standard errors in Vmax were in the range of ±2.5 to ±11.1% of the mean with a mean error of ±6.3%. Standard errors in Km were in the range of ±7.8 to ±31.8% of the mean with a mean error of ±19.4%. The mean of control propofol activities was 0.465 ± 0.12 nmols/min/mg.