k(h−1) | Buffer/MeCN Ratio | |||||
---|---|---|---|---|---|---|
100:0 v/v | 90:10 v/v | 80:20 v/v | 70:30 v/v | 60:40 v/v | 50:50 v/v | |
β1-D | 0.026 | 0.021 | 0.015 | 0.012 | 0.007 | 0.005 |
β1–2 | 0.18 | 0.14 | 0.10 | 0.072 | 0.047 | 0.032 |
Ratio am/h | 6.9 | 6.5 | 6.9 | 6.2 | 6.4 | 6.1 |
The dependence of the first order degradation rate constantskβ1-D (hydrolysis) andkβ1–2 (acyl migration) ofS-naproxen-β-1-O-acyl glucuronide in mixtures of 25 mM potassium phosphate buffer, pH 7.40, and increasing amounts of acetonitrile. Ratio am/h is the ratio between acyl migration (kβ1–2) and hydrolysis (kβ1-D) for S-nap-g. All nine first order rate constants in the equilibrium (data not shown) are slowed down by increasing amounts of acetonitrile.