Table 1

In vitro and bacterial cell–based assays for β-glucuronidase activity and inhibitor efficacy. kcat, catalytic rate; Km, Michaelis constant; N/A, not applicable. N.E., not effective. Errors represent standard deviation, where N = 3.

E. coli β-glucuronidase in vitroE. coli cell–based
IC50 (nM)kcat/Km (s–1 μM–1)Ki (nM)EC50 (nM)
No inhibitorN/A0.134 ± 0.0123N/AN/A
Glucaro-δ-lactam26400 ± 483N/A7750 ± 475N.E.
Inhibitor 1283 ± 26.10.0987 ± 0.00621164 ± 13.017.7 ± 7.42
Inhibitor 2369 ± 2.510.119 ± 0.00473208 ± 25.428.3 ± 2.11
Inhibitor 3586 ± 31.10.136 ± 0.00633684 ± 81.6233.2 ± 2.99
Inhibitor 41060 ± 3.540.122 ± 0.02051380 ± 1661322.8 ± 1.15