CHEMBL3705501

Inhibition Assay: For the measurement of β-lactamase inhibitory activity, 100 μM (final concentration) nitrocefin (Oxoid) was used as a substrate, and 2.5% DMSO, 10 μg/mL bovine serum derived albumin (Sigma-Aldrich) and 50 mM phosphate buffer at pH 7.0 were used as a reaction solution. To each well of a 96-well plate were added test compounds (compounds shown in Table 14) and AmpC (final concentration 0.5 nM), followed by pre-incubation at 30° C. for 10 minutes. Nitrocefin was added to each well to be mixed therein, followed by incubation at 30° C. for 20 minutes, and Multiskan Ascent (Thermo Fisher Scientific) was used to measure 492 nm wavelength, thereby measuring nitrocefin hydrolytic activity of AmpC, to determine enzyme inhibitory activity. As a control, a reaction solution excluding AmpC was prepared, and the concentration of a test compound exhibiting 50% inhibition was determined to be IC50 value.