CHEMBL5732069

β-Glucuronidase Activity Assay: The β-glucuronidase assay was performed by the addition of 0.5 μl of compound (or DMSO) to the well of a black 384-well plate followed by the addition of 30 μl of diluted β-glucuronidase enzyme. The enzyme was diluted in assay buffer (50 mM HEPES, pH 7.4) plus 0.0166% Triton X-100 for a final enzyme concentration of 50 pM and final detergent concentration of 0.01%. After a 15 minute incubation at room temperature (23° C.), 20 ul of substrate, 4-Methylumbelliferyl β-D-glucuronide hydrate (4MUG) diluted into assay buffer, was added to the reaction for a final concentration of 125 uM. β-glucuronidase hydrolyzes the non-fluorescent 4MUG resulting in a fluorescent product, 4-methylumbelliferyl. After a 30 minute incubation at room temperature, the reaction was stopped by the addition of 20 ul 1 M Na2CO3. The fluorescence (in relative fluorescence units, RFU) was measured using a 355 nm excitation filter and 460 nm emission filter using a Victor V (Perkin Elmer) plate reader. Minimum (min) controls were performed using reactions with no enzyme. Maximum (max) controls were performed using no compound. 1% DMSO was maintained in all reactions. Percent inhibition was calculated using RFU data by the following formula: [1−(assay readout-average of min)/(Average of Max-Average of Min)]×100