Inhibition Assay: The activated cathepsin A was diluted in assay buffer (25 mM MES, pH 5.5, containing 5 mM DTT) and mixed with the test compound (dissolved in assay buffer containing (v/v) 3% DMSO) or, in the control experiments, with the vehicle in a multiple assay plate. After incubation for 15 min at room temperature, as substrate then bradykinin carrying an N-terminal ®Bodipy FL (4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-propionyl) label (JPT Peptide Technologies GmbH; dissolved in assay buffer) was added to the mixture. The final concentration of cathepsin A was 833 ng/ml and the final concentration of labeled bradykinin 2 μM. After incubation for 15 min at room temperature the reaction was stopped by the addition of stop buffer (130 mM 2-(4-(2-hydroxy-ethyl)-piperazin-1-yl)-ethanesulfonic acid, pH 7.4, containing (v/v) 0.013% ®Triton X-100, 0.13% Coating Reagent 3 (Caliper Life Sciences), 6.5% DMSO and 20 μM ebelactone B (Sigma, #E0886)).