ROS produced by (A) CL-E1 (10 μM) in the absence (purple line) or presence (orange line) of singlet oxygen scavenger NaN3 (10 mM) monitored by the fluorescence of the ROS sensor, DCFH2 (5 μM), which produces the green, fluorescent product DCF upon oxidation. A higher fluorescence intensity was observed upon incubation with CL-E1 compared to CL-E1 in the presence of NaN3. (B) Increasing concentrations of CL-E1 were incubated with DCFH2 (5 μM), where a concentration-dependent increase in DCF fluorescence was observed. Analyzed by the two-tailed t-test, p-value <0.01 indicated by **. (C) To confirm that no ROS was produced by CL control compounds, each compound at a final concentration of 10 μM was incubated with DCFH2 (5 μM). A minimal increase in the fluorescence of DCF was observed for all controls. Conditions: PBS pH 7.4 (5% DMSO) at 37 °C. λex 490 nm. Measurements were performed in triplicate using independent samples.