Fig. 4: Effects of compound 6c on the iron chelation and ROS generation in MRSA.

a Intracellular concentration of iron from MRSA treated with varying concentrations of 6c (mean ± s.d, n = 3 biological replicates). b The effect of supplementing iron ions (FeCl3) on rescuing 6c-mediated killing of MRSA for varying ratios of 6c (7.5 µg/mL) and Fe3+ (1:0, 1:5, and 1:10) (mean ± s.d, n = 3 biological replicates). c Top: chemical structure of iron-6c complex, [Fe(6c)2(OH)]4; Bottom: molecular structure of iron-6c complex from single crystal X-ray diffraction. d Intracellular level of ROS from MRSA treated with 1×MIC concentration of 6c (mean ± s.d, n = 3 biological replicates). e The effect of superoxide dismutase (SOD) on rescuing 6c-mediated killing of MRSA treated with varying concentrations of 6c (mean ± s.d, n = 3 biological replicates). *p < 0.05, **p < 0.01, ****p < 0.001, and ****p < 0.0001.