Discovery and characterization of halogenated xanthene inhibitors of DUSP5 as potential photodynamic therapeutics

•Xanthene-ring analogs all inhibit DUSP5 in vitro, with relative potencies: rose bengal > merbromin > erythrosin B > eosin Y.•Inhibition is time-dependent, with inhibition increasing over time and fitting a slow-binding model of irreversible inactivation.•Inhibition potency is correlated with the xanthene dye’s LUMO energy, which affects ability to form light-activated radical anions.•Rose bengal inhibition is light-dependent, with a Kd of 690 nM.•Xanthene dyes could be used in photodynamic therapy, for treating vascular diseases that respond to DUSP5 inhibition.