Scheme 1.

(a) Design and (b) Schematic Cartoon Showing the Working Principle of Peroxymycin-1 for Histochemical Detection of H₂O₂ in Various Biological Samples and (c) Chemical Structures of Probes Investigated in This Study^a

^aPeroxymycin-1 and Ctrl-Peroxymycin-1 are novel histochemical H₂O₂ probe and negative control compounds, respectively, developed in this study, whereas Peroxyfluor-2 (PF2) and Mitochondria Peroxy Yellow-1 (MitoPY1) are previously reported fluorescent probes for imaging H₂O₂ in cells, and 4-HNE is an oxidized lipid used to indirectly assess increased oxidative stress in fixed biological specimens.