Figure 1.
Chemical structures of the BC1 scaffold and BODIPY-FL-labeled analogs. R1 is the adduct of hydrazine-functionalized BODIPY-FL, and R2 is the adduct of maleimide-functionalized BODIPY-FL. Fluorescein-labeled peptides were also prepared and tested to rule out dye-dependent effects on cell uptake. HT1-Neut and HT1-Neg are head-to-tail cyclic analogs of BC1-Neut and BC1-Neg, and Lin-Neut and Lin-Neg are linear analogs of BC1-Neut and BC1-Neg. See Supplementary Information for complete structural and synthesis details.