Figure 8.

Pd⁰-mediated carbamate cleavage of rhodamine precursors in zebrafish. (a) BOOM conversion of nonfluorescent lipophilic compounds 8a,p,b into highly fluorescent hydrophilic rhodamine 110. (b) 3-dpf zebrafish embryos (n = 5) containing a nonfunctionalized resin (indicated with white arrows) after incubation with 5 μM of compounds 8a (top), 8p (middle), and 8b (bottom) for 24 h at 31 °C. (c) 3-dpf zebrafish embryos (n = 5) containing a Pd⁰-resin (indicated with purple arrows) after incubation with 5 μM of compounds 8a (top), 8p (middle), and 8b (bottom) for 24 h at 31 °C. Fish were imaged by phase contrast and fluorescent microscopy (ex., 470/40; em., 525/50). (d) Analysis of fluorescence intensity/pixel across a horizontal line of approximately 300 μm drawn in the yolk sac of the zebrafish embryos and encompassing both the resin and the area surrounding it. Note: the red and blue lines represent the areas of fluorescence intensity profile measured over the inactive resin (b, middle right panel) and the Pd⁰-resin (c, middle left panel), respectively.