Understanding the Mechanism of Sweet Taste:  Synthesis of Ultrapotent Guanidinoacetic Acid Photoaffinity Labeling Reagents

Azido-functionalized analogs of potently sweet guanidinoacetic acids have been synthesized for use as sweetener receptor photoaffinity labeling reagents. These compounds have been synthesized using readily available starting materials. One of the azido-labeled guanidinoacetic acids has been evaluated in an electrophysiological model in the Rhesus monkey. We found that the photoaffinity-labeling reagent caused irreversible inhibition in electrophysiological response to sweeteners upon exposure of the monkey tongue to a combination of the reagent and UV light.