Ligands for the study of sweet taste receptors: Synthesis of fluorescent N,N′-disubstituted guanidineacetic acids

The synthesis of three different fluorescent N,N′-disubstituted guanidino acetic acids with intense sweet taste properties is reported. The preparation of disubstituted guanidino acetic acids containing an alpha-naphthylamine, beta-naphthylamine or methylcoumarin substitution produced compounds with fluorescent properties which will make them useful for spectroscopic studies of sweetener-receptor binding site interactions.