Taste response to 2,5-anhydro-d-hexitols; rigid stereospecificity of the furanose site in the sugar receptor of the flesh fly

2,5-Anhydro-d-mannitol with a fixed furanose ring stimulated the sugar receptor of the flesh fly (Fig. 1) and reacted with the furanose site (Fig. 3). This is the first direct evidence that a furanose can stimulate the sugar receptor and supports strongly the assumption thatβ-d-fructofuranose is the only stimulatory component in the solution ofd-fructose.