Relationship between the structure and the properties of carbohydrates in aqueous solutions: sweetness of chlorinated sugars.

The structural basis of the sweet taste of D-galactose, D-glucose, D-mannose, sucrose, and some of their chlorinated derivatives has been derived from an interpretation of their F.t.-i.r. spectra. AH-B glucophores are proposed in the light of the observed OH vibrations, and an explanation of the differences in sweetness of the monosaccharides is proposed. The hydrophobic character of the CH2Cl, "gamma" centre in the tripartite template does not seem to play the same role in monosaccharides and 4,1',6'-trichloro-4,1',6'-trideoxy-galacto-sucrose. The enhancement of sweetness in the disaccharide derivative is due to the enhanced hydrophobicity of the CH2Cl groups as well as to specific interactions with water. A sharp i.r. absorption characteristic of free hydroxyl is found in the spectra of most of the very sweet polyhydroxy compounds.