Sweet structural requirement

B). This also suggests that the AH-B concept represents only a first approximation in the case of peptides. Certainly, the AH-B system is required in the molecule. However, the structural characteristics of the second amino acid sometimes may completely mask any AH-B effect. To test the above hypothesis, we have synthesized a number of peptides with or without a sweet taste. 

Cabochard is a perfume that repays a considerable amount of study, since it is full of interesting relationships between materials. Sadly, however, it is today more-or-less out of fashion, partly due the family having been hijacked by the male market but also because of its lack of many of the attributes required of a modem perfume. It is not monolithic in structure, sweet, powdery, or dominantly floral. Someday, when chypres again come back into fashion it may perhaps be reworked using modem materials such as Iso E super, Timberol, and Hedione, with perhaps a violet note, as in another of the older quinoline chypres, Jolie Madame. 

A first requirement for a substance to produce a taste is that it be water soluble. The relationship between the chemical structure of a compound and its taste is more easily established than that between structure and smell. In general, all acid substances are sour. Sodium chloride and other salts are salty, but as constituent atoms get bigger, a bitter taste develops. Potassium bromide is both salty and bitter, and potassium iodide is predominantly bitter. Sweetness is a property of sugars and related compounds but also of lead acetate, beryllium salts, and many other substances such as the artificial sweeteners saccharin and cyclamate. Bitterness is exhibited by alkaloids such as quinine, picric acid, and heavy metal salts. 

Hon WC, McKay GA, Thompson PR, Sweet RM, Yang DS, Wright GD, Berghuis AM. Structure of an enzyme required for aminoglycoside antibiotic resistance reveals homology to eukaryotic protein kinases. Cell 1997 89 887-895. 

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