Sweet compounds, design

Much of the research on sweeteners involves probing the structure of sweetness receptor sites. One model proposed for a sweetness receptor incorporates eight binding interactions that involve hydrogen bonding as well as van der Waals forces. Sucronic acid is a synthetic compound designed on the basis of this model. Sucronic acid is reported to be 200,000 times as sweet as sucrose. 

Rodenticides are a broad class of chemicals designed to kill mammals, particularly rats and mice. Compounds that inhibit blood clotting, anticoagulants, are commonly used to control rat populations. One of the first was warfarin, which is related to the plant-derived coumadin (from spoiled sweet clover). In the 1950s rats developed resistance to warfarin, which prompted the development of more potent anticoagulants. Other rodenticides include fluoroacetic acid and zinc phosphide (very toxic) and thiourea-based compounds. The primary alternative to using rodenticides is trapping. 

Meanwhile, intensive studies have been performed on the structure-sweetness relationship and many hypotheses have been proposed.17 18 Based on these hypotheses, new, highly intense sweeteners are currently being designed. As a result, several compounds that are hundreds of thousands of times sweeter than sugar have been synthesized.19... 

This isomer of sorbitol and mannitol is less soluble and less sweet than the other two compounds. Also it is less available for the multiplicity of uses which mannitol and sorbitol have enjoyed. Dulcitol was first designated as the mannite of Madagascar manna and was shown by Laurent in 1850 to be an isomer of mannitol. It is a meso form. In 1871 Bouchardat synthesized the compound by reducing D-galactose with sodium amalgam. Until ten years ago, the only biological studies available on dulcitol were of a bacteriological nature. At that time the authors studied the fate of dulcitol and dulcitan in the animal body. 

In this section, the presently known highly sweet substances of natural origin are described. Sweet-tasting compounds are listed in Table 1, with information published subsequent to an earlier chapter [16] then discussed in more detail. The structures of the compounds mentioned will be interspersed in the text, with the following abbreviations used to designate the sugar units of glycosides api = D-apiofuranosyl ara = L-... 

Monoterpenoids. It was mentioned earlier in this chapter that the semi-synthetic oxime, perillartine (1), is sweet and has some commercial use in Japan. In experiments designed to optimize the sensory attributes of the oxime sweeteners, it was found that the introduction of ether groups was advantageous, while hydroxyl groups and ring oxygen atoms tended to lower sweetness intensity and to destroy the sweet taste, respectively (16). Despite the discovery of cyclic derivatives of perillartine that are sweeter than this lead compound (20), the further development of this class of sweet substances is limited by poor water solubility and inappropriate hedonic qualities (20,21). 

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