Sweet compounds

Acesulfame-K. Acesulfame-K [55589-62-3] (4), the potassium salt of acesulfame [33665-90-6] (6-methyl-l,2,3-oxathiaziQ-4(3ff)-one 2,2-dioxide), is a sweetener that resembles saccharin in stmcture and taste profile. 5,6-Dimethyl-l,2,3-oxathiazine-4(3ff)-one 2,2-dioxide, the first of many sweet compounds belonging to the dihydrooxathia2inone dioxide class, was discovered accidentally in 1967 (63). From these many sweet compounds, acesulfame was chosen for commercialisation. To improve water solubiUty, the potassium salt was made. Acesulfame-K (trade name Sunette) was approved for dry product use in the United States in 1988 and in Canada in October, 1994. Later, it was approved by the FDA for additional food categories such as yogurts, frosen and refrigerated desserts, and baked goods. 

Saccharin. Saccharin [81-07-2] 3-oxo-2,3-dihydro-l,2-ben2isothia2ole 1,1-dioxide (i9-sulfoben2imide or (9-ben2osulfimide), (5) was accidentally discovered to be a sweet compound in 1878. A pilot plant was set up in New York to manufacture saccharin, which was displayed in a London exposition in 1885 (70). Since that time, saccharin has been used in many parts of the world. 

The evaluation of sweet compounds by taste panels is crucial to the development of worthwhile structure-taste relationships. Many structure-taste studies have employed dubious, taste-panel techniques. Therefore, a critical examination of structure-taste data in the light of this observation is relevant, as are recommendations for a consistent approach in utilizing taste techniques. ... 

By 1938, one fact was clearly established. Sweet compounds, unlike salty and sour compounds, are found in all classes of chemical compounds, including such inorganic salts as beryllium ( glucinium ) and lead salts. They are also found among compounds of all molecular shapes and sizes, and stereochemical changes may result in a very dramatic change in the taste, as seen in the gustatory differences between enantiomorphs. 

Dzendolet pointed out that the property common to all sweet compounds is that of being a proton acceptor. Based on electrophysiological... 

An extension of this concept to other classes of sweet compounds is, however, lacking. 

Of this class of naturally occurring, sweet compounds, the flavanone glycosides found in citrus fruits have achieved considerable interest, owing to the systematic studies of Horowitz and Gentili " (see Fig. 20). 

Hi) Sulfamates.—The two most well known sweet compounds in this class are cyclamate (9) and saccharin (10). Considerable structural modifications have been recorded, and their tastes ascertained. 

That the sweet and bitter responses are intimately associated is clear from the results of gustatory studies of all of the conformationally defined sugars and of other organic compounds. If a carbohydrate has any taste at all, this is invariably sweet, bitter-sweet, or bitter. Chemical modification may alter the taste of a sweet compound so that the product is bitter-sweet or bitter, and it is now generally agreed that the two basic tastes may each be a feature of a single compound. It appears, therefore, that the interactions of these polyfunctional stimulants involve two different sets of receptor sites, representing sweet and bitter modalities. ... 

Fig. 37.—Binding of One Molecule of a Bitter-sweet Compound to (i) a Sweet Receptor, and of a Second Molecule of the Same Compound to (ii) a Bitter Receptor.

Compadre, C. M., Pezzuto, J. M., Kinghorn, A. D. and Kamath, S. K. 1985. Hernandulcin an intensely sweet compound discovered by review of ancient literature. Science 227 417 19. 

Most sweet compounds including the commercial sweeteners, are small molecular weight compounds but there are also sweet macromolecules both synthetic and natural. It was thought that compounds with molecular masses over 2 500 would generally be tasteless. It was assumed that macromolecules such as proteins could elicit a sweet taste similar to small molecules such as sucrose and stevioside until the discovery of miraculin. 

KimNC, KinghornAD,Highly Sweet Compounds ofPlantOrigin,ylrc/ / / [Pg.206]

In a similar approach, Shishido et al. (241) used oxime 215 [derived from the monoterpene (+)-citronellal (214)] for the synthesis of (—)-mintlactone (218) and (+)-isomintlactone (219), sweet compounds isolated from some Mentha species (Scheme 6.89). Bicyclic isoxazoline 216 was obtained in good yield from the cycloaddition. As expected, the product possessing tra i-l,4-substimtion prevailed. Reductive hydrolysis of the major isomer of 216 using hydrogen-Raney Ni-trimethyl borate provided p-hydroxyketone 217. This compound was dehydrated to give an enone and this was followed by carbonyl reduction-lactonization to complete the synthesis of both lactones 218 and 219 (241). 

The current accepted theory suggests that a bitter compound and a sweet compound bind independently at specitic receptors. This situation will be referred to as "independent" in this report. The data to follow will demonstrate that a bitter compound and a sweet compound bind at the same receptor in a competitive manner. Therefore, this situation will be referred to as "competitive" in this report. Which theory was the functioning mechanism of taste reception should be determinable when one measured the taste intensities of mixed solutions of bitter and sweet tasting compounds. In this experiment the mechanism could be predicted to elicit a considerable difference in taste intensity and response that was varying based on the final concentration of each component. The "independent" receptor mechanism would be expected to yield data in which the intensities of bitter and sweet would be unaffected by mixing the two tastes, no matter what the concentration. On the other hand, with the "competitive" receptor mechanism one would expect both flavors to become altered, i.e., one stronger and the other weaker, as component concentrations varied the latter would occur because of competition of the substances for the same site. 

Figure 30-31 Structures of some very sweet compounds. The backbone structure of the protein thaumatin I is included. The main body of this structure consists of two (3 sheets forming a flattened (3 barrel. (3 Strands in the top sheet are shaded light, and those in the bottom sheet are darker. Open bars represent disulfide bonds, and the regions with sequences homologous to monellin are indicated by the hatched marks. From de Vos et al.9i0...

It was with the sweet taste of enantiomorphs that we encountered the strongest criticism to our explanation of why sugars vary in their sweetness and also as to the identification of the saporous unit as an AH,B system in all sweet compounds. 

Bertoni, a plant native to Paraguay and now commercially cultivated in Asia and South America. Several extracts from the Stevia plant ate available which contain different levels of stevioside and also other sweet compounds (rebau-diosides, dulcosides). This inconsistency of extracts is probably the reason much variation exists in the data about stevioside. 

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