Saccharin, action

Pseudo saccharin chloride (II) is prepared by the action of phosphorus penta-chloride upon saccharin (I) ... 

Finally, some amphiphilic sweeteners, eg, aspartame, saccharin, and neohesperidin dihydrochalcone, have been shown to be capable of stimulating a purified G-protein direcdy in an in vitro assay (136). This suggests some sweeteners may be able to cross the plasma membrane and stimulate the G-protein without first binding to a receptor. This type of action could explain the relatively longer response times and the lingering of taste associated with many high potency sweeteners. 

By the action of chlorine on saccharin. P. Bertolo and A. Bertolo, Gazz. chim. ital. 62, 487 (1932). 

The sweetening agent saccharin is also derived from a sulphonamide it is prepared from toluene-o-sulphonamide by oxidising the CHs-group to carboxyl with permanganate ring closure is subsequently brought about by the action of concentrated hydrochloric acid ... 

This benzilic acid type of rearrangement is the result of the action of alkali on the dicarbonyl compound, and is accelerated by calcium ions. The formation of saccharinic acids by the action of aqueous alkali on sugars is very well known 82,84,92 however, if ammonia is present, very little8 or no production of saccharinic acid has been reported. The reaction of the intermediate carbonyl compounds with ammonia is faster than the benzilic acid type of rearrangement to give saccharinic acid, and, hence, substituted imidazoles are formed, as illustrated in Scheme 9. 

Komoto detected lactic acid in the mixture from reaction of D-glucose with ammonia,4 and presumed that it was produced from pyruvaldehyde formed by decomposition of D-glucose. Lactic acid has, indeed, been found as a product of the action of alkali (lime-water) on substituted D-glucose and substituted D-fructose,81,83,96 and the mechanism of its formation involves the reversible aldol reaction, followed by formation of pyruvaldehyde, and the benzilic acid rearrangement already described for saccharinic acid this is illustrated83,96 in Scheme 11. 

V. Catalysts.—Electrolytic oxidation reactions are often facilitated by the presence of catalysts capable of existing in two valence stages examples of such oxygen carriers are cerium, chromium, manganese and vanadium ions. Their action is probably similar to that previously described for hydrogen carriers. These catalysts have been used to facilitate the oxidation of toluene to benzaldehyde or benzoic acid, of toluene sulfonamide to saccharin, and of anthracene to anthraquinone. 

Saccharin Proliferative changes in male rat bladder epithelium Considered to be species-specific with large doses used. Mechanism of action may involve urinary proteins not normally found in humans [23,40,47-49]... 

Earlier investigators of the alkaline-degradation products of lactose found succinic acid, formic acid, and a crystalline lactone, later identified by Kiliani as a -D-isosaccharinic lactone. This lactone was obtained in about 20% yield from the action of lime-water on lactose also detected as products of this reaction were D-galactose, lactic acid, pyruvaldehyde, formaldehyde, and other saccharinic acids. The... 

Shortly after the discovery of Peligot s a -D-glucosaccharin, Dubrun-faut reported that the calcium salt of a monobasic acid resulted from the action of lime-water on maltose. Cuisinier named the acid isosaccharinic acid, after he had prepared from it a crystalline lactone (CeHioOt) isomeric with Peligot s a -D-glucosaccharin. The name was expanded to a -D-iso-saccharinic acid after Nef obtained evidence of the concurrent formation of its epimer, /3 -D-isosaccharinic acid, in the hexose-alkali reaction. 

An experimental demonstration that the Nef mechanism for the initial conversion of a sugar by alkali to the a-dicarbonyl structure is not acceptable was provided by a study of the action of alkali on 2 hydroxy-3-meth-oxy-3-phenylpropiophenone. Nicolet observed that the products in this case are 2,3-diphenyllactic acid and methanol. This conversion, which is completely analogous to the formation of a saccharinic acid from a reducing sugar, demonstrated clearly that carbon-oxygen cleavage occurs at the /3-carbon atom, rather than at the a-carbon atom, with respect to the carbonyl group. 

The preceding explanation of the failure of a 2-0-substituted aldose to form saccharinic acids (on treatment with alkali) finds substantiation in the results of a study of the action of lime-water, at room temperature, on 2,3-di-O-methyl-D-glucose. The presence, in this latter reaction mixture, of an fl[,/3-unsaturated aldehyde(IV, R = CH3) was established by its further, facile conversion to 5-(hydroxymethyl)-2-furaldehyde upon acidification. 

Do these diverse compounds give rise to a common perception of sweetness or to qualitatively different sensations Sweetness does indeed appear to be a unitary percept (Breslin et al. 1994,1996). However, some sweeteners may be discriminable on the basis of their activation of other sensory transduction mechanisms or differences in the temporal properties of their sensory action. For example, the sweetener sodium saccharin activates bitter receptors in some people (Kuhn et al. 2004 Pronin et al. 2007), and also inhibits sweet taste at high concentrations (Galindo-Cuspinera et al. 2006). Sweet proteins such as thaumatin and monellin can have a slow onset or evoke a prolonged sweetness compared with sugars (Faus 2000), likely owing to a relatively high affinity for the sweet taste receptor. 

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