5-Nitroanilines sweetness

Deutsch and Hansch applied this principle to the sweet taste of the 2-substituted 5-nitroanilines. Using the data available (see Table VII), the calculated regression Eqs. 5-7 (using the method of least squares) optimally expressed the relationship between relative sweetness (RS), the Hammett constant, cr, and the hydrophobic-bonding constant, ir. 

Further studies of the 2-substituted 5-nitroanilines, conducted by Kier and coworkers, searched for a linear combination of structural variables that describes a line, plane, or surface that separates the molecule classes in the optimum manner. They found that sweetness correlated very well with the substituent polarizability-constants for the 2-substituent, implicating the involvement of the 2-substituents in dispersive-binding interactions at the receptor. This is in agreement with the results of Hansch " and McFarland. The correlation equation was not, however, reported. 

Tinti and coworkers compared the sweetness of the derivatives of 2-propoxy-5-nitroanilines in which the nitro group was replaced by a CN or a CO J substituent. They found that the cyano derivative is sweet (although the sweetness is only one-third that of the nitro derivative), whereas the carboxyl derivative is not this seemed to suggest that the nitro group may not be the B unit of the AH,B system, as assigned by both Shallenberger... 

The binding specificity of d-[ C]glucose by the taste-papillae membranes, compared to that of control membranes isolated from epithelial tissue, has been confirmed in two studies. One inherent problem in the approach is that the stimuli, primarily carbohydrate sweeteners, are not ideal model compounds to use, as they are not active at low concentrations and do not show sufficiently high binding-constants. The use of other stimulus compounds that are at least several hundred times sweeter than sucrose, such as saccharin, dihydrochalcone sweeteners, dipeptide sweeteners, stevioside, perillartine and other sweet oximes, the 2-substituted 5-nitroanilines, and... 

Hemker was one of the first to attempt the quantitative correlation of biochemical response using both partition coefficients and ionization constants to account for the uncoupling action of phenols. The linear combination of it and o has been found to hold for several enzymic reactions > as well as the binding of phenols by protein , the toxicity of phenols , the uncoupling action of phenols , and the relative sweetness of nitroanilines . An interesting application is that of McMahon . Equation 14 was formulated for the enzymic reduction of aromatic ketones to alcohols. 

From analysis of third sites for different sweeteners, inter-class relationships have been developed by a Dutch group for the sweet classes oximes, nitroanilines, sulphamates, dipeptides and isocoumarins104. 

Properties Yel. needle-like cryst. burning sweet odor mod. sol. in ethanol, diethyl ether, methanol, acetone si. sol. in oxygenated soivs. insol. in water m.w. 138.12 dens. 1.43 (20 C) m.p. 112-114 C b.p. 306 C (dec.) flash pt. 199 C Toxicology LD50 (oral, rat) 535 mg/kg LDLo (IP, dog) 70 mg/kg poison by ing. and IP routes toxic absorbed thru skin may cause methemoglobinemia cyanosis on acute exposure chronic exposure may cause liver damage mutagenic data TSCA listed Precaution Flamm. mod. fire risk dec. exothermically 247 C possible explosive reaction with ethylene oxide 130 C Hazardous Decomp. Prods. CO, CO2, NOx Uses Dyestuff intermediate Manuf./Distrib. Aceto http //www.aceto.com, Alchemie USA o-Nitroaniline... 

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