Boiling Points of Ternary Azeotropic Mixtures Modeled with the Use of the Universal Solvation Equation and Neural Networks

Azeotropic mixtures, an important class of technological fluids, constitute a challenge to theoretical modeling of their properties. The number of possible intermolecular interactions in multicomponent systems grows combinatorially as the number of components increases. Ab initio methods are barely applicable, because rather large clusters would need to be calculated, which is prohibitively time-consuming. The quantitative structure–property relationships (QSPR) method, which is efficient and extremely fast, could be a viable alternative approach, but the QSPR methodology requires adequate modification to provide a consistent treatment of multicomponent mixtures. We now report QSPR models for the prediction of normal boiling points of ternary azeotropic mixtures based on a training set of 78 published data points. A limited set of meticulously designed descriptors, together comprising the Universal Solvation Equation (<i>J. Chem. Inf. Model.</i> <b>2009</b>, <i>49</i>, 634), was used to provide input parameters for multiple regression and neural network models. The multiple regression model thus obtained is good for explanatory purposes, while the neural network model provides a better quality of fit, which is as high as 0.995 in terms of squared correlation coefficient. This model was also properly validated and analyzed in terms of parameter contributions and their nonlinearity characteristics

A General Treatment of Solubility. 2. QSPR Prediction of Free Energies of Solvation of Specified Solutes in Ranges of Solvents

Article on a general treatment of solubility and quantitative structure-property relationship (QSPR) prediction of free energies of solvation of specified solutes in ranges of solvents

A General Treatment of Solubility. 1. The QSPR Correlation of Solvation Free Energies of Single Solutes in Series of Solvents

Article on a general treatment of solubility and the quantitative structure-property relationship (QSPR) correlation of solvation free energies of single solutes in series of solvents

Sweet-Tasting Ionic Conjugates of Local Anesthetics and Vasoconstrictors

Local anesthetics are widely utilized in dentistry, cosmetology, and medicine. Local anesthesia is essential to providing a pain-free experience during dental and local surgeries as well as cosmetic procedures. However, the injection itself may produce discomfort and be a source of aversion. A novel approach toward the taste modulation of local anesthetics is proposed, in which the anesthetics of the “-caine” family serve as cations and are coupled with anionic sweeteners such as saccharinate and acesulfamate. Ionic conjugates of vasoconstrictor epinephrine such as epinephrine saccharinate and epinephrine acesulfamate have also been synthesized. Novel ionic conjugates were developed using anion exchange techniques. Reported compounds are sweet-tasting and are safe to use both topically and as injections

MFTA model: (a) molecular super-graph, (b) factor dynamics, and (c) fit plot.

<p>(a) The molecular supergraph is shown with two superimposed structures: DEET and <i>N</i>-cyclohexyl-<i>N</i>-ethyl-3-methylbutanamide (5m). The manner in which structures appear on MSG depends on how they can be superimposed onto the MSG as a whole. (b) The plot displays the change in correlation coefficient (R) and squared cross-validation coefficient (Q²) change as the number of factors changes. The best model is the one with the minimum possible number of factors and with R and Q² at their highest values.</p

Synthesis, Bioassay, and Molecular Field Topology Analysis of Diverse Vasodilatory Heterocycles

A diverse training set composed of 76 in-house synthesized and 61 collected from the literature was subjected to molecular field topology analysis. This resulted in a high-quality quantitative structure–activity relationships model (<i>R</i>² = 0.932, <i>Q</i>² = 0.809) which was used for the topological functional core identification and prediction of vasodilatory activity of 19 novel pyridinecarbonitriles, which turned out to be active in experimental bioassay

Chemical structures of 43 carboxamides.

<p>The most active compounds, with MED < 0.150 µmol/cm², are marked with squares; the least active compounds, with MED > 5 µmol/cm², are marked with circles.</p