scholarly journals Estimation of the retention behaviour of s-triazine derivatives applying multiple regression analysis of selected molecular descriptors

2013 ◽  
pp. 229-237 ◽  
Author(s):  
Lidija Jevric ◽  
Sanja Podunavac-Kuzmanovic ◽  
Strahinja Kovacevic ◽  
Natasa Kalajdzija ◽  
Bratislav Jovanovic

The estimation of retention factors by correlation equations with physico-chemical properties can be of great helpl in chromatographic studies. The retention factors were experimentally measured by RP-HPTLC on impregnated silica gel with paraffin oil using two-component solvent systems. The relationships between solute retention and modifier concentration were described by Snyder?s linear equation. A quantitative structure-retention relationship was developed for a series of s-triazine compounds by the multiple linear regression (MLR) analysis. The MLR procedure was used to model the relationships between the molecular descriptors and retention of s-triazine derivatives. The physicochemical molecular descriptors were calculated from the optimized structures. The physico-chemical properties were the lipophilicity (log P), connectivity indices (?), total energy (Et), water solubility (log W), dissociation constant (pKa), molar refractivity (MR), and Gibbs energy (GibbsE) of s-triazines. A high agreement between the experimental and predicted retention parameters was obtained when the dissociation constant and the hydrophilic-lipophilic balance were used as the molecular descriptors. The empirical equations may be successfully used for the prediction of the various chromatographic characteristics of substances, with a similar chemical structure.

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Adrian Beteringhe ◽  
Ana Cristina Radutiu ◽  
Titus Constantinescu ◽  
Luminita Patron ◽  
Alexandru T. Balaban

In a preceding study, the molecular hydrophobicity (RM0) was determined experimentally from reverse-phase thin-layer chromatography data for several substituted phenols and 2-(aryloxy-a-acetyl)-phenoxathiin derivatives, obtained from the corresponding phenoxides and 2-(a-bromoacetyl)-phenoxathiin. QSPR correlations for RM0 were explored using four calculated molecular descriptors: the water solubility parameter (log Sw), log P, the Gibbs energy of formation (DGf), and the aromaticity index (HOMA). Triparametric correlations do not improve substantially the biparametric correlation of RM0 in terms of log Sw and HOMA.


2013 ◽  
Vol 11 (2) ◽  
pp. 799-813 ◽  
Author(s):  
Cécile Raillard ◽  
Valérie Héquet ◽  
Bifen Gao ◽  
Heyok Choi ◽  
Dionysios D. Dionysiou ◽  
...  

Abstract The photocatalytic oxidation of seven typical indoor volatile organic compounds (VOCs) is experimentally investigated using novel nanocrystalline TiO2 dip-coated catalysts. Not only the role of hydrophilicity of the reactants but also other physico-chemical properties and molecular descriptors are studied and related to kinetic and equilibrium constants. The main objective of this work consists in establishing simple relationships that will be useful to deepen the understanding of gas-phase heterogeneous photocatalytic mechanisms and for the prediction of degradation rates of these VOCs using an indoor air treatment process.


Author(s):  
Adelina Ion ◽  
Mirela Praisler ◽  
Steluta Gosav

Molecular descriptors play a fundamental role in chemistry and pharmaceutical sciences, being defined as a way to transform molecules into a set of numbers, allowing the mathematical assessment of the chemical information characterizing a molecule. This study presents the usefulness of molecular descriptors for the determination of physico-chemical properties of a series of new hallucinogenic amphetamines. Molecular descriptors of these compounds was performed with the Dragon 5.5 software. The chemometric processing of the information allowed the determination of structural correlations (similarities) between this class of designer drugs and an unknown compound.


2011 ◽  
Vol 65 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Lidija Jevric ◽  
Bratislav Jovanovic ◽  
Sonja Velimirovic ◽  
Aleksandra Tepic ◽  
Gordana Koprivica ◽  
...  

Considerable attention has been paid to the analysis of chemicals in the s-triazine group, due to their widespread use in agricultural chemistry and their subsequent impact on biological systems. For initial chemical screening of the activity of newly synthesized compounds, it is recommended to determine their lipophilicity and physico-chemical property in relation to biological activity. Lipophilicity is difficult to quantify. The most widely accepted measure of lipophilicity is the octanol-water partition coefficient. Measurement of the octanol-water partition coefficients is achieved by an alternative method, i.e. reversed-phase liquid chromatography. Reversed-phase thin-layer chromatography (RP TLC) is a rapid method for the analysis of large number of s-triazine type compounds. Certain relationship between the structure of s-triazine compounds and their mobility on silica gel impregnated with paraffin oil have recently been demonstrated. The retention behavior of compounds in various chromatographic systems strongly depends on their physico-chemical properties. Recently, much effort was given in finding adequate mathematical model relating the retention of the given analyte to its physico-chemical and structural parameters (descriptors). These correlations are known as quantitative structure-retention relationships (QSRR), which offer a powerful tool for the prediction of separation behavior. The QSRR equations describing retention constants RM0, determined for different modifiers in mobile phase in terms of logarithms of n-octanol-water partition coefficients, were derived. The partition coefficients (AlogPs, AClogP, AB/logP, milogP, AlogP, MlogP, logPKowin, XlogP2, XlogP3, ACDlogP i ClogP) were calculated by application of different software packages. The goal of this paper was to select the logP data and TLC system that best characterize octanol/water partitioning and thus the lipophilicity of the investigated molecules.


2021 ◽  
Author(s):  
shuang han ◽  
Juan Hong ◽  
Qingwei Luo ◽  
Hanbing Xu ◽  
Haobo Tan ◽  
...  

<p>Hygroscopic properties of 23 organic compounds with different physico-chemical properties including carboxylic acids, amino acids, sugars and sugar alcohols were measured using a Hygroscopicity Tandem Differential Mobility Analyzer (HTDMA). We converted our experimental GF data of organics at 90% RH to κ to facilitate the comparison and we find that organic compounds with different molecular functionality present quite different hygroscopicity. Compounds with extra functional groups usually show higher hygroscopicity compared to their parental molecular compounds. Moreover, some compounds share the same molecular structure or functionality but vary differently in hygroscopicity. In general, the hygroscopicity of organics increase with functional groups in the following order: (-CH3/-NH2) < (-OH) < (-COOH/C=C/C=O). For highly soluble organics, the hygroscopicity decreases with molecular weight; while for slightly soluble organics which are not fully dissolved in aerosol droplets, their hygroscopicity can be divided into two categories. One is non-hygroscopic compounds, which may not fully deliquesce in the aerosol droplets. The other is moderate hygroscopic compounds, of which the hygroscopicity is mainly limited by their water solubility. Moreover, the hygroscopicity of organic compounds generally increased linearly with O:C ratios, although some of them have the same O:C ratio of but with different hygroscopicity. The experimental determined hygroscopicity are also compared with model predictions using the Extended Aerosol Inorganics Model (E-AIM) and the UManSysProp at 10-90% RH. Both models poorly represent the hygroscopic behavior of some organics, which may due to that the phase transition and intermolecular interactions are not considered in the simulations.</p>


2018 ◽  
Vol 4 (1) ◽  
pp. 19-30 ◽  
Author(s):  
F.G. Irungu ◽  
C.M. Mutungi ◽  
A.K. Faraj ◽  
H. Affognon ◽  
N. Kibet ◽  
...  

Fish farming is faced with the challenge of high cost of feeds because of the cost of high quality protein needed for formulation of the feeds. Thus, there is urgent need for alternative protein sources. The effects of substituting freshwater shrimp meal (FWSM) with black soldier fly larvae meal (BSFM) or adult cricket meal (ACM) on physico-chemical properties of hot-extruded fish feed pellets were investigated. The FWSM protein in a 26 g/100 g protein fish feed formulation was substituted at 0, 25, 50 and 75%, and moisture content of the formulated blends adjusted to 10, 20 or 30 g/100 g prior to extrusion. Floatability, expansion rate, bulk density, durability index, water absorption index, water solubility index, and water stability of extruded pellets were determined. Sinking velocity and the total suspended and dissolved solids in water were determined for the optimal pellets. Pellet floatability was not influenced by the type of insect meal but the interaction between level of inclusion and moisture content of the feed at extrusion. Pellets with high floatability >90% were produced from all feed blends at 30 g/100 g moisture content. Expansion ratio, was not influenced by type of insect meal or the level of inclusion but by the moisture content whereby feed blends extruded at 30 g/100 g moisture gave pellets with high expansion ratio ~60%. Bulk density was influenced by the interaction of the three factors. Pellet durability and water absorption indices were not influenced by the investigated factors or their interactions. Processed pellets were generally highly durable (99%) out of water, but the stability in water was significantly influenced by the interaction of type of insect meal level of inclusion and moisture content at extrusion. Water solubility increased with increasing extrusion moisture. Overall, it was possible to process good quality extruded pellets with 75% BSFM or 75% ACM at 30 g/100 g feed moisture.


2014 ◽  
Vol 61 (2) ◽  
pp. 49-54
Author(s):  
M. Stankovičová ◽  
Ž. Bezáková ◽  
P. Mokrý ◽  
P. Salát ◽  
M. Kočík ◽  
...  

Abstract The aim of this paper is the study of physico-chemical properties of the chosen compounds, derivatives of 2-hydroxy-3-[2-(4-methoxyphenyl) ethylamino]propyl-4-[(alkoxycarbonyl)amino]benzoates and 2-hydroxy-3-[2-(2-methoxyphenyl)ethylamino]propyl-4-[(alkoxycarbonyl) amino]benzoates with potential ultra-short beta-adrenolytic activity. The studied compounds are different in the position of the substituent on the benzene ring in the side chain as well as in the aromatic ring in position 4 with alkyl- (methylto butyl-) carbamate. The physico-chemical characteristics, for example, lipophilicity, surface activity, adsorbability, acidobasic properties etc., are very important for the explanation of the relationship between structure and biological activity of the drug. These parameters serve as the base of quantitative structure-activity study. The goal of this work is to establish the spectral characteristics of studied compounds in UV-area, pKa values, the parameters of lipophilicity (the values of Rf and RM from thin layer chromatography, retention time t´R and capacity factor k´ from liquid chromatography and experimental partition coefficients log P´ values), surface tension, critical micelle concentrations, the adsorbability of compounds expressed by percent of adsorbed compound on active charcoal β% as well as by Freundlich adsorption isotherms. The obtained values are correlated with the parameters characterising the size of molecule, for example, the number of carbon atoms on carbamate functional group.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1824
Author(s):  
Katia Rubini ◽  
Elisa Boanini ◽  
Silvia Parmeggiani ◽  
Adriana Bigi

In this paper we used curcumin as a functionalizing agent of gelatin films with the aim to get antioxidant materials with modulated physico-chemical properties. To this aim, we prepared gelatin films at different contents of curcumin up to about 1.2 wt%. The as-prepared films, as well as glutaraldehyde crosslinked films, were submitted to several tests: swelling, water solubility, differential scanning calorimetry, X-ray diffraction, mechanical tests and curcumin release. The radical scavenging activity of the as-prepared films is similar to that of free curcumin, indicating remarkable antioxidant properties. All the other tested properties vary as a function of curcumin content and/or the presence of the crosslinking agent. In particular, the films exhibit sustained curcumin release in different solvents. Thanks to its biocompatibility, biodegradability and lack of antigenicity, gelatin uses span from food processing to packaging and biomaterials. It follows that the modulated properties exhibited by the functionalized materials developed in this work can be usefully employed in different application fields.


2013 ◽  
Vol 22 (1) ◽  
pp. 33-40
Author(s):  
ZOITA-MARIOARA BERINDE ◽  

The molecular hydrophobicity (RMO) of several newly synthesized phenoxathiin derivatives and of phenols with congeneric structures have been recently correlated with some simple physico-chemical calculated parameters of compounds: the water solubility (log Sw); the partition coefficient (log P); the Gibbs energy of formation (∆Gf ), and the aromaticity index (HOMA) [Beteringhe, A., Radutiu, A. C., Constantinescu, T., Patron, L. and Balaban, A. T., Quantitative Structure-Property Relationship (QSPR) study of the hydrophobicity of phenols and 2-(aryloxy-α-acetyl)- phenoxathiin derivatives, Rev. Chim. (Bucures¸ti) , 59 (2008), No. 11, 1175–1179]. The best correlation was found as a biparametric regression equation in terms of log Sw and HOMA, which cannot be improved by adding one or two of the parameters aforementioned. In the present work we describee the weighted electronic distance based topological index (ZEP) and then use it for QSPR studies of RMO in combination with log Sw, log P, ∆Gf and HOMA. Most of the three parameter QSPR correlations of RMO are significantly improved by involving the theoretical parameter ZEP.


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