Capillary Gas-Chromatographic Retention Behavior and Physico-Chemical Properties of Underivatized Equine Estrogens

1995 ◽  
Vol 60 (5) ◽  
pp. 813-819 ◽  
Author(s):  
Jasmina Novakovic ◽  
Eva Tvrzická ◽  
Václav Všetečka ◽  
Vladimír Pouzar ◽  
Ladislav Feltl
Keyword(s):  
Dipole Moments ◽  
Chemical Properties ◽  
Retention Indices ◽  
Chromatographic Retention ◽  
Retention Behavior ◽  
Kováts Retention Indices ◽  
Physico Chemical ◽  
In Series ◽  
Mixed Stationary Phase ◽  
Equine Estrogens

The capillary gas-chromatographic retention behavior of six underivatized equine estrogens (estrone, equilin, equilenin and their corresponding 17α-diols) on a mixed stationary phase (non-polar CP-Sil 5 CB and slightly polar CP-Sil 19 CB capillary columns coupled in series) was characterized by their Kovats retention indices and steroid numbers. In order to find whether a correlation exists between the chromatographic retention and some physico-chemical properties of the compounds, their octanol-water partition coefficients and dipole moments were measured. No straightforward correlation was observed between the physico-chemical properties and the retention behavior, which suggests that the GC separation of equine estrogens is governed by some specific electron donor-electron acceptor interactions of a chemical nature.

scholarly journals Congener-specific partition properties of chlorinated paraffins evaluated with COSMOtherm and gas chromatographic retention indices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jort Hammer ◽  
Hidenori Matsukami ◽  
Satoshi Endo
Keyword(s):  
Chemical Properties ◽  
High Volume ◽  
Retention Indices ◽  
Chromatographic Retention ◽  
Linear Free Energy Relationship ◽  
Linear Free Energy ◽  
Chlorinated Paraffins ◽  
Gas Chromatographic Retention Indices ◽  
High Volume Production ◽  
Volume Production

AbstractChlorinated Paraffins (CPs) are high volume production chemicals and have been found in various organisms including humans and in environmental samples from remote regions. It is thus of great importance to understand the physical–chemical properties of CPs. In this study, gas chromatographic (GC) retention indexes (RIs) of 25 CP congeners were measured on various polar and nonpolar columns to investigate the relationships between the molecular structure and the partition properties. Retention measurements show that analytical standards of individual CPs often contain several stereoisomers. RI values show that chlorination pattern have a large influence on the polarity of CPs. Single Cl substitutions (–CHCl–, –CH2Cl) generally increase polarity of CPs. However, many consecutive –CHCl– units (e.g., 1,2,3,4,5,6-C11Cl6) increase polarity less than expected from the total number of –CHCl– units. Polyparameter linear free energy relationship descriptors show that polarity difference between CP congeners can be explained by the H-bond donating properties of CPs. RI values of CP congeners were predicted using the quantum chemically based prediction tool COSMOthermX. Predicted RI values correlate well with the experimental data (R2, 0.975–0.995), indicating that COSMOthermX can be used to accurately predict the retention of CP congeners on GC columns.

scholarly journals Application of lipophilicity parameters in QSRR analysis of newly synthesized s-triazine derivatives: Prediction of the retention behavior

2011 ◽  
Vol 65 (5) ◽  
pp. 533-540 ◽  
Author(s):  
Lidija Jevric ◽  
Bratislav Jovanovic ◽  
Sonja Velimirovic ◽  
Aleksandra Tepic ◽  
Gordana Koprivica ◽  
...  
Keyword(s):  
Partition Coefficients ◽  
Structural Parameters ◽  
Chemical Properties ◽  
Reversed Phase ◽  
Retention Behavior ◽  
Chemical Screening ◽  
Physico Chemical ◽  
Agricultural Chemistry ◽  
Triazine Derivatives ◽  
Coefficient Measurement

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.

scholarly journals Congener-Specific Partition Properties of Chlorinated Paraffins Evaluated with COSMOtherm and Gas Chromatographic Retention Indices

2020 ◽  
Author(s):  
Jort Hammer ◽  
Hidenori Matsukami ◽  
Satoshi Endo
Keyword(s):  
Chemical Properties ◽  
High Volume ◽  
Retention Indices ◽  
Chromatographic Retention ◽  
Linear Free Energy Relationship ◽  
Linear Free Energy ◽  
Chlorinated Paraffins ◽  
Gas Chromatographic Retention Indices ◽  
High Volume Production ◽  
Volume Production

<p>Chlorinated Paraffins (CPs) are high volume production chemicals and have been found in various organisms including humans and in environmental samples from remote regions. It is thus of great importance to understand the physical-chemical properties of CPs. In this study, gas chromatographic (GC) retention indexes (RIs) of 26 CP congeners were measured on various polar and nonpolar columns to investigate the relationships between the molecular structure and the partition properties. Retention measurements show that analytical standards of individual CPs often contain several stereoisomers. RI values show that chlorination pattern have a large influence on the polarity of CPs. Single Cl substitutions (-CHCl-, -CH<sub>2</sub>Cl) generally increase polarity of CPs. However, many consecutive -CHCl- units (e.g., 1,2,3,4,5,6-C<sub>11</sub>Cl<sub>6</sub>) increase polarity less than expected from the total number of -CHCl- units. Polyparameter linear free energy relationship descriptors show that polarity difference between CP congeners can be explained by the H-bond donating properties of CPs. RI values of CP congeners were predicted using the quantum chemically based prediction tool COSMO<i>thermX</i>. Predicted RI values correlate well with the experimental data (R<sup>2</sup>, 0.975–0.995), indicating that COSMO<i>thermX</i> can be used to accurately predict the retention of CP congeners on GC columns. </p>

Electro-Optical Parameters of Some Benzene Derivatives obtained by Molecular Orbital Calculations

2008 ◽  
Vol 59 (2) ◽  
pp. 216-219 ◽  
Author(s):  
Mihaela Dimitriu ◽  
Liliana-Mihaela Ivan ◽  
Dana-Ortansa Dorohoi
Keyword(s):  
Dipole Moments ◽  
Chemical Properties ◽  
Valence Vibration ◽  
Oscillator Strengths ◽  
Molecular Orbital Calculations ◽  
Optical Parameters ◽  
Covalent Bonds ◽  
Physico Chemical ◽  
Hyperchem Software ◽  
Derivatives Of

A series of structural and physico � chemical properties of some monosubstituted halogene � derivatives of benzene were analyzed by using HyperChem software package. The bond lengths, the angle between the covalent bonds, atomic charges, the symmetry class, the energies of the ground and excited states, the dipole moments, the polarizabilities, the wavelengths of the electronic transitions and the corresponding oscillator strengths have been obtained and correlated with experimental data published for the studied compounds. The computed molecular polarizability a is directly correlated with the measured halogene atomic electronegativity. A polynomial dependence of order two was evidenced between the valence vibration wavenumber of C-X bond, experimentally determined and the computed polarizability.

scholarly journals 6-Hydroxyisocaryophyllene and isocaryophyllenic acid from birches vegetative buds

2018 ◽  
pp. 115-122
Author(s):  
Dmitriy Nikolaevich Vedernikov ◽  
Svetlana Vitalievna Teplyakova ◽  
Olesya Valerievna Khoroshilova
Keyword(s):  
Betula Pendula ◽  
Retention Indices ◽  
Chromatographic Retention ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nmr Data ◽  
Vegetative Buds ◽  
Physico Chemical ◽  
Gas Chromatographic Retention Indices ◽  
Chromatographic Retention Indices

The new isocaryophyllene derivatives were first detected in the birch vegetative buds. The structure of 6-hydroxyisocaryophyllene [(1R,4Z, 6R, 9S)-8-methylene-11,11-dimethylbicyclo[7.2.0]undec-4-ene-6-ol] isolated from the Betula pendula Roth. birch buds was determined by NMR spectroscopy.  The structures of caryophyllenic acid and isocaryphyllenic acid isolated from the Betula grandifolia Litv., B. albo-sinensis Burk., B. fusca Pall.ex Georg, B. obscura A. Kotula, B. litwinowii Doluch., B. hallii Howell, B. grandifolia Litv. birch buds was determined by X-ray diffraction analysis. The physico-chemical characteristics and NMR data of 6-hydroxyisocaryophyllene, epoxide of 6-hydroxyisocaryophyllene and all the isolated acids are given.  The gas chromatographic retention indices of all identified compounds were determined.

scholarly journals Congener-Specific Partition Properties of Chlorinated Paraffins Evaluated with COSMOtherm and Gas Chromatographic Retention Indices

2020 ◽  
Author(s):  
Jort Hammer ◽  
Hidenori Matsukami ◽  
Satoshi Endo
Keyword(s):  
Chemical Properties ◽  
High Volume ◽  
Retention Indices ◽  
Chromatographic Retention ◽  
Linear Free Energy Relationship ◽  
Linear Free Energy ◽  
Chlorinated Paraffins ◽  
Gas Chromatographic Retention Indices ◽  
High Volume Production ◽  
Volume Production

<p>Chlorinated Paraffins (CPs) are high volume production chemicals and have been found in various organisms including humans and in environmental samples from remote regions. It is thus of great importance to understand the physical-chemical properties of CPs. In this study, gas chromatographic (GC) retention indexes (RIs) of 26 CP congeners were measured on various polar and nonpolar columns to investigate the relationships between the molecular structure and the partition properties. Retention measurements show that analytical standards of individual CPs often contain several stereoisomers. RI values show that chlorination pattern have a large influence on the polarity of CPs. Single Cl substitutions (-CHCl-, -CH<sub>2</sub>Cl) generally increase polarity of CPs. However, many consecutive -CHCl- units (e.g., 1,2,3,4,5,6-C<sub>11</sub>Cl<sub>6</sub>) increase polarity less than expected from the total number of -CHCl- units. Polyparameter linear free energy relationship descriptors show that polarity difference between CP congeners can be explained by the H-bond donating properties of CPs. RI values of CP congeners were predicted using the quantum chemically based prediction tool COSMO<i>thermX</i>. Predicted RI values correlate well with the experimental data (R<sup>2</sup>, 0.975–0.995), indicating that COSMO<i>thermX</i> can be used to accurately predict the retention of CP congeners on GC columns. </p>

A new approach to the prediction of gas chromatographic retention indices from physico-chemical constants

1991 ◽  
Vol 56 (10) ◽  
pp. 2042-2054 ◽  
Author(s):  
Igor G. Zenkevich ◽  
Lyudmila M. Kuznetsova
Keyword(s):  
Molecular Weight ◽  
Stationary Phases ◽  
Retention Indices ◽  
Molar Refraction ◽  
Boiling Temperature ◽  
Chromatographic Retention ◽  
New Approach ◽  
Physico Chemical ◽  
Gas Chromatographic Retention Indices ◽  
Chromatographic Retention Indices

A general approach is proposed to the calculation of gas chromatographic retention indices (RI) of organic compounds on standard polydimethylsiloxane stationary phases based on their principal physico-chemical constants such as the boiling temperature, molar refraction or molecular weight. A combination of logical criteria was established for comparing functions of the above parameters for the identification of substances whose RI values are only determined by their boiling temperatures. It is demonstrated that within homologous series, the dependence of the RI value on the boiling temperature or any additive molecular parameter (molecular weight, molar refraction, number of carbon atoms in the molecule, etc.) is nonlinear. If this dependence is taken into account, the RI value of any organic compound can be predicted with a precision comparable to the standard deviation of the statistically processed values determined in nonequivalent conditions.

scholarly journals p-COUMARATES OF BETULA PENDULA (BETULACEAE) VEGETATIVE BUDS SESQUITERPENE ALCOHOLS

2020 ◽  
pp. 127-132
Author(s):  
Dmitriy Nikolaevich Vedernikov ◽  
Elizaveta Mihailovna Ipanova
Keyword(s):  
Antimicrobial Activity ◽  
Betula Pendula ◽  
Retention Indices ◽  
Methyl Tert Butyl Ether ◽  
Chromatographic Retention ◽  
Klebsiella Pneumonia ◽  
Alcoholic Extract ◽  
Butyl Ether ◽  
Vegetative Buds ◽  
Physico Chemical

The composition of coumarates sesquiterpene alcohols of Betula pendula Roth. birch vegetative buds was determined. Fraction was isolated from buds extract by preparative liquid chromatography. The extract was isolated by sequential extraction of an alcoholic extract of the buds with methyl tert-butyl ether. The new sesquiterpene derivatives were first detected in the birch vegetative buds. The structure of 6-hydroxyisocaryophyllene [(1R,4Z,6R,9S)-8-methylene-11,11-dimethylbicyclo[7.2.0]undec-4-ene-6-ol] trans-p-coumarate isolated from the birch buds was determined by NMR spectroscopy. The physico-chemical characteristics and NMR data of 6-hydroxyisocaryophyllene p-coumarate and others coumarates are demonstrated. The gas chromatographic retention indices of all identified compounds were determined. Birch buds contain derivatives of trans-coumaric acid. The antimicrobial activity of sesquiterpene alcohols coumarates was evaluated. The antimicrobial activity of sesquiterpene alcohols coumarates in relation to the following microorganisms: Escherichia coli, Proteus mirabilis, Staphylococcus aureus, Staphylococcus pneumonia and Klebsiella pneumonia was evaluated. The fraction of sesquiterpene alcohols coumarates showed activity against Staphylococcus epidermidis.

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