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1.
Food Chem ; 305: 125457, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505414

RESUMO

Taking into account a growing market and small number of articles related to honeydew honey, a metabolomic approach associated with multivariate analysis and modelling was proposed to discriminate five varieties of honey. Advanced analytical techniques were used for determination of 20 elements, 14 carbohydrates and stable carbon isotope ratio. No chemical marker has been found within sugar compounds, but several elements (Ba, Ca, Mg, Sr, Mn, Al, Co, Ni, Se) were marked as characteristic of honey type and allow classification of three botanical origins (Abies alba, Quercus frainetto, Quercus ilex). Sugars turanose, trehalose, arabinose and raffinose, elements Ba, Sr, P, Cd and Se, and δ13C values of honey, have different concentrations in honeys of the same botanical origin but harvested in different season. In addition to a confirmation of authenticity in terms of production, the values of δ13C of protein could be a good indicator of botanical origin.

2.
ScientificWorldJournal ; 2014: 862796, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24587761

RESUMO

The lipophilicity of ten ruthenium(II)-arene complexes was assessed by reversed-phase thin-layer chromatography (RP-TLC) on octadecyl silica stationary phase. The binary solvent systems composed of water and acetonitrile were used as mobile phase in order to determine chromatographic descriptors for lipophilicity estimation. Octanol-water partition coefficient, logK(OW), of tested complexes was experimentally determined using twenty-eight standard solutes which were analyzed under the same chromatographic conditions as target substances. In addition, ab initio density functional theory (DFT) computational approach was employed to calculate logK(OW) values from the differences in Gibbs' free solvation energies of the solute transfer from n-octanol to water. A good overall agreement between DFT calculated and experimentally determined logK(OW) values was established (R(2) = 0.8024-0.9658).


Assuntos
Complexos de Coordenação/química , Modelos Químicos , Piridinas/química , Compostos de Rutênio/química , Cromatografia em Camada Delgada , Complexos de Coordenação/síntese química , Interações Hidrofóbicas e Hidrofílicas , Octanóis/química , Piridinas/síntese química , Solventes
3.
J Sep Sci ; 34(19): 2659-67, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21805630

RESUMO

Both quantitative structure-retention (QSRR) and quantitative structure-activity relationship (QSAR) studies have been performed to correlate the molecular characteristics of seven pairs of cis-trans isomeric bis-steroidal tetraoxanes with their reversed-phase thin-layer chromatography (RPTLC) retention as well as with their antiproliferative activity. 2D and 3D molecular descriptors as whole molecule representations together with retention parameters as well as with biological activity data were subjected to the multivariate statistical analysis (principal component analysis--PCA and hierarchical cluster analysis--HCA) in order to determine the most influential factors governing the retention and activity against human cervix carcinoma (HeLa) and human malignant melanoma (Fem-X) cell lines. Both QSRR and QSAR models were built by means of the partial least-squares (PLS) statistical method. It was found that hydrogen bond donating (HBD), hydrogen bond accepting (HBAcc), hydrophilic surface percentage (%HS) and hydrophilic-lipophilic balance (HLB) exhibit the strongest influence on retention. The most prominent factors affecting antiproliferative activity of the investigated substances are those relating to the size and shape of a molecule such as: connectivity indices, refractivity (Ref), surface area (SA), molecular volume and weight, polarizability (Pol) and those regarding the ability of hydrogen bonding (HB).


Assuntos
Antineoplásicos/química , Ácido Cólico/química , Tetraoxanos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ácido Cólico/farmacologia , Cromatografia em Camada Delgada , Humanos , Isomerismo , Estrutura Molecular , Relação Quantitativa Estrutura-Atividade , Tetraoxanos/farmacologia
4.
Chemosphere ; 81(3): 299-305, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20709353

RESUMO

In order to determine the soil-water partition coefficient for eleven mono- and poly-substituted phenolic compounds, for which there is still no literature data available, the possibility of using thin-layer chromatography (TLC) as a means for rapid and reliable logK(OC) estimation was examined. A series of chromatographically derived descriptors: R(M)(0), b, C(0) and PC1 (first principal component), calculated from retention data obtained under reversed-phase conditions, were used for the assessment of models as well as for a direct calibration procedure. The final calibration models are discussed with regard to the achieved accuracy and statistical quality, the type of descriptors used and the corresponding chromatographic conditions. The estimated logK(OC) values of the studied phenols were compared with those obtained by other means: (a) the present OECD guideline based on an HPLC technique; (b) the KOCWIN software package, available free of charge from the US Environmental Protection Agency web site and (c) general LSER models established by Nguyen and coworkers, and Poole and coworkers. The proposed method showed the best agreement with the results obtained by the OECD procedure, followed by the LSER models of Poole and Nguyen. Lower quality correlations were achieved with the KOCWIN calculated values, especially those predicted by molecular connectivity indices.


Assuntos
Fenóis/análise , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Cromatografia em Camada Delgada , Modelos Químicos , Fenóis/química , Fenóis/normas , Poluentes do Solo/química , Poluentes do Solo/normas , Poluentes Químicos da Água/química , Poluentes Químicos da Água/normas
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