Márcia Miguel Castro Ferreira | Universidade Estadual de Campinas (original) (raw)

Papers by Márcia Miguel Castro Ferreira

Journal of the Brazilian Chemical Society, 2018

In the present investigation, a collection of twenty two nerol derivatives, containing 1,2,3-tria... more In the present investigation, a collection of twenty two nerol derivatives, containing 1,2,3-triazolic appendages, was synthesized and screened in vitro for their cytotoxic activity against HL60, Nalm6, and Jurkat human leukemia cells as well as against B16F10 (melanoma cell line). In most cases, derivatives were able to reduce cell viability. The most potent compound (Z)-4-(((3,7-dimethylocta-2,6-dien-1-yl)oxy)methyl)-1-(4-(trifluoromethoxy)benzyl)-1H-1,2,3 triazole showed antiproliferative activity against Jurkat cells and reduced B16F10 cell migration. Physicochemical properties of the compounds were calculated in order to evaluate their potential for drug development. Most of the evaluated physicochemical parameters seemed to be favorable for drug development. In addition, for a better understanding of the biological activity results, 3D quantitative structure-activity relationship (QSAR) studies were carried out. 3D-QSAR studies indicate that the anticancer activities observed for the cell lines HL60 and Jurkat may occur by a similar mechanism of action and the same was found for the Nalm6 and B16F10 cell lines.

Omics : a journal of integrative biology, Jan 14, 2015

Excessive body fat and obesity have adverse health effects and result in significant morbidity su... more Excessive body fat and obesity have adverse health effects and result in significant morbidity such as type 2 diabetes mellitus. The health burden of obesity can be reduced with the Roux-en-Y gastric bypass (RYGB) weight-loss bariatric surgery. Little is known on the molecular changes that occur at the metabolome level before and after bariatric surgery, with a view to clinical biomarker development. Hence, we employed a metabolomics approach in 10 obese diabetic patients who underwent bariatric surgery. Metabolomics data were obtained by T2- and diffusion-edited hydrogen nuclear magnetic resonance ((1)H NMR) spectra to monitor the metabolic and lipoprotein profiles, and gas chromatography-mass spectrometry (CG-MS) to access the fatty acid profile before and 12 months after RYGB. Using hierarchical partial least squares discriminant analysis, we found that RYGB induces several key metabolic alterations associated with glucose homeostasis, as well as fatty acid and amino acid metabol...

Journal of the Chemical Society, Perkin Transactions 2, 2001

Talanta, 2011

Mathematical models based on chemometric analyses of the coffee beverage sensory data and NIR spe... more Mathematical models based on chemometric analyses of the coffee beverage sensory data and NIR spectra of 51 Arabica roasted coffee samples were generated aiming to predict the scores of acidity, bitterness, flavour, cleanliness, body and overall quality of coffee beverage. Partial least squares (PLS) were used to construct the models. The ordered predictor selection (OPS) algorithm was applied to select the wavelengths for the regression model of each sensory attribute in order to take only significant regions into account. The regions of the spectrum defined as important for sensory quality were closely related to the NIR spectra of pure caffeine, trigonelline, 5-caffeoylquinic acid, cellulose, coffee lipids, sucrose and casein. The NIR analyses sustained that the relationship between the sensory characteristics of the beverage and the chemical composition of the roasted grain were as listed below: 1-the lipids and proteins were closely related to the attribute body; 2-the caffeine and chlorogenic acids were related to bitterness; 3-the chlorogenic acids were related to acidity and flavour; 4-the cleanliness and overall quality were related to caffeine, trigonelline, chlorogenic acid, polysaccharides, sucrose and protein.

Química Nova, 2007

Recebido em 22/8/05; aceito em 25/4/06; publicado na web em 30/8/06 THEORETICAL STUDY OF THE INTE... more Recebido em 22/8/05; aceito em 25/4/06; publicado na web em 30/8/06 THEORETICAL STUDY OF THE INTERACTION BETWEEN ARTEMISININ AND HEME. The purpose of this work is to study theoretically stereoelectronic aspects of the interaction between heme and artemisinin in the transitional heme-artemisinin complex. Through semi-empirical calculations using the PM3 method, the potential energy barrier of artemisinin rotation relative to heme in the heme-artemisinin complex was studied in vacuum and in the partially solvated state. The minimum heat of formation obtained for the complex with and without water molecules is-702.39 and-100.86 kcal mol-1 , respectively, which corresponds to the dihedral angle C-Fe-O1-O2 of 43.93º and 51.90º around the iron-oxygen O1 bond, respectively. The water molecules bind to heme via 13 hydrogen bonds and O-H•••O and 6 C-H•••O interactions, which accounts for-67.23 kcal mol-1. It is observed that the inclusion of water molecules does not affect significantly the stability of the heme-artemisinin complex.

Química Nova, 2003

A STUDY OF OCTANOL/WATER PARTITION COEFFICIENT OF POLYCHLORINATED BIPHENYLS (PCBs) USING TOPOLOGI... more A STUDY OF OCTANOL/WATER PARTITION COEFFICIENT OF POLYCHLORINATED BIPHENYLS (PCBs) USING TOPOLOGICAL INDICES. A model based on chemical structure was developed for the accurate prediction of octanol/water partition coefficient (K OW) of polychlorinated biphenyls (PCBs), which are molecules of environmental interest. Partial least squares (PLS) was used to build the regression model. Topological indices were used as molecular descriptors. Variable selection was performed by Hierarchical Cluster Analysis (HCA). In the modeling process, the experimental K OW measured for 30 PCBs by thin-layer chromatography-retention time (TLC-RT) has been used. The developed model (Q 2 = 0,990 and r 2 = 0,994) was used to estimate the log K OW values for the 179 PCB congeners whose K OW data have not yet been measured by TLC-RT method. The results showed that topological indices can be very useful to predict the K OW.

Química Nova, 2013

QSAR modeling is a novel computer program developed to generate and validate QSAR or QSPR (quanti... more QSAR modeling is a novel computer program developed to generate and validate QSAR or QSPR (quantitative structure-activity or property relationships) models. With QSAR modeling, users can build partial least squares (PLS) regression models, perform variable selection with the ordered predictors selection (OPS) algorithm, and validate models by using y-randomization and leave-N-out cross validation. An additional new feature is outlier detection carried out by simultaneous comparison of sample leverage with the respective Studentized residuals. The program was developed using Java version 6, and runs on any operating system that supports Java Runtime Environment version 6. The use of the program is illustrated. This program is available for download at lqta. iqm.unicamp.br.

LWT - Food Science and Technology, 2009

This work describes using 1 H NMR data and pattern recognition analysis to classify vinegars. Vin... more This work describes using 1 H NMR data and pattern recognition analysis to classify vinegars. Vinegar authenticity is linked to raw ingredient source and manufacturing conditions. Application of PCA and HCA methods resulted in the natural clustering of the samples according to the raw material used. Wine vinegars were characterized by a high concentration of ethyl acetate, glycerol, methanol and tartaric acid, while glycerol and ethyl acetate signals were not visible in alcohol/agrin vinegars. Apple vinegars showed to be richer in alanine. The KNN, SIMCA and PLS-DA methods were used to build predictive models for classification of vinegar type wine, apple and alcohol/agrin (27 samples-22 as training set). The models were tested using an independent set (5 samples), no samples were wrongly classified. Validated models were used to predict the class of 21 commercial samples, which, as expected, were correctly classified. Eight commercial vinegars (honey, orange, pineapple and rice) were discriminated from these samples using PCA method. Honey vinegars did not present ethanol signals and pineapple vinegars presented the largest amount of tartaric acid. Rice and orange vinegars are richer in lactic acid and did not present the methanol signal. Alanine signals were not visible in orange vinegars.

Journal of Wood Chemistry and Technology, 2005

Journal of the Brazilian Chemical Society, 2002

Neste trabalho, são apresentadas as técnicas usuais de quimiometria em estudos de relações quanti... more Neste trabalho, são apresentadas as técnicas usuais de quimiometria em estudos de relações quantitativas estrutura-atividade biológica (QSAR). Elas são introduzidas em ordem cronológica, iniciando pela análise de Hansch, e os métodos de análise exploratória de componentes principais e agrupamento hierárquico (PCA e HCA). Os métodos de regressão que usam a análise de componentes principais como fundamento (PCR e PLS) são apresentados a seguir. São introduzidos também os dois métodos de reconhecimento de padrões usados para classificação (KNN e SIMCA). Diferentes aplicações são usadas para ilustrar os diferentes métodos quimiométricos. É feito então um resumo da metodologia de regressão usada em QSAR-3D. Finalmente é apresentada uma nova metodologia, denominada PLS multilinear, já utilizada em química analítica, mas não explorada ainda pela comunidade de QSAR. Este método de regressão mantém a estrutura de ordem superior dos dados em lugar do desdobramento utilizado em QSAR-3D e apresenta vantagens computacionais, maior estabilidade e simplicidade do modelo, uma vez que o número de parâmetros calculados é bastante reduzido. In this work, the chemometric techniques most frequently used in QSAR (quantitative structureactivity relationships) studies are reviewed. They are introduced in chronological order, beginning with Hansch analysis and the exploratory data analysis methods of principal components and hierarchical clustering (PCA and HCA). Principal component regression and partial least squares regression methods (PCR and PLS) are discussed, followed by the pattern recognition methods (KNN and SIMCA). Different applications are presented to illustrate these chemometric techniques. The methodology used for regression in 3D-QSAR is presented (unfolding PLS). Finally, the higher order method called Multilinear PLS, already used in analytical chemistry but not yet explored by the QSAR community, is introduced. This method maintains the multiway structure of the data and has several advantages over bilinear PLS including speed in calculation, simplicity and stability, since the number of parameters to be estimated can be greatly reduced.

Journal of Molecular Graphics and Modelling, 2002

Structure-activity relationships (SAR) of the contraceptive progestogens for (I) oral contracepti... more Structure-activity relationships (SAR) of the contraceptive progestogens for (I) oral contraceptive activity (OCA), (II) androgenic effect, and (III) binding affinity for sex hormone binding globulin (SHBG) were studied using four different methods: principal component analysis (PCA), hierarchical cluster analysis (HCA), neural networks (NN), and electronic indices method (EIM) employing descriptors calculated by the semi-empirical Austin Model 1 (AM1) method. An additional set of molecules was used to check the reliability of the results obtained for OCA by PCA. Using PCA, three different sets of descriptors were found to correlate with the three different biological activities, I-III, indicating that the interaction between the receptor and the progestogen must depend on the type of biological activity. The descriptors selected by PCA were also employed for SAR analysis of the contraceptive progestogens using two other methods, HCA and NN. Both HCA and NN correctly classified high activity molecules as different from low activity ones. Thus, those descriptors selected by PCA work well in the other two methods of classification. Using the sign of ρ, a difference of electron densities of selected molecular orbitals in a specified region in a molecule, it was possible to discriminate high activity molecules from low activity molecules in the three different types of activities studied, I-III, with one exception.

Journal of Food Quality, 2010

In this work, the potential of mid‐infrared diffuse reflectance spectroscopy with Fourier transfo... more In this work, the potential of mid‐infrared diffuse reflectance spectroscopy with Fourier transform for discrimination of 29 commercial Brazilian coffee samples with different industrial processing, i.e., caffeine extraction and roasting degree, was evaluated. The statistical treatments applied to pre‐treated spectral data were principal component analysis and partial least squares – discriminant analysis (PLS‐DA). The ordered predictors selection method was used for variable selection. The chemometric analyses of the mid‐infra‐red spectra allowed inferring on the lower carbohydrate, caffeine and chlorogenic acid concentration as well as on the higher water content in the decaffeinated coffee. The technique also allowed speculation on the higher lipid and lower water content in the dark roasted coffee compared with traditional roasted coffee. A clear discrimination of decaffeinated from medium and dark roasted coffees was observed in PC1. PLS‐DA was used for the discrimination betwe...

Journal of Chemometrics, 2006

Internet surfing for the word chemometrics in national languages and, in the Science Citation Ind... more Internet surfing for the word chemometrics in national languages and, in the Science Citation Index (SCI), searching for articles containing chemometr * were performed. The bibliometric, webometric, and country development descriptors from literature were then treated by Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA). In total, 82 written and 127 pronunciation forms of chemometrics were found in 48 languages worldwide. The forms ending in ‘‐y’ (chemometry) and ‘‐ics’ (chemometrics) can be grouped into at least three groups (I, J, K). Scientific collaboration, country development, geography, history, and language were shown to be important determinants in creation of form(s) of chemometrics in a particular country or language. PCA and HCA show that tradition in chemometrics, level of country development, and its scientific production are important for the existence of chemometric societies and laboratories worldwide. Today, the world tends toward becoming ...

Journal of Chemometrics, 2010

An evaluation of computational performance and precision regarding the cross‐validation error of ... more An evaluation of computational performance and precision regarding the cross‐validation error of five partial least squares (PLS) algorithms (NIPALS, modified NIPALS, Kernel, SIMPLS and bidiagonal PLS), available and widely used in the literature, is presented. When dealing with large data sets, computational time is an important issue, mainly in cross‐validation and variable selection. In the present paper, the PLS algorithms are compared in terms of the run time and the relative error in the precision obtained when performing leave‐one‐out cross‐validation using simulated and real data sets. The simulated data sets were investigated through factorial and Latin square experimental designs. The evaluations were based on the number of rows, the number of columns and the number of latent variables. With respect to their performance, the results for both simulated and real data sets have shown that the differences in run time are statistically different. PLS bidiagonal is the fastest a...