Analytical techniques to recognize inclusion complexes formation involving monoterpenes and cyclodextrins: A study case with (-) borneol, a food ingredient.

Monoterpenes are non-polar secondary metabolites widely used by industry due to their excellent therapeutic, food-ingredient and cosmetic properties. However, their low solubility in water limits their use. In this sense, cyclodextrins (CDs) have been widely used to solve these technological challenges. Thus, this study aims to use (-)-borneol as a monoterpene model to prepare inclusion complexes between ß-CD and hydroxypropyl-ß-CD (HP-ß-CD) through different ways and characterize them in order to choose the best inclusion method to improve physicochemical properties of monoterpenes. To achieve this goal, the samples were prepared by physical mixture (PM), paste complex (PA) and freeze-drying complex (FD) and then, extensively characterized by thermal analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, size particle, X-ray diffraction and nuclear magnetic resonance. The physicochemical results showed that freeze-drying was more effective to form inclusion complexes between (-)-borneol with both CDs. This research highlights the importance of recognizing the best method to prepare inclusion complexes, including food additives as (-)-borneol, to achieve better results in food preparations.

Distribution and abundance of freshwater decapods in an Atlantic rainforest catchment with a dammed future / Distribuição e abundância de decápodes de água doce e sua associação com variáveis ambientais em uma bacia hidrográfica de Mata Atlântica que será represada

Abstract Variations in physical characteristics along the course of a river influence habitat availability which reflects in species distribution. Knowledge of ecology and diversity of lotic species is important for evaluating how river ecosystems will respond to environmental impacts. Freshwater decapods are a group of high ecological and economic importance, but the knowledge about factors influencing their distribution is scarce in Brazil. We performed a survey of decapods to describe their abundance and distribution as well as to study their relationships with stream physical variables and especially their association with different substrates types. We studied 23 sites located in 15 tributaries of Guapiaçú River, RJ, where we collected decapods in different substrates types and measured a set of physical variables. We found five decapods species, including amphidromous and non-amphidromous shrimps and crabs. Decapods were strongly associated with leaf-litter substrates and their abundance was related to a multivariate axis describing longitudinal changes in stream characteristics. We concluded that decapods occurring in the Guapiaçú catchment inhabit mainly small streams with preserved riparian forests where they find shelter and potential prey of invertebrates. The ongoing project to build a dam on the Guapiaçú River will have negative consequences to migrating shrimps and we strongly recommend that mitigating actions, such the construction of structures to allow the passage of migrating fauna, should be taken.

Resumo Variações nas características físicas de um rio ao longo do seu curso influenciam a disponibilidade de habitas e dessa forma a distribuição de espécies. O conhecimento sobre a ecologia e diversidade de espécies lóticas é importante para avaliar como esses ecossistemas responderão a impactos ambientais. Decápodes de água doce são um grupo de grande importância ecológica e econômica, contudo o conhecimento sobre fatores influenciando sua distribuição ainda é escasso no Brasil. Nós realizamos um levantamento de decápodes para descrever sua abundância e distribuição, bem como estudar sua relação com características físicas dos rios, especialmente sua associação com tipos diferentes de substrato. Nós estudamos 23 localidades distribuídas em 15 rios tributários do Rio Guapiaçú, RJ, onde coletamos decápodas em diferentes tipos de substratos e medimos um conjunto de variáveis físicas. Nós encontramos cinco espécies de decápodas incluindo camarões anfídromos e não anfídromos e caranguejos. Esses organismos foram fortemente associados a substratos de folhiço alóctone e sua abundância foi relacionada com um eixo PCA que descreve as mudanças nas características físicas longo do curso do rio. Nós concluímos que os decápodas que ocorrem na bacia do Rio Guapiaçú habitam principalmente pequenos córregos com mata ciliar preservada, onde podem encontrar abrigo e um potencial campo de caça onde predam invertebrados. O projeto atualmente em curso para a construção de uma represa no Rio Guapiaçú irá afetar negativamente a fauna de camarões anfídromos, assim nós recomendamos fortemente que ações mitigadoras, como a construção de estruturas para permitir a passagem da fauna migrante sejam tomadas.

Quantum Mechanical (QM) Calculations Applied to ADMET Drug Prediction: A Review.

The discovery of new drugs is generally considered a long and expensive process, which often leads to molecules with low efficacy and high toxicity, which in many cases can be related to metabolism. In an attempt to reduce these failures and the production costs of a new drug, in silico studies have been used to obtain important information about the behavior of these compounds in the metabolism phases: absorption, distribution, metabolism (or biotransformation) and elimination (or excretion). Quantum Mechanical (QM) calculations are based on Schrödinger's equation that can be used to develop models and theoretical parameters able to explain properties observed experimentally. In recent years, there has been an increase in the development of studies involving the application of QM methods to describe properties related to ADMET profile of new compounds. Amongst these, the most commonly used methods are ab initio (Hartree-Fock), Semiempirical (AM1 and PM3) and Density Functional Theory (DFT). The application of these methods allows the modeling of the predicted profile of absorption and elimination of chalcone-chloroquinoline hybrids; the ability of drugs to cross the blood-brain barrier (distribution); proposal of the route for oxidation of several compounds, via CYP450; and to predict the toxicity of pyrethroid analogs. Finally, QM methods can be considered as a valuable tool in the prediction of metabolism when applied to drug discovery.

Distribution and abundance of freshwater decapods in an Atlantic rainforest catchment with a dammed future.

Variations in physical characteristics along the course of a river influence habitat availability which reflects in species distribution. Knowledge of ecology and diversity of lotic species is important for evaluating how river ecosystems will respond to environmental impacts. Freshwater decapods are a group of high ecological and economic importance, but the knowledge about factors influencing their distribution is scarce in Brazil. We performed a survey of decapods to describe their abundance and distribution as well as to study their relationships with stream physical variables and especially their association with different substrates types. We studied 23 sites located in 15 tributaries of Guapiaçú River, RJ, where we collected decapods in different substrates types and measured a set of physical variables. We found five decapods species, including amphidromous and non-amphidromous shrimps and crabs. Decapods were strongly associated with leaf-litter substrates and their abundance was related to a multivariate axis describing longitudinal changes in stream characteristics. We concluded that decapods occurring in the Guapiaçú catchment inhabit mainly small streams with preserved riparian forests where they find shelter and potential prey of invertebrates. The ongoing project to build a dam on the Guapiaçú River will have negative consequences to migrating shrimps and we strongly recommend that mitigating actions, such the construction of structures to allow the passage of migrating fauna, should be taken.

Design, synthesis, molecular docking and biological evaluation of thiophen-2-iminothiazolidine derivatives for use against Trypanosoma cruzi.

In this study, we designed and synthesized a series of thiophen-2-iminothiazolidine derivatives from thiophen-2-thioureic with good anti-Trypanosoma cruzi activity. Several of the final compounds displayed remarkable trypanocidal activity. The ability of the new compounds to inhibit the activity of the enzyme cruzain, the major cysteine protease of T. cruzi, was also explored. The compounds 3b, 4b, 8b and 8c were the most active derivatives against amastigote form, with significant IC50 values between 9.7 and 6.03µM. The 8c derivative showed the highest potency against cruzain (IC50=2.4µM). Molecular docking study showed that this compound can interact with subsites S1 and S2 simultaneously, and the negative values for the theoretical energy binding (Eb=-7.39kcal·mol(-1)) indicates interaction (via dipole-dipole) between the hybridized sulfur sp(3) atom at the thiazolidine ring and Gly66. Finally, the results suggest that the thiophen-2-iminothiazolidines synthesized are important lead compounds for the continuing battle against Chagas disease.

Avaliação da atividade antibacteriana, citotóxica e antioxidante da espécie vegetal Opuntia cochenillifera (L. ) Mill / Evaluation of antibacterial, cytotoxic, and antioxidant activity of the plant species Opuntia cochenillifera (L. ) Mill

RESUMO O presente estudo teve como objetivo avaliar a atividade antibacteriana, antioxidante e citotóxica da espécie Opuntia cochenillifera (L.) Mill. Foi realizada a prospecção fitoquímica e espectroscopia de absorção de infravermelho (IV) dos extratos etanólicos brutos e frações dos cladódios grande e pequeno. A atividade antioxidante foi avaliada pelo método da capacidade sequestradora de radicais livres utilizando o radical sintético 2,2-difenil-1-picrilhidrazila (DPPH). A atividade citotóxica foi obtida através do método colorimétrico do Metiltetrazolium (MTT). Já a atividade antibacteriana foi avaliada pelo método de microdiluição em caldo para determinar a concentração inibitória mínima (CIM) frente às estirpes bacterianas Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa e Escherichia coli. A prospecção fitoquímica revelou principalmente a presença de fenóis, esteroides livres, alcaloides, alcanos, além de outras classes químicas. O IV apresentou grupos funcionais como alcanos, carbonilas, grupos de metila, duplas ligações de carbono, grupamentos alquilamina, entre outros. Sobre a citotoxicidade na concentração de 100 μg/mL, os dois extratos brutos, todas as frações do cladódio grande e as frações de clorofórmio e metanol do cladódio pequeno não apresentaram toxicidade. Os extratos brutos e frações do cladódio grande e pequeno, não demonstraram atividade antibacteriana e nem antioxidante. Esses resultados podem fornecer suporte para pesquisas futuras, visando outras atividades biológicas da presente espécie vegetal.

ABSTRACT The purpose of this study was to evaluate the antibacterial, antioxidant, and cytotoxic activity of Opuntia cochenillifera (L.) Mill. A phytochemical screening and infrared (IR) absorption spectroscopy were performed in the crude ethanolic extracts and fractions of large and small cladodes. The antioxidant activity was evaluated through the qualitative method of free-radical scavenging capacity using the synthetic radical 2,2-diphenyl-1-picrylhydrazyl (DPPH). The cytotoxic activity was obtained by the cell viability assay using methyl thiazolyl tetrazolium (MTT). Antibacterial activity was evaluated by broth microdilution method to determine the minimum inhibitory concentration (MIC) against the bacterial strains Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Escherichia coli. The phytochemical screening mainly revealed the presence of phenols, flavonoids, free steroids, alkaloids, alkanes, and other chemical classes. The IR spectroscopy presented functional groups such as alkanes, carbonyls, methyl groups, carbon double bonds, and alkylamino groups, among others. Regarding cytotoxicity in the concentration of 100 μg/mL, neither the crude extracts, the fractions of the large cladode, nor the chloroform and methanol fractions of small cladode presented toxicity. The crude ethanolic extracts and fractions of large and small cladode showed no antibacterial or antioxidant activity. These results may provide support for future research aimed at other biological activities of this plant species.

Conducting polymer/silicon heterojunction diode for gamma radiation detection.

In this work, alternative heterojunction devices to be used for gamma-radiation detection are presented. The high quality silicon/polyaniline heterostructures use polyaniline thin films as an active part of the device structure. Polyaniline thin films 40 nm thick were deposited onto silicon substrates (n-type, <100>, 1 ohm x cm) using the spin-coating technique from soluble polyaniline. The devices present excellent electrical characteristics, with a rectification ratio of 60,000 at +/- 1.0 V, reverse currents in the order of a few nA and ideality factor approximately 2. These electrical characteristics indicate great potential for their use in sensor applications. The heterojunction diode is very sensitive to gamma radiation in the dose range of 0-7000 Gy, presenting a linear response in the forward and reverse bias. The excellent electrical characteristics, together with the linear response with the dose strongly suggest the application of this device for spectrometry or dosimetry of low and high doses of gamma ray radiation.

Hemodinamica pulmonar na hiperidratacao Estudo experimental em caes. / Pulmonary hemodynamics in hyperhydration - Experimental study in dogs

Os autores estudaram as alteracoes sobre a hemodinamica pulmonar provocadas pela hiperidratacao com solucao salina fisiologica, em caes anestesiados e ventilados mecanicamente.Observou-se uma importante hemodiluicao comprovada pela queda dos valores do hematocrito (Ht), da hemoglobina (Hb) e das proteinas totais (Pt) do plasma. A pressao arterial media sistemica (PAM) manteve-se inalterada, o debito cardiaco (Q) elevou-se, a resistencia vascular sistemica (RVST) reduziu-se significantemente (4720,70 +/- 0932,14 dinas/seg/cm5 para 2893,09 +/- 1405,25 dinas/seg/cm5). A pressao media de arteria pulmonar (Ppm) elevou-se, bem como a pressao capilar hidrostatica (Pc) enquanto a resistencia arteriolar pulmonar (Rap) nao apresentou mudancas significantes (143,30 +/- 66,33 para 108,80 +/- 50,14 dinas/seg/cm5). Os resultados obtidos levam os autores a concluir que a circulacao pulmonar ao contrario do que se acrediatava nao se adapta facilmente a variacoes agudas do fluxo e volume sanguineo quando comparada com a circulacao sistemica