Search

Snakebites produce several toxic effects in victims, such as hemorrhage, tissue necrosis, hemostatic, renal, or cardiotoxic alterations, inflammation, and death. To counteract these symptoms, antivenom is the official treatment. Although such therapy prevents death, it does not efficiently neutralize necrosis or other local effects, leading to amputation or morbidities of the affected limb. Therefore, the search for better and more efficient therapies deserves attention; further, plants have been used to ameliorate a number of diseases and medical conditions, including snakebites, for many years. Thus, the aim of this work was to evaluate the antivenom effect of the crude extract, fractions (aqueous and diethyl acetate), and subfractions derived from the aqueous fraction (P1, P2, P3, and P4) of the plant Stryphnodendron adstringens against in vitro (coagulation and proteolytic) and in vivo (edema, hemorrhage, and myotoxic) activities caused by Bothrops jararacussu venom. Overall, all extracts inhibited the toxic effect of B. jararacussu venom, but with different potencies, regardless of whether plant samples were incubated together with venom or injected before or after venom injection into animals; the crude extract and aqueous fraction were found to be the most effective. Indeed, phytochemical and mass spectrometry analysis of S. adstringens samples revealed the presence of flavonols, tannins, and saponins. In conclusion, the plant S. adstringens may represent a promising natural source of molecules to treat the toxic effects associated with envenomation by B. jararacussu snakebites.

Metabolic profiling of complex biological matrices based on liquid chromatography-mass spectrometry (LC-MS) allows detecting a wide range of metabolites with distinct concentrations and physicochemical properties. Given the complexity of samples and the necessity of a comprehensive approach in untargeted metabolomics, quality control strategies are mandatory to obtain high-quality data. The LC-MS performance must be monitored and evaluated to guarantee data reliability. In this study, a test mixture (TM) was developed, systematically evaluated, and applied to untargeted metabolomics of urine samples from individuals suspected of inborn errors of metabolism. The TM was composed of fifteen analytes that eluted across the entire gradient in reversed-phase columns and ionized in positive/negative electrospray modes. It helped set the LC-MS conditions for urine analysis, from sample reconstitution solvent to selecting the MS ion source parameters. The TM quickly indicated column stationary phase degradation during the batch analysis when employed to monitor and evaluate the LC-MS system in an untargeted metabolomic analysis. Thus, in addition to pooled QC samples, a TM can be employed in untargeted metabolomics to rapidly assess the system performance avoiding unnecessary efforts for further data treatment and multivariate analysis of poor-quality data

Kefiran is a polysaccharide present in kefir grains that have been widely explored due to its potential health benefits. The objective of this work was to characterize and quantify the components present in the ethanolic extract of milk kefir grains; to study its pharmacokinetic and toxicological properties in silico and evaluate the acute toxicity of the kefiran in zebrafish. The prediction of pharmacokinetic properties was performed by QikProp software. In silico toxicity assessment was performed using the DEREK (deductive estimate of risk from existing knowledge) software. In the chromatographic, kefiran was identified as the major component. Results showed that the kefiran had low human oral absorption and intestinal absorption its due poor solubility profile; low logP value, indicating its lipophilicity and the low MDCK and Caco-2 cells permability, and unable to cross the blood–brain barrier. Kefiran did not present any structural warning for in silico toxicity. In zebrafish, the dose of 2,000 mg/kg of kefiran produced nonsignificant alterations in the analyzed organs. It can be said then that kefiran has an acceptable degree of safety for use in the development of drugs or functional foods. Further research such as in vivo testing to confirm its pharmacological potential is currently underway.

The aqueous extract of Joazeiro stem bark (EJSB) and its high molecular weight fraction (HMWF) were examined as potential corrosion inhibitors of mild steel in 1 mol L−1 hydrochloric acid media, using weight-loss measurements, potentiodynamic polarization curves and an electrochemical impedance spectroscopy (EIS).Varying the concentration of the inhibitors from 100 to 800 mg L−1, the results show an increase in anticorrosive efficiency from 85.4 to 89.8 and 89.8 to 93.0% for EJSB and its HMWF, respectively, using the data of the gravimetric essay, and from 84.5 to 94.5 and 89.9 to 94.7% for EJSB and its HMWF, respectively, from the impedance data. The composition of the crude extract was chemically characterized by liquid chromatography-high resolution mass spectrometry. Additionally, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used, respectively, to morphologically and chemically characterize the surface. Considering that the saponin molecules, the main constituent from juá, are responsible for its inhibitory action, quantum chemical calculations showed that the C67, C69 and O144 atoms likely have an important role in the process of electron-donation of saponin to metal, due to the higher values of ƒk+ and %HOMO observed on these atoms.

Coffee quality is strongly related to postharvest processes. Dry and wet are the most traditional and employed processes. However, more recently, the semi-dry process has been introduced and applied for producing coffees of good quality in a more environmental friendly manner compared to the wet process. In this work, green Arabica coffee cherries from two consecutive crops were submitted to the dry and semi-dry postharvest processes and their methanol:water extracts were characterized by ESI(−) FT-ICR MS followed by chemometric data analysis. Thirty-three compounds were identified in the extracts by their high-resolution and accurate m/z values and MS/MS spectra being nine of them diterpenes related to atractyligenin derivatives. The dry and semi-dry processes led to distinct extracts in which compounds such as atractyloside II, carboxyatractyloside II and carboxyatractyloside III showed the greatest contributions (p

Reports on the determination of emerging contaminants (EC) in aqueous samples have been increasingly common. Due to the low levels of concentration of the analytes as well as the complexity of this matrix, the analysis is done preferably by liquid chromatography (LC). Owing to the polar character of most of the EC determination by gas chromatography is deprecated. One way to overcome this barrier is through derivatization, which, in some cases, can be a lengthy step, presents risks to the analyst as well as to the environment due to the toxicity of the derivatizing agent, and, thus, ends up favoring the use of LC. An analytical protocol was developed in this work to increase the efficiency of derivatization in a shorter reaction time for the determination of ibuprofen, 4-octylphenol, 4-nonylphenol, triclosan, bisphenol A, diclofenac, estrone, 17-β-estradiol, estriol, coprostanol, and cholesterol. The proposal then was to carry out the silylation reaction of the analytes with the aid of a domestic microwave oven. The results indicated that the use of the device provided an increase in the efficiency of the reaction, due to the homogeneous heating of the solution. Besides, there was a significant decrease in the derivatization time of the analytes from 30 min to 5 min. Additionally, through a design of experiments (DOE), it was possible to perceive the influence of some instrumental parameters of GC-MS, such as temperature, pressure intensity, and pressure pulse time in the injector on the detectability of the investigated analytes. This study allowed a satisfactory separation of the analytes and an average increase in their areas of up to 35%. These aspects made it possible to obtain an analytical method with limits for the detection and quantification of EC between 0.03-11.00 ng mL-1 and 0.10-33.35 ng mL-1, respectively, and uncertainties below 9%. The developed method was applied in the determination of the analytes in coastal seawater and the determined concentrations varied from 0.24 ng L-1 for estriol and 43.60 ng L-1 for cholesterol. Thus, the improvement of the silylation reaction, combined with the strategy of instrumental optimization, proved to be simple, efficient, and fast, as well as being a comparable alternative to liquid chromatography.

Viscum album L., commonly known as European mistletoe, is a hemi-parasitic plant of the Santalaceae family. The in vitro and in vivo effects of V. album differ, according to its host tree. However, little is known about the host-dependent phytochemical diversity in V. album. In this study, the metabolic profiles of V. album ssp. album from Malus domestica Bork., Quercus robur L., and Ulmus carpinifolia Gled were compared. Leaves, stems, and berries were collected in Switzerland, by the same procedure, in September 2016 and 2017. The methanolic extracts were analyzed by ultra-performance liquid chromatography, coupled to electrospray quadrupole time-of-flight mass spectrometry in positive ionization mode. The data were submitted to partial-least square discriminant analysis (PLS-DA) and the results showed that the V. album ssp. album samples were clustered into three groups, according to the three distinct host trees. Seven compounds, with high VIP scores (variable importance in projection), were responsible for this differentiation. The following four compounds were detected in both the harvest years: arginine, pipecolic acid or lysine, dimethoxycoumarin, and sinapyl alcohol, suggesting their use as host specific V. album biomarkers. The present work highlights the importance of standardized harvest and analytical procedures for the reproducibility of the chemical results of herbal materials.

GUIDE FOR CHROMATOGRAPHY COUPLED TO MASS SPECTROMETRY DATA PROCESSING. In this work, a discussed and step-wise tutorial for LC-MS and GC-MS data processing using the open-access software MZMine2 is presented and discussed. The rationale behind each step was demonstrated to enable the readers to go through their own data and process it accordingly. The main lesson to be learned is that each parameter must be chosen in light of the raw data and no guidelines should suggest a predetermined value. Still, it is worth mentioning that ideal values for each parameter do not exist, and that the user might end up investing too much time futilely optimizing values. Our suggestion is to process your data in light of the raw data (and the study design) following the preview figure result and the resulting feature list generated in each processing step, interpret your data, and go back to process it again to tune the detection of important features.

The comprehended knowledge of the metabolic profile of the fecal matter has been recognized as an important point for understanding metabolic changes in the human systemic metabolism and it can provide precious information about host-gut microbiota interactions. However, few analytical strategies have been addressed for a broad analysis of metabolites with different chemical properties to better understand the chemical space of fecal samples. Here we report a systematic pipeline to achieve comprehensive coverage of the fecal metabolome, from high polar to nonpolar metabolites, using dog fecal samples as a proof-of-concept. This pipeline comprises a monophasic (ACN/H2O) and a biphasic extraction (methyl tert-butyl ether (MTBE)/MeOH/H2O) of the sample, followed by three liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS) methods using HILIC-amide, RP-C18 and CSH-C18 columns, and a switch polarity acquisition mode in the electrospray ion source. This approach allowed the annotation of 376 metabolites from 70 different chemical classes. The chemical space analysis by molecular networking and the pathway analysis revealed the complexity of the fecal sample and the importance of combined methods to better understand biochemical pathways. This pipeline can be used as a valuable tool to comprehend the relationship between host-gut microbiota metabolites and the influence of diet, medication, or environmental changes.

Background: Viscum album L. is a semi-parasitic plant with antitumor activity attributed to the aqueous extracts. However, European V. album ethanolic extracts (VAE) have also demonstrated in vitro activity in tumor models. Aims: Evaluate the metabolic profiles of fifty VAE harvested during summer and winter seasons and their antitumor activity through 2D and 3D models. Methodology: VAE were prepared by maceration from: V. album subsp. album growing on Malus domestica, Quercus sp. and Ulmus sp.; V. album subsp. austriacum from Pinus sylvestris; V. album subsp. abietis from Abies alba. Chemical analyses were performed through liquid chromatography coupled with high resolution mass spectrometry and Partial Least Squares Discriminant Analysis (PLS-DA) was performed in the Metaboanalyst 4.0. The antitumor potential of the selected VAE was evaluated in 2D and 3D models (MDA-MB-231 cancer cells) by MTT, crystal violet and glycolytic pathway analysis. Results and discussion: The first 3 principal components in PLS-DA explained 60% and 40% of data variation in positive and negative modes respectively. Three groups were formed and showed chemical similarity among V. album subspecies. The compounds responsible for group separation were tentatively identified as: pinobankasin or naringenin hexoside; isorhamnetin-3-hexoside, meglutol and different amino acids. The summer VAE at 0.5% v/v induced higher cytotoxic damage than the winter preparations, and Abies alba and Quercus sp. VAE promoted 49% and 42% reduction of tumor viability in 3D model (72h incubation), respectively. MDA-MB-231 glycolytic pathway in 2D model showed a decrease in the glucose consumption and extracellular lactate production. Also, PFK (6- phosphofructo-1-kinase) and PK (Pyruvate kinase) activities were inhibited by Abies alba and Quercus sp. VAE at 48h of incubation. Conclusion: VAE extracts showed different metabolomes and the glycolytic pathway should be an important target involved in the inhibition of tumor growth by these extracts.

Polar phenolic compounds of anthropogenic sources are widely studied by the scientific community since their effects are considered harmful to aquatic biota. From an environmental point of view, information regarding the presence of these contaminants allows promoting broader studies of environmental assessment. An evaluation of the presence of phenol, o-cresol, m-cresol, p-cresol, and 2,4-dimethylphenol in aqueous samples was carried out, to investigate the possibility of contamination owing to the shale mining activities in the most important Brazilian oil shale reserve, in the region of São Mateus do Sul, Paraná State, Brazil. Ten water samples were collected near this region and the five mentioned phenolic compounds were preconcentrated using a previously validated liquid-phase microextraction procedure. Their quantitation was realized by liquid chromatography coupled with diode array detector. The presence of phenol was estimated in some samples below 3.3 μg L− 1 and 2,4-dimethylphenol was determined (4.7 ug L -1) in one sample, whereas the cresols were not found in any sample. To confirm the presence or the absence of the analytes, the samples were spiked with the phenolic compounds, and satisfactory recovery values between 52.2 and 120.5% and relative standard deviations less than 17.2% for triplicate samples of these compounds were observed, suggesting that this chromatographic/extraction method was adequate for quantitation of these compounds in environmental samples and wastewater from shale mining area. The results suggested no contribution of the phenolic compounds as pollutants of the rivers and streams for the studied area owing to the shale activities. Made available in DSpace on 2020-12-03T09:05:50Z (GMT). No. of bitstreams: 1 Dolatto2020-Article-EvaluationOfPolarPhenolicCompo.pdf: 813272 bytes, checksum: 4b7e8acfa142b452b27f26654734f1e4 (MD5) Previous issue date: 2020 Short Communication. Published 19 October 2020.

Background Viscum album L. (Santalaceae), commonly known as mistletoe, is a hemiparasitic plant traditionally used in complementary cancer treatment. Its antitumor potential is mostly attributed to the presence of aqueous soluble metabolites; however, the use of ethanol as solvent also permits the extraction of pharmacological compounds with antitumor potential. The clinical efficacy of mistletoe therapy inspired the present work, which focuses on ethanolic extracts (V. album “mother tinctures”, MT) prepared from different host trees. Methods Samples from three European subspecies (album, austriacum, and abietis) were harvested, and five different V. album-MT strains were prepared. The following phytochemical analyses were performed: thin layer chromatography (TLC), high-performance liquid chromatography (HPLC) and liquid chromatography-high resolution mass spectrometry (LC-HRMS). The proliferation assay was performed with WST-1 after incubation of tumor (Yoshida and Molt-4) and fibroblast cell lines (NIH/3 T3) with different MT concentrations (0.5 to 0.05% v/v). The cell death mechanism was investigated by flow cytometry (FACS) using Annexin V-7AAD. Results Chemical analyses of MT showed the presence of phenolic acids, flavonoids and lignans. The MT flavonoid and viscotoxin contents (mg/g fresh weight) were highest in Quercus robur (9.67 ± 0.85 mg/g) and Malus domestica (3.95 ± 0.58 mg/mg), respectively. The viscotoxin isoform proportions (% total) were also different among the VA subspecies with a higher content of A3 in V. album growing on Abies alba (60.57 ± 2.13). The phytochemical compounds as well as the viscotoxin contents are probably related to the antitumor effects of MT. The cell death mechanisms evaluated by colorimetric and FACS methodologies involved necrotic damage, which was host tree-, time- and dose- dependent, with different selectivity to tumor cells. Mother tincture from V. album ssp. abietis was the most effective at inducing in vitro cellular effects, even when incubated at the smallest concentration tested, probably because of the higher content of VT A3. Conclusion Our results indicate the promising antitumor potential of Viscum album ethanolic extracts and the importance of botanical and phytochemical characterization for in vitro anti-proliferative effects.

Xenobiotics from oil tanker leaks and industrial discharges are amongst the main human impacts to confined coastal areas. We assessed the genotoxic responses to the water-soluble fraction of diesel oil in the polychaete Laeonereis culveri and the bivalve Anomalocardia flexuosa, two widespread benthic species in subtropical estuaries from the Southwestern Atlantic. We hypothesized that the highest responsiveness would be expressed by significantly different biomarkers responses between control and oil-impacted treatments. Responsiveness to diesel oil was investigated using an experimental design with two fixed factors (contaminant percentages and times of exposure). After exposure, we monitored the responses of the oxidative stress enzymes and performed micronuclei tests. Results were congruent for both species. Antioxidant defense of glutathione S-transferase and the induction of micronuclei and nuclear buds, the latter just for the bivalve, were significantly affected by polycyclic aromatic hydrocarbons, with significant increases on the seventh day of exposure and in the higher concentrations, compared to controls groups. We assessed the benefits and drawbacks of using each biomarker in laboratory experiments. Both species are indicators of early, and rapid responses to genotoxic contaminants in subtropical estuarine habitats. We suggest that the micronuclei frequency in A. flexuosa is a simple, fast and cheap test for genotoxicity in oil-impacted areas. Such early biomarkers are needed to develop better protocols for impact assessment and monitoring under real field conditions.

The plant species Libidibia ferrea (Mart. ex Tul.) LP Queiroz var. ferrea basionym of Caesalpinia ferrea (Mart. ex Tul.) is used in various regions of Brazil in folk medicine in the treatment of several health problems, especially in acute and chronic inflammatory processes. Most of the preparations employed are alcoholic. Therefore, this study aimed to evaluate the acute toxicity of the hydroethanolic extract of fruits of Libidibia ferrea (EHEFLf) in zebrafish, emphasizing the possible changes in the organic-cellular level of the gills, liver, kidneys, and intestine and on embryos. The result obtained by LC-M/MS from EHEFLf indicated a high concentration of possible polyhydroxylated substances. EHEFLf, at a dose of 2 g/kg orally, produced non-significant alterations of the analyzed organs. However, for embryos, the treatment with different concentrations demonstrated heart toxicity that was concentration-dependent. There is no evidence of a correlation of the observed effects with the phytochemical composition, and considering the species of animal used, it can be suggested that the oral use of L. ferrea hydroethanolic extract has an acceptable degree of safety for use as an oral medicinal product. and embryo results have shown significant affinity to the heart, however, it is perceived to be related to the concentrations used.

Carboxymethyl cellulose (CMC)-based films were developed by incorporating green coffee oil (GCO) obtained by cold pressing and hydroalcoholic extracts of its residues. The effect of cake (CE) and sediment extracts (SE) in different proportions (20-40%) and GCO on chemical, morphological, physical, mechanical, optical, and antioxidant properties of the films was investigated. Eight fatty acids and four major phenolic compounds were identified by High-Resolution Direct-Infusion Mass Spectrometry in GCO and residue extracts. FTIR indicated interactions among CMC, phenolic compounds, and fatty acids. Films enriched with residue extracts presented heterogeneous microstructure. The tensile strength of the films decreased from 58 to 3 MPa with the extracts concentration, while elongation increased from 28 to 156% (p 0.05). The water vapor permeability (averaging 3.94 × 10

Endosperm tissue of cross-sectioned green arabica coffee beans was analyzed by the ambient ionization technique desorption electrospray ionization-mass spectrometry (DESI-MS) imaging and the spatial distribution of chlorogenic acids and sucrose across the bean endosperm was revealed. Quinic acid and feruloylquinic acid were located, preferably, in the hard external region of the endosperm, while caffeoylquinic acid was detected in high levels in the soft internal region. This non-homogeneous spatial distribution appears to be related to different functions of these distinct tissue regions. Sucrose was detected across the whole coffee bean endosperm. A damaged green coffee bean with holes caused by the coffee berry borer (Hypothenemus hampei) was also analyzed and increased levels of caffeoyl-sinapoylquinic acid and the unidentified m/z ion 535 were observed in the injured endosperm region compared to other regions. This new approach, of using DESI-MS imaging for coffee analysis, could help expand our knowledge about coffee chemistry and physiology.

Ambient ionization methods allow for the examination of surfaces in their native conditions at atmospheric pressure with minimal or no preparation. Spray-based ambient ionization methods such as desorption electrospray ionization (DESI) and easy ambient sonic-spray ionization (EASI) have been successfully applied to imaging mass spectrometry. In 2012, a comparative study between DESI and EASI on spatial resolution and sensitivity was published by Janfelt and Norgaard (J. Am. Soc. Mass Spectrom., 23 (2012) 1670–1678). We expand on that work by comparing DESI and EASI techniques for the assessment of the limit of detection (LOD) of several drugs on a PTFE surface and for the determination of the spray spot size varying flow rate and solvent composition for imaging purposes. MS/MS imaging was also done with both methods for performance comparison. The results showed that good ion images can be obtained by both techniques in the MS or MS/MS mode. No significant difference was observed in the spray spot size produced by DESI and EASI. DESI was found to have similar or higher sensitivity than EASI depending on the analyte interrogated.

This work proposes a liquid-phase microextraction (LPME) method to extract the highly polar compounds phenol (Ph), o-cresol (o-Cr), m-cresol (m-Cr), p-cresol (p-Cr), and 2,4-dimethylphenol (2,4-DMP) from aqueous matrices. The first extraction step of the LPME method employed a common volumetric flask and n-octanol, and the second extraction step used NaOH as the acceptor phase. The optimized extraction conditions were 900 μL of n-octanol as the extraction solvent, NaOH at 0.60 mol L(-1) as the acceptor phase, an extraction time of 5.0 min, HCl at 0.01 mol L(-1) and NaCl at 20.0% as the donor phase, and an extraction temperature of 20.0°C. The analysis of 50.0 mL of aqueous sample, pretreated under the optimized LPME conditions, afforded a limit of detection (LOD) between 0.3 and 3.5 μg L(-1), a limit of quantification (LOQ) between 1.2 and 11.6 μg L(-1), and a linear range from 2.50 to 50.0 μg L(-1) for Ph, o-Cr, m-Cr and p-Cr and from 12.5 to 250 μg L(-1) for 2,4-DMP. The proposed LPME method was a successful sample preparation strategy, and allowed for precise and accurate quantification of polar phenolic compounds in aqueous matrices such as tap water, river water, groundwater, and seawater, and also in a soil extract. The recovery values ranged from 72.5% to 126.0%, and the relative standard deviation was between 0.3 and 11.5%.

Contamination of aquatic environments by petroleum and its products (e.g. gasoline) is a hazard for aquatic organisms as a result of the potential toxicity of monocyclic aromatic hydrocarbons (BTEX) and polycyclic aromatic hydrocarbons (PAH). Our goal was to evaluate the acute effects of the water-soluble fraction of gasoline (WSFG) on nitrogen excretion, osmoregulation, and metabolism of goldfish Carassius auratus. We first chemically characterized the WSFG and then tested its effects on these physiological aspects of C. auratus, in several different exposure scenarios (0, 0.25, 5, 10 and 25% of WSFG). The WSFG contained high concentrations BTEX (toluene 70% and benzene 17%) relative to PAH (

Although several species of ferns possess a characteristic odor, only a few published studies have described their volatile constituents. The aim of the present study was to evaluate the chemical composition of essential oils from two chemically unexplored fern species, Anemia hirsuta and Anemia raddiana. These species were collected during the day in ravine banks of Rio de Janeiro state, Brazil. Fresh leaves of the ferns were individually turbolized with distilled water and submitted to hydrodistillation in a Clevenger-type apparatus for three hours. The essential oils obtained were subjected to gas chromatography/mass spectrometry for identification. Nine compounds were identified in Anemia raddiana essential oil, accounting for 81.3% of the total oil, where the sesquiterpene β-selinene (46.8%) was the major compound. Thirteen compounds were identified in Anemia hirsuta (92.3% of the total oil) and the sesquiterpene β-caryophyllene was the major compound (48.7%). No similarity was observed between the chemical profile of essential oils obtained from A. hirsuta and A. raddiana. Likewise, extremely low similarities (≤6.2%) were observed between these species and three previously published profiles of Anemia tomentosa var. anthriscifolia.

Green beans of Coffea arabica (arabica coffee) cultivars with Sarchimor and Catuai genetic background were grown under the same edaphoclimatic conditions, in two different regions, and analysed by direct-infusion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) followed by a metabolomic approach. A total of 20 coffee metabolites including phenolic compounds, fatty acids, sucrose, and diterpene glycosides were identified by negative ESI FT-ICR MS with a mass error

This study describes the isolation of a flavonoid fraction from leaves of Ocotea notata (Nees & Mart.) Mez, Lauraceae, the identification of six major compounds (an A-type proanthocyanidin trimer [3], isoquercitrin [4], reynoutrin [5], miquelianin [6], quercitrin [7], afzelin [8]) and four minor compounds (catechin [1], epicatechin [2], quercetin [9], kaempferol [10]) present in the fraction and its activity against the Herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). The 50% effective concentrations values (EC50) calculated from the dose-response curve and the selectivity indices (SI) against the virus were: EC50 35.8 µg/mL and SI 5.5 to HSV-1 and EC50 23.5 µg/mL and SI 8.5 to HSV-2. The flavonoid fraction was more active against HSV-2 than HSV-1. The mechanisms of antiviral action of the flavonoid fraction against the virus were also evaluated. The percentage inhibition (PI) obtained for HSV-2 was higher than 90% in the following assays: virucidal, pre-treatment of cells, treatment of cells after viral adsorption and treatment of cells after viral penetration. For HSV-1, the flavonoid fraction had no effect in pre-treatment of cells and showed 60% of inhibition in virucidal assay.

Orientador: Prof. Dr. Gilberto Abate Coorientadora: Profa. Dra. Iara Messerschmidt Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Exatas, Programa de Pós-Graduação em Química. Defesa : Curitiba, 27/02/2015 Inclui referências: p.102-108 Resumo: Neste trabalho foi investigado o desenvolvimento de metodo analitico empregando microextracao por solvente (SME) para extracao e pre-concentracao de fenol (Ph), o-Cresol (o-Cr), m-Cresol (m-Cr), p-Cresol (p-Cr) e 2,4-dimetil-fenol (2,4- DMF), visando a quantificacao em amostras aquosas e extrato de solo previamente condicionado com xisto retortado (XR). As quantificacoes foram realizadas por cromatografia a liquido com deteccao por arranjo de diodos (LC-DAD), fase movel composta por acetonitrila:acido acetico 1,0 % (40:60), vazao de 1,00 mL min-1, por eluicao isocratica, coluna C18 (25 x 0,46 cm, 5 _m) a 40,0 oC, volume de injecao de 20,0 _L e deteccao em comprimento de onda de 270 nm. Depois da avaliacao de alguns procedimentos baseados em SME, foi proposta uma estrategia de extracao em duas etapas (two-step SME), utilizando um balao volumetrico como frasco de extracao. Na primeira etapa foi feita a extracao com n-octanol, seguido por um segundo passo usando solucao de NaOH como uma fase aceptora. As condicoes de extracao como tipo de solvente extrator, volume de solvente, volume de amostra, pH, temperatura, tempo de agitacao, efeito da forca ionica, volume e concentracao de solucao aceptora de NaOH foram cuidadosamente investigadas de forma univariada e de modo multivariado por planejamento fatorial de experimentos fracionado 25-1. De acordo com os resultados do planejamento fatorial nao foram observadas interacoes significativas entre as variaveis testadas, sendo que os efeitos mais importantes foram as concentracoes de NaOH e NaCl e volume de n-octanol. Com base nos dois estudos as melhores condicoes de extracao foram: 900 _L de n-octanol como solvente, NaOH 0,60 mol L-1 como fase aceptora, tempo de extracao de 5,0 min, HCl 0,01 mol L-1 e NaCl 15,0 % na fase doadora, e 20,0 °C como temperatura de extracao. Sob estas condicoes e utilizando 50,0 mL de amostra, o metodo apresentou limite de deteccao entre 0,3 e 3,5 _g L-1, limite de quantificacao entre 1,2 e 10,6 _g L-1, intervalo linear de 2,50 a 50,0 _g L-1 (Ph, o-Cr, m-Cr+p-Cr) e entre 12,5 e 250,0 _g L-1 (2,4-DMF). O metodo proposto, two-step SME foi aplicado com sucesso para a determinacao dos compostos alvo em amostras aquosas de agua da torneira, agua de rio, agua subterranea, agua do mar e um extrato aquoso obtido de um solo condicionado com XR. Foram observados resultados de recuperacao de 72,5 a 126,0 % e desvio padrao relativo entre 0,3 e 11,5 %, sugerindo a utilizacao do metodo para a quantificacao de compostos fenolicos polares em amostras aquosas, com exatidao e precisao adequadas. Palavras-chave: Compostos fenolicos. Microextracao por solvente. Cromatografia a liquido. Xisto retortado. Solo. Abstract: In the present work a solvent microextraction method (SME) was investigated for the extraction and preconcentration of phenol (Ph), o-Cresol (o-Cr), m-Cresol (m-Cr), p-Cresol (p-Cr) e 2,4-dimethylphenol (2,4-DMP), aiming the quantification in aqueous samples and in a soil extract from a soil previously conditioned with retorted shale (RS). Liquid chromatography with diode-array detector (LC-DAD) was employed with mobile phase composed by acetonitrile:1,0 % acetic acid (40:60), flow rate 1.00 mL min-1 under isocratic elution, column C18 (25 x 0.46 cm, 5 _m) at 40.0 oC, volume of injection 20.0 _L, and detection in the wavelength of 270 nm. Some SME procedures were evaluated, and after that, the approach of two-step SME was proposed using a volumetric flask as an extraction flask. In the first step an extraction using n-octanol was made, followed by the second step of extraction by NaOH as an acceptor phase. All the extraction conditions as kind of extraction solvent, solvent volume, sample volume, pH, temperature, stirring time, ionic strength effect, volume and concentration of the NaOH as acceptor solution were thoroughly investigated by univariate study and using multivariate fractional design of experiments 25-1. The results of factorial design indicated no significant interactions between the variables, and the more important effects were the NaOH and NaCl concentrations and n-octanol volume. Based on both studies, the best conditions of microextraction were: 900 _L of n-octanol as solvent, 0.60 mol L-1 NaOH as acceptor phase, extraction time of 5.0 min, 0.01 mol L-1 HCl and 15.0 % NaCl in the donor phase, and 20.0 °C as temperature of extraction. Using these conditions and 50.0 mL of sample volume, the method presented limit of detection between 0.3 and 3.5 _g L-1, limit of quantification between 1.2 and 11.6 _g L-1, linear range from 2.50 to 50.0 _g L-1 (Ph, o-Cr, m-Cr+p-Cr) and between 12.5 and 250.0 _g L-1 (2,4-DMP). The proposed method two-step SME was successfully employed for determination of the target compounds in aqueous samples of tap water, river water, groundwater, sea water and an aqueous extract from a soil (Ultisol) conditioned with RS. Recovery results from 72.5 to 126.0 % and relative standard deviation between 0.3 and 11.5 % were observed, suggesting the use of the method for the quantification of polar phenolic compounds in aqueous samples, with appropriate accuracy and precision. Keywords: Phenolic compounds. Solvent Microextraction. Liquid chromatography. Retorted Shale. Soil.