Navegando por Assunto "Cromatografia líquida de alta eficiência"

Agora exibindo 1 - 12 de 12

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Ácidos fenólicos, flavonoides e atividade antioxidante em méis de Melipona fasciculata, M. flavolineata (Apidae, Meliponini) e Apis mellifera (Apidae, Apini) da Amazônia
(2012) OLIVEIRA, Patricia Sertão; MÜLLER, Regina Celi Sarkis; DANTAS, Kelly das Graças Fernandes; ALVES, Claudio Nahum; VASCONCELOS, Marcus Arthur Marçal de; VENTURIERI, Giorgio Cristino
Honey produced by three stingless bee species (Melipona flavolineata, M. fasciculata and Apis mellifera) from different regions of the Amazon was analyzed by separating phenolic acids and flavonoids using the HPLC technique. Data were subjected to multivariate statistical analysis (PCA, HCA and DA). Results showed the three species of honey samples could be distinguished by phenolic composition. Antioxidant activity of the honeys was determined by studying the capacity of inhibiting radicals using DPPH assay. Honeys with higher phenolic compound contents had greater antioxidant capacity and darker color.
Acesso aberto (Open Access)
Alcalóides de Aspidosperma auriculatum Standl
(2003) BARBOSA, Wagner Luiz Ramos; TAVARES, Isabel Cecília de Castro; SOARES, Daniela Cristina
Species from genus Aspidosperma show the presence of indol alkaloids. From Aspidosperma quebracho-blanco Schlecht quebracacidine was obtained1, from A. olivaceum. Schmutz and Hunziker2 isolated olivacine, among others substances. This work reports the determination of the chromatographic profile of alkaloid fractions from Aspidosperma auriculatum, by Thin Layer Chromatography and High Performance Liquid Chromatography. At the Brazilian state Pará this plant species has the vernacular name carapanaúba and is traditionally indicated to heal fever and others affections and also malaria. The plant material - stem bark - was extracted with hydrochloridric acid 5%. Three principal alkaloid fractions were extracted at pH 7, pH 8 and pH 11, which were analysed in suitable systems showing characteristic profiles
Acesso aberto (Open Access)
Aplicação da cromatografia líquida de alta eficiência na investigação de hidrocarbonetos policíclicos aromáticos em testemunhos sedimentares
(Universidade Federal do Pará, 2013-07-31) EVANGELISTA, Camila do Carmo Pereira; KAWAKAMI, Silvia Keiko; http://lattes.cnpq.br/5306256489815710
Polycyclic aromatic hydrocarbons are organic (PAH) compounds originated from natural or anthropogenic sources and are considered priority substances by environmental agencies because of carcinogenic and mutagenic potentials. Therefore, rapid and low cost analytical methods for these compounds are of significant relevance for environmental purposes. The present study aimed the optimization of an analytical method for PAHs using High Performance Liquid chromatography with a diode array detector (HPLC-DAD) for the application to an estuarine sediment core. For the optimization and evaluation of the method, a sedimentary column measuring 46 cm length was collected at the mouth of the Igarapé Tucunduba (Belém, Pará) and sectioned in 2 cm portions. After dryness, 30 g of each portion were extracted with a mixture of dichloromethane in acetone in ultrasound bath for 40 min. the extracts obtained were centrifuged, purified on silica gel as a clean-up adaptation mainly to retained fine particles, then concentrated using vacuum evaporator and filtered through 0,2 μm nylon membrane before HPLC injection. Samples spiked with 16 PAH analytical standards and procedural blanks were processed on the same way. The parameters assessed showed: (1) good linearity, the calibration curves presented high correlation coefficients ; (2) adequate accuracy: relative standard deviations within acceptable values with 2,1% for acenaphthylene and maximum of 19,7% for fluoranthene; (3) low detection limits between 0,004 to 1,085 ng g-1 which make in situ determinations feasible; (4) adequate recovery for traces with minimum of 40,0% for acenaphthylene and maximum of 103,1% for benzo(k)fluoranthene. The total PAH concentration in the sediment core ranged between 60,77 to 783,3 ng g-1 dry sediment. The optimized method showed advantages over the traditional methods based on soxhlet extrations and clean up adsorption columns in terms of time of analysis and reduced costs with the use of smaller amounts of solvents. The limitation, however, was de coelution of some compounds, which is probably due to the low efficiency of the chromatographic column that was available at the time of the analysis. The method was applicable to estuarine complex samples, rich in silt and clay. Diagnostic ratios using parental PAHs indicated petrogenic sources at 24 - 26 cm and 28 – 30 cm depth; and pirolitics sources at 6 - 8 cm, 10 - 12 cm , and 14 - 16 cm respectively.
Acesso aberto (Open Access)
Avaliação da atividade antinociceptiva e anti-inflamatória de Mikania lindleyana DC: validação do uso na medicina popular
(Universidade Federal do Pará, 2011-06-20) SILVA, Andressa Santa Brigida da; BARBOSA, Wagner Luiz Ramos; http://lattes.cnpq.br/1372405563294070; SOUSA, Pergentino José da Cunha; http://lattes.cnpq.br/9909053957915090
Mikania lindleyana DC. (Asteraceae), popularly named sucuriju, is a common plant in Brazilian Amazonia. Ethnopharmacological studies show a diversity of uses of this species such in treatment of gastritis, infection, pain and inflammation. To validate the claim form and use was decided to study the acute toxicity and the antinociceptive and anti-inflammatory activities in experimental animal models and the chemical composition of lyophilized crude aqueous extract of Mikania lindleyana (AEML). The phytochemical screening of AEML showed the presence of saponins, proteins, amino acids, phenols, tannins, organic acids and flavonoids. On the thin layer chromatography (TLC) blues fluorescence characteristics of the coumaric acid were identifieds. The analisis on high-performance liquid chromatography coupled to mass spectrometry (HPLC-DAD-MS) seems compounds highly glycosylated. The dose 5000mg/kg of EAML did not cause death in animals. The AEML, at doses 125, 250, 500, 750, 1000 and 1500mg/kg, significantly inhibited (in a dose-dependant way) the number of contortions induced by acetic acid on writhing test. The median effective dose (ED50) of 692.6 mg/kg did not prolong the latency-time in the hot plate. The AEML showed activity in both first and second phase of formalin-induced licking response decreasing of the lick paw of mice, where this effect was reversed by the opioid antagonist naloxone. The AEML was able to inhibite the erythema formation when compared to control group, but did not inhibite the paw edema formation induced by dextran. The AEML inhibited the paw edema carrageenan-induced from 2nd hour and reduced neutrophil migration to peritoneal cavity. Our results indicate that AEML demonstrate an antinociceptive effect with probable involvement of the opioid system, and anti-inflammatory activity through inhibition of prodution of inflammatory mediators as PGs, and also on adhesion molecules with involvement of cytokines.
Acesso aberto (Open Access)
Caracterização da cinética de captação de glutamato por cromatografia líquida de alta eficiência em tecido retiniano
(Universidade Federal do Pará, 2011-08-19) MORAES, Edinaldo Rogério da Silva; SILVA, Anderson Manoel Herculano Oliveira da; http://lattes.cnpq.br/8407177208423247
The present study describes a simple and efficient method utilizing high performance liquid chromatography (HPLC) coupled to fluorescence detection for the determination of kinetic parameters of glutamate uptake in nervous tissue. Retinal tissue obtained from 7-day-old chicks was incubated to known concentrations of glutamate (50-2000 μM) for 10 minutes, and the levels of the o-phtaldehyde (OPA)-derivatized neurotransmitter in the incubation medium were measured. By assessing the difference between initial and final concentrations of glutamate in the medium, a saturable uptake mechanism was characterized (Km = 8,2 e Vmax = 9,8 nmol/mg protein/minute). This measure was largely sodium- and temperature-dependent, strongly supporting that the mechanism for concentration decrements is indeed uptake by high-affinity transporters. Added to this, our results also demonstrated that zinc chloride (an inhibitor of glutamate/aspartate transporters) evoked a concentration dependent decrease in the glutamate uptake, demonstrating an elevate specificity of our methodology. Overall, the present work characterizes an alternative methodology to evaluate glutamate uptake in nervous tissue using HPLC. This approach could be an important tool for studies associated to the characterization of glutamate transport related with central nervous system injury
Acesso aberto (Open Access)
Caracterização físico-química e análises por espectrofotometria e cromatografia de Peperomia pellucida L. (H. B. K.)
(2013) SILVA, Rosali Maria Ferreira da; RIBEIRO, Jeane Francisca Alves; FREITAS, Manolo Cleiton Costa de; ARRUDA, Mara Silvia Pinheiro; NASCIMENTO, M.N.; BARBOSA, Wagner Luiz Ramos; ROLIM NETO, Pedro José
The aim of this study was the physical chemical characterization of the powder and the tincture, and the chromatographic and spectrophotometric analysis of the Peperomiapellucida L. (H. B. K.) dry extract. The methodology followed the Farmacopeia Brasileira IV ed., except for the chemical prospection, the chromatographic profile obtained and the spectrophotometry of the dry extract, and determination of dried residues. The chemical prospection revealed the presence of foaming saponins; reducing sugars; proteins and amino acids; phenols; tannins; flavonoids; steroids and triterpenoids; depsideos and depsidones. The best profile from TLC for flavonoidic fraction was obtained with methanol/formic acid (90:10 v/v). HPLC confirmed the presence of 3 ‘,4’,7-tri-methoxyflavone in the dry extract of the plant material. The results obtained in this work should contribute for the determination of specifications for a future monograph on Peperomia pellucida L. (H.B.K.)
Acesso aberto (Open Access)
Desenvolvimento metodológico e avaliação de contaminação por HPAs em sedimentos da baia de Guajará
(Universidade Federal do Pará, 2014-03-31) SODRÉ, Silvana do Socorro Veloso; CAVALCANTE, Rivelino Martins; http://lattes.cnpq.br/2253127527012522; CORRÊA, José Augusto Martins; http://lattes.cnpq.br/6527800269860568
Polycyclic Aromatic Hydrocarbons (PAHs) are pollutants with toxic effects, harmful to the environment and to human health. They are part of a group of persistent organic pollutants (POPs), which by its characteristics have an impact on the environment and are extensively studied for this reason. They may be present in particulate, dissolved and/or gaseous forms, in different environments such as soil, sediment, air, water, particulate matter in the atmosphere, organisms and food (Kennish, 2007). Natural sources of PAHs include volcanic activity, natural fires, oil oozing and biogenic processes. Anthropogenic PAH pollution may occur by incomplete oil combustion (automotive and industrial), intentional burning of wood and plantations, domestic and/or industrial wastewater, urban water flow, accidental spills of oil and derivatives. Hydrophobic and lipophilic, these substances can be easily adsorbed by sediments, so that this matter is an important reservoir for them. To evaluate the presence of these compounds in the environment, this work used High Performance Liquid Chromatography. The samples used in the development and optimization of the methodology were collected in the Guajará bay (Belém - PA). This work consisted in the development of a methodological procedure (with adaptations and optimizations) to quantify 16 PAHs in 10 points in the Guajará bay in two field campaigns, so that 20 samples were analysed. In the development stage of the analytical method, elution systems, system polarity and eluent flow were tested, among others. In order to validate the method, the following parameters were assessed: fidelity, linearity, detection limit and quantification limit. Diagnostic ratios were calculated to identify the primary sources of PAHs found in the bay. The primary sources of the 16 PAHs studied in the sediments of the bay were identified based on ΣPAHs BMM/ΣPAHsAMM; Phe/Ant; Flt/Pyr; Ant/Σ178; Flt/Σ202; B(a)P/Σ228 and Ind(123cd)pyrene/Σ276. In the first field campaign, the total concentration of light PAHs ranged from 132.3 ng.g-1 to 1704.14 ng.g-1, the ΣPAHs of the heavy ones, from 125.82 ng.g-1 to 1269.71 ng.g-1 and the total ΣPAHs, from 317.84 ng.g-1 to 3117.06 ng.g-1. In the second field campaign, the total concentration of light PAHs ranged from 76.12 ng.g-1 to 1572.80 ng.g-1, the ΣPAHs of the heavy ones, from 213.90 ng.g-1 to 1423.03 ng.g-1, and the total ΣPAHs, from 290.02 ng.g-1 to 2995.82 ng.g-1. Based on these results, the Guajará bay can be classified as moderately impacted. The combustion is the predominant source of PAHs in the sediments of the bay, followed by vegetal biomass combustion and by the contribution of oil and supplies. Most of the points studied in this work, during the two field campaigns, showed concentrations of individual PAHs above the SQGs.
Acesso aberto (Open Access)
Determinação das concentrações plasmáticas de amitriptilina por cromatografia líquida de alta eficiência em pacientes com hanseníase e estados reacionais
(Universidade Federal do Pará, 2008-10-24) MORAES, Tânia Mara Pires; VIEIRA, José Luiz Fernandes; http://lattes.cnpq.br/2739079559531098
Leprosy is a granulomatous disease affecting the skin and peripheral nerves caused by Mycobacterium leprae. The alterations in peripheral nerves can originate pain symptoms and deformities, with consequent reduction of patient life quality. Amitriptyline is the drug of choice for the treatment of pain symptoms in patients with leprosy. Amitriptyline had a narrow therapeutic range and a great variability in plasmatic concentrations between patients. Thus the therapeutic monitoring of the plasmatic concentrations of this drug its a important tool for therapy optimization. In this sense this work aimed the validation of an analytical procedure for determination of amitriptyline by high performance liquid chromatography, in patients with hansenic reactions using amitriptyline daily doses of 25mg or 50mg, as well make the comparison between amitriptyline plasmatic concentrations in the presence or absence of multidrug therapy and in the reactions type I and II. This study was conducted in Tropical Medicine Institute from Para Federal University. Were enrolled 21 patients, 12(57%) male and 9 (43%) female. Eight patients (38%) were in curse of multidrug therapy and 10 (47%) presented hansenic reaction type I. The medium plasmatic amitriptyline concentration in dose of 25mg was 318144ng/mL and 361182ng/mL. No statistical significance was observed between medium plasmatic amitriptyline concentrations in doses of 25mg and 50mg, as well in the presence of multidrug therapy.
Acesso aberto (Open Access)
Determinação das concentrações plasmáticas e teciduais de itraconazol em pacientes com cromoblastomicose
(Universidade Federal do Pará, 2008-09-01) GRISÓLIA, Daniella Paternostro de Araújo; VIEIRA, José Luiz Fernandes; http://lattes.cnpq.br/2739079559531098
Chromoblastomycosis is a subcutaneous mycosis caused by deployment transcutaneous of several species of dematiaceous fungi, that is, melanized fungi. Considering the incidence of this disease in the state of Pará and the resulting morbidity of patients affected, with economic and social repercussions, it was made to the optimization of therapeutic schemes adopted, to the best knowledge of the relation dose x response. The itraconazole is one of the few drugs available for treatment, which has marked variability kinetic intra and inter individual, which compromises the establishment of the relation dose and response, as well as tissue and plasma concentrations achieved. In this sense, this work aimed at validation of analytical methodology by High Performance Liquid Chromatography and subsequent determination of itraconazole in samples of plasma and tissue in 20 patients with chromoblastomycosis, assisted in the laboratory of dermatoimmunology Dr. Marcello Candia, Marituba, Pará, who used the drug in doses of 200mg/day and 400mg/day. The technique employed was validated and proved adequate results in accordance with applicable law. Concentrations of plasma and tissue of itraconazole in the dose of 200mg/day were 121.3 87.9 ng/mL and 5.36 5.9 μg/g. The average plasma concentration of itraconazole in patients using 400mg/day was 290 234 ng/mL, and the plasma and tissue mean concentrations of itraconazole in patients who showed no clinical favourable, at doses of 200mg, making it necessary to increase to 400mg were 217 216 and 304 173 ng/mL; 14.87 12.94 e 21.80 6.62 μg/g. The average of relation between tissue and plasma concentrations in patients who had positive developments in clinical in the doses of 200mg/day was 44.29 67.12 and those that did not show positive developments in clinical in the doses of 200mg/day, making necessary to increase to 400mg/day were 68.52 59.90 and 71.71 38.26 respectively.
Acesso aberto (Open Access)
Determinação das concentrações sanguíneas de pirazinamida em pacientes com tuberculose pulmonar
(Universidade Federal do Pará, 2018-04-26) LUCENA, Stefania de Medeiros Araújo; VIEIRA, José Luiz Fernandes; http://lattes.cnpq.br/2739079559531098
Tuberculosis is an important health problem in Brazil. The first-line treatment regimen adopted by the Ministry of Health for the treatment of the disease consists of rifampicin, isoniazid, pyrazinamide and ethambutol in the intensive phase (02 months), and rifampicin and isoniazid in the maintenance phase (04 months) of the treatment. The determination of the concentrations of these drugs in biological fluids is determinant to confirm the adequate exposure, besides helping to identify the causes of the multiresistance. In Brazil, the concentrations of these drugs have not yet been described in the course of treatment of the disease. Therefore, this study aims to determine the blood concentrations of pyrazinamide in patients with clinical and laboratory diagnosis of pulmonary tuberculosis, evaluating the influence of sex and hyperglycemia on the plasma levels of these drugs. For this, 54 adult patients of both sexes, diagnosed with active pulmonary tuberculosis, submitted to the first line treatment were included in the study, from which blood samples were collected before treatment (D0), at the end of the first month (D30) and at the end of the second month of treatment (D60). Patients' socio-demographic data were collected through a questionnaire. Pyrazinamide concentrations were determined by high performance liquid chromatography with ultraviolet detection and glycemia by conventional spectrophotometric method. Of the patients included in the study, 53% are male and 90% are between 19 and 59 years old. In addition, 37% completed only elementary education. Eight patients were excluded by noncompliance. The mean plasma concentration of pyrazinamide in pre-dose samples was 3.4 μg / mL and in the post-dose samples it was 72.5 μg / mL. These data point to adequate exposure of M. tuberculosis to the drug. Patients' sex did not influence plasma pyrazinamide concentrations. These results allow us to conclude that the doses of pyrazinamide used in tuberculosis patients caused by M. tuberculosis ensure effective therapeutic blood concentrations in post-dose samples, as well as the pre-dose concentrations were consistent with the pharmacokinetics of the drug. Finally, post-dose concentrations were significantly higher in patients with hyperglycemia.
Acesso aberto (Open Access)
Determinação de mefloquina e carboximefloquina em pacientes com malária por plasmodium falciparum no estado do Amapá
(Universidade Federal do Pará, 2008) BORGES, Larissa Maria Guimarães; VIEIRA, José Luiz Fernandes; http://lattes.cnpq.br/2739079559531098
The determination of plasmatic and erythrocyte concentrations of mefloquine (MQ) and carboxymefloquine (CMQ) were studied in children and adults with malaria by Plasmodium falciparum not complicated in the Amapa state. The adult patients received oral outline of MQ 20 mg/kg divided in two days and artesunate 4 mg/kg/day for three days. For children the dose of MQ followed the schedule recommended by the manual of malaria therapy. Concentrations of MQ and CMQ in erythrocytes were quantified by high performance liquid chromatography on the third day of treatment (D3) and plasma levels were measured in the third and second fortieth day after the institution of therapy (D3 and D42). The average concentration of MQ and CMQ in plasma of children in D3 were 1.84 ± 0.83 μg/mL and 1.44 ± 0.70 μg/mL, and in erythrocytes 5.26 ± 1.46 μg/mL and 1.18 ± 0.65 μg/mL. In D42 the plasma concentrations were 0.45 ± 0.11 μg/mL and 0.51 ± 0.10 μg/mL, respectively. The relationship between plasma and erythrocytes concentrations of MQ and CMQ were 2.86 ± 1.27 and 0.75 ± 0.26. In adults, concentrations of MQ and CMQ in plasma were 2.43 ± 1.13 μg/mL and 1.10 ± 0.38 μg/mL, and in erythrocytes 5.51 ± 1.92 μg/mL and 1.08 ± 0.35 μg/mL, respectively. The plasma concentrations in D42 were 0.54 ± 0.15 μg/mL and 0.58 ± 0.93 μg/mL, respectively. The relationship erythrocyte:plasma for MQ was 3.03 ± 1.56 and 1.12 ± 0.29 to CMQ. The correlation coefficient between plasma and erythrocytes concentrations of MQ in children was 0.035 and adults 0.0436. For CMQ the correlation coefficient in children was 0.8722 and in adults 0.5155. The higher accumulation of MQ in the red blood cells allows us to emphasize the importance of the simple diffusion for the entry of the drug in the cell because of their physical and chemical characteristics.
Acesso aberto (Open Access)
Validação de método para determinação de cloroquina e desetilcloroquina em amostras de sangue adsorvidas em papel de filtro por cromatografia líquida de alta eficiência com detector de UV
(Universidade Federal do Pará, 2008) NASCIMENTO, Margareth Tavares Silva; VIEIRA, José Luiz Fernandes; http://lattes.cnpq.br/2739079559531098
The determination of the antimalarial blood concentrations employing by fast simple and sensitive methods represents important tool for the optimization of therapeutic regimens currently used in Brazil. In this sense, this paper describes the validation of an analytical methodology by high performance liquid chromatography with ultraviolet detection for the determination of chloroquine in blood samples adsorbed on filter paper, from patients with vivax malaria. It was evaluated: precision intra and inter assay, recovery, limits of detection and quantification, robustness, stability, linearity and selectivity. The results showed that the coefficients of variation of intra assay, at concentrations of 100 to 1000 ng/ml ranged from 6 to 10% for both chloroquine and desethylchloroquine. The coefficient of variation inter assay, at concentrations of 100 to 1000 ng/ml ranged from 5 to 10% and 4 to 10% for chloroquine and desethylchloroq uine, respectively. The limits of detection were 62.5 ng/mL for chloroquine and 50.0 ng/mL f or desethylchloroquine and limits of quantificatio n were 100 ng/mL for both analytes. The recovery in the concentration from 100 to 1000 ng/ml ranged from 90 to 105 % and 95% to 105 for chloroquine and desethylchloroquine, respectively. The method was linear in the range of concentration of 100 to 2000 ng/ml for chl oroquine and 100 to 800 ng/ml for desethylchloroquine. The method showed to be robust for small changes in flow, pH of the mobile phase and composition of the organic phase. It was not observed interferents in the validated procedure among those drugs used to treat malaria. The determination of chloroquine and desethylchloroquine in patients with vivax malar ia whose average values were 1266±455 ng/mL and 357±165 ng/mL, characterized the applicabilityof the validated procedure for the determination of antimalarial drugs in these patients.