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1.
Int J Phytoremediation ; 24(14): 1475-1490, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35216535

RESUMO

Pollution of the soils with toxic elements is a serious problem all over the world. One of environmentally friendly techniques of their removal is phytoremediation. This paper is a summary of literature data and the results of own studies about the potential of Sinapis alba for bioaccumulation of Tl, As and PGEs, and its usefulness in remediation of polluted environment. S. alba is characterized with low living requirements, BFs ≫ 1 and high TFs, especially for Tl (up to 3). The influence of different forms of studied elements on plants was discussed based on biomass production, morphological changes and the impact on photosynthesis activity. The plants were cultivated in hydroponics and solid media of various composition, for example, in soil supplemented with MnO2, which resulted in BFs lower 6-7 times for leaves, and about 3-4 times for stems, as well as twice lower leaf development. Application of advanced analytical techniques was presented in studies of the detoxification mechanisms, identification of particular chemical forms of the elements and the presence of phytochelatins and their complexes with the investigated elements.Novelty StatementThe paper summarizes both literature and original data on Sinapis alba exposed to such elements as thallium, arsenic and platinum group metals. The influence of different forms of studied elements on white mustard was discussed based on biomass production and morphological changes, as well as the impact on photosynthesis activity. The study covers such aspects as bioaccumulation, phytotoxicity as well as the usefulness of white mustard in remediation of polluted environment.


Assuntos
Sinapis , Poluentes do Solo , Biodegradação Ambiental , Tálio , Poluentes do Solo/análise , Compostos de Manganês , Óxidos , Solo/química , Plantas , Mecanismos de Defesa
2.
Artigo em Inglês | MEDLINE | ID: mdl-33302355

RESUMO

The aim of this pilot intervention study was to assess the effectiveness of selected forms of therapy (massage and relaxation) in reducing the perceived burden and improving the emotional status of caregivers of people with dementia and to determine which form of physical intervention is most effective. The study group was made up of 45 informal caregivers, who were divided into three subgroups (the massage group, relaxation group and control group). The Caregiver Burden Scale (CBS), Beck Depression Inventory (BDI), Berlin Social Support Scale (BSSS) and the Satisfaction with Life Scale (SWLS) were used. In the study group of caregivers, an average level of perceived burden, satisfactory life satisfaction and moderate severity of depressive symptoms were found. Massage led to a reduction in perceived burden and an improvement in mood and well-being of the examined group of caregivers. Group relaxation activities had no effect on the level of burden experienced by the caregivers, but significantly improved their mood. Both massage and relaxation were equally effective in improving the well-being of caregivers. Due to the lower cost of group activities, relaxation activities seem to be more effective and easier to organize, but further studies are necessary.


Assuntos
Cuidadores , Demência , Adulto , Idoso , Berlim , Efeitos Psicossociais da Doença , Demência/terapia , Depressão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação Pessoal , Projetos Piloto , Qualidade de Vida , Apoio Social
3.
Chemistry ; 26(49): 11266-11275, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32259329

RESUMO

In eukaryotes, mature mRNA is formed through modifications of precursor mRNA, one of which is 5' cap biosynthesis, involving RNA cap guanine-N7 methyltransferase (N7-MTase). N7-MTases are also encoded by some eukaryotic viruses and facilitate their replication. N7-MTase inhibitors have therapeutic potential, but their discovery is difficult because long RNA substrates are usually required for activity. Herein, we report a universal N7-MTase activity assay based on small-molecule fluorescent probes. We synthesized 12 fluorescent substrate analogues (GpppA and GpppG derivatives) varying in the dye type, dye attachment site, and linker length. GpppA labeled with pyrene at the 3'-O position of adenosine acted as an artificial substrate with the properties of a turn-off probe for all three tested N7-MTases (human, parasite, and viral). Using this compound, a N7-MTase inhibitor assay adaptable to high-throughput screening was developed and used to screen synthetic substrate analogues and a commercial library. Several inhibitors with nanomolar activities were identified.


Assuntos
Avaliação Pré-Clínica de Medicamentos , Ensaios Enzimáticos , Inibidores Enzimáticos/isolamento & purificação , Inibidores Enzimáticos/farmacologia , Ensaios de Triagem em Larga Escala , Metiltransferases/metabolismo , Capuzes de RNA/metabolismo , Guanina/análogos & derivados , Guanina/metabolismo , Humanos , Metiltransferases/antagonistas & inibidores , Capuzes de RNA/química
4.
Metallomics ; 11(9): 1498-1505, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31389928

RESUMO

Palladium is recognized as a technologically critical element (TCE) because of its massive use in automobile exhaust gas catalytic converters. The release of Pd into the environment in the form of nanoparticles of various size and chemical composition requires an understanding of their metabolism by leaving organisms. We provide here for the first time a chemical speciation insight into the identity of the ligands produced or used by a plant Sinapis alba L. exposed in hydropony to Pd nanoparticles and soluble Pd (nitrate). The analytical method developed was based on the concept of 2D HPLC with parallel inductively coupled plasma mass spectrometry (ICP MS) and electrospray MS detection. Size exclusion chromatography - ICP MS of the plant extracts showed no difference between the speciation of Pd after the exposure to nanoparticles and after that to Pd2+ which indicated the reactivity and dissolution of Pd nanoparticles. A comparative investigation of the Pd speciation in a control plant extract spiked with Pd2+ and of an extract of a plant having metabolized palladium indicated the response of the Sinapis alba by the formation of a Pd-histidine complex. The complex was identified via Orbitrap MS; the HPLC-MS chromatogram produced two peaks at m/z 415.0341 each corresponding to a Pd-His2 complex. An investigation by ion-mobility MS revealed a difference in their collision cross section indicating that the complexes present varied in terms of spatial conformation. A number of other Pd complexes with different ligands (including nicotianamine) circulating in the plant were detected but these ligands were already observed in a control plant and their concentrations were not affected by the exposure to Pd.


Assuntos
Histidina/metabolismo , Paládio/metabolismo , Sinapis/metabolismo , Exposição Ambiental , Poluentes Ambientais/metabolismo , Nanopartículas/metabolismo
5.
Inorg Chem ; 57(4): 1935-1949, 2018 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-29411979

RESUMO

Considerable effort has been devoted to the development of first-row transition-metal catalysts containing redox-active imino-pyridine ligands that are capable of storing multiple reducing equivalents. This property allows abundant and inexpensive first-row transition metals, which favor sequential one-electron redox processes, to function as competent catalysts in the concerted two-electron reduction of substrates. Herein we report the syntheses and characterization of a series of iron complexes that contain both π-donating thiolate and π-accepting (α-imino)-N-heterocycle redox-active ligands, with progressively larger N-heterocycle rings (imidazole, pyridine, and quinoline). A cooperative interaction between these complementary redox-active ligands is shown to dictate the properties of these complexes. Unusually intense charge-transfer (CT) bands, and intraligand metrical parameters, reminiscent of a reduced (α-imino)-N-heterocycle ligand (L•-), initially suggested that the electron-donating thiolate had reduced the N-heterocycle. Sulfur K-edge X-ray absorption spectroscopic (XAS) data, however, provides evidence for direct communication, via backbonding, between the thiolate sulfur and the formally orthogonal (α-imino)-N-heterocycle ligand π*-orbitals. DFT calculations provide evidence for extensive delocalization of bonds over the sulfur, iron, and (α-imino)-N-heterocycle, and TD-DFT shows that the intense optical CT bands involve transitions between a mixed Fe/S donor, and (α-imino)-N-heterocycle π*-acceptor orbital. The energies and intensities of the optical and S K-edge pre-edge XAS transitions are shown to correlate with N-heterocycle ring size, as do the redox potentials. When the thiolate is replaced with a thioether, or when the low-spin S = 0 Fe(II) is replaced with a high-spin S = 3/2 Co(II), the N-heterocycle ligand metrical parameters and electronic structure do not change relative to the neutral L0 ligand. With respect to the development of future catalysts containing redox-active ligands, the energy cost of storing reducing equivalents is shown to be lowest when a quinoline, as opposed to imidazole or pyridine, is incorporated into the ligand backbone of the corresponding Fe complex.

7.
Artigo em Inglês | MEDLINE | ID: mdl-27547228

RESUMO

UNLABELLED: Introduction. Patients with end-stage renal disease (ESRD) have poor physical performance and exercise capacity due to frequent dialysis treatments. Tai Chi exercises can be very useful in the area of rehabilitation of people with ESRD. OBJECTIVES: The aim of the study was to assess exercise capacity in ESRD patients participating in 6-month Tai Chi training. Patients and Methods. Twenty dialysis patients from Wroclaw took part in the training; at the end of the project, 14 patients remained (age 69.2 ± 8.6 years). A 6-minute walk test (6MWT) and spiroergometry were performed at the beginning and after 6 months of training. RESULTS: After 6 months of Tai Chi, significant improvements were recorded in mean distance in the 6MWT (387.89 versus 436.36 m), rate of perceived exertion (7.4 versus 4.7), and spiroergometry (8.71 versus 10.08 min). Conclusions. In the ESRD patients taking part in Tai Chi training, a definite improvement in exercise tolerance was recorded after the 6-month training. Tai Chi exercises conducted on days without dialysis can be an effective and interesting form of rehabilitation for patients, offering them a chance for a better quality of life and fewer falls and hospitalisations that are the result of it.

8.
Environ Pollut ; 218: 1023-1036, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27574802

RESUMO

The studied soil profile under the Main Market Square (MMS) in Krakow was characterised by the influence of medieval metallurgical activity. In the presented soil section lithological discontinuity (LD) was found, which manifests itself in the form of cultural layers (CLs). Moreover, in this paper LD detection methods based on soil texture are presented. For the first time, three different ways to identify the presence of LD in the urban soils are suggested. The presence of LD had an influence on the content and distribution of heavy metals within the soil profile. The content of heavy metals in the CLs under the MMS in Krakow was significantly higher than the content in natural horizons. In addition, there were distinct differences in the content of heavy metals within CLs. Profile variability and differences in the content of heavy metals and phosphorus within the CLs under the MMS were activity indicators of Krakow inhabitants in the past. This paper presents alternative methods for the assessment of the degree of heavy metal contamination in urban soils using selected pollution indices. On the basis of the studied total concentration of heavy metals (Zn, Pb, Cu, Mn, Cr, Cd, Ni, Sn, Ag) and total phosphorus content, the Geoaccumulation Index (Igeo), Enrichment Factor (EF), Sum of Pollution Index (PIsum), Single Pollution Index (PI), Nemerow Pollution Index (PINemerow) and Potential Ecological Risk (RI) were calculated using different local and reference geochemical backgrounds. The use of various geochemical backgrounds is helpful to evaluate the assessment of soil pollution. The individual CLs differed from each other according to the degree of pollution. The different values of pollution indices within the studied soil profile showed that LDS should not be evaluated in terms of contamination as one, homogeneous soil profile but each separate CL should be treated individually.


Assuntos
Metalurgia , Metais Pesados/análise , Poluentes do Solo/análise , Monitoramento Ambiental , Poluição Ambiental/análise , Fósforo/análise , Polônia , Solo/química
9.
J Biol Inorg Chem ; 21(5-6): 793-805, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27251139

RESUMO

A series of vanadium compounds was studied by K-edge X-ray absorption (XAS) and K[Formula: see text] X-ray emission spectroscopies (XES). Qualitative trends within the datasets, as well as comparisons between the XAS and XES data, illustrate the information content of both methods. The complementary nature of the chemical insight highlights the success of this dual-technique approach in characterizing both the structural and electronic properties of vanadium sites. In particular, and in contrast to XAS or extended X-ray absorption fine structure (EXAFS), we demonstrate that valence-to-core XES is capable of differentiating between ligating atoms with the same identity but different bonding character. Finally, density functional theory (DFT) and time-dependent DFT calculations enable a more detailed, quantitative interpretation of the data. We also establish correction factors for the computational protocols through calibration to experiment. These hard X-ray methods can probe vanadium ions in any oxidation or spin state, and can readily be applied to sample environments ranging from solid-phase catalysts to biological samples in frozen solution. Thus, the combined XAS and XES approach, coupled with DFT calculations, provides a robust tool for the study of vanadium atoms in bioinorganic chemistry.


Assuntos
Compostos de Vanádio/química , Teoria Quântica , Espectrometria por Raios X , Espectroscopia por Absorção de Raios X
10.
RNA ; 22(4): 518-29, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26826132

RESUMO

Dcp1/2 is the major eukaryotic RNA decapping complex, comprised of the enzyme Dcp2 and activator Dcp1, which removes the 5' m(7)G cap from mRNA, committing the transcript to degradation. Dcp1/2 activity is crucial for RNA quality control and turnover, and deregulation of these processes may lead to disease development. The molecular details of Dcp1/2 catalysis remain elusive, in part because both cap substrate (m(7)GpppN) and m(7)GDP product are bound by Dcp1/2 with weak (mM) affinity. In order to find inhibitors to use in elucidating the catalytic mechanism of Dcp2, we screened a small library of synthetic m(7)G nucleotides (cap analogs) bearing modifications in the oligophosphate chain. One of the most potent cap analogs, m(7)GpSpppSm(7)G, inhibited Dcp1/2 20 times more efficiently than m(7)GpppN or m(7)GDP. NMR experiments revealed that the compound interacts with specific surfaces of both regulatory and catalytic domains of Dcp2 with submillimolar affinities. Kinetics analysis revealed that m(7)GpSpppSm(7)G is a mixed inhibitor that competes for the Dcp2 active site with micromolar affinity. m(7)GpSpppSm(7)G-capped RNA undergoes rapid decapping, suggesting that the compound may act as a tightly bound cap mimic. Our identification of the first small molecule inhibitor of Dcp2 should be instrumental in future studies aimed at understanding the structural basis of RNA decapping and may provide insight toward the development of novel therapeutically relevant decapping inhibitors.


Assuntos
Análogos de Capuz de RNA/química , Proteínas de Schizosaccharomyces pombe/antagonistas & inibidores , Avaliação Pré-Clínica de Medicamentos , Clivagem do RNA , RNA Mensageiro/química , Schizosaccharomyces/enzimologia
11.
Water Air Soil Pollut ; 226(4): 126, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25859065

RESUMO

Nanoparticles (NPs) are commonly used, and concerns about their possible adverse effects are being voiced as well. However, little is known about the fates of NPs released to the environment. The aim of the study was to (i) evaluate the ability of Sinapis alba and Lepidium sativum plants to take up platinum nanoparticles (Pt-NPs) and translocate them to aboveground organs, (ii) compare the accumulation efficiency of different forms of platinum and (iii) identify the forms in which platinum is stored in plant tissues. Plants were cultivated on medium supplemented with different concentrations of Pt-NPs and [Pt(NH3)4](NO3)2. Platinum content in plants was determined using inductively coupled plasma mass spectrometry. For the identification of the presence of Pt-NPs in plant tissues, gamma spectrometry following iron irradiation was applied. It was found that L. sativum and S. alba are tolerant to applied concentrations of Pt-NPs and have an ability to take up platinum from the medium and translocate it to aboveground organs. The highest concentration of platinum was observed in plant roots (reaching 8.7 g kg-1 for S. alba). We tentatively conclude that platinum is accumulated as nanoparticles. The obtained results suggest future application of plants for phytoremediation and recovery of noble metal nanoparticles.

12.
Acta Pol Pharm ; 71(4): 583-92, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25275204

RESUMO

The objective of the study was to assess the effects of Na[V(V)O(O2)2(2,2'-bpy)] x 8 H2O (complex 1), Na[V(V)O(O2)2(1,10'-phen)] x 5 H2O (complex 2), Na[V(V)O(O2)2(4,4'-Me-2,2'-bpy)] x 8 H2O (complex 3), [V(V)O(SO,)(1,10'-phen)] x 2 H2O, (complex 4), [V(IV)O(SO4)(2,2'-bpy)] x H2O (complex 5), where: 2,2'-bpy = 2,2'-bipyridine, 1.10'-phen = 1,10'-phenanthroline, 4,4'-Me-2,2'-bpy = 4,4'-dimethyl-2,2'-bipyridine and a small insulin injection on V, Cu, Mn, K, Fe, Zn, and Ca concentration in the STZ (streptozotocin) diabetic rats pancreas during a 5-week treatment with the tested complexes. In all groups of animals metal concentration in the pancreas was investigated by means of Proton Induced X-ray Emission (PIXE) method. Maximum concentration of vanadium was observed in the pancreas for complex 5 (1.69 +/- 0.09 mg/kg dry weight), lower for complex 3 (1.51 +/- 0.10 mg/kg dry weight), and the lowest for complex 1 (1.21 +/- 0.27 mg/kg dry weight) supplementation. The influence of vanadium administration on other metals' concentration in the rats' pancreas was also investigated. All vanadium-tested complexes showed an increase of zinc concentration in the examined pancreas in comparison to the diabetic animals not treated with vanadium. The results were the highest for complex 1 and the lowest for complex 5. The concentration of Fe, Cu, Mn, K and Ca in the pancreas is not evidently influenced by administration of the vanadium complexes.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Metais/análise , Pâncreas/química , Vanádio/administração & dosagem , Animais , Diabetes Mellitus Experimental/metabolismo , Suplementos Nutricionais , Masculino , Ratos , Ratos Wistar , Estreptozocina
13.
Biol Trace Elem Res ; 153(1-3): 319-28, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23661329

RESUMO

The objective of the study was to investigate the effects of five organic vanadium complexes supplement and a small dose of insulin injection on V, Fe, Cu, Zn, Mn, Ca, and K level in the streptozotocin diabetic rat's kidney during a 5-week treatment with the tested complexes. In all groups of animals, metal level in the lyophilized kidney organs was investigated by means of the proton induced X-ray emission method. Tissue vanadium level was naturally higher in vanadium-treated rats. The maximum level of vanadium was observed in the kidney (x(mean) = 16.6 µg/g). The influence of vanadium administration on other metal level in rat's tissue was also investigated. Spectacular influence of vanadium action was observed on copper and zinc level in examined tissue.


Assuntos
Rim/metabolismo , Metais/metabolismo , Vanádio/uso terapêutico , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Ligantes , Masculino , Ratos , Ratos Wistar , Estreptozocina
14.
Acta Pol Pharm ; 70(1): 71-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23610961

RESUMO

Abstract: The objective of the study was to assess the effects of five vanadium organic complexes administered with small insulin injection, on V, Fe, Cu, Zn, Mn, Ca and K concentration in STZ (streptozotocin) diabetic rats tissues during a 5-week treatment with the tested complexes. In all groups of animals, metal concentration in a dry spleen samples was investigated by the proton induced X-ray emission (PIXE) method. Obviously, vanadium tissue concentration was higher in vanadium-treated rats. Concentration of vanadium in the spleen was x = 21.3 microg/g of dry sample. Vanadium administration influenced other metals concentration of rats tissues. The most pronounced influence of vanadium was observed on iron concentration in the spleen. All results were calculated for correlation between different groups of animals. Present study showed small interferences between trace element changes in diabetic, or non diabetic rats after vanadium treatment. Measured elements, especially zinc, manganese and copper, are co-factors of enzymes and their content changes can influence on organism homeostasis in diabetes treatment. Understanding and recognizing these relationship may permit better diabetes treatment in the future.


Assuntos
Cálcio/metabolismo , Cobre/metabolismo , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Ferro/metabolismo , Manganês/metabolismo , Potássio/metabolismo , Baço/efeitos dos fármacos , Vanadatos/farmacologia , Compostos de Vanádio/farmacologia , Zinco/metabolismo , Administração Oral , Animais , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/metabolismo , Insulina/farmacologia , Masculino , Ratos , Ratos Wistar , Espectrometria por Raios X , Baço/metabolismo , Estreptozocina , Fatores de Tempo , Vanadatos/administração & dosagem , Vanadatos/metabolismo , Compostos de Vanádio/administração & dosagem , Compostos de Vanádio/metabolismo
15.
Biol Trace Elem Res ; 144(1-3): 560-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21416340

RESUMO

The purpose of this study was to determine glutathione peroxidase (GSHPx) activity in the liver of red deer in relation to selenium concentrations in the liver, as well as to evaluate changes in GSHPx activity according to sex, body weight and season of the year. Total selenium concentration in the liver of red deer averaged 0.095 ± 0.018 µg/g of wet weight. GSHPx activity in the liver of red deer ranged widely from 4.4 to 45.8 U/g of protein. Females were characterized by higher GSHPx activity compared to males (21.2 vs. 17.0 U/g protein). The highest GSHPx activity was recorded in autumn and the lowest in summer. The lowest GSHPx activity in the liver was found in the heaviest animals (>100 kg body weight), averaging 14.0 U/g protein. Animals weighing <66 kg and 66-100 kg were characterized by similar activity of 25.1 and 24.5 U/g, respectively. Despite the differences in GSHPx activity according to sex, body weight and season of the year, these factors had no significant effect on the activity of this enzyme. The main factor regulating GSHPx activity in the liver of examined red deer was selenium concentration.


Assuntos
Peso Corporal/fisiologia , Cervos/fisiologia , Glutationa Peroxidase/metabolismo , Fígado/enzimologia , Fígado/metabolismo , Estações do Ano , Selênio/metabolismo , Animais , Interpretação Estatística de Dados , Feminino , Indicadores e Reagentes , Masculino , Caracteres Sexuais , Comportamento Sexual Animal , Espectrometria de Fluorescência
16.
RNA ; 17(5): 978-88, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21447710

RESUMO

Decapping is an essential step in multiple pathways of mRNA degradation. Previously, we synthesized mRNAs containing caps that were resistant to decapping, both to dissect the various pathways for mRNA degradation and to stabilize mRNA for more sustained protein expression. mRNAs containing an α-ß CH(2) group are resistant to in vitro cleavage by the decapping enzyme hDcp2 but poorly translated. mRNAs containing an S substitution at the ß-phosphate are well translated but only partially resistant to hDcp2. We now describe seven new cap analogs substituted at the ß-phosphate with BH(3) or Se, or substituted at either the α-ß or ß-γ O with NH. The analogs differ in affinity for eIF4E and efficiency of in vitro incorporation into mRNA by T7 RNA polymerase. Luciferase mRNAs capped with these analogs differ in resistance to hDcp2 hydrolysis in vitro, translational efficiency in rabbit reticulocyte lysate and in HeLa cells, and stability in HeLa cells. Whereas mRNAs capped with m(2)(7,2'-O)Gpp(S)pG were previously found to have the most favorable properties of translational efficiency and stability in mammalian cells, mRNAs capped with m(7)Gpp(BH3)pm(7)G are translated with the same efficiency but are more stable. Interestingly, some mRNAs exhibit a lag of up to 60 min before undergoing first-order decay (t(1/2) ≅ 25 min). Only mRNAs that are efficiently capped, resistant to decapping in vitro, and actively translated have long lag phases.


Assuntos
Ácidos Bóricos/metabolismo , Compostos de Nitrogênio/metabolismo , Polifosfatos/metabolismo , Biossíntese de Proteínas , Estabilidade de RNA , RNA Mensageiro/análise , Selênio/metabolismo , Animais , RNA Polimerases Dirigidas por DNA/metabolismo , Endorribonucleases/metabolismo , Células HeLa , Humanos , Camundongos , Estrutura Molecular , Polifosfatos/química , Capuzes de RNA , RNA Mensageiro/química , RNA Mensageiro/metabolismo , Coelhos , Reticulócitos/química , Estereoisomerismo , Especificidade por Substrato , Proteínas Virais/metabolismo
18.
J Chromatogr A ; 1107(1-2): 9-18, 2006 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-16388811

RESUMO

Tropane alkaloids solid-liquid extraction methods were developed and comprised ambient pressure ones: extraction with hot solvent, extraction at room temperature, on ultrasonic bath as well as pressurised liquid extraction (PLE) techniques. The highest yields of l-hyoscyamine in methanol PLE method (3 x 5 min, 110 degrees C) and scopolamine extracted with 1% tartaric acid in methanol (15 min, 90 degrees C) were determined. A mixed-mode reversed-phase cation-exchange solid-phase extraction (SPE) procedure was optimised for simultaneous recoveries of L-hyoscyamine, scopolamine, scopolamine-N-oxide from plant extracts as well as quaternary alkaloid representative: scopolamine-N-methyl bromide. First three alkaloids were efficiently eluted (recoveries 80-100%) from an Oasis MCX cartridge with methanol-10% ammonia (3:1, v/v) solution, whereas for the quaternary salt tetrahydrofuran-methanol-25% ammonia (6:1:3, v/v) was used with recoveries 52-6%. HPTLC-densitometric assay on silica gel plates was elaborated at 205 nm without derivatization and included: single development (over a distance 9.5 cm) with acetone-methanol-water-25% ammonia (85:5:5:8, v/v) mobile phase for L-hyoscyamine and scopolamine separation, whereas for scopolamine-N-oxide and scopolamine-N-methyl bromide a second development (to a distance 5.5 cm) with acetonitrile-methanol-85% formic acid (120:5:5, v/v) was applied. Newly elaborated RP-HPLC-diode array detection method was performed on Waters XTerra RP-18 column with gradient of acetonitrile in 15 mM ammonia solution and alkaloids were baseline separated within 20 min. Both chromatographic methods were validated and their quantitative results were compared. Good correlation between HPLC and HPTLC quantitative results was measured (correlation coefficients of mean values were 0.92086 and 0.99995 for L-hyoscyamine and scopolamine, respectively). In the RP-HPLC method, which was from 1.5- up to 7-fold more sensitive than HPTLC, limits of detection (LOD) and limits of quantitation (LOQ, in bracket) were (in ng/microl) as follows: 0.25 (0.82) for L-hyoscyamine, 0.29 (0.97) for scopolamine, 0.13 (0.45) for scopolamine-N-oxide and 0.58 (1.91) for scopolamine-N-methyl bromide. By the use of the optimised chromatographic methods, 14 various samples from the leaves and fruits of Datura sp. were screened for L-hyoscyamine and scopolamine contents and the most promising samples were established.


Assuntos
Alcaloides/isolamento & purificação , Resinas de Troca de Cátion , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Datura/química , Polímeros/química , Alcaloides/química , Cromatografia em Camada Fina , Sensibilidade e Especificidade
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