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1.
Cell ; 157(6): 1324-1338, 2014 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-24906150

RESUMO

The Hippo-signaling pathway is an important regulator of cellular proliferation and organ size. However, little is known about the role of this cascade in the control of cell fate. Employing a combination of lineage tracing, clonal analysis, and organoid culture approaches, we demonstrate that Hippo pathway activity is essential for the maintenance of the differentiated hepatocyte state. Remarkably, acute inactivation of Hippo pathway signaling in vivo is sufficient to dedifferentiate, at very high efficiencies, adult hepatocytes into cells bearing progenitor characteristics. These hepatocyte-derived progenitor cells demonstrate self-renewal and engraftment capacity at the single-cell level. We also identify the NOTCH-signaling pathway as a functional important effector downstream of the Hippo transducer YAP. Our findings uncover a potent role for Hippo/YAP signaling in controlling liver cell fate and reveal an unprecedented level of phenotypic plasticity in mature hepatocytes, which has implications for the understanding and manipulation of liver regeneration.


Assuntos
Desdiferenciação Celular , Fígado/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular , Hepatócitos/metabolismo , Via de Sinalização Hippo , Fígado/citologia , Camundongos , Fosfoproteínas/metabolismo , Receptores Notch/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Proteínas de Sinalização YAP
2.
Nature ; 606(7915): 747-753, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35705805

RESUMO

Haematopoietic stem cells (HSCs) arise in the embryo from the arterial endothelium through a process known as the endothelial-to-haematopoietic transition (EHT)1-4. This process generates hundreds of blood progenitors, of which a fraction go on to become definitive HSCs. It is generally thought that most adult blood is derived from those HSCs, but to what extent other progenitors contribute to adult haematopoiesis is not known. Here we use in situ barcoding and classical fate mapping to assess the developmental and clonal origins of adult blood in mice. Our analysis uncovers an early wave of progenitor specification-independent of traditional HSCs-that begins soon after EHT. These embryonic multipotent progenitors (eMPPs) predominantly drive haematopoiesis in the young adult, have a decreasing yet lifelong contribution over time and are the predominant source of lymphoid output. Putative eMPPs are specified within intra-arterial haematopoietic clusters and represent one fate of the earliest haematopoietic progenitors. Altogether, our results reveal functional heterogeneity during the definitive wave that leads to distinct sources of adult blood.


Assuntos
Envelhecimento , Linhagem da Célula , Embrião de Mamíferos , Hematopoese , Células-Tronco Hematopoéticas , Animais , Embrião de Mamíferos/citologia , Células-Tronco Hematopoéticas/citologia , Camundongos , Células-Tronco Multipotentes/citologia
3.
Nature ; 578(7794): 278-283, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32025033

RESUMO

The biology of haematopoietic stem cells (HSCs) has predominantly been studied under transplantation conditions1,2. It has been particularly challenging to study dynamic HSC behaviour, given that the visualization of HSCs in the native niche in live animals has not, to our knowledge, been achieved. Here we describe a dual genetic strategy in mice that restricts reporter labelling to a subset of the most quiescent long-term HSCs (LT-HSCs) and that is compatible with current intravital imaging approaches in the calvarial bone marrow3-5. We show that this subset of LT-HSCs resides close to both sinusoidal blood vessels and the endosteal surface. By contrast, multipotent progenitor cells (MPPs) show greater variation in distance from the endosteum and are more likely to be associated with transition zone vessels. LT-HSCs are not found in bone marrow niches with the deepest hypoxia and instead are found in hypoxic environments similar to those of MPPs. In vivo time-lapse imaging revealed that LT-HSCs at steady-state show limited motility. Activated LT-HSCs show heterogeneous responses, with some cells becoming highly motile and a fraction of HSCs expanding clonally within spatially restricted domains. These domains have defined characteristics, as HSC expansion is found almost exclusively in a subset of bone marrow cavities with bone-remodelling activity. By contrast, cavities with low bone-resorbing activity do not harbour expanding HSCs. These findings point to previously unknown heterogeneity within the bone marrow microenvironment, imposed by the stages of bone turnover. Our approach enables the direct visualization of HSC behaviours and dissection of heterogeneity in HSC niches.


Assuntos
Células-Tronco Hematopoéticas/metabolismo , Imagem Molecular , Animais , Remodelação Óssea , Movimento Celular , Proliferação de Células , Sobrevivência Celular , Feminino , Genes Reporter , Hipóxia/metabolismo , Proteína do Locus do Complexo MDS1 e EVI1/genética , Proteína do Locus do Complexo MDS1 e EVI1/metabolismo , Masculino , Camundongos , Oxigênio/metabolismo , Crânio/citologia , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo
4.
Molecules ; 28(5)2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36903513

RESUMO

In recent years, carob and its derived products have gained wide attention due to their health-promoting effects, which are mainly attributed to their phenolic compounds. Carob samples (carob pulps, powders, and syrups) were analyzed to investigate their phenolic profile using high-performance liquid chromatography (HPLC), with gallic acid and rutin being the most abundant compounds. Moreover, the antioxidant capacity and total phenolic content of the samples were estimated through DPPH (IC50 98.83-488.47 mg extract/mL), FRAP (48.58-144.32 µmol TE/g product), and Folin-Ciocalteu (7.20-23.18 mg GAE/g product) spectrophotometric assays. The effect of thermal treatment and geographical origin of carobs and carob-derived products on their phenolic composition was assessed. Both factors significantly affect the concentrations of secondary metabolites and, therefore, samples' antioxidant activity (p-value < 10-7). The obtained results (antioxidant activity and phenolic profile) were evaluated via chemometrics, through a preliminary principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA). The OPLS-DA model performed satisfactorily, differentiating all samples according to their matrix. Our results indicate that polyphenols and antioxidant capacity can be chemical markers for the classification of carob and its derived products.


Assuntos
Antioxidantes , Fabaceae , Antioxidantes/química , Flavonoides/química , Quimiometria , Fenóis/química , Fabaceae/química
5.
Blood ; 136(20): 2296-2307, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-32766876

RESUMO

The exact localization of hematopoietic stem cells (HSCs) in their native bone marrow (BM) microenvironment remains controversial, because multiple cell types have been reported to physically associate with HSCs. In this study, we comprehensively quantified HSC localization with up to 4 simultaneous (9 total) BM components in 152 full-bone sections from different bone types and 3 HSC reporter lines. We found adult femoral α-catulin-GFP+ or Mds1GFP/+Flt3Cre HSCs proximal to sinusoids, Cxcl12 stroma, megakaryocytes, and different combinations of those populations, but not proximal to bone, adipocyte, periarteriolar, or Schwann cells. Despite microanatomical differences in femurs and sterna, their adult α-catulin-GFP+ HSCs had similar distributions. Importantly, their microenvironmental localizations were not different from those of random dots, reflecting the relative abundance of imaged BM populations rather than active enrichment. Despite their functional heterogeneity, dormant label-retaining (LR) and non-LR hematopoietic stem and progenitor cells both had indistinguishable localization from α-catulin-GFP+ HSCs. In contrast, cycling juvenile BM HSCs preferentially located close to Cxcl12 stroma and farther from sinusoids/megakaryocytes. We expect our study to help resolve existing confusion regarding the exact localization of different HSC types, their physical association with described BM populations, and their tissue-wide combinations.


Assuntos
Células-Tronco Adultas/citologia , Células-Tronco Hematopoéticas/citologia , Nicho de Células-Tronco , Animais , Camundongos
6.
Electrophoresis ; 43(23-24): 2392-2401, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36189902

RESUMO

During this study, a simple and easy-to-prepare electrophoretic method was developed for the enantioseparation of amphetamine and cathinone derivatives. Different types of ß-cyclodextrin and cyclofructan-based chiral selectors (CSs), both native and derivatized, were utilized, and the most effective ones, in terms of resolution and analysis time, were identified. In addition, several electrophoretic parameters, such as background electrolyte concentration and pH, and CS concentration, were examined to optimize the separation conditions. Under the optimal electrophoretic conditions, 10 psychoactive substances were enantiomerically separated using 1 mM sulfated cyclofructan-6 (SCF-6) for the amphetamine derivatives and 1 mM sulfated cyclofructan-7 (SCF-7) for the cathinone derivatives dissolved in an aqueous solution of 20-mM monobasic sodium phosphate at pH 2.5, a temperature of 25°C, and an applied voltage of 25 kV. In addition, the method was validated by estimating the intra- and interday precision.


Assuntos
Ciclodextrinas , Ciclodextrinas/química , Estereoisomerismo , Eletroforese Capilar/métodos , Anfetamina , Sulfatos
7.
Anal Bioanal Chem ; 414(3): 1323-1333, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34779900

RESUMO

In this study, cyclofructan (CF)-, cyclodextrin (CD)-, and polysaccharide-based chiral stationary phases (CSPs) were exploited in high-performance liquid chromatography (HPLC) for the chiral separations of different clinically and pharmaceutically important compounds. In particular, R-naphthylethyl carbamate CF6 (RN-CF6), 3,5-dimethylphenyl carbamate CF7 (DMP-CF7), neutral beta cyclodextrin (ß-CD), 3,5-dimethylphenyl carbamate ß-CD (DMP-ß-CD), and cellulose tris-(3,5-dimethylphenylcarbamate) (Cellulose-Tris DMP) columns were utilized under isocratic elution. The performance of these CSPs as chiral separation media was evaluated by use of nine analytes: acidic, basic, and amphiprotic. A possible correlation between the functional groups of these analytes and the chiral-recognition ability of each chiral column was also examined. The enantioseparations were optimized by varying different parameters, such as mobile phase additives, column temperature, and flow rate. Finally, a comparison was made between all CSPs, and it was expressed in terms of resolution (RS), efficiency (N), selectivity (α), retention factors (k1', k2') and analysis time (tR1, tR2). It was observed that RN-CF6 was the most suitable and efficient CSP for the chiral separation of various types of analytes, including acids, primary and tertiary amines, alcohols, and many neutral compounds. It was the only CSP that provided baseline enantioseparation of thyroxine (RS = 1.6) and cetirizine (RS = 2.0).


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Ciclodextrinas/química , Frutanos/química , Preparações Farmacêuticas/isolamento & purificação , Polissacarídeos/química , Estereoisomerismo
8.
Electrophoresis ; 42(19): 1945-1955, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34240758

RESUMO

In this work, a simple, reliable, and fast capillary electrophoretic method was developed and validated for the simultaneous determination of 12 polyphenolic compounds, the most frequently found in carob's pulp and seeds. The present work deals with the development of a novel dual electrophoretic system based on the combined use of ß-CD and ionic liquid (IL) as buffer additives. A baseline separation of the target analytes was achieved in less than 10 min by using a BGE consisting of 35 mM borate along with 15 mM ß-CD and 3 mM l-alanine tert butyl ester lactate (l-AlaC4 Lac) IL as buffer additives at pH 9.5, a temperature of 25°C, and an applied voltage of 30 kV. The application of the developed electrophoretic method to real samples enabled the identification and quantification of the main phenolic constituents of both ripe and unripe carob pulp extracts. The results revealed the predominance of gallic acid in both ripe (183.92 µg/g carob pulp) and unripe (205.10 µg/g carob pulp) carob pulp and highlighted the great influence of the ripening stage on carobs polyphenolic composition, with unripe pods being more enriched in polyphenols (total phenolics detected: 912.58 and 283.13 µg/g unripe and ripe carob pulp).


Assuntos
Fabaceae , Líquidos Iônicos , Fenóis , beta-Ciclodextrinas , Eletrólitos , Galactanos , Mananas , Gomas Vegetais
9.
Proc Natl Acad Sci U S A ; 115(37): 9252-9257, 2018 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-30139917

RESUMO

Epoxyeicosatrienoic acids (EETs) are lipid-derived signaling molecules with cardioprotective and vasodilatory actions. We recently showed that 11,12-EET enhances hematopoietic induction and engraftment in mice and zebrafish. EETs are known to signal via G protein-coupled receptors, with evidence supporting the existence of a specific high-affinity receptor. Identification of a hematopoietic-specific EET receptor would enable genetic interrogation of EET signaling pathways, and perhaps clinical use of this molecule. We developed a bioinformatic approach to identify an EET receptor based on the expression of G protein-coupled receptors in cell lines with differential responses to EETs. We found 10 candidate EET receptors that are expressed in three EET-responsive cell lines, but not expressed in an EET-unresponsive line. Of these, only recombinant GPR132 showed EET-responsiveness in vitro, using a luminescence-based ß-arrestin recruitment assay. Knockdown of zebrafish gpr132b prevented EET-induced hematopoiesis, and marrow from GPR132 knockout mice showed decreased long-term engraftment capability. In contrast to high-affinity EET receptors, GPR132 is reported to respond to additional hydroxy-fatty acids in vitro, and we found that these same hydroxy-fatty acids enhance hematopoiesis in the zebrafish. We conducted structure-activity relationship analyses using both cell culture and zebrafish assays on diverse medium-chain fatty acids. Certain oxygenated, unsaturated free fatty acids showed high activation of GPR132, whereas unoxygenated or saturated fatty acids had lower activity. Absence of the carbon-1 position carboxylic acid prevented activity, suggesting that this moiety is required for receptor activation. GPR132 responds to a select panel of oxygenated polyunsaturated fatty acids to enhance both embryonic and adult hematopoiesis.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Hematopoese/efeitos dos fármacos , Oxilipinas , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas de Peixe-Zebra/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Células Cultivadas , Hematopoese/genética , Camundongos , Camundongos Knockout , Oxilipinas/química , Oxilipinas/farmacologia , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais/genética , Relação Estrutura-Atividade , Peixe-Zebra , Proteínas de Peixe-Zebra/genética
10.
Molecules ; 26(16)2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34443605

RESUMO

Extracts derived from the Ceratonia siliqua L. (carob) tree have been widely studied for their ability to prevent many diseases mainly due to the presence of polyphenolic compounds. In this study, we explored, for the first time, the anti-cancer properties of Cypriot carobs. We produced extracts from ripe and unripe whole carobs, pulp and seeds using solvents with different polarities. We measured the ability of the extracts to inhibit proliferation and induce apoptosis in cancer and normal immortalized breast cells, using the MTT assay, cell cycle analysis and Western Blotting. The extracts' total polyphenol content and anti-oxidant action was evaluated using the Folin-Ciocalteu method and the DPPH assay. Finally, we used LC-MS analysis to identify and quantify polyphenols in the most effective extracts. Our results demonstrate that the anti-proliferative capacity of carob extracts varied with the stage of carob maturity and the extraction solvent. The Diethyl-ether and Ethyl acetate extracts derived from the ripe whole fruit had high Myricetin content and also displayed specific activity against cancer cells. Their mechanism of action involved caspase-dependent and independent apoptosis. Our results indicate that extracts from Cypriot carobs may have potential uses in the development of nutritional supplements and pharmaceuticals.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Fabaceae/química , Fenóis/química , Fenóis/farmacologia , Solventes/química , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Frutas/química , Humanos , Sementes/química
11.
Electrophoresis ; 40(4): 539-546, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30450594

RESUMO

The combined use of chiral ionic liquids (CILs) and conventional chiral selectors (CSs) in CE, to establish a synergistic system, has proven to be an effective approach for the separation of enantiomeric pairs. In this study, a new CE method was developed, employing a binary system of a CS, either a cyclodextrin (CD) or a cyclofructan (CF), and a chiral amino acid ester-based ionic liquid (AAIL), for the chiral separation of four basic, acidic and zwitterionic drug compounds. In particular, the enantioseparation of two anticoagulants, warfarin (WAR) and coumachlor (COU), a non-opioid analgesic, nefopam (NEF) and a third-generation antihistamine, fexofenadine (FXD), was examined, by supporting the BGE with a CS and the chiral AAIL L-alanine tert butyl ester lactate (L-AlaC4 Lac). Parameters, such as the type of the CS, the concentration of both the CS and L-AlaC4 Lac, and the BGE pH, were methodically examined in order to optimize the chiral separation of each analyte. It was observed that, in some cases, the addition of the AAIL into the BGE improved both resolution (Rs ) and efficiency (N) significantly. In other cases, the synergistic effect enabled baseline separation of analyte enantiomers, at a much lower concentration of the CS. Finally, after optimization of separation conditions, baseline separations (Rs >1.5) of all four analytes were achieved in less than 5 min.


Assuntos
Ciclodextrinas/química , Eletroforese Capilar/métodos , Frutanos/química , Líquidos Iônicos , Alanina/química , Concentração de Íons de Hidrogênio , Líquidos Iônicos/química , Líquidos Iônicos/isolamento & purificação , Lactatos/química , Preparações Farmacêuticas/química , Preparações Farmacêuticas/isolamento & purificação , Estereoisomerismo
12.
Electrophoresis ; 38(6): 786-819, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27921310

RESUMO

This report, which is a sequence of a series of reviews, records the most important chiral selectors (CSs) applied in CE. It highlights the CSs that were used during the period 2014 to mid-2016. In this review, method developments, validations, and pharmaceutical along with biomedical applications are presented. The different CSs include CDs, antibiotics, cyclofructants, linear and branched oligo- and polysaccharides, and polymeric surfactants. In addition, the advantages of these CSs, along with their chiral recognition mechanisms, and their performance, are discussed.


Assuntos
Eletroforese Capilar/métodos , Animais , Antibacterianos/análise , Ciclodextrinas/análise , Humanos , Polissacarídeos/análise , Estereoisomerismo , Tensoativos/análise
13.
Electrophoresis ; 37(7-8): 1101-8, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26333847

RESUMO

This paper reports the development and validation of a new method based on ultra-performance LC coupled to MS/MS for the simultaneous determination of four cholesterol oxidation products (COPs) in foodstuffs in only 4.1 min. The COPs were detected by ESI in positive-ion mode with multiple reaction monitoring, and the mass spectrometric conditions were optimized in order to increase sensitivity. The developed method was validated in terms of linearity, precision, LODs, and LOQs. Recoveries of the extraction process ranged from 86 to 98.5% when the samples were fortified at 100, 500, and 1500 ng/mL. The applicability of the method was confirmed by analyzing different food samples. Considering the paucity of data regarding the content of COPs in Cypriot foods, particular attention was devoted, for the first time, to the determination of the profile of the main COPs in widely consumed, traditional Cypriot foodstuffs (halloumi cheese, hiromeri, snails, etc.).


Assuntos
Colesterol/análise , Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/métodos , Espectrometria de Massas em Tandem/métodos , Animais , Chipre , Laticínios/análise , Limite de Detecção , Modelos Lineares , Carne/análise , Oxirredução , Coelhos , Reprodutibilidade dos Testes , Caramujos , Suínos
14.
Electrophoresis ; 36(1): 101-23, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25263224

RESUMO

There is a large number of chiral selectors (CSs) that have, over the years, been synthesized and used in electrophoretic enantioseparations. This report highlights the most important CSs applied in CE during the period 2012 to mid-2014. It is mainly focused on method developments and validations, along with pharmaceutical and biomedical applications. Even though numerous publications have, through the years, reported the utilization of CSs in enantioseparations, only the ones applied in electrophoretic techniques the last approximately three years are demonstrated in this review article. In particular, cyclodextrins, cyclofructants, linear and branched oligo- and polysaccharides, antibiotics, and polymeric surfactants are presented, and their advantages, their chiral recognition mechanisms, and their performance are discussed.


Assuntos
Eletroforese Capilar/métodos , Animais , Antibacterianos/química , Ciclodextrinas/química , Eletroforese Capilar/instrumentação , Humanos , Modelos Moleculares , Polissacarídeos/química , Estereoisomerismo , Tensoativos/química
15.
Electrophoresis ; 36(24): 3061-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26444144

RESUMO

Cyclofructans (CFs) and their derivatives have recently been proven to be efficient chiral selectors (CSs) for the enantioseparation of several analytes in CE, HPLC, and GC. In this study, the chiral separation ability of a number of native and derivatized CFs was examined in CE. Particularly, six different CFs, with different derivatization groups and cavity sizes [native CF-6 and CF-7, isopropyl cyclofructan-6 (IPCF-6), IPCF-7, sulfated cyclofructan-6 (SCF-6), and SCF-7] were used as CSs for the enantioseparation of huperzine A, warfarin, and coumachlor. Almost all of the examined CFs, except from SCF-6 & -7, demonstrated relatively low and sometimes no chiral separation ability for huperzine A. In an effort to improve both resolution and efficiency, the chiral ionic liquid D-Alanine tert butyl ester lactate (D-AlaC4Lac) was added into the BGE. In most of the cases, the combination of CF with D-AlaC4Lac resulted in an improvement in peak efficiency and/or resolution. When CF-6 was utilized with D-AlaC4Lac, a resolution of 1.4 was obtained, while the use of IPCF-6/D-AlaC4Lac provided a baseline enantioseparation. Although the combination of SCF-7 and 40 mM D-AlaC4Lac did not affect resolution, it dramatically increased peak efficiency from 24,000 to 117,000. In the case of warfarin and coumachlor, IPCF-6 and IPCF-7 proved to be the most effective CSs. It is, therefore, concluded that the size of the cavity and the CF derivatization are the key parameters for the chiral separation capability. It is also clear from this study that D-AlaC4Lac is necessary for improved peak efficiencies and resolutions.


Assuntos
Alcaloides/isolamento & purificação , Cumarínicos/isolamento & purificação , Eletroforese Capilar/métodos , Frutanos/química , Líquidos Iônicos/química , Sesquiterpenos/isolamento & purificação , Alcaloides/análise , Alcaloides/química , Cumarínicos/análise , Cumarínicos/química , Reprodutibilidade dos Testes , Sesquiterpenos/análise , Sesquiterpenos/química , Estereoisomerismo
16.
Electrophoresis ; 36(19): 2442-50, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26080944

RESUMO

In this study, a new CE method, employing a binary system of trimethyl-ß-CD (TM-ß-CD) and a chiral amino acid ester-based ionic liquid (AAIL), was developed for the chiral separation of seven 2-arylpropionic acid nonsteroidal anti-inflammatory drugs (NSAIDs). In particular, the enantioseparation of ibuprofen, ketoprofen, carprofen, indoprofen, flurbiprofen, naproxen, and fenoprofen was improved significantly by supporting the BGE with the chiral AAIL l-alanine tert butyl ester lactate (l-AlaC4 Lac). Parameters, such as concentrations of TM-ß-CD and l-AlaC4 Lac, and buffer pH, were systematically examined in order to optimize the chiral separation of each NSAID. It was observed that the addition of the AAIL into the BGE improved both resolution and efficiency significantly. After optimization of separation conditions, baseline separation (Rs >1.5) of five of the analytes was achieved in less than 11 min, while the resolution of ibuprofen and flurbiprofen was approximately 1.2. The optimized enantioseparation conditions for all analytes involve a BGE of 5 mM sodium acetate/acetic acid (pH 5.0), an applied voltage of 30 kV, and a temperature of 20°C. In addition, the results obtained by computing the %-RSD values of the EOF and the two enantiomer peaks, demonstrated excellent run-to-run, batch-to-batch, and day-to-day reproducibilities.


Assuntos
Alanina/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Eletroforese Capilar/métodos , Lactatos/química , Fenilpropionatos/isolamento & purificação , beta-Ciclodextrinas/química , Anti-Inflamatórios não Esteroides/análise , Anti-Inflamatórios não Esteroides/química , Fenilpropionatos/análise , Fenilpropionatos/química , Reprodutibilidade dos Testes , Estereoisomerismo
17.
Chirality ; 27(12): 973-8, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26447904

RESUMO

A fast screening method of whole blood was proposed for enantiorecognition of free L-T3 , L-T4 , and D-T4 . Stochastic microsensors based on four inulins (IN, IQ, TEX, and HD) immobilized on diamond paste (DP) were used for recognition of free L-T3 , L-T4 , and D-T4 . For the enantiorecognition of free L-T4 and D-T4 in whole blood and pharmaceutical samples, the best microsensor was the one based on TEX/DP (wide linear concentration ranges, and low limits of quantification). The best limit of detection for the assay of free L-T3 (400 fmol/L) was recorded using the microsensors based on HD/DP, while for the assay of free L-T4, and D-T4 the best limit of determination (1 pmol/L) was recorded using the TX/DP-based microsensor. For the enantiorecognition of free L-T3 in whole blood and pharmaceutical samples the best microsensor was the one based on HD/DP (the wider linear concentration range, and the lower limit of quantification - of pmol/L magnitude order). For the enantiorecognition of free L-T3 in whole blood and pharmaceutical samples the best microsensor was the one based on HD/DP (the wider linear concentration range, and the lower limit of quantification - of pmol/L magnitude order). Free L-T3 , L-T4 , and D-T4 were recovered with high reliabilities in whole blood samples (recoveries higher than 99.00%, with RSD values lower than 1.00%) and pharmaceutical samples (recoveries higher than 95.00% with RSD values lower than 1.00%).


Assuntos
Tiroxina/sangue , Tri-Iodotironina/sangue , Humanos , Limite de Detecção , Estereoisomerismo
18.
Electrophoresis ; 35(18): 2573-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24853394

RESUMO

The aim of the present study is the CE performance evaluation for the separation of 2-arylpropionic acid nonsteroidal anti-inflammatory drugs. In particular, the separation of indoprofen, carprofen, ketoprofen, ibuprofen, and flurbiprofen was obtained by supporting the BGE either with SDS or an amino acid ester-based ionic liquid (AAIL). The performance of these additives was evaluated by comparing migration times, efficiencies and %RSD values. The addition of the AAIL into the BGE provided baseline separation within 10 min, while in the case of SDS, the analytes eluted within 23 min. The optimum conditions involve a BGE of 100 mM Tris/10 mM sodium tetraboratedecahydrate (pH 8) and 40 mM l-alanine tert butyl ester lactate or 10 mM SDS and a temperature of 35°C for AAIL and 20°C for SDS. The run-to-run reproducibility was evaluated by computing the %RSD values of the EOF and the analyte peaks. When the AAIL was used, an excellent reproducibility was obtained, since all %RSD values were below 1.3%. On the contrary, the addition of SDS resulted in much higher RSD values (2.1-11.7%). The efficiency values of all analyte peaks were above 102 000 for l-AlaC4 Lac, in comparison to SDS, which provided efficiency values between 47000 and 76000. Finally, in an attempt to study the synergistic effect of SDS and AAIL, both additives were added into the BGE at concentrations of 10 and 40 mM, respectively. The results were similar to the ones obtained when SDS was used as the sole additive.


Assuntos
Anti-Inflamatórios não Esteroides/isolamento & purificação , Eletroforese Capilar/métodos , Líquidos Iônicos/química , Fenilpropionatos/isolamento & purificação , Aminoácidos/química , Anti-Inflamatórios não Esteroides/análise , Anti-Inflamatórios não Esteroides/química , Soluções Tampão , Carbazóis/análise , Carbazóis/química , Carbazóis/isolamento & purificação , Ésteres/química , Flurbiprofeno/análise , Flurbiprofeno/química , Flurbiprofeno/isolamento & purificação , Concentração de Íons de Hidrogênio , Fenilpropionatos/análise , Fenilpropionatos/química , Reprodutibilidade dos Testes , Dodecilsulfato de Sódio , Temperatura
19.
Antioxidants (Basel) ; 13(2)2024 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-38397760

RESUMO

In this study, an optimized environmentally friendly procedure was employed to enhance the sustainable utilization of phenolic antioxidants derived from aloe vera rind by-products. The procedure involved the application of ultrasound-assisted extraction (UAE) in combination with deep eutectic solvents (DESs). Eleven different DESs and three conventional solvents were employed as extraction media for polyphenolic compounds. Choline chloride-citric acid (ChCl-CA) was selected as the most suitable extractant, considering its extraction efficiency in relation to the total phenolic content. The operating conditions of UAE were optimized and modeled by the use of response surface methodology in order to maximize the yield of total phenolics and antioxidant capacity. The optimal operational parameters for the UAE procedure were determined to be 16.5 min, 74% (v/v) DES in water, and a solvent-to-solid ratio equal to 192. HPLC analysis, which was performed on the optimum extract, revealed significant levels of phenolics present in the aloe rind. Efficient recovery of the extracted antioxidants was obtained by the use of solid-phase extraction (SPE) and polyamide cartridges. The ChCl-CA DES exhibited excellent recycling capability with a yield of over 90% through SPE. Finally, the greenness of the method was evaluated using the green AGREE and AGREEprep metrics. The results highlighted the sustainability and the greenness of the proposed extraction procedure for the aloe by-product.

20.
J Pharm Biomed Anal ; 239: 115897, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38071765

RESUMO

A comprehensive study was performed to determine an optimum enantioseparation method for fluorine-substituted amphetamine and cathinone derivatives (fluor-amphetamine and fluor-cathinone derivatives), using a binary system consisting of carboxymethyl-ß-CD (CM-ß-CD) and a deep eutectic solvent (DES), namely choline chloride-ethylene glycol (ChCl-EG). Under this framework, the optimization and modeling of the separation conditions in a binary system were performed with the objective of maximizing resolution and minimizing analysis time. This was achieved through the application of response surface methodology. In particular, the effect of chiral selector concentration and percentage of DES on resolution and analysis time were investigated and optimized using a complete experimental design. The optimum enantioseparation conditions were determined to be 13.84 mM CM-ß-CD and 0.15% v/v ChCl-EG for fluorine-substituted amphetamine derivatives and 14.36 mM and 0.75% v/v ChCl-EG for fluorine-substituted cathinone derivatives, respectively. This combination resulted in a baseline separation for eight out of the nine analytes studied. Overall, the results demonstrated the synergistic effect of the CM-ß-CD/DES dual system and highlighted the significance of DESs as additives in capillary electrophoresis.


Assuntos
Solventes Eutéticos Profundos , Flúor , Eletroforese Capilar/métodos , Colina , Anfetaminas , Estereoisomerismo
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