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1.
Polymers (Basel) ; 16(13)2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39000734

RESUMO

Tetra pak packaging is one of the most frequently used types of packaging in the food industry. The recycling of the tetra pak packaging waste presents a difficult task because of its multi-layered, multi-component structure. In this study, the degradation of tetra pak packaging in subcritical (SubCW) and supercritical (SCW) water was investigated. The experiments were carried out in one (SCW) or two stages (SubCW and SCW), whereby the influence of the reaction temperature and time on the yield and composition of the products obtained was investigated. The maximum oil phase yield achieved in a one-stage and a two-stage degradation process was 60.7% and 65.5%, respectively. The oil and gas phases were composed of different types of hydrocarbons. Higher temperature and longer time led to higher amounts of saturated aliphatic hydrocarbons in both the oil and gas phases. The aqueous phase contained sugars (glucose, fructose) and sugar derivatives (levulinic acid, glyceraldehyde, furfurals). Based on these results, the degradation pathway of waste tetra pak packaging in SubCW and SCW was proposed. The results of the study show that the degradation of waste tetra pak packaging with SubCW and SCW is a promising recycling process.

2.
Front Psychol ; 15: 1278396, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38449760

RESUMO

Mental fatigue (MF) arises during prolonged demanding cognitive activity and results in acute feelings of tiredness and a decreased physical and/or cognitive performance capacity. An often-overlooked population that is significantly at risk for the development of MF are university students. The current study investigated the impact of prolonged in-person theoretical classes on the perceptions of MF, boredom, and sleepiness among 27 Slovenian university students (first-year physiotherapy). Their subjective experiences at various time points during a 4-h class interspersed with a 20 min break were assessed with a repeated measures ANOVA and consequent Bonferroni post-hoc tests (significance set at <0.05). Subjective MF and sleepiness significantly increased during the first and the second part of the class (p < 0.05), while they significantly decreased during the break (p < 0.05). Boredom levels only increased significantly during the second part of the class (p < 0.05). Additionally, students who had inadequate sleep the night before the class reported higher levels of MF at the beginning of the class. This study highlighted a significant impact of a theoretical class on subjective feelings of mental fatigue and showed that a break in the middle of the class temporarily alleviated this negative impact. These results emphasize the importance of adequate sleep, effective breaks, and strategies to manage cognitive workload in optimizing students' cognitive well-being and academic performance. Further research is needed to better understand the underlying factors and develop targeted interventions to support students' cognitive functioning and well-being during prolonged academic sessions.

3.
Foods ; 13(4)2024 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-38397530

RESUMO

Plant waste materials are important sources of bioactive compounds with remarkable health-promoting benefits. In particular, industrial by-products such as mango peels are sustainable sources of bioactive substances, with antioxidant, enzymatic, and antimicrobial activity. Appropriate processing is essential to obtain highly bioactive compounds for further use in generating value-added products for the food industry. The objective of the study was to investigate and compare the biological activity of compounds from fresh and dried mango peels obtained by different conventional methods and unconventional extraction methods using supercritical fluids (SFE). The highest total phenolic content (25.0 mg GAE/g DW) and the total content of eight phenolic compounds (829.92 µg/g DW) determined by LC-MS/MS were detected in dried mango peel extract obtained by the Soxhlet process (SE). SFE gave the highest content of proanthocyanidins (0.4 mg PAC/g DW). The ethanolic ultrasonic process (UAE) provided the highest antioxidant activity of the product (82.4%) using DPPH radical scavenging activity and total protein content (2.95 mg protein/g DW). Overall, the dried mango peels were richer in bioactive compounds (caffeic acid, chlorogenic acid, gallic acid, catechin, and hesperidin/neohesperidin), indicating successful preservation during air drying. Furthermore, outstanding polyphenol oxidase, superoxide dismutase (SOD), and lipase activities were detected in mango peel extracts. This is the first study in which remarkable antibacterial activities against the growth of Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) were evaluated by determining the microbial growth inhibition rate after 12 and 24 h incubation periods for mango peel extracts obtained by different methods. Ethanolic SE and UAE extracts from dried mango peels resulted in the lowest minimum inhibitory concentrations (MIC90) for all bacterial species tested. Mango peels are remarkable waste products that could contribute to the sustainable development of exceptional products with high-added value for various applications, especially as dietary supplements.

4.
Molecules ; 28(23)2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38067554

RESUMO

Hemp is probably one of the most studied plants for its health-promoting properties, with countless documented and patented extraction methods, but literature is scarce on the simultaneous extraction of mixture of raw materials. Hemp, along with other plant materials, could represent a potentially highly valuable source material with resulting reciprocal effects. In this study, hemp (Cannabis sativa) and three members of the Zingiberaceae family, ginger (Zingiber officinale), turmeric (Curcuma longa), and cardamom (Elettaria cardamomum), were extracted simultaneously, and their bioactive component values were investigated. Two extraction methods were used, namely ultrasound-assisted extraction with ethanol and supercritical fluid extraction with carbon dioxide. First, extracts were obtained from separate plant materials. Then, hemp was extracted in combination with ginger, turmeric, and cardamom in a 1:1 ratio. The extracts obtained were evaluated for their antioxidant activity and total phenolic content using UV/VIS spectrophotometry; cannabinoid content, 6-gingerol, and 6-shogaol were measured using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS); volatile components such as 1,8-cineole, alpha-terpinyl acetate, linalool, and aR-turmerone were measured using gas chromatography with mass spectrometry (GC/MS).


Assuntos
Cannabis , Elettaria , Zingiberaceae , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Líquida , Espectrometria de Massas em Tandem , Elettaria/química , Extratos Vegetais/química
5.
Foods ; 12(21)2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37959119

RESUMO

Turmeric Curcuma longa is a well-known spice with various health benefits, attributed primarily to curcumin. Soxhlet extraction, cold maceration, ultrasound-assisted extraction (UAE), and supercritical fluid extraction were performed, and the content of total phenols, proanthocyanidins, and antioxidants was analysed by UV/VIS spectrophotometry. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was employed to identify and quantify the curcumin content. Supercritical extracts had the highest total phenolic content (538.95 mg GA/100 g material), while the Soxhlet extracts had the highest content of proanthocyanidins (4.77 mg PAC/100 g of material). Extracts obtained by UAE and supercritical extraction have the highest antioxidant potential. Antioxidant activity measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH•) was 64.27% and 1750.32 mg Trolox per g dry weight by 2,2-azinobis(3-ethylbenzothiazoline 6 sulphonic acid) (ABTS+•) for the extract obtained by supercritical extraction. The UAE resulted in the highest amount of curcumin (1.91 mg curcumin/g material). A kinetic study showed that extraction yield in supercritical extracts decreased with increasing temperature and that the content of isolated curcumin was inversely proportional to solvent-to-feed ratio (S/F). The present study has confirmed that turmeric is an excellent source of antioxidants, such as curcumin, that play an important role in reducing cellular stress by neutralising free radicals.

6.
Molecules ; 27(22)2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36431795

RESUMO

The prevention and treatment of skin diseases remains a major challenge in medicine. The search for natural active ingredients that can be used to prevent the development of the disease and complement treatment is on the rise. Natural extracts of ginger and hemp offer a wide range of bioactive compounds with potential health benefits. This study evaluates the effectiveness of hemp and ginger extract as a supportive treatment for skin diseases. It reports a synergistic effect of hemp and ginger extract. The contents of cannabinoids and components of ginger are determined, with the highest being CBD (587.17 ± 8.32 µg/g) and 6-gingerol (60.07 ± 0.40 µg/g). The minimum inhibitory concentration for Staphylococcus aureus (156.5 µg/mL), Escherichia coli (625.2 µg/mL) and Candida albicans (78.3 µg/mL) was also analyzed. Analysis of WM-266-4 cells revealed the greatest decrease in metabolic activity in cells exposed to the extract at a concentration of 1.00 µg/mL. Regarding the expression of genes associated with cellular processes, melanoma aggressiveness, resistance and cell survival, a significant difference was found in the expression of ABCB5, CAV1 and S100A9 compared with the control (cells not exposed to the extract).


Assuntos
Cannabis , Zingiber officinale , Extratos Vegetais/farmacologia , Extratos Vegetais/análise , Testes de Sensibilidade Microbiana
7.
Polymers (Basel) ; 14(20)2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36297994

RESUMO

In the following work, the hydrothermal degradation of polypropylene waste (PP) using supercritical water (SCW) has been studied. The procedure was carried out in a high-pressure, high-temperature batch reactor at 425 °C and 450 °C from 15 to 240 min. The results show a high yield of the oil (up to 95%) and gas (up to 20%) phases. The gained oil phase was composed of alkanes, alkenes, cycloalkanes, aromatic hydrocarbons, and alcohols. Alkanes and alcohols predominated at 425 °C and shorter reaction times, while the content of aromatic hydrocarbons sharply increased at higher temperatures and times. The higher heating values (HHVs) of oil phases were in the range of liquid fuel (diesel, gasoline, crude and fuel oil), and they were between 48 and 42 MJ/kg. The gas phase contained light hydrocarbons (C1-C6), where propane was the most represented component. The results for PP degradation obtained in the present work were compared to the results of SCW degradation of colored PE waste, and the potential degradation mechanism of polyolefins waste in SCW is proposed. The results allowed to conclude that SCW processing technology represents a promising and eco-friendly tool for the liquefaction of polyolefin (PE and PP) waste into oil with a high conversion rate.

8.
Plants (Basel) ; 11(13)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35807701

RESUMO

Natural medicines and products are becoming increasingly important in the pharmaceutical and food industries. The most important step in obtaining a natural remedy is the processing of the natural material. This study offers the separation of the industrial hemp plant into fractions by mechanical treatment, which has a significant impact on the selectivity of the obtained fractions. This study also offers a solution to reduce waste by fractionating industrial hemp, focusing on the fraction with the highest cannabinoid content (49.5% of CBD). The study confirmed the anticancer potential of the extract, which prevents further division of WM-266-4 melanoma cells at a concentration of 10-3 mg/mL. However, application of the extract (c = 10-3 mg/mL) to normal human epidermal melanocytes proved to be insignificant, as the metabolic activity of the cells was the same as in the control cell group.

9.
Thorac Cardiovasc Surg ; 70(7): 566-574, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35643076

RESUMO

OBJECTIVES: Acute kidney injury (AKI) is associated with higher perioperative mortality and morbidity. Oxidative stress has been proposed as a cause of postoperative AKI. Ascorbic acid (AA) supplementation was suggested as a novel and promising antioxidant. The aim of this study was to evaluate the capability of AA to reduce the incidence of postoperative AKI in cardiac surgery patients. METHODS: A prospective randomized trial was conducted in patients scheduled for on-pump cardiac surgery. Subjects in the AA group received 2 g of AA intravenously during the induction of anesthesia, 2 g before aortic cross-clamp removal and 1 g every 8 hours for five postoperative days (the JERICA protocol). Postoperatively, the patients were monitored for AKI and other complications. Malondialdehyde levels were monitored in a subpopulation of 100 patients to evaluate the effect of AA on oxidative stress level. RESULTS: The AA and control group consisted of 163 and 169 patients, respectively. The groups were well matched for baseline demographics and had similar intraoperative characteristics. The incidence of AKI in the AA and control group was 20.9 and 28.4%, respectively (p = 0.127). The estimated glomerular filtration rate did not differ between the study groups in the entire postoperative period. There was a trend toward higher malondialdehyde values with statistical significance on postoperative day 1 and lower in-hospital mortality in the AA group (0.6 vs. 4.1%, p = 0.067). CONCLUSION: Our results do not support the effectiveness of AA supplementation in reducing the incidence of postoperative AKI in on-pump cardiac surgery patients. CLINICAL REGISTRATION NUMBER: This study was registered with the ISRCTN Registry under the trial registration number ISRCTN98572043.


Assuntos
Injúria Renal Aguda , Procedimentos Cirúrgicos Cardíacos , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/etiologia , Antioxidantes/efeitos adversos , Ácido Ascórbico/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Humanos , Incidência , Malondialdeído , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Resultado do Tratamento
10.
Plants (Basel) ; 11(7)2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35406908

RESUMO

This study is focused on different extractions (Cold Maceration (CM), Ultrasonic Extraction (UE), Soxhlet Extraction (SE) and Supercritical Fluid Extraction (SFE)) of bioactive compounds from pomegranate (Punica Granatum L.) fruit peels using methanol, ethanol, and acetone as solvents in conventional extractions and changing operating pressure (10, 15, 20, 25 MPa) in SFE, respectively. The extraction yields, total phenols (TP) and proanthocyanidins (PAC) contents, and antioxidant activity of different extracts are revealed. TP and PAC recovered by extracts ranged from 24.22 to 42.92 mg gallic acid equivalents (GAE)/g and 2.01 to 5.82 mg PAC/g, respectively. The antioxidant activity of extracts ranged from 84.70% to 94.35%. The phenolic compound identification and quantification in selective extracts was done using the LC-MS/MS method. The contents of different flavonoids and phenolic acids have been determined. SFE extract, obtained at 20 MPa, contained the highest content (11,561.84 µg/g) of analyzed total polyphenols, with predominant ellagic acid (7492.53 µg/g). For the first time, Microbial Growth Inhibition Rates (MGIRs) were determined at five different concentrations of pomegranate SFE extract against seven microorganisms. Minimal Inhibitory Concentration (MIC90) was determined as 2.7 mg/mL of SFE pomegranate peel extract in the case of five different Gram-negative and Gram-positive bacteria.

11.
Plants (Basel) ; 10(3)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802757

RESUMO

Cannabis sativa is one of the oldest medicinal plants used by humans, containing hundreds of bioactive compounds. The biological effects and interplay of these compounds are far from fully understood, although the plant's therapeutic effects are beyond doubt. Extraction methods for these compounds are becoming an integral part of modern Cannabis-based medicine. Still, little is known about how different methods affect the final composition of Cannabis extracts and thus, their therapeutic effects. In this study, different extraction methods were tested, namely maceration, Soxhlet, ultrasound-assisted extraction (UAE), and supercritical CO2 extraction methods. The obtained extracts were evaluated for their cannabinoid content, antioxidant properties, and in vitro bioactivity on human colon cancer and healthy colon cells. Our data suggest that Cannabis extracts, when properly prepared, can significantly decrease cancer cell viability while protecting healthy cells from cytotoxic effects. However, post-processing of extracts poses a significant limitation in predicting therapeutic response based on the composition of the crude extract, as it affects not only the actual amounts of the respective cannabinoids but also their relative ratio to the primary extracts. These effects must be carefully considered in the future preparations of new therapeutic extracts.

12.
Molecules ; 26(2)2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33440878

RESUMO

Intestinal transepithelial transport of glucose is mediated by glucose transporters, and affects postprandial blood-glucose levels. This study investigates the effect of wood extracts rich in hydrolyzable tannins (HTs) that originated from sweet chestnut (Castanea sativa Mill.) and oak (Quercus petraea) on the expression of glucose transporter genes and the uptake of glucose and HT constituents in a 3D porcine-small-intestine epithelial-cell model. The viability of epithelial cells CLAB and PSI exposed to different HTs was determined using alamarBlue®. qPCR was used to analyze the gene expression of SGLT1, GLUT2, GLUT4, and POLR2A. Glucose uptake was confirmed by assay, and LC-MS/ MS was used for the analysis of HT bioavailability. HTs at 37 µg/mL were found to adversely affect cell viability and downregulate POLR2A expression. HT from wood extract Tanex at concentrations of 4 µg/mL upregulated the expression of GLUT2, as well as glucose uptake at 1 µg/mL. The time-dependent passage of gallic acid through enterocytes was influenced by all wood extracts compared to gallic acid itself as a control. These results suggest that HTs could modulate glucose uptake and gallic acid passage in the 3D cell model.


Assuntos
Expressão Gênica/efeitos dos fármacos , Transportador de Glucose Tipo 2/genética , Transportador de Glucose Tipo 4/genética , Taninos Hidrolisáveis/farmacologia , Transportador 1 de Glucose-Sódio/genética , Animais , Linhagem Celular , Fagaceae/química , Glucose/metabolismo , Transportador de Glucose Tipo 2/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Taninos Hidrolisáveis/química , Taninos Hidrolisáveis/farmacocinética , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacocinética , Extratos Vegetais/farmacologia , Transportador 1 de Glucose-Sódio/metabolismo , Suínos , Regulação para Cima/efeitos dos fármacos
13.
Pharmaceutics ; 14(1)2021 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-35056965

RESUMO

A fundamental step in developing a protein drug is the selection of a stable storage formulation that ensures efficacy of the drug and inhibits physiochemical degradation or aggregation. Here, we designed and evaluated a general workflow for screening of protein formulations based on small-angle X-ray scattering (SAXS). Our SAXS pipeline combines automated sample handling, temperature control, and fast data analysis and provides protein particle interaction information. SAXS, together with different methods including turbidity analysis, dynamic light scattering (DLS), and SDS-PAGE measurements, were used to obtain different parameters to provide high throughput screenings. Using a set of model proteins and biopharmaceuticals, we show that SAXS is complementary to dynamic light scattering (DLS), which is widely used in biopharmaceutical research and industry. We found that, compared to DLS, SAXS can provide a more sensitive measure for protein particle interactions, such as protein aggregation and repulsion. Moreover, we show that SAXS is compatible with a broader range of buffers, excipients, and protein concentrations and that in situ SAXS provides a sensitive measure for long-term protein stability. This workflow can enable future high-throughput analysis of proteins and biopharmaceuticals and can be integrated with well-established complementary physicochemical analysis pipelines in (biopharmaceutical) research and industry.

14.
Biomed Pharmacother ; 132: 110877, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33096350

RESUMO

BACKGROUND: An unavoidable consequence of cardiac surgery is oxidative stress and resulting peroxidation of biological molecules, in particular unsaturated lipids. The detection of peroxidation metabolites in biological environments is difficult due to their large variety, small concentration, and high reactivity. One of the most studied lipid peroxidation products is malondialdehyde and as such an important marker of oxidative stress. The aim of this study was to monitor the perioperative serum concentration of malondialdehyde as an oxidative stress marker in patients undergoing arrested-heart cardiopulmonary bypass surgery. METHODS: This observational study was performed on 40 patients scheduled for on-pump arrested-heart open-heart surgery. Blood samples for the analysis of serum malondialdehyde were obtained preoperatively and intraoperatively immediately after the aortic clamp was removed. Afterwards, samples were obtained 12, 24, 48 and 72 h postoperatively. A gas chromatography-mass spectrometry analytical method was used to detect serum concentrations of malondialdehyde. RESULTS: A significant increase in serum malondialdehyde concentration was detected at the time of aortic declamping. The malondialdehyde serum concentration continued to increase and peaked 12 h postoperatively. Afterwards it started to decline, but remained significantly higher compared to preoperative values both at 24 and 48 h postoperatively. CONCLUSION: In contrast to some previous studies, our results demonstrate that in this patient population, the malondialdehyde levels do not peak at the end of the surgery, but continue to rise a few hours after surgery. Our findings indicate that in this patient population, oxidative stress with consequent lipid peroxidation is maintained and is even attenuated in the early postoperative period. This study was registered with the ISRCTN Registry under the trial registration number ISRCTN98572043.


Assuntos
Ponte Cardiopulmonar , Parada Cardíaca Induzida , Malondialdeído/sangue , Estresse Oxidativo , Idoso , Biomarcadores/sangue , Ponte Cardiopulmonar/efeitos adversos , Feminino , Parada Cardíaca Induzida/efeitos adversos , Humanos , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Período Perioperatório , Fatores de Tempo , Regulação para Cima
15.
Acta Chim Slov ; 66(4): 751-761, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34057490

RESUMO

The current work concerns solid liquid extraction from red and white grapes skin and the rosehip (Rosa canina) to obtain extracts with a high phenolic content. Extracts have been acquired using conventional extraction techniques and extraction with supercritical fluids (SCFs). The effect of extraction method and experimental parameters (time, pressure, temperature and solvent mixture) mostly believed to affect the extraction process was undertaken. The quantitative parameters studied are: total phenolic compounds, proanthocyanin content, and the phenolic constituent profile. The qualitative parameter analyzed is antioxidant capacity. The results demonstrate that the contents of the major constituents significantly varied among the different types of materials. The highest content of total phenolics was determined in the extract from the white grape skin, macerated with MeOH (26.7 mg GA/g extract), and similar, 25.6 mg GA/g extract in the MeOH extract attained by Soxhlet. Ellagic acid (0.650 mg/100 g extract), catechin (0.164 mg/100 g extract), gallic acid (0.133 mg/100 g extract) as well as caffeic acid (0.038 mg/100 g extract) are the major compounds present in the rosehip extracts attained by maceration using MeOH as solvent. The presence of epictechin, hesperidin/neohesperidin, rutin, and chlorogenic acid was also confirmed. Aspects of each type of processing were correlated with the chemistry of the material. The obtained extracts could be used as natural bioactive compounds in several industrial applications.

16.
J Pharm Biomed Anal ; 150: 137-143, 2018 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-29223062

RESUMO

A quantitative analysis of zinc endopeptidases matrix metalloproteinase 9 (MMP9) and matrix metalloproteinase 3 (MMP3) from human blood serum are presented. Both matrix metalloproteinases (MMP) are present in human blood serum and can be used as biomarkers for different diseases. The analysis was performed using LC-MS/MS with a triple quadrupole mass spectrometer, based on two specific peptides of each MMP in comparison with an enzyme-linked immunosorbent assay (ELISA). While the conditions for the LC-MS/MS analysis of MMP9 peptides were previously reported for bronchoalveolar lavage fluid, the analysis of MMP3 peptides was newly quantified for human blood serum herein for the first time. For MMP3, the linear behaviour was determined in the concentration range from 1.0-200.0ng/mL (R2=0.997) with an LLOD of 0.5ng/mL. For MMP9, linearity was determined in the concentration range from 6.5-65.0ng/mL (R2=0.995) with an LLOD of 2.0ng/mL.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Metaloproteinase 3 da Matriz/sangue , Metaloproteinase 9 da Matriz/sangue , Espectrometria de Massas em Tandem/métodos , Ensaio de Imunoadsorção Enzimática , Humanos , Limite de Detecção
17.
Acta Chim Slov ; 61(4): 746-58, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25551714

RESUMO

The influence of process parameters on supercritical fluid chromatography (SFC) was investigated together with scaling-up to the preparative scale. Within this scope, separation of model compounds (caffeine and theophylline), dependencies on pressures, temperatures, types and concentrations of the modifiers, and types of stationary phases, were examined separately. Experiments were performed on analytical scale and on pilot preparative scale SFC apparatus. Bare silica and silica 2-ethylpyridine were used as stationary phases, with CO(2)/methanol or CO(2)/ethanol at elevated pressures and temperatures as mobile phase. Observations obtained on the analytical scale were used for scaling-up to preparative scale. The aim of this study is evaluating the influences of process parameters when separating model compounds using SFC, and s practical demonstration of the scaling-up method of SFC along with the operation of a pilot preparative to production scale SFC apparatus, which is one of the bigger similar apparatuses worldwide.

18.
Toxicol In Vitro ; 27(4): 1267-76, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23470418

RESUMO

Bisphenol A analogs are a class of chemicals known as diphenylmethanes, which contain two benzene rings separated by one central carbon atom, usually with a para-hydroxy group on both benzene rings. Bisphenol A (BPA) can induce an uterotrophic response in immature CD-1 mice and elicits estrogenic responses in many other experimental systems. Besides highlighting endocrine effects, a number of metabolic studies provide strong support for the idea that reactive species of BPA are formed in vitro and in vivo that can form covalent adducts with nucleophilic macromolecules and/or produce oxidative stress. We used a liquid chromatography with a triple quadrupole tandem mass spectrometry (LC-MS/MS) for the detection of metabolites and glutathione conjugates of BPA and its analogs (BPF, BPAF, BPZ and DMBPA) in human liver microsomes (HLM) or with recombinant CYP isozymes in the presence of NADPH and GSH as a trapping agent. We have confirmed that BPA and its structural analogs form hydroxylated metabolites and electrophilic species during bioactivation in HLM and CYP isozymes. These results provided important mechanistic insight into the metabolic fate of BPA structural analogs in vitro.


Assuntos
Compostos Benzidrílicos/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Disruptores Endócrinos/metabolismo , Estrogênios/metabolismo , Microssomos Hepáticos/metabolismo , Fenóis/metabolismo , Biotransformação , Cromatografia Líquida , Glutationa/metabolismo , Humanos , Isoenzimas/metabolismo , NADP/metabolismo , Proteínas Recombinantes/metabolismo , Espectrometria de Massas em Tandem
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