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1.
J Chromatogr A ; 1623: 461170, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505276

RESUMO

In this study, a multiresidue analytical method was developed, validated, and applied for quantifying 85 persistent organic pollutants (POPs), including 38 polychlorinated biphenyls (PCBs), 23 polybrominated diphenyl ethers (PBDEs), and 24 organochlorine pesticides (OCPs) from 200 µL of human serum. A modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method was applied to minimize the required sample amount and optimize various conditions including the extraction solvent and the number of extractions. The extraction efficiency was optimized using double extraction with an ethyl acetate/hexane/acetone mixture. Gas chromatography coupled with triple-quadrupole mass spectrometry was used for analysis, and two different ionization sources, electron impact ionization (EI) and atmospheric pressure chemical ionization (APCI), were used to compare their sensitivity. The APCI source employed soft ionization at atmospheric pressure, producing abundant molecular ion formation with minimal fragmentation, in contrast to extensive fragmentation caused by EI. Of the 85 POPs analyzed, 59 target compounds (69.4%) showed lower limits of detection that were two- to fifty-fold lower in APCI than those determined using EI. The developed method was validated for its detection limit (0.5-10 pg/mL for PCBs, 2-20 pg/mL for PBDEs, and 2-40 pg/mL for OCPs), precision (0.8%-34.3% of coefficient of variation), recovery (49.6%-77.1%), matrix effect (46.7%-156.9%), and accuracy (81.2%-113.1% for PCBs, 85.8%-112.2% for PBDEs, and 55.2%-113.9% for OCPs). Its linearity was R2 > 0.99 for 84 compounds, and 96% average accuracy (for APCI) was obtained using the National Institute of Standards and Technology (NIST) standard reference materials (NIST 1957 and 1958). These ionization methods were compared by analyzing 25 real human serum samples. The observed species were 1.1-24.6 pg/mL of 28 PCBs, 2.5 pg/mL of BDE-47, and 6.5-195.1 pg/mL of 6 organochlorine pesticides (median concentration for each species), and only 11 compounds were detected with APCI owing to its enhanced sensitivity.


Assuntos
Poluentes Ambientais/sangue , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectrometria de Massas em Tandem/métodos , Acetatos/química , Acetona/química , Pressão Atmosférica , Poluentes Ambientais/isolamento & purificação , Feminino , Éteres Difenil Halogenados/sangue , Hexanos/química , Humanos , Hidrocarbonetos Clorados/sangue , Limite de Detecção , Praguicidas/sangue , Bifenilos Policlorados/sangue
2.
J Oleo Sci ; 69(5): 449-453, 2020 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-32238621

RESUMO

A poly(ethylene oxide) (PEO)-poly(propylene oxide) (PPO) alternating multiblock (AMB) copolymer with various molecular weights was prepared via precipitation fractionation from an acetone/n-hexane mixture. The cloud point (Tc) of the aqueous solution of PEO-PPO AMB copolymer decreased as the number-average molecular weight of the sample increased. This phenomenon is generally observed for certain homopolymer systems having a lower critical solution temperature, such as PEO/water and poly(N,N-diethylacrylamide)/water systems. The relationship between the Tc of the solutions and the number of monomer units of the AMB copolymer suggests that the Shultz-Flory theory is applicable to this system.


Assuntos
Compostos de Epóxi/química , Peso Molecular , Polietilenoglicóis/química , Polímeros/química , Água , Acetona/química , Precipitação Fracionada , Hexanos/química , Soluções , Temperatura
3.
Chemosphere ; 249: 126215, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32088460

RESUMO

Nonthermal plasma (NTP) degradation has been shown to be a promising method for volatile organic compounds (VOCs) removal from air. However, there have been few studies on the degradation of indoor VOCs using NTP, and even less on their reaction kinetics. In this study, NTP degradation of acetone, a representative of oxygenated VOCs, in a closed-loop reactor operating in recirculation mode was investigated. Acetone and organic by-products were characterized in real-time by proton transfer reaction time-of-flight mass spectrometry. The results showed that approximately 85.7% of the acetone degraded within 7.5 h with dielectric barrier discharge treatment at 4.3 W. Methanol, acetaldehyde, formic acid, and acetic acid were observed to be the main organic byproducts with concentrations time-dependent on the order of ppb/ppm. The concentrations of the inorganic by-products O3 and NO2 are also time-dependent and can decrease to nearly 0 after a sufficient degradation time. Based on the concentration measurement in real-time, several rate laws were used to fit the concentration variations of acetone and the organic by-products, and it was observed that they strictly followed the simple kinetic reaction rate laws: acetone followed the first-order rate law, and formic acid formation followed the one-half-order rate law, etc. This study provides a good example of characterizing NTP removal of VOCs in airtight spaces and has important theoretical and practical significance in designing a better NTP device, predicting NTP degradation reaction rate, and accelerating the practical application of NTP technology for indoor air treatment.


Assuntos
Acetona/química , Acetaldeído , Cinética , Estudos Longitudinais , Espectrometria de Massas/métodos , Metanol , Modelos Químicos , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
4.
Food Chem ; 314: 125959, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31991283

RESUMO

Anthocyanins from purple-fleshed sweetpotatoes constitute highly valued natural colorants and functional ingredients. In the past, anthocyanin extraction conditions and efficiencies using a single acidified solvent have been assessed. However, the potential of solvent mixes that can be generated by fermentation of biomass-derived sugars have not been explored. In this study, the effects of single and mixed solvent, time, temperature, sweetpotato genotype and preparation, on anthocyanin and phenolic extraction were evaluated. Results indicated that unconventional diluted solvent mixes containing acetone, butanol, and ethanol were superior or equally efficient for extracting anthocyanins when compared to commonly used concentrated extractants. In addition, analysis of anthocyanidins concentrations including cyanidin (cy), peonidin (pe), and pelargonidin (pl), indicated that different ratios of pn/cy were obtained depending on the solvent used. These results could be useful when selecting processing conditions that better suit particular end-use applications and more environmentally friendly process development for purple sweetpotatoes.


Assuntos
Antocianinas/isolamento & purificação , Fracionamento Químico/métodos , Ipomoea batatas/química , Solventes/química , Acetona/química , Antocianinas/análise , Antocianinas/química , Butanóis/química , Etanol/química , Fenóis/isolamento & purificação , Extratos Vegetais/química
5.
J Chromatogr A ; 1610: 460555, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31561971

RESUMO

Many different designs of microfabricated gas chromatography columns have recently been proposed and demonstrated. These designs either incorporate a stationary phase directly into the device which limits the versatility of the column as a separator, or require coating, which presents its own problems with determining the proper conditions for each different stationary phase a user may need. Here, we present a new approach: Uniformly spin coating a flat surface with the stationary phase and creating a column by pressing a lid, with micro-fabricated ridges, down onto the coated substrate. The lids are molded using commercially available epoxies so that when pressed onto a flat surface they create an airtight seal. The epoxy material is rendered inert by a thin layer of gold. We describe the fabrication and initial results from a standard, OV-1, stationary phase as proof of concept.


Assuntos
Cromatografia Gasosa/métodos , Elastômeros/química , Microtecnologia/métodos , Acetona/química , Alcanos/química
6.
Biosci Biotechnol Biochem ; 84(1): 208-215, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31532348

RESUMO

Dihomo-γ-linolenic acid (DGLA, C20: 3n-6) is known to have an anti-inflammatory activity, but its range of effects was not well studied because of its limited natural sources. We addressed these issues by constructing an yeast Saccharomyces cerevisiae strain having a complete metabolic pathway for DGLA synthesis by introducing two desaturase and one elongase genes to convert endogenous oleic acid to DGLA. Taking advantage of well-known safety of S. cerevisiae, we previously investigated the efficacy of heat-killed whole DGLA-producing yeast cells on irritant contact dermatitis, and showed that oral intake of this yeast significantly suppressed inflammatory reactions, whereas no such suppression was observed by the intake of 25 times the amount of purified DGLA. Since this method is considered to be a simple and efficient way to suppress inflammation, we examined its effectiveness against allergic contact dermatitis (ACD) in this study and showed that this method was also effective against ACD.


Assuntos
Ácido 8,11,14-Eicosatrienoico/farmacologia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Dermatite Alérgica de Contato/terapia , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/metabolismo , Ácido 8,11,14-Eicosatrienoico/administração & dosagem , Ácido 8,11,14-Eicosatrienoico/metabolismo , Acetona/química , Administração Oral , Animais , Quimiocina CCL2/análise , Quimiocinas/análise , Dermatite Alérgica de Contato/etiologia , Dinitrofluorbenzeno/efeitos adversos , Dinitrofluorbenzeno/imunologia , Orelha Externa/patologia , Feminino , Imunização , Inflamação/terapia , Interferon gama/análise , Camundongos , Ácido Oleico/metabolismo , Azeite de Oliva/química
7.
Chemosphere ; 245: 125664, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31877458

RESUMO

Most of the volatile organic compounds (VOCs) are toxic and harmful to human health and environment. In this study, hydrochars activated with CO2 were applied to remove VOCs. Two typical VOCs, acetone and cyclohexane, were used as the 'model' adsorbates to evaluate hydrochars' performance. Specific surface areas of pristine hydrochars were small (<8 m2/g), whereas activated hydrochars showed much higher values (up to 1308 m2/g). As a result, the adsorption of VOCs onto the pristine hydrochars (13.24-24.64 mg/g) was lower than that of the activated ones (39.42-121.74 mg/g). The adsorption of the two VOCs onto the hydrochars was exothermal. In addition, there were significant correlations (R2 > 0.91) between the VOC removal and hydrochars' specific surface area. These results suggest that the governing mechanism was mainly physical adsorption. Increasing experimental temperature (80-139 °C) desorbed the VOCs from the hydrochars. Due to its higher boiling point, cyclohexane desorption required a higher temperature than acetone desorption. The reusability of the activated hydrochars to the two VOCs was confirmed by five continuous adsorption-desorption cycles. The overall results indicated that hydrochars, particularly after CO2 activation, are sufficient for VOC abatement.


Assuntos
Acetona/química , Dióxido de Carbono/química , Carbono/química , Cicloexanos/química , Compostos Orgânicos Voláteis/isolamento & purificação , Adsorção , Carvão Vegetal/química , Recuperação e Remediação Ambiental/métodos , Propriedades de Superfície , Temperatura , Compostos Orgânicos Voláteis/química
8.
J Am Soc Mass Spectrom ; 30(12): 2571-2575, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31758521

RESUMO

Exposure of electrospray droplets to organic vapors was shown to dramatically reduce alkali-metal adduction on protein ions and shift protein charge states. Since DESI-MS is affected by similar adduct species as ESI-MS and shares similar ionization mechanisms, polar organic vapor additives should likewise also improve the DESI-MS analysis of proteins. Here the DESI spray was exposed to a variety of polar organic vapor additives. Head space vapors of polar organic solvents were entrained in nitrogen gas and delivered to the atmosphere inside a semi-enclosed plastic enclosure surrounding the spray plume. The vapors of acetone, acetonitrile, ethyl acetate, methanol, and water were investigated. Vapor dependent effects were observed with respect to changes in protein charge state distributions and signal intensities. With ethyl acetate vapor addition, the signal intensities of all proteins investigated were significantly increased, including proteins larger than 25 kDa such as carbonic anhydrase II and bovine serum albumin.


Assuntos
Proteínas/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Acetatos/química , Acetona/química , Acetonitrilos/química , Animais , Anidrase Carbônica II/análise , Bovinos , Citocromos c/análise , Desenho de Equipamento , Cavalos , Metanol/química , Soroalbumina Bovina/análise , Solventes/química , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Volatilização , Água/química
9.
BMC Vet Res ; 15(1): 404, 2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31706312

RESUMO

BACKGROUND: Many studies have revealed that bioactive compounds for different indications are not extracted from plants with water, the only extractant practically available to rural communities. We compared the acaricidal activity of acetone extracts of 13 species used traditionally to protect cattle against ticks. We also investigated if the extraction of biologically active compounds against Rhipicephalus (Boophilus) decoloratus ticks could be enhanced by adding a liquid soap that is locally available to smallholder farmers. METHODS: A total of 13 plant species selected based on reported traditional use in Zimbabwe, were dried and finely ground before extraction with water, or water plus a surfactant, or acetone. The adapted Shaw Larval Immersion Test (SLIT) method was used to determine the activity of acetone and crude water extracts with or without liquid soap against the tick larvae. The activity of four fractions of crude acetone extracts (extracted using solvents of different polarity), of the most active plant species, Maerua edulis (tuber and leaf) was also compared to identify the most active fraction. RESULTS: Aqueous plant extracts were not toxic to ticks, but the addition of 1% liquid soap as a surfactant increased mortality of the R. (B) decoloratus larvae significantly. With the Maerua edulis tuber extract, the efficacy of the 1% liquid soap was comparable to that of the amitraz based commercial synthetic acaricide. The use of acetone as an extractant, also increased the mortality of the tick larvae in all the plant species. With M. edulis (tuber and leaf), Monadenium lugardae and Kleinia sp. acetone extracts, the activity was comparable to that of the positive control (a commercially available amitraz-based synthetic acaricide). The non-polar fractions of the acetone extract of leaf and tuber of M. edulis caused up to 100% mortality. This indicates that non-polar to intermediate polarity compounds are responsible for the acaricidal activity. CONCLUSION: Organic solvents such as acetone extracted active compounds but water did not. By adding commonly available dishwashing soap to water active compounds were extracted leading to a high acaricidal activity of the plant extracts. In some cases, it was as active as non-polar extracts and a synthetic commercial acaricide (positive control). This approach makes it possible for the smallholder farmers and traditional healers to extract biologically active compounds from plants by using water.


Assuntos
Acaricidas , Extratos Vegetais/farmacologia , Rhipicephalus/efeitos dos fármacos , Tensoativos/química , Acetona/química , Animais , Larva/efeitos dos fármacos , Magnoliopsida/química , Rhipicephalus/crescimento & desenvolvimento , Toluidinas , Água/química , Zimbábue
10.
Molecules ; 24(20)2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31623198

RESUMO

Monosialotetrahexosylganglioside (GM1) has good activity on brain diseases and was developed to be a drug applied in clinics for neurological disorders and nerve injury. It is difficult to isolate GM1 in industry scale from the brains directly. In this work, a simple and highly efficient method with high yield was developed for the isolation, conversion, and purification of GM1 from a pig brain. Gangliosides (GLS) were first extracted by supercritical CO2 (SCE). The optimum extraction time of GLS by SCE was 4 h, and the ratio of entrainer to acetone powder from the pig brain was 3:1 (v/w). GM1 was then prepared from GLS by immobilized sialidase and purified by reverse-phase silica gel. Sodium alginate embedding was used for the immobilization of sialidase. Under the optimized method, the yield of high-purity GM1 was around 0.056%. This method has the potential to be applied in the production of GM1 in the industry.


Assuntos
Dióxido de Carbono/química , Enzimas Imobilizadas , Gangliosídeo G(M1)/química , Neuraminidase/química , Acetona/química , Animais , Encéfalo , Ácidos Graxos , Neuraminidase/isolamento & purificação , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Especificidade por Substrato , Suínos
11.
Eur J Med Chem ; 183: 111689, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31541871

RESUMO

A series of ß-azole-phenylacetone derivatives with novel structures were designed and synthesized to combat the increasing incidence of susceptible fungal infections and drug-resistant fungal infections. The antifungal activity of the synthesized compounds was assessed against five susceptible strains and five fluconazole-resistant strains. Antifungal activity tests showed that most of the compounds exhibited excellent antifungal activities against five pathogenic strains with MIC values in the range of 0.03-1 µg/mL. Compounds with R1 = 3-F substituted and 15o and 15ae exhibited moderate antifungal activities against fluconazole-resistant strains 17# and CaR with MIC values in the range of 1-8 µg/mL. Compounds with R1 = H or 2-F (such as 15a, 15o, 15p) displayed moderate to good antifungal activity against fluconazole-resistant strains 632, 901 and 904 with MIC values in the range of 0.125-4 µg/mL. Notably, 15o and 15ae exhibited antifungal activity against five susceptible strains and five fluconazole-resistant strains. Preliminary mechanistic studies showed that the potent antifungal activity of compound 15ae stemmed from inhibition of C. albicans CYP51. Compounds 15o, 15z and 15ae were nearly nontoxic to mammalian A549 cells.


Assuntos
Acetona/análogos & derivados , Antifúngicos/farmacologia , Azóis/farmacologia , Candida albicans/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Células A549 , Acetona/química , Acetona/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Azóis/química , Relação Dose-Resposta a Droga , Fluconazol/química , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade
12.
Int J Biol Macromol ; 140: 102-108, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419558

RESUMO

Precipitation has been widely applied to purification and fractionation of biological macromolecules. Several physical-chemical factors contribute to the destabilization of those solutions, such as the nature of solvent employed, presence of salts, temperature, and concentration of the macromolecule. In the case of charged biopolymers, electrostatic forces are the major contributors to their stability in solution. However, the role of each variable and the exact mechanism of precipitation are not completely understood yet. The aim of this work was to study the precipitation of polyribosyl-ribitol-phosphate (PRP, a linear homogeneous anionic biopolymer) in presence of salts and non-solvents, in order to contribute to the elucidation of its precipitation mechanism. The solvents tested (acetone, ethanol, and isopropanol) presented distinct dielectric constants. The salts used (NH4Cl, NaCl, KCl, MgCl2, and CaCl2) differ by their cations. For each salt concentration, the solvent fraction that induces precipitation was identified and the dielectric constant of the bulk solution was calculated. Precipitation always occurred at well-defined combinations of solvents and salts. At low concentration of monovalent salts, there was a linear correlation between the logarithm of the salt concentration and the inverse of the medium dielectric constant at a defined precipitation point. This is a strong indication that the stability of the solution depends almost exclusively on the balance of electrostatic forces. This behavior is compatible with the DLVO modeling of colloidal systems. When divalent salts were used, low concentrations of the counterion were sufficient to induce precipitation, due to a phenomenon called ionic condensation. Apparently, PRP precipitates when around 90% of its charges are neutralized, value that is similar to charge neutralization for DNA precipitation.


Assuntos
Precipitação Química , Cloretos/química , Modelos Químicos , Polissacarídeos/química , Solventes/química , 2-Propanol/química , Acetona/química , Etanol/química , Concentração de Íons de Hidrogênio , Água/química
13.
Talanta ; 205: 120100, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31450412

RESUMO

An extraction method based on a multivariate analytical approach was developed for enhancement of the phenolic compounds in cashew nut extracts. The different extractor solvents (acetone, water, ethanol, and methanol) and their binary, ternary, and quaternary combinations were evaluated using a simplex-centroid design and surface response methodology. The special cubic model exhibits no lack of fit and explains 89.2% of the variance. The total phenolic measurements by the Folin-Ciocalteu method revealed the highest values for ethanol (5.93 mg GAE g-1) and acetone-methanol-ethanol ternary mixture (5.92 mg GAE g-1) extracts. ESI (-)-Q/TOFMS analyses combined with PCA and HCA revealed the presence of fatty acids, phospholipids, and sugars in the ternary mixture cashew extract, while for the ethanol extract only phenolic compounds, such as anacardic acids and derivatives, were found. The proposed approach was adequate to reach the optimal extractor which ethanol, a low-toxicity solvent, enabled the selective extraction of a high content of phenolic compounds from cashew nuts.


Assuntos
Ácidos Anacárdicos/análise , Anacardium/química , Nozes/química , Extração em Fase Sólida/métodos , Acetona/química , Ácidos Anacárdicos/isolamento & purificação , Análise por Conglomerados , Etanol/química , Metanol/química , Análise Multivariada , Análise de Componente Principal , Solventes/química , Espectrometria de Massas por Ionização por Electrospray/métodos
14.
Mikrochim Acta ; 186(8): 588, 2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31367797

RESUMO

A method is described for non-invasive glucose monitoring of diabetics by means of breath analysis. The metal-organic frameworks (MOFs) ZIF-7, UiO-66 and MOF-5 were chosen as sorbents in packed tubes for sampling and preconcentration of acetone and isopropanol which are established diabetes biomarkers. The MOF UiO-66 was found to be the most appropriate sorbent. Following thermal desorption, acetone and isopropanol where quantified by GC. The method has low limits of detection (0.79-0.84 µg·L-1) and wide linear ranges (5-2000 µg·L-1). It is assumed that the good performance of UiO-66 as a sorbent results from its large surface area and unique porous structure, and from van der Waals interactions. The relative standard deviation for six replicate cycles of sampling and preconcentration using one 50 mg UiO-66 packed tube ranged between 2.3 and 6.7% for intra-day assays, and from 2.7 to 4.3% for inter-day assays. A tube packed with 50 mg of UiO-66 packed tube can be used in over 120 cycles of adsorption/desorption without significant loss of collection efficiency. The GC method has been applied for the analysis of diabetic breath samples, and the recoveries from spiked samples ranged from 89.1 to 107.6%. Graphical abstract Schematic presentation of metal-organic frameworks as sorbents combined with thermal desorption-gas chromatography for the determination of acetone and isopropanol in exhaled breath of diabetics.


Assuntos
2-Propanol/análise , Acetona/análise , Cromatografia Gasosa/métodos , Estruturas Metalorgânicas/química , 2-Propanol/química , 2-Propanol/isolamento & purificação , Acetona/química , Acetona/isolamento & purificação , Adsorção , Testes Respiratórios , Diabetes Mellitus/metabolismo , Diabetes Mellitus/patologia , Humanos , Limite de Detecção , Extração em Fase Sólida
15.
Chemosphere ; 237: 124439, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31376693

RESUMO

Dielectric barrier discharge (DBD) has been widely used as end-of-pipe technology to degrade low-concentration volatile organic compound (VOC) emissions. In this work, the influence of DBD conditions including discharge voltage, VOC residence time in DBD plasma, VOC initial concentration and synergistic effect of multiple VOC mixing on the decomposition efficiency of three VOCs (toluene, ethyl acetate and acetone) were investigated systematically. One focus of this work was to investigate size distribution and chemical composition of aerosol by-products. The results suggested that high discharge voltage, long residence time and low VOC initial concentration would increase VOC removal ratio and their conversion to CO2. Among the three VOCs, toluene was easiest to form particles with a mode diameter between 40 and 100 nm and most difficult to be decomposed completely to CO2. Maximum aerosol yield from toluene was observed to account for 13.1 ±â€¯1.0% of initial concentration (400 ppm) in the condition of discharge voltage 6 kV and residence time 0.52 s. Gas chromatography-mass spectrometry analysis showed that non-nitrogen containing benzene derivatives, nitrophenol derivatives and amines were the main components of toluene aerosol by-products. For ethyl acetate and acetone, aerosols could only be produced in the condition of high discharge voltages (>7.5 kV) and long gas residence time (≥0.95 s) with a bimodal distribution below 20 nm. When the mixture of three VOCs was fed into the plasma, we observed a strong synergistic effect that led to higher VOC removal ratio, but lower conversion of decomposed VOCs to CO2 and aerosols.


Assuntos
Acetatos/química , Acetona/química , Aerossóis/química , Tolueno/química , Compostos Orgânicos Voláteis/química , Dióxido de Carbono/química , Recuperação e Remediação Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas , Tamanho da Partícula , Tolueno/análise , Compostos Orgânicos Voláteis/análise
16.
Food Chem Toxicol ; 133: 110749, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31377139

RESUMO

A new protocol to obtain egg yolk phospholipids in ethanol is presented. Rutin-phospholipids nanoliposomes were prepared and characterized. The procedure takes advantage of the different solubility of egg yolk lipids in ethanol and acetone at low temperature, to efficiently obtain a phospholipid-rich fraction of high purity degree. The phospholipid content in the final fraction is 208.65 ± 26.46 µmol/g fresh egg yolk (16%), accounting for ca. 96% of the extract's dry weight. The phospholipid-rich fraction contains cholesterol (0.069-0.082 cholesterol/phospholipid molar ratio), and vestigial amounts of lutein and zeaxanthin (89.24 ± 9.76 and 14.9 ± 2.16 ng/g of fresh egg yolk, respectively). Saturated fatty acids dominate the extracted phospholipids (50% of egg's total yolk phospholipids), the levels of monounsaturated ranging from 20 to 25%, and polyunsaturated up to 35%. Rutin-liposomes, prepared with phospholipid-rich fraction, presented mean diameter <140 nm, negative surface charge (Zeta potential ~ -13 mV), and entrapment efficiency of rutin up to 87%. In human neuroblastoma cell line SH-SY5Y, rutin-liposomes (lipid 25 µM + rutin 16.7 µM) attenuated glutamate-induced cytotoxicity, in part by reducing the formation of intracellular reactive species, pointing to their potential application as new functional neuroprotective agents.


Assuntos
Portadores de Fármacos/química , Gema de Ovo/química , Lipossomos/química , Fármacos Neuroprotetores/farmacologia , Fosfolipídeos/química , Rutina/farmacologia , Acetona/química , Animais , Carotenoides/análise , Carotenoides/isolamento & purificação , Linhagem Celular Tumoral , Colesterol/análise , Colesterol/isolamento & purificação , Etanol/química , Humanos , Extração Líquido-Líquido/métodos , Fosfolipídeos/análise , Fosfolipídeos/isolamento & purificação
17.
Eur J Pharm Sci ; 138: 105037, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31394257

RESUMO

This study aimed to develop a PLGA, Levan-based drug delivery system (DDS) of Curcumin using a quality-by-design (QbD) approach to reveal how formulation parameters affect the critical quality attributes (CQAs) of this DDS and to present an optimal design. First, a risk assessment was conducted to determine the impact of various process parameters on the CQAs of the DDS (i.e., average particle size, ZP, encapsulation efficiency and polydispersity index). Plackett-Burman design revealed that potential risk factors were Levan molecular weight, PLGA amount and acetone amount. Then, the optimization of the DDS was achieved through a Box-Behnken Design. The optimum formulation was prepared using low molecular weight Levan (134 kDa), 51.51 mg PLGA and 10 ml acetone. The model was validated and the optimized formulation was further characterized using different physic-chemical methods. The study resulted in the most stable NP with a spherical and uniform shape and physical stability tests indicated its stability for at least 60 days at room temperature. In conclusion, this study was an effort for developing a DDS which solubilizes Curcumin in clinically applicable concentrations.


Assuntos
Curcumina/química , Frutanos/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Acetona/química , Química Farmacêutica/métodos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Peso Molecular , Nanopartículas/química , Tamanho da Partícula , Medição de Risco/métodos , Temperatura
18.
Biomed Res Int ; 2019: 3520675, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31467882

RESUMO

It is well established that various extraction factors, including the method, temperature, time, and solvent system, significantly influence the antioxidant quality of plant-derived products. Previously, we observed that extraction of Pinus densiflora bark (PDB) by the most common traditional Soxhlet method using water at two different temperature conditions 60°C and 100°C for 6-15 h noticeably altered their antioxidant quality. In this study, we examined the impact of different extraction solvents such as ethanol, methanol, isopropanol, acetonitrile, and acetone at a different percentage with water (vol/vol) on antioxidant efficiency as well as the total phenolic content (TPC) of PDB extracts. Among the fourteen different PDB extracts, the extracts obtained from 20% ethanol (E20), 40% ethanol (E40), and 20% acetonitrile (ACN20) showed more significant antioxidant potential, as well as high total phenol content (TPC). Extracts from other aqueous mixtures of organic solvents such as isopropanol, acetone, and methanol, as well as water, showed lesser antioxidant capacity and also had less TPC compared to these three most active extracts, E20, E40, and ACN20. Moreover, using ethanol at 100% for extraction significantly decreased the TPC and antioxidant capacity of PDB extracts. Data are implicating that an increased phenolic content in PDB extracts proportionally increases their antioxidant efficiency.


Assuntos
Antioxidantes/química , Pinus/química , Extratos Vegetais/isolamento & purificação , Solventes/química , Acetona/química , Antioxidantes/farmacologia , Etanol/química , Flavonoides/química , Metanol , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Água/química
19.
J Pharm Biomed Anal ; 176: 112797, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31404800

RESUMO

Profiling the endogenous tissue metabolites with spatial features is significant for our understanding of molecular histology, and provides an insightful way to uncover the complex associations between tissue metabolic response and external stimuli. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is an effective molecular imaging technology to illustrate the spatial locations of molecules in tissue. However, due to the limited sensitivity and the presence of multiple matrix-related ions, it is still challenging to globally image the small molecule metabolites (SMMs) using MALDI, especially for those low-content functional ones. Here, a simple acetone washing method was developed to improve the sensitivity of MALDI-MS for imaging SMMs. After immersing in acetone and shaken for 15 min, key functional SMMs were well-visualized with significantly enhanced ion intensities. In addition to lipids, more than 160 SMM ions, including polyamines, cholines, carnitines, amino acids, nitrogenous bases, nucleosides, carbohydrates, organic acids, vitamins were imaged. The acetone washes-based MALDI-MSI was then applied to profile the metabolic alternations that occurred in osteosarcoma, and the abnormally altered SMMs and lipids were clearly visualized. Moreover, with the protection of acetone against tissue antigenicity, we successfully characterized the expression of three metabolites-related enzymes, fatty acid synthase (FASN), glutaminase (GLS), and cytosolic phospholipase A2 (cPLA2) in osteosarcoma. The spatially-resolved metabolite and corresponding enzyme information reveals what occured in osteosarcoma at the molecular level, providing new insights into the understanding of tumour metabolic reprogramming.


Assuntos
Acetona/química , Técnicas de Preparação Histocitológica/métodos , Imagem Molecular/métodos , Osteossarcoma/diagnóstico por imagem , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Modelos Animais de Doenças , Ácido Graxo Sintase Tipo I/análise , Ácido Graxo Sintase Tipo I/metabolismo , Glutaminase/análise , Glutaminase/metabolismo , Humanos , Imersão , Camundongos , Osteossarcoma/metabolismo , Osteossarcoma/patologia , Fosfolipases A2 Citosólicas/análise , Fosfolipases A2 Citosólicas/metabolismo , Ratos
20.
Int J Pharm ; 567: 118501, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31288055

RESUMO

Manufacturing poorly water-soluble active pharmaceutical ingredients (API) with sufficient bioavailability is a significant challenge in pharmaceutical research. A higher bioavailability can reduce both the applied dosage and the side effects for the patient. One method of increasing the bioavailability is to reduce the particle size of the drug down to the nanoscale. An innovative procedure for the preparation of particles in the submicron size range is spray drying with aerosol conditioning, followed by subsequent separation of the particles in an electrostatic precipitator (ESP). This process has been tested before in an earlier work with aqueous model substances at high production rates (1 g/h) and narrow particle-size distributions (mannitol: d50,0 = 455 nm, span = 0,8) in the submicron range. Spray drying from an aqueous solution with low drug concentrations (<1 wt-%) leads to particles in the lower nanosize range, but the low concentrations make this process inefficient. A custom-made plant was modified in order to handle the organic spray-drying process. In addition, explosion protection had to be considered. This work focuses on the spray drying of submicron particles from organic solvents for the purpose of increasing the dissolution rate of the API griseofulvin. API particles were successfully produced in the submicron size-range, characterized and the dissolution behavior was investigated. The dissolution time to dissolve 80% of the drug, t80, was reduced from 21.5 min for the micronized grade API to 8.5 min for the submicron product.


Assuntos
Dessecação , Tecnologia Farmacêutica , Acetona/química , Liberação Controlada de Fármacos , Griseofulvina/química , Hidroclorotiazida/química , Ozônio/química , Tamanho da Partícula , Solventes/química
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