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1.
PLoS One ; 15(10): e0235526, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33022005

RESUMO

Since broflanilide is a newly developed pesticide, analytical methods are required to determine the corresponding pesticide residues in diverse crops and foods. In this study, a pesticide residue analysis method was optimized for the detection and quantification of broflanilide and its two metabolites, DM-8007 and S(PFH-OH)-8007, in brown rice, soybean, apple, green pepper, mandarin, and kimchi cabbage. Residue samples were extracted from the produce using QuEChERS acetate and citrate buffering methods and were purified by dispersive solid-phase extraction (d-SPE) using six different adsorbent compositions with varying amounts of primary secondary amine (PSA), C18, and graphitized carbon black. All the sample preparation methods gave low-to-medium matrix effects, as confirmed by liquid chromatography-tandem mass spectrometry using standard solutions and matrix-matched standards. In particular, the use of the citrate buffering method, in combination with purification by d-SPE using 25 mg of PSA and a mixture of other adsorbents, consistently gave low matrix effects that in the range from -18.3 to 18.8%. Pesticide recoveries within the valid recovery range 70-120% were obtained both with and without d-SPE purification using 25 mg of PSA and other adsorbents. Thus, the developed residue analysis method is viable for the determination of broflanilide and its metabolites in various crops.


Assuntos
Benzamidas/análise , Cromatografia Líquida/métodos , Produtos Agrícolas/metabolismo , Resíduos de Praguicidas/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Acetatos/química , Citratos/química , Produtos Agrícolas/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas
2.
J Chromatogr A ; 1624: 461201, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540063

RESUMO

Nowadays, sensitive chiral methods are required for the determination of chiral impurities and for assays in biological samples. Supercritical fluid chromatography (SFC), one of the main techniques to separate chiral molecules, can be coupled to MS to provide such sensitive methods. Moreover, chiral separation strategies are very useful to reduce the development time and cost of such methods. This study investigates the transfer of an existing non-MS compatible screening step (as part of a separation strategy) into an MS-compatible one. The initial step had a cumulative success rate of 100 % for 57 tested compounds using methanol or 2-propanol as mobile phase modifier on one of four chiral stationary phases. The additives applied in the original mobile phases, i.e. isopropylamine and trifluoroacetic acid, negatively affect the ionization in SFC-MS and thus need to be replaced. Formic acid, acetic acid, water, ammonia, ammonium acetate and ammonium formate were investigated as MS-compatible additives in different combinations and concentrations. Only methanol-based mobile phases were considered in this study because high system pressures were obtained with isopropanol. The other experimental parameters remained the same as in the initial screening step. The effects of the alternative additives on the obtained resolutions as well as on the global success rate were investigated. The best alternative MS-compatible mobile phase contained 0.5 % CH3COOH and 40 mM NH3 as additives. This mobile phase provided the highest number of separations and rather high resolutions. An MS-compatible screening step was defined with this alternative mobile phase. Compared to the original additives, a similar success rate was obtained.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Acetatos/química , Ácido Acético/química , Amônia/química , Formiatos/química , Espectrometria de Massas , Estereoisomerismo
3.
PLoS One ; 15(6): e0234781, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32559209

RESUMO

In meat processing, antimicrobial treatment applied during slaughter and deboning may not control pathogens and spoilage organisms during subsequent transportation and storage. "Functional Ice" (FICE), an innovation over traditional ice, was investigated for its effects on food safety, shelf life, and quality of raw poultry thigh meat during refrigerated storage. FICE was prepared by freezing aqueous solutions of sodium tripolyphosphate (STPP) (2.5% and 5% w/v) and sodium lactate-sodium diacetate (SL-SD) (1% and 2.5% v/v). Potable water was used to prepare ice for the control treatment. Thigh meat inoculated with Salmonella Typhimurium (108 CFU/sample) was placed in FICE treatments, stored at 4 °C and sampled at 0, 12, 24, 36 and 48 h (n = 375). Weight pick-up was recorded for the uninoculated thighs. Additionally, shelf life and quality were evaluated for 8 days on tray-packed thighs that were stored in FICE treatments for 48 h (STPP 5%, and SL-SD 2.5%). Differences among treatments were determined using ANOVA with LSMeans (p ≤ 0.05). Results indicated that inoculated thighs stored in individual STPP 5%, and SL-SD 2.5% treatments lead to a significant reduction in Salmonella Typhimurium compared to the control (p ≤ 0.05) after 48 h of storage. FICE treated thighs showed higher yields, lower cook loss, and an extended shelf life of 1-2 days, without any color changes. FICE has the potential to improve food safety and shelf life while improving the yields and quality during storage and transportation of raw poultry meat.


Assuntos
Inocuidade dos Alimentos , Armazenamento de Alimentos/métodos , Carne/microbiologia , Acetatos/química , Acetatos/farmacologia , Animais , Temperatura Baixa , Polifosfatos/química , Polifosfatos/farmacologia , Aves Domésticas , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/crescimento & desenvolvimento , Lactato de Sódio/química , Lactato de Sódio/farmacologia
4.
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
5.
Food Chem ; 331: 127200, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32554308

RESUMO

In this work, synthesis of phytosteryl ornithine ester hydrochloride was studied for the first time using an intermediate phytosteryl N,N'-bis[tert-butoloxycarbonyl(BOC)]-ornithine ester. This method also involved esterification of phytosterols with N,N'-bis(BOC)-ornithine and deprotection. The maximum yield was 90% and deprotection of BOC group was more than 99% using the HCl/ethyl acetate method. As a result, thermal stability and water solubility as well as emulsifying activity and stability of phytosterols were improved through coupling with ornithine, which is favorable for their application in water-based food systems. We also observed increased bioaccessibility of phytosteryl ornithine hydrochloride (4.5%) and 65% of phytosteryl ornithine hydrochloride was hydrolyzed in vitro. These results indicated that ornithine phytosteryl ester hydrochloride can reduce dissolution capacity of cholesterol in vitro, representing improved cholesterol-reducing activity, which will further expand the applications of phytosteryl ornithine ester hydrochloride.


Assuntos
Anticolesterolemiantes/química , Acetatos/química , Anticolesterolemiantes/síntese química , Anticolesterolemiantes/farmacocinética , Disponibilidade Biológica , Colesterol/metabolismo , Digestão , Emulsificantes/química , Esterificação , Humanos , Hidrólise , Espectroscopia de Ressonância Magnética , Ornitina/química , Fitosteróis/síntese química , Solubilidade , Óleo de Soja/química , Espectroscopia de Infravermelho com Transformada de Fourier , Água
6.
Nucleic Acids Res ; 48(12): e71, 2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32463449

RESUMO

The dynamic conformation of RNA molecules within living cells is key to their function. Recent advances in probing the RNA structurome in vivo, including the use of SHAPE (Selective 2'-Hydroxyl Acylation analyzed by Primer Extension) or kethoxal reagents or DMS (dimethyl sulfate), provided unprecedented insights into the architecture of RNA molecules in the living cell. Here, we report the establishment of lead probing in a global RNA structuromics approach. In order to elucidate the transcriptome-wide RNA landscape in the enteric pathogen Yersinia pseudotuberculosis, we combined lead(II) acetate-mediated cleavage of single-stranded RNA regions with high-throughput sequencing. This new approach, termed 'Lead-seq', provides structural information independent of base identity. We show that the method recapitulates secondary structures of tRNAs, RNase P RNA, tmRNA, 16S rRNA and the rpsT 5'-untranslated region, and that it reveals global structural features of mRNAs. The application of Lead-seq to Y. pseudotuberculosis cells grown at two different temperatures unveiled the first temperature-responsive in vivo RNA structurome of a bacterial pathogen. The translation of candidate genes derived from this approach was confirmed to be temperature regulated. Overall, this study establishes Lead-seq as complementary approach to interrogate intracellular RNA structures on a global scale.


Assuntos
Análise de Sequência de RNA/métodos , Transcriptoma , Acetatos/química , Chumbo/química , Conformação de Ácido Nucleico , RNA Bacteriano/química , Yersinia pseudotuberculosis/genética
7.
J Chromatogr A ; 1621: 461052, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32268956

RESUMO

Ion chromatography-electrospray tandem mass spectrometry (IC-ESI-MS/MS) is used to determine nine haloacetic acids (HAAs), bromate, and dalapon in drinking water samples in U.S. EPA Method 557. In this method, all target analytes are separated and measured with good sensitivity without the need for sample preconcentration or derivatization. However, the separation time is relatively long. In order to reduce the sample analysis time in EPA Method 557, a new anion exchange column has been developed to perform fast separation of the target analytes. Using this new anion exchange column, nine HAAs, bromate, and dalapon can be resolved and separated from interfering matrix ions within 40 minutes, about 33% faster than the analysis time obtained using an earlier anion exchange column reported in EPA Method 557. The new anion exchange column has unique selectivity and high exchange capacity. Method optimization, simplification and improvements in robustness are demonstrated while validating the new column suitability for the determine of HAAs, bromate and dalapon according to EPA Method 557.


Assuntos
Acetatos/análise , Bromatos/análise , Cromatografia por Troca Iônica/métodos , Água Potável/química , Propionatos/análise , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos , Acetatos/química , Halogênios
8.
Bull Environ Contam Toxicol ; 104(4): 497-502, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32152685

RESUMO

The effect of vermicompost added to a loam soil on the leaching behaviour of two herbicides (triclopyr and fluroxypyr) was examined. Mobility of the herbicides was assessed using disturbed soil columns under laboratory conditions. In both cases, the addition of vermicompost significantly increased the sorption of the compounds. For both, DT50 values were slightly higher in the amended soil, due to the increased adsorption. Rate constants (k) calculated according to pseudo-first order model were significantly lower in the case of triclopyr (very persistent), which led to a much lower degradation rate compared to fluroxypyr (persistent) in both unamended and amended soils. Values calculated for the experimental leaching index (ELI) in unamended and amended soils showed medium and high leachability for fluroxypyr (0.31 and 0.29) and triclopyr (0.72 and 0.70), respectively. Other index-based screening models (GUS, RLPI, LIX) also catalogue both herbicides as potential leachers. Results confirm that triclopyr and fluroxypyr may contaminate groundwater resources.


Assuntos
Acetatos/análise , Compostagem , Glicolatos/análise , Água Subterrânea/química , Modelos Teóricos , Piridinas/análise , Poluentes do Solo/análise , Solo/química , Acetatos/química , Adsorção , Glicolatos/química , Herbicidas/análise , Herbicidas/química , Piridinas/química , Poluentes do Solo/química
9.
Proc Natl Acad Sci U S A ; 117(12): 6349-6355, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32156732

RESUMO

A combined analytical, theoretical, and experimental study has shown that the vaping of vitamin E acetate has the potential to produce exceptionally toxic ketene gas, which may be a contributing factor to the upsurge in pulmonary injuries associated with using e-cigarette/vaping products. Additionally, the pyrolysis of vitamin E acetate also produces carcinogen alkenes and benzene for which the negative long-term medical effects are well recognized. As temperatures reached in vaping devices can be equivalent to a laboratory pyrolysis apparatus, the potential for unexpected chemistries to take place on individual components within a vape mixture is high. Educational programs to inform of the danger are now required, as public perception has grown that vaping is not harmful.


Assuntos
Etilenos/análise , Cetonas/análise , Lesão Pulmonar , Vaping , Vitamina E/química , Acetatos/análise , Acetatos/química , Sistemas Eletrônicos de Liberação de Nicotina , Etilenos/toxicidade , Cetonas/toxicidade , Lesão Pulmonar/induzido quimicamente , Estrutura Molecular , Fenóis/análise , Fenóis/química , Pirólise , Vaping/efeitos adversos , Vitamina E/análise
11.
Carbohydr Polym ; 235: 115976, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32122507

RESUMO

Chitosan-based membranes were prepared via electrospinning technique using a low concentrated acetic acid solution as solvent and poly(ethylene oxide) as co-spinning agent. Different solutions were rheologically characterized and increasing the solution viscosity was found to correspond to a better-defined morphology. The membranes were first subjected to a coagulation process with different baths in order to stabilize chitosan and the mats were found not able to withstand a strongly basic environment. Subsequently, a physical and a chemical crosslinking approach were separately optimized to obtain stable mats whose composition was assessed via thermogravimetric and spectroscopic techniques, proving in both cases the elimination of the co-spinning agent. Above all, the ionically crosslinked mats represent a class of extremely promising biomedical products being probably highly biocompatible and characterized by thin and homogenous nanofibers with a diameter of 200 nm, thus showing the ideal structure to foster cell viability.


Assuntos
Acetatos/química , Quitosana/química , Reagentes para Ligações Cruzadas/química , Membranas Artificiais , Polietilenoglicóis/química , Condutividade Elétrica , Tamanho da Partícula , Soluções , Propriedades de Superfície , Viscosidade
12.
Phytomedicine ; 68: 153142, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32045840

RESUMO

BACKGROUND: The dried heartwood of Caesalpinia sappan L. is traditionally prescribed in the formula of traditional Chinese medicine (TCM) for the treatment of acute myeloid leukemia (AML), while nothing is yet known of the active fractions and the underlying mechanisms. PURPOSE: This study aims to investigate the effect of the ethyl acetate extract of the dried heartwood of Caesalpinia sappan L. (C-A-E) on induction of apoptosis and promotion of differentiation in vitro and anti-AML activity in vivo. STUDY DESIGN/METHODS: The aqueous extract was sequentially separated with solvents of increasing polarity and the active fraction was determined through the inhibition potency. The inhibition of the active fraction on cell viability, proliferation and colony formation was performed in different AML cells. Induction of apoptosis and the promotion of differentiation were further determined. Then, the level of the reactive oxygen species (ROS) and its potential role were assessed. Finally, anti-AML activity was evaluated in NOD/SCID mice. RESULTS: C-A-E exhibited the highest inhibition on the cell viability of HL-60 cells. Meanwhile, C-A-E significantly suppressed the proliferation and the colony formation ability of HL-60 and Kasumi-1 cells. Moreover, C-A-E significantly induced the apoptosis, which was partially reversed by Z-VAD-FMK. C-A-E also reduced the level of mitochondrial membrane potential, promoted the release of cytochrome C, decreased the Bcl-2/Bax ratio, and promoted the cleavage of caspase-9 and -3. In addition, Mdivi-1 (mitochondrial fission blocker) remarkably reduced the apoptosis caused by C-A-E. Meanwhile, C-A-E also induced the expression of Mff and Fis1 and increased the location of Drp1 in mitochondria. Furthermore, C-A-E obviously promoted the differentiation of AML cells characterized by the typic morphological changes, the increased NBT positive cells, as well as the increased CD11b and CD14 levels. Notably, C-A-E significantly enhanced the intracellular ROS level. Moreimportantly, C-A-E-mediated apoptosis and differentiation of HL-60 cells was significantly mitigated by NAC. Additionally, C-A-E also exhibited an obvious anti-AML effect in NOD/SCID mice with the injection of HL-60 cells. CONCLUSIONS: C-A-E exhibited an inhibitory effect on AML cells by inducing mitochondrial apoptosis and promoting differentiation, both of which were highly correlated to the activation of ROS.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Caesalpinia/química , Leucemia Mieloide Aguda/tratamento farmacológico , Extratos Vegetais/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Acetatos/química , Animais , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Antígeno CD11b/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células HL-60 , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patologia , Receptores de Lipopolissacarídeos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos Endogâmicos NOD , Camundongos SCID , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Int J Med Sci ; 17(2): 214-223, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32038105

RESUMO

Purpose: Dynamic [11C]-acetate positron emission tomography (PET) can be used to study tissue perfusion and carbon flux simultaneously. In this study, the feasibility of the quantification of prostate cancer aggressiveness using parametric methods assessing [11C]-acetate kinetics was investigated in prostate cancer subjects. The underlying uptake mechanism correlated with [11C]-acetate influx and efflux measured in real-time in vitro in cell culture. Methods: Twenty-one patients with newly diagnosed low-to-moderate risk prostate cancer underwent magnetic resonance imaging (MRI) and dynamic [11C]-acetate PET/CT examinations of the pelvis. Parametric images of K1 (extraction × perfusion), k2 (oxidative metabolism) and VT (=K1/k2, anabolic metabolism defined as carbon retention) were constructed using a one-tissue compartment model with an arterial input function derived from pelvic arteries. Regions of interest (ROIs) of the largest cancer lesion in each patient and normal prostate tissue were drawn using information from MRI (T2 and DWI images), biopsy results, and post-surgical histopathology of whole prostate sections (n=7). In vitro kinetics of [11C]-acetate were studied on DU145 and PC3 cell lines using LigandTracer® White equipment for the measurement of the radioactivity uptake in real-time at 37°C. Results: Mean prostate specific antigen (PSA) was 8.33±3.92 ng/mL and median Gleason Sum 6 (range 5-7). K1, VT and standardized uptake values (SUVs) were significantly higher in cancerous prostate tissues compared to normal ones for all patients (p<0.001), while k2 was not (p=0.26). PSA values correlated to early SUVs (r=0.50, p=0.02) and K1 (r=0.48, p=0.03). Early and late SUVs correlated to VT (r>0.76, p<0.001) and K1 (r>0.64, p<0.005). In vitro studies demonstrated higher extraction and retention (p<0.01) of [11C]-acetate in the more aggressive PC3 cells. Conclusion: Parametric images could be used to visualize the [11C]-acetate kinetics of the prostate cancer exhibiting elevated extraction associated with the cancer aggressiveness. The influx rate of [11C]-acetate studied in cell culture also showed dependence on the cancer aggressiveness associated with elevated lipogenesis. Dynamic [11C]-acetate/PET demonstrated potential for prostate cancer aggressiveness estimation using parametric-based K1 and VT values.


Assuntos
Acetatos/química , Ciclo do Carbono/fisiologia , Tomografia Computadorizada com Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/fisiopatologia , Idoso , Humanos , Cinética , Masculino , Pessoa de Meia-Idade
14.
Carbohydr Polym ; 233: 115828, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32059882

RESUMO

In this study, the impact of drug and hydroxypropyl methylcellulose acetate succinate (HPMCAS) grades physicochemical properties on extrusion process, dissolution and stability of the hot melt extruded amorphous solid dispersions (ASDs) of nifedipine and efavirenz was investigated. Incorporation of drugs affected the extrusion temperature required for solid dispersion preparation. Differential scanning calorimetry and powder X-ray diffraction studies confirmed the amorphous conversion of the drugs in the prepared formulations. The amorphous nature of ASDs was unchanged after 3 months of stability testing at 40 °C and 75% relative humidity. The dissolution efficiency of the ASDs was dependent on the log P of the drug. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and dose of the drug. The dissolution efficiency and dissolution rate of the ASDs were dependent on the log P of the drug and solubility and hydrophilicity of the polymer grade respectively. The inhibitory effect of HPMCAS on drug precipitation was dependent on the hydrophobic interactions between drug and polymer, polymer grade, and the dissolution dose of the drug.


Assuntos
Benzoxazinas/química , Excipientes/química , Derivados da Hipromelose/química , Nifedipino/química , Acetatos/química , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Tecnologia de Extrusão por Fusão a Quente , Temperatura Alta , Metilcelulose/análogos & derivados , Metilcelulose/química , Solubilidade , Succinatos/química
15.
Molecules ; 25(4)2020 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-32079080

RESUMO

In the last decade, there has been growing interest in the food industry in replacing synthetic chemicals with natural products with bioactive properties. This study's aims were to determine the chemical composition and the antioxidant properties of the essential oil of Pastianica sylvestris. The essential oil was isolated with a yield of 0.41% (w/v) by steam distillation from the dried seeds and subsequently analysed by GC-MS. Octyl acetate (78.49%) and octyl hexanoate (6.68%) were the main components. The essential oil exhibited an excellent activity for the inhibition of primary and secondary oxidation products for cold-pressed sunflower oil comparable with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), which were evaluated using peroxide and thiobarbituric acid values. The antioxidant activity of the essential oil was additionally validated using DPPH radical scavenging (0.0016 ± 0.0885 mg/mL), and ß-carotene-linoleic acid bleaching assays. Also, the amounts of total phenol components (0.0053 ± 0.0023 mg GAE/g) were determined.


Assuntos
Acetatos/química , Antioxidantes/química , Óleos Voláteis/química , Pastinaca/química , Sementes/química , Acetatos/isolamento & purificação , Antioxidantes/isolamento & purificação , Bioensaio , Compostos de Bifenilo/antagonistas & inibidores , Compostos de Bifenilo/química , Hidroxianisol Butilado/química , Hidroxianisol Butilado/isolamento & purificação , Hidroxitolueno Butilado/química , Cromatografia Gasosa-Espectrometria de Massas , Ácido Linoleico/química , Óleos Voláteis/isolamento & purificação , Fenóis/química , Picratos/antagonistas & inibidores , Picratos/química , Extratos Vegetais/química , Óleo de Girassol/química , Tiobarbitúricos/química , beta Caroteno/química
16.
J Agric Food Chem ; 68(7): 2124-2131, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31985223

RESUMO

Lignin acylated with acetate and/or p-coumarate is common in many herbaceous plants. Herein, the biomimetic oxidation of γ-acylated monolignols with Ag2O was studied to understand the effect of γ-acyl groups on monolignol polymerization. The oxidation of sinapyl acetate gave γ-acylated and α-acylated ß-O-4 dimers in 71 and 9.5% yields, respectively. The oxidation of sinapyl p-coumarate produced γ-acylated ß-O-4 and γ-acylated tetralin ß-ß dimers in 53 and 16% yields, respectively. Only the sinapyl alcohol moiety in sinapyl p-coumarate reacted, and the p-coumarate moiety remained unchanged, suggesting that p-coumaric acid is not incorporated into the lignin backbone in the acylated lignins. All of the γ-acylated monolignols used in this study produced the γ-acylated ß-O-4 dimers, which suggests that the γ-acylated monolignols act as lignin monomers. The relatively high yields of the ß-O-4 dimers indicate that Ag2O oxidation of the monolignols can be used as an easy method for synthesizing the ß-O-4 dimer model compounds.


Assuntos
Ácidos Cumáricos/química , Dioxanos/química , Lignina/química , Óxidos/química , Compostos de Prata/química , Acetatos/química , Biomimética , Oxirredução
17.
Chemosphere ; 247: 125793, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31931310

RESUMO

Haloacetic acids (HAAs) were reported to be the most abundant category of DBPs in swimming pool water. In this study, the formation of HAAs from different organic precursors in swimming pool water, including UV filters, human body fluids, and natural organic matter (NOM), during chlorination was examined, and the effects of chlorine dose and halide concentrations on the formation of HAAs were evaluated. The results show that the total HAA yields from benzophenone-3 (BP-3) and Suwannee River humic acid (SRHA) were the highest among the nine organic precursors, and the yields of dichloroacetic acid and bromochloroacetic acid were higher than that of the other HAA species. In all the chlorinated samples of different organic precursors, longer chlorination time enhanced HAA formation. Both chlorine dose and bromide concentration significantly affected the formation of HAAs from BP-3 and SRHA during chlorination. With the increasing chlorine dose, the total HAA yields from SRHA and BP-3 significantly increased. Besides, the proportion of trihaloacetic acids (THAAs) rose while that of dihaloacetic acids (DHAAs) and monohaloacetic acids (MHAAs) declined with the increasing chlorine dose. With the increasing bromide concentration, HAA formation from SRHA increased while that of BP-3 decreased. The bromine incorporation factor (BIF) of the formed MHAAs, DHAAs and THAAs from SRHA and BP-3 both increased with the increasing bromide concentration in the following order: BIFDHAAs > BIFTHAAs > BIFMHAAs, indicating that bromine was easier to be incorporated into DHAAs rather than MHAAs or THAAs. Moreover, bromide promoted the formation of Br-HAAs.


Assuntos
Halogenação , Piscinas , Purificação da Água/métodos , Acetatos/química , Benzofenonas/química , Ácido Dicloroacético/química , Desinfetantes/análise , Desinfetantes/química , Desinfecção/métodos , Substâncias Húmicas , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
18.
J Pept Sci ; 26(3): e3241, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31984553

RESUMO

The dual interaction with integrins and neuropilin-1 receptor is the peculiar feature of iRGD peptide. Hence, in the present study, two iRGD peptide analogs were synthesized with DOTAGA and NODAGA as bifunctional chelator and aminohexanoic acid as a spacer for radiometalation with 68 GaCl3 . Negatively charged 68 Ga-DOTAGA-iRGD and neutral 68 Ga-NODAGA-iRGD radiotracers were investigated through in vitro cell uptake studies and in vivo biodistribution studies. Significant internalization of radiotracers in murine melanoma B16F10 cells was observed during in vitro studies. During in vivo studies, tumor uptake was higher for neutral 68 Ga-NODAGA-iRGD, but 68 Ga-DOTAGA-iRGD exhibited better tumor-to-blood ratio due to faster blood clearance. High kidney uptake of the two radiotracers was the limitation, which needs to be resolved through modification either in the peptide backbone or spacer/chelator.


Assuntos
Quelantes/química , Radioisótopos de Gálio/química , Melanoma Experimental/metabolismo , Peptídeos/farmacocinética , Acetatos/química , Administração Intravenosa , Anidridos/química , Animais , Linhagem Celular Tumoral , Compostos Heterocíclicos com 1 Anel/química , Integrinas/química , Camundongos , Neuropilina-1/química , Peptídeos/administração & dosagem , Peptídeos/química
19.
J Enzyme Inhib Med Chem ; 35(1): 549-554, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31967484

RESUMO

A small series of 2,4-dioxothiazolidinyl acetic acids was prepared from thiourea, chloroacetic acid, aromatic aldehydes, and ethyl-2-bromoacetate. They were assayed for the inhibition of four physiologically relevant carbonic anhydrase (CA, EC 4.2.1.1) isoforms of human (h) origin, the cytosolic hCA I and II, and the transmembrane hCA IX and XII, involved among others in tumorigenesis (hCA IX and XII) and glaucoma (hCA II and XII). The two cytosolic isoforms were not inhibited by these carboxylates, which were also rather ineffective as hCA IX inhibitors. On the other hand, they showed submicromolar hCA XII inhibition, with KIs in the range of 0.30-0.93 µM, making them highly CA XII-selective inhibitors.


Assuntos
Acetatos/farmacologia , Anidrase Carbônica IX/antagonistas & inibidores , Inibidores da Anidrase Carbônica/classificação , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Tiazóis/farmacologia , Acetatos/síntese química , Acetatos/química , Antígenos de Neoplasias/metabolismo , Anidrase Carbônica IX/metabolismo , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/química
20.
Org Lett ; 22(2): 745-749, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31904985

RESUMO

Stereoselective total synthesis of marine secondary metabolite penicitide A has been accomplished for the first time following a convergent approach. The salient feature of this study includes Horner-Wadsworth-Emmons (HWE) olefination, Evans methylations, Crimmins acetate aldol reaction, and cross olefin metathesis. Our synthetic study established the stereochemistry of unassigned C-10 and C-12 centers and also disclosed the absolute configurations of C-3 and C-5 stereocenters.


Assuntos
Acetatos/química , Aldeídos/química , Alcenos/química , Conformação Molecular , Estereoisomerismo
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