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1.
Int Immunopharmacol ; 81: 106261, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32058928

RESUMO

Exacerbation of chronic obstructive pulmonary disease (COPD) is characterized by acute airway inflammation and mucus hypersecretion, which is by far the most costly aspect of its management. Thus, it is essential to develop therapeutics with low side effects for CODP exacerbation. Sodium tanshinone IIA sulfonate (STS) is a water-soluble derivative of tanshinone IIA isolated as the major active component of Chinese herbal medicine Danshen. Although it possesses anti-inflammatory, anti-oxidative and anti-apoptotic properties, it remains unknown whether STS protects against COPD exacerbation. In this study, we challenged cigarette smoke (CS)-exposed mice with lipopolysaccharide (LPS), and then treated these mice with STS. We found that STS significantly ameliorated pulmonary inflammatory responses, mucus hypersecretion and lung function decline in CS-exposed mice challenged with LPS. STS treatment also significantly attenuated increased IL-6 and IL-8 releases from cigarette smoke extract (CSE)-treated human bronchial epithelial cells (16HBE) challenged with LPS. Mechanistically, STS reduced activation of ERK1/2 and NF-κB in lungs of CS-exposed mice and CSE-treated 16HBE cells challenged with LPS. Taken together, STS protects against acute exacerbation of CS-induced lung injury, which provides a promising and potential therapeutic avenue to halt acute exacerbation of COPD.

2.
Int Immunopharmacol ; : 105979, 2019 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-31771816

RESUMO

Chronic obstructive pulmonary fibrosis (COPD) is a chronic and fatal lung disease with few treatment options. Sodium hydrosulfide (NaHS), a donor of hydrogen sulfide (H2S), was found to alleviate cigarette smoke (CS)-induced emphysema in mice, however, the underlying mechanisms have not yet been clarified. In this study, we investigated its effects on COPD in a CS-induced mouse model in vivo and in cigarette smoke extract (CSE)-stimulated alveolar epithelial A549 cells in vitro. The results showed that NaHS not only relieved emphysema, but also improved pulmonary function in CS-exposed mice. NaHS significantly increased the expressions of tight junction proteins (i.e., ZO-1, Occludin and claudin-1), and reduced apoptosis and secretion of pro-inflammatory cytokines (i.e., TNF-α, IL-6 and IL-1ß) in CS-exposed mouse lungs and CSE-incubated A549 cells, indicating H2S inhibits CS-induced inflammation, injury and apoptosis in alveolar epithelial cells. NaHS also upregulated prolyl hydroxylase (PHD)2, and suppressed hypoxia-inducible factor (HIF)-1α expression in vivo and in vitro, suggesting H2S inhibits CS-induced activation of PHD2/HIF-1α axis. Moreover, NaHS inhibited CS-induced phosphorylation of ERK, JNK and p38 MAPK in vivo and in vitro, and treatment with their inhibitors reversed CSE-induced ZO-1 expression and inflammation in A549 cells. These results suggest that NaHS may prevent emphysema via the suppression of PHD2/HIF-1α/MAPK signaling pathway, and subsequently inhibition of inflammation, epithelial cell injury and apoptosis, and may be a novel strategy for the treatment of COPD.

3.
Biomed Chromatogr ; : e4745, 2019 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-31725903

RESUMO

Using LC-MS/MS, a rapid and sensitive method for the simultaneous determination of pyraclostrobin and azoxystrobin residues in banana matrices (leaf and whole banana) and soil was established. The samples were extracted using acetonitrile and purified through C18 dispersive solid-phase extraction. The average recovery of the analytes in various matrices was in the range of 77.3%-103.9% with an RSD range of 0.9%-9.5%. The initial deposition amounts of pyraclostrobin and azoxystrobin at 2 h in the banana leaves of the mineral oil group were 1.43 and 1.31 times in Guangxi, and 2.10 and 1.81 times in Hainan for the water group, whereas those in the soil of the water group were 3.45 and 3.03 times in Guangxi, and 2.14 and 3.48 times in Hainan for the mineral oil group. The half-lives in the leaves and soil of the mineral oil group were not remarkably different from those of the water group. The terminal residue of the analytes on the whole banana was <0.02 mg/kg at 14 days after application from the two sites. The results of this work may indicate and promote the safety of using pyraclostrobin and azoxystrobin in banana production, especially with mineral oil spray adjuvants.

4.
Org Lett ; 21(23): 9493-9496, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31742417

RESUMO

A carbene-catalyzed reaction between α-bromoenals and thioamides was developed. Key steps include enantioselective 1,4-addition of thioamide sulfur atoms to α,ß-unsaturated acyl azolium intermediate. Subsequent intramolecular annulation eventually affords thiazinone heterocycles with high optical purities. The introduction of Lewis acid additives such as Cu(OTf)2 to this NHC catalytic reaction could provide small but consistent improvements to reaction enantioselectivities.

5.
J Agric Food Chem ; 67(41): 11312-11321, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31557019

RESUMO

Two enantiomers of glufosinate were separated under reverse-phase conditions on a chiral crown stationary phase (CROWNPAK CR(+)). An efficient and reliable chiral analytical method was developed to determine the glufosinate enantiomers and two metabolites in soil and water samples using high-performance liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS). The linearities of the matrix-matched calibration curves in five water and four soil samples were good with a correlation coefficient R2 > 0.998, and the mean recoveries were 85.2-100.4%, with relative standard deviations of 1.0-7.1%. l-Glufosinate was degraded faster than d-glufosinate in four nonsterile natural soil and two nonsterile natural water samples. The degradation half-lives of the enantiomers ranged from 3.4 to 33.0 days in the soil samples, but glufosinate was stable in the five water samples, less than 22% of the applied substance degraded at the end of the experiment (100 days). Degradation in sterile soil was not enantioselective. The two enantiomers were configurationally stable in the four soil and five water samples. In most cases of glufosinate degradation in soils, the percentage of 3-methylphosphinicopropionic in relation to the parent was higher than that of N-acetyl-glufosinate. l-Glufosinate was preferentially degraded in the four soils, and formation of 3-methylphosphinicopropionic acid and N-acetyl-glufosinate was enantiomer dependent.


Assuntos
Aminobutiratos/química , Compostos Organofosforados/química , Praguicidas/química , Propionatos/química , Poluentes do Solo/química , Poluentes Químicos da Água/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Estereoisomerismo
6.
Artigo em Inglês | MEDLINE | ID: mdl-30563033

RESUMO

Hydrolysis and photolysis kinetics of Fubianezuofeng (FBEZF) in water were investigated in detail. The hydrolysis half-lives of FBEZF depending on pH, initial concentration, and temperature were (14.44 d at pH = 5; 1.60 d at pH = 7), (36.48 h at 1.0 mg L-1; 38.51 h at 5.0 mg L-1; and 31.51 h at 10.0 mg L-1), and (77.02 h at 15 °C; 38.51 h at 25 °C; 19.80 h at 35 °C; and 3.00 h at 45 °C), respectively. The photolysis half-life of FBEZF in different initial concentrations were 8.77 h at 1.0 mg L-1, 8.35 h at 5.0 mg L-1, and 8.66 h at 10.0 mg L-1, respectively. Results indicated that the degradation of FBEZF followed first-order kinetics, as the initial concentration of FBEZF only had a slight effect on the UV irradiation effects, and the increase in pH and temperature can substantially accelerate the degradation. The hydrolysis Ea of FBEZF was 49.90 kJ mol-1, which indicates that FBEZF belongs to medium hydrolysis. In addition, the degradation products were identified using ultra-high-performance liquid chromatography coupled with an Orbitrap high-resolution mass spectrometer. One degradation product was extracted and further analyzed by ¹H-NMR, 13C-NMR, 19F-NMR, and MS. The degradation product was identified as 2-(4-fluorobenazyl)-5-methoxy-1,3,4-oxadiazole, therefore a degradation mechanism of FBEZF in water was proposed. The research on FBEZF can be helpful for its safety assessment and increase the understanding of FBEZF in water environments.


Assuntos
Antibacterianos/química , Hidrólise , Oxidiazóis/química , Fotólise , Sulfonas/química , Água/química , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Espectrometria de Massas , Temperatura Ambiente , Raios Ultravioleta
7.
Biomed Chromatogr ; 32(7): e4226, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29500909

RESUMO

In this study, a modified quick, easy, cheap, effective, rugged and safe method coupled with gas chromatography with electron capture detection was established to determine dimethachlon residues in paddy soil, rice husk, rice straw, brown rice and cooked rice. The limits of quantification of dimethachlon were 0.01 mg/kg for paddy soil, brown rice and cooked rice and 0.02 mg/kg for rice straw and rice husk. The mean recoveries were in the range 78.59-104.7% with relative standard deviation values of <10% for dimethachlon in the five matrices. For field experiments, the final residues of dimethachlon in paddy soil were < 0.05 mg/kg and were < 1.21 mg/kg in rice straw from six sites. The final residues of dimethachlon in the brown rice at 21, 28 and 35 days after spraying from six sites were 0.08-7.58 mg/kg, and 0.16-30.1 mg/kg in rice husk. Our six test sites covered the main rice-producing areas of China. The routine rice cooking process of a Chinese family could apparently increase the removal of dimethachlon in rice compared with brown rice, and the reduction ratios were > 96%.


Assuntos
Clorobenzenos/análise , Cromatografia Gasosa/métodos , Oryza/química , Resíduos de Praguicidas/análise , Succinimidas/análise , Culinária , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
8.
Biomed Chromatogr ; 32(4)2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29165829

RESUMO

A simple method was developed and validated for the simultaneous determination of clethodim, clethodim sulfoxide, and clethodim sulfone in soil and tobacco by liquid chromatography with tandem mass spectrometry. The three target compounds were extracted from tobacco and soil with acetonitrile, and the extracts were purified using octadecyl silane. The proposed method showed satisfactory linearity (R2 ≥ 0.9973) for the target compounds. The limits of detection and quantitation of the three analytes in all matrices were 0.024-0.06 and 0.08-0.2 mg/kg, respectively. The recovery was tested in blank soil and tobacco leaf samples and calculated to be 74.8-104.4% with relative standard deviations of 1.9-12.1%. The developed method was successfully applied to the analysis of residues of clethodim, clethodim sulfoxide and clethodim sulfone in real soil and tobacco samples. The results indicated that the developed method can meet the requirements for the analysis of trace amounts of all three analytes in soil and tobacco.


Assuntos
Cromatografia Líquida/métodos , Cicloexanonas/análise , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Tabaco/química , Cicloexanonas/química , Limite de Detecção , Modelos Lineares , Resíduos de Praguicidas/química , Folhas de Planta/química , Reprodutibilidade dos Testes , Poluentes do Solo/análise , Poluentes do Solo/química , Sulfonas/análise , Sulfonas/química , Sulfóxidos/análise , Sulfóxidos/química
9.
Se Pu ; 35(6): 620-626, 2017 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-29048789

RESUMO

A QuEChERS-liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of pyraclostrobin, thiophanate-methyl and its metabolite carbendazim in soil and citrus. The samples were extracted with methanol or acetonitrile, purified by primary secondary amine (PSA), then separated by LC, detected in multiple reaction monitoring (MRM) mass spectrometry mode via positive electrospray ionization. The analytes were quantified by matrix-matched standard solutions with external standard method. The limits of quantification (LOQs) of pyraclostrobin, thiophanate-methyl and carbendazim in different matrices were 5.8-7.0 µg/kg, 9.3-14.1 µg/kg and 2.1-2.6 µg/kg, respectively. For all the samples, the spiked recoveries ranged from 75.48% to 109.18%, and the relative standard deviations (RSDs) were 0.60%-5.11% (n=5). The method is quick, easy, effective, sensitive and accurate. The matrix-matched calibration solutions can efficiently compensate matrix effects of the pyraclostrobin, thiophanate-methyl and carbendazim in LC-MS/MS analysis. The established method can be applied to the residue analysis of the real samples of soil, citrus peel, citrus pulp and citrus fruits.


Assuntos
Benzimidazóis/análise , Carbamatos/análise , Resíduos de Praguicidas/análise , Estrobilurinas/análise , Espectrometria de Massas em Tandem , Tiofanato/análise , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Citrus , Pirazóis , Solo
10.
J AOAC Int ; 100(5): 1551-1558, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28429676

RESUMO

Determination of the polar characteristics of dinotefuran and metabolite residues in orange matrixes (orange pulp, orange peel, and whole orange) is difficult. Thus, the purpose of the present study was to develop an extraction method for the determination of dinotefuran and its metabolites in oranges by using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Matrix suppression effects were observed for all analytes in the orange matrixes. The proposed method displayed satisfactory linearity (R2 ≥ 0.9856) for the target molecules. The LODs were 0.03-0.10 mg/kg, whereas LOQs were 0.08-0.40 mg/kg for dinotefuran and its metabolites. Recoveries were 79.1-98.7% with RSD values <20% for all analytes in the orange matrixes. The proposed method was used to authenticate the samples and dinotefuran residues observed in field-incurred orange matrixes. The results of the proposed method could help the Chinese government establish maximum residue limits for dinotefuran in oranges and promote the safe and proper use of dinotefuran dosages in orange trees.


Assuntos
Citrus sinensis/química , Análise de Alimentos , Frutas/química , Guanidinas/análise , Neonicotinoides/análise , Nitrocompostos/análise , Resíduos de Praguicidas/análise , Cromatografia Líquida , Espectrometria de Massas em Tandem
11.
Curr Drug Metab ; 17(7): 681-91, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27216792

RESUMO

BACKGROUND: Angiotensin receptor blockers (ARBs) are the most recent class of agents for the treatment of hypertension. However, ARBs may cause a low incidence of headache, upper respiratory infection, back pain, muscle cramps, fatigue, dizziness, and many other side effects. In some cases, such toxicity is associated with pharmacokinetic alterations. METHODS: The cytochrome P450 (CYP) enzyme system plays an important role in a lot of clinically important pharmacokinetic drug interactions. To identify relevant studies on drug-drug and food-drug pharmacokinetic interactions with the ARBs, a literature search of Google Scholar was performed from January 1994 to June 2015, with the following keywords: 'losartan', 'valsartan,' 'candesartan,' 'irbesartan,' 'telmisartan,' 'eprosartan,' 'olmesartan,' and 'azilsartan', combined with the keyword 'pharmacokinetic interactions' and 'CYP'. RESULTS: Based on the literatures published, it has been demonstrated that pharmacokinetic interactions of losartan with other agents are mainly via CYP2C9- and CYP3A4-mediated, the role played by CYP enzyme system in the metabolism of valsartan, candesartan, irbesartan, and azilsartan appears modest, and cytochrome P450 system has no influence on the metabolism of telmisartan, eprosartan, olmesartan. Therefore, according to these pharmacokinetic findings, no dosage adjustment is recommended when eprosartan, telmisartan and olmesartan are combined with other pharmacological agents in patients with hypertension. CONCLUSION: This review summarize the available data on cytochrome P450 - related drug-drug interactions reported in the literature for the eight ARBs. Knowledge of the pharmacokinetic properties of the ARBs should allow the avoidance of the majority of drug interactions without compromising therapeutic benefits.


Assuntos
Antagonistas de Receptores de Angiotensina/farmacocinética , Sistema Enzimático do Citocromo P-450/metabolismo , Animais , Interações de Medicamentos , Humanos
12.
Biomed Chromatogr ; 30(2): 142-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26043404

RESUMO

This study developed and used a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) method coupled with gas chromatography with electron capture detection to determine eight pyrethroid pesticide residues in green, red and dehydrated red peppers. Pyrethroids were extracted with acetonitrile, partitioned with sodium chloride and purified with primary secondary amino and graphitized carbon black in hexane. The QuEChERS extraction conditions were optimized, and the matrix effects that might influence recoveries were evaluated and minimized using matrix-matched calibration curves. Under the optimized conditions, the calibration curves for pyrethroid pesticides showed good linearities in the concentration range of 0.05-20 µg/mL with determination coefficients (R(2) ) >0.997. The limits of quantification of eight pyrethroids were 0.004-0.04 mg/kg for green and red pepper and 0.04-0.5 mg/kg for dehydrated red pepper. These values are below the suggested regulatory maximum residue limits. The mean recoveries ranged between 79.0 and 104%, and the relative standard deviations were <11%. The developed method was successfully applied to commercial samples. Some samples were found to contain pyrethroid pesticides with levels below the legal limits.


Assuntos
Capsicum/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/isolamento & purificação , Piretrinas/análise , Piretrinas/isolamento & purificação , Limite de Detecção , Modelos Lineares , Resíduos de Praguicidas/química , Piretrinas/química , Reprodutibilidade dos Testes
13.
Org Biomol Chem ; 11(35): 5954-62, 2013 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-23907113

RESUMO

An interesting sequential reaction involving Sonogashira coupling, propargyl-allenyl isomerization, intramolecular [4 + 2] cycloaddition, and bridged oxa-ring opening has been realized, providing a facile method for the synthesis of functionalized dihydroisobenzofurans from easily accessible starting materials with a decent diastereoselectivity.

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