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1.
Cell Mol Biol (Noisy-le-grand) ; 70(7): 206-211, 2024 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-39097873

RESUMEN

The objective of this study was to investigate the impact of ethyl pyruvate (EP), an HMGB1 inhibitor, on ESCC cells both in vitro and in vivo. The viability of ESCC cells was assessed using the MTT method to evaluate the correlation between EP and cell viability. A scratch test was used to investigate the relationship between EP and cell migration and invasion. The effects of EP on tumor growth and survival in cancerous nude mice were examined using a tumor formation model. Immunohistochemical staining was performed to evaluate the expression levels of HMGB1, TLR4, and MyD88 in tumor tissues. EP, an anti-HMGB1 inhibitor, inhibited ESCC cell proliferation and metastasis in vitro and in vivo. Furthermore, compared with the control treatment, EP improved the activity, diet, and drinking behaviour of nude mice; inhibited tumour growth; and led to lower protein expression levels of HMGB1, TLR4, and MyD88. EP has the potential to regulate the HMGB1/TLR4-MyD88 signaling pathway, thereby inhibiting the proliferation and metastasis of ESCC, suppressing tumor growth, improving quality of life, and serving as an effective drug for ESCC treatment.


Asunto(s)
Carcinoma de Células Escamosas , Proliferación Celular , Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Proteína HMGB1 , Ratones Desnudos , Factor 88 de Diferenciación Mieloide , Piruvatos , Receptor Toll-Like 4 , Animales , Piruvatos/farmacología , Humanos , Proteína HMGB1/metabolismo , Proteína HMGB1/genética , Receptor Toll-Like 4/metabolismo , Receptor Toll-Like 4/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Factor 88 de Diferenciación Mieloide/genética , Línea Celular Tumoral , Carcinoma de Células Escamosas de Esófago/tratamiento farmacológico , Carcinoma de Células Escamosas de Esófago/patología , Carcinoma de Células Escamosas de Esófago/metabolismo , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/metabolismo , Proliferación Celular/efectos de los fármacos , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto , Movimiento Celular/efectos de los fármacos , Ratones , Transducción de Señal/efectos de los fármacos , Ratones Endogámicos BALB C , Supervivencia Celular/efectos de los fármacos , Masculino
2.
J Appl Microbiol ; 135(6)2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38849305

RESUMEN

AIMS: Irritable bowel syndrome (IBS) is a prevalent gastrointestinal disorder, encompassing diarrhea-predominant irritable bowel syndrome (IBS-D). Here, we utilized 16S rDNA gene sequencing to identify potential microbial drivers of IBS-D. METHODS AND RESULTS: A total of 30 healthy relatives and 27 patients with IBS-D were recruited. Clinical data and fecal samples were collected from patients and controls. 16S rDNA gene sequencing was performed to obtain fecal bacterial data. Differences in community composition were evaluated utilizing analysis of similarity (ANOSIM) using Bray-Curtis dissimilarity. The Wilcoxon rank sum test was used to compare differences in taxa and functional pathways. Finally, the key gut microbiota was identified using the random forest algorithm. Gut microbiota diversity, estimated through the Observe, Chao1, and abundance-based coverage estimator (ACE) indices, was significantly lower in the IBS-D patients than in the healthy relatives. ANOSIM analysis further confirmed significant differences in the composition of the gut microbiota between IBS-D patients and healthy relatives, with an R value of 0.106 and a P-value of 0.005. Notably, the IBS-D patients exhibited a significant enrichment of specific bacterial genera, including Fusicatenibacter, Streptococcus, and Klebsiella, which may possess potential pathogenic properties. In particular, the bacterial genus Klebsiella demonstrated a positive correlation with irritable bowel syndrome severity scoring system scores. Conversely, healthy subjects showed enrichment of bacterial genera such as Alistipes, Akkermansia, and Dialister, which may be beneficial bacteria in IBS-D. Utilizing the random forest model, we developed a discriminative model for IBS-D based on differential bacterial genera. This model exhibited impressive performance, with an area under the curve value of 0.90. Additionally, our analysis did not reveal any gender-specific differences in the microbiota community composition among IBS-D patients. CONCLUSIONS: Our findings offer preliminary insights into the potential relationship between intestinal microbiota and IBS-D. The identification model for IBS-D, grounded in gut microbiota, holds promising prospects for improving early diagnosis of IBS-D.


Asunto(s)
Bacterias , Diarrea , Heces , Microbioma Gastrointestinal , Síndrome del Colon Irritable , ARN Ribosómico 16S , Síndrome del Colon Irritable/microbiología , Humanos , Diarrea/microbiología , Adulto , Heces/microbiología , Femenino , Masculino , Bacterias/genética , Bacterias/clasificación , Bacterias/aislamiento & purificación , ARN Ribosómico 16S/genética , Persona de Mediana Edad , Estudios de Casos y Controles , ADN Bacteriano/genética , Adulto Joven
3.
Angew Chem Int Ed Engl ; 63(28): e202404477, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38669345

RESUMEN

Intermolecular pnictogen bonding (PnB) catalysis has received increased interest in non-covalent organocatalysis. It has been demonstrated that organic electron-deficient pnictogen atoms can act as prospective Lewis acids. Here, we present a catalytic approach for the asymmetric synthesis of chiral PIII compounds by combining intramolecular PnB interactions and carbene catalysis. Our design features a pre-chiral phosphorus molecule bearing two electron-withdrawing benzoyl groups, resulting in the formation of a σ-hole at the P atom. X-ray and non-covalent interaction (NCI) analysis indicate that the model substrates exhibit intrinsic PnB interaction between the oxygen atom of the formyl group and the phosphorus atom. This induces a conformational locking effect, leading to the crystallization of the phosphorus substrate in a preferred conformation (P212121 chiral group). Under the catalysis of N-heterocyclic carbene, the aldehyde moiety activated by the pnictogen bond selectively reacts with an alcohol to yield the corresponding chiral monoester/phosphorus product with excellent enantioselectivity. This Lewis acidic phosphorus center, aroused by the non-polarized intramolecular pnictogen bond interaction, assists in conformational and selective regulations, providing unique opportunities for catalysis and beyond.

4.
ACS Omega ; 9(11): 12927-12940, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38524431

RESUMEN

Irregular coal pillars inevitably appear in the layout of the current long-wall mining method, which easily forms stress concentrations and becomes a heavy disaster area of rock burst. In order to solve the impact risk of irregular coal pillar working face, it is necessary to study the instability mechanism of the coal pillar and put forward effective prevention and control measures. Based on the research background of 14320 working face of the Dongtan Coal Mine in the Yanzhou mining area of China, this paper studies the prediction and prevention of rock bursts in this kind of coal pillar by means of theoretical calculation, numerical simulation, engineering analogy, and field monitoring. The results show that (1) the absolute stability of coal pillar is that the width of coal pillar B reaches twice the support pressure of 2L, and the possibility of instability from large to small is coal pillars 2, 5, 3, 1, and 4. (2) The ratio of coal pillar strength to its average load determines the stability coefficient of the coal pillar, and it is judged that coal pillars 1 and 4 are in a stable state, coal pillars 3 and 5 are in a limit equilibrium state, and coal pillar 2 is in an unstable state. The numerical simulation shows that the maximum stress value inside the coal pillar during the mining process is basically consistent with the theoretical calculation of the bearing strength of the coal pillar. (3) The new evaluation method is used to evaluate the rock burst risk degree of the working face roadway: 156.75 m is a strong rock burst risk zone, 728.18 m is a medium rock burst risk zone, and 176.88 m is a weak rock burst risk zone. (4) Regional prevention and local prevention measures are proposed for the risk of rock burst in the roadway, which reduces the stress concentration of the coal pillar. It is verified that the pressure relief effect is remarkable, and the safe mining of such an irregular coal pillar working face is completed, which provides a solution for studying and solving such rock burst risk.

5.
Environ Pollut ; 337: 122483, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37669698

RESUMEN

The rapid growth of maritime traffic, transportation, and fishery activities has increased shipping emissions and degraded the air quality in coastal areas. As a result, controlling ocean-based pollution sources have become increasingly important. This study investigated the real-world emission characteristics of oxygenated polycyclic aromatic hydrocarbons (OPAHs, a group of highly toxic semi-volatile organic compounds) from five types of offshore ships using diesel oil: small and medium fishing ships, tug boats, ferry, and engineering ships, under various driving mode. Both gaseous and particle emission factors (EF) of four specific OPAHs were determined in our study. Among the OPAHs species emitted from ships, 9-fluorenone (9FO; 72%) and anthrathrace-9,10-quinone (ATQ; 25%) were the most abundant. The arithmetic mean of the sum of gaseous OPAHs EFs for all ships in this study was 2.5 ± 4.4 mg/kg fuel burned, and the mean particulate OPAHs EF was 4.7 ± 7.9 mg/kg. Small fishing ships had the highest total OPAHs EFs (31.0 ± 17.0 mg/kg). Apart from small fishing ships, there was no significant difference in the total EF of OPAHs for the other four types of ships. The emissions of the four OPAHs are predominantly in the particulate phase. There were no significant differences in the emissions of the four OPAHs under different driving mode. According to estimates, the annual OPAH emissions from the four types of ships in Hainan in 2017 were approximately 4.2 (range: 2.7-7.0) tons, dwarfing the OPAH emissions from diesel-powered on-road vehicles in China (23.5 kg).


Asunto(s)
Contaminantes Atmosféricos , Hidrocarburos Policíclicos Aromáticos , Contaminantes Atmosféricos/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Emisiones de Vehículos/análisis , Navíos , Monitoreo del Ambiente , China , Polvo , Gases , Carbón Mineral
6.
Nat Commun ; 14(1): 4878, 2023 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-37573355

RESUMEN

A carbene-catalyzed asymmetric access to chiral ß-cyano carboxylic esters is disclosed. The reaction proceeds between ß,ß-disubstituted enals and aromatic thiols involving enantioselective protonation of enal ß-carbon. Two main factors contribute to the success of this reaction. One involves in situ ultrafast addition of the aromatic thiol substrates to the carbon-carbon double bond of the enal substrate. This reaction converts almost all enal substrate to a Thiol-click Intermediate, significantly reducing aromatic thiol substrates concentration and suppressing the homo-coupling reaction of enals. Another factor is an in situ release of enal substrate from the Thiol-click Intermediate for the desired reaction to proceed effectively. The optically enriched ß-cyano carboxylic esters from our method can be readily transformed to medicines that include γ-aminobutyric acids derivatives such as Rolipram. In addition to synthetic utilities, our control of reaction outcomes via in situ substrate modulation and release can likely inspire future reaction development.

7.
J Oncol ; 2022: 5091154, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35669242

RESUMEN

We aimed to explore the role of Solute Carrier Family 35 Member F2 (SLC35F2) in pancreatic cancer (PCa) and to further study whether SLC35F2 regulates cisplatin resistance of PCa cells through the modulation of RNA binding motif protein 14 (RBM14) expression. SLC35F2 expression in 60 pairs of PCa tissues and adjacent ones was studied by RT-PCR analysis. Meanwhile, SLC35F2 expression levels in PCa cell lines were also evaluated by qPCR assay. In addition, SLC35F2 knockdown models were constructed in PCa cisplatin-resistant cells. Furthermore, we determined the interaction between SLC35F2 and RBM14 via luciferase assay. The findings of the present study demonstrated that SLC35F2 was significantly upregulated in PCa tissues. High level of SLC35F2 indicated higher incidence of metastasis and shorter survival rates. In vitro cell experiments revealed that knockdown of SLC35F2 suppressed cell invasion and metastasis capacity of cisplatin-resistant PCa cell lines PANC-1/DDP and CFPAC-1/DDP. It was also suggested that the key protein RBM14 in the SLC35F2 knockdown group was remarkably reduced. SLC35F2 can bind to RBM14 specifically. Overexpression of RBM14 partially reversed the effects of knockdown of SLC35F2 on the development of PCa. SLC35F2 expression in PCa tissues and cell lines is remarkably increased. In addition, it was also suggested that SLC35F2 may regulate cisplatin resistance of PCa cells through modulating RBM14 expression. In conclusion, it is conceivable from the study that SLC35F2 was remarkably upregulated in PCa and promoted the malignancy of PCa via regulating RBM14.

8.
Medicine (Baltimore) ; 101(51): e32380, 2022 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-36595766

RESUMEN

Herein, we aimed to evaluate the clinical value and safety of transendoscopic submucosal tunnel tumor resection (STER) and endoscopic submucosal dissection (ESD) for the resection of esophageal submucosal intrinsic muscle tumors. We retrospectively analyzed the clinical data of 68 patients with esophageal submucosal intrinsic muscle tumors treated with STER (STER group, n = 38, March 2018 to January 2020) or ESD (ESD group, n = 30, January 2017 to January 2020) at the First People's Hospital of Lianyungang to compare the treatment efficacy, hospitalization time and costs, and postoperative complications between the 2 groups. All 68 cases were of single lesions. The mean operative duration was shorter in the STER group (53.39 ±â€…11.57 min) than in the ESD group (68.33 ±â€…18.52 min, P < .05). The postoperative hospital stay duration was significantly shorter in the STER group (5.86 ±â€…1.01 days; P < .05) than in the ESD group (8.2 ±â€…3.4 days, P < .05). The mean hospitalization cost was significantly lower in the STER group than in the ESD group (12,468.8 + 4966.8 yuan vs 17,033.3 ±â€…4547.2 yuan; P < .05). Only 1 case of intraoperative perforation occurred in ESD group. There were no other complications in both groups. The wound healed in both groups, and no residual or recurrent tumors were detected during the follow-up period. Both STER and ESD can be used for the treatment of esophageal intrinsic muscular layer (MP) tumors, and STER is safer and more efficient for lesions with a diameter <3.5 cm.


Asunto(s)
Resección Endoscópica de la Mucosa , Neoplasias Esofágicas , Neoplasias de los Músculos , Neoplasias Gástricas , Humanos , Resección Endoscópica de la Mucosa/efectos adversos , Estudios Retrospectivos , Recurrencia Local de Neoplasia/patología , Neoplasias Esofágicas/patología , Resultado del Tratamiento , Neoplasias Gástricas/patología
9.
Kaohsiung J Med Sci ; 38(2): 129-138, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34741399

RESUMEN

Increased abnormal spindle-like microcephaly (ASPM) expression has been linked to clinical stage and poor prognosis in cancers, but the molecular mechanisms by which ASPM promotes cell metastasis in colorectal cancer (CRC) has not been identified. This study showed that the abilities of cell migration, invasion, and epithelial-mesenchymal transition (EMT) were attenuated in ASPM-deficient CRC cell lines. Furthermore, we reported that attenuation of ASPM expression inhibited CRC cell metastasis in vivo. Additionally, the expression of ASPM was positively correlated with ß-catenin level in CRC tissues. Mechanistically, ASPM can upregulate ß-catenin transcription by stimulating the ß-catenin promoter and enhancing the nuclear translocation of ß-catenin in CRC cells, which leads to the activation of the Wnt/ß-catenin pathway. Finally, we showed that ASPM effectively induced CRC cell migration and invasion in a ß-catenin-dependent manner.


Asunto(s)
Movimiento Celular , Neoplasias Colorrectales/metabolismo , Neoplasias Colorrectales/patología , Proteínas del Tejido Nervioso/fisiología , beta Catenina/biosíntesis , Núcleo Celular , Humanos , Invasividad Neoplásica , Transporte de Proteínas , Células Tumorales Cultivadas
10.
Bioengineered ; 12(2): 10023-10036, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34666602

RESUMEN

Methyltransferase like 3 (METTL3) has been identified to serve as a definitive inducer in cancer progression. This study sought to analyze the regulatory mechanism of METTL3 in epithelial-mesenchymal transition (EMT), invasion, and metastasis in esophageal cancer (ESCA). The METTL3 expressions in cancer tissues and cells were detected with extensive analysis of its correlation with clinical baseline data. The cells were transfected with sh-RNA-METTL3 and microRNA (miR)-20a-5p mimic, followed by evaluation of invasion, migration, and EMT. The N6-methyladenosine (m6A) level and enrichment of DiGeorge Critical Region 8 (DGCR8) and m6A were observed. The binding relationship between miR-20a-5p and Nuclear Factor I-C (NFIC) was verified, followed by Pearson correlation analysis. A subcutaneous tumor formation assay was conducted prior to observation of lung metastases. Our results revealed that METTL3 was highly expressed in ESCA patients and associated with severe lymph node involvement and distant metastasis. METTL3 downregulation radically inhibited the invasiveness, migration, and EMT. METTL3 elevated the miR-20a-5p expression via improving m6A modification. METTL3 inhibition downregulated the miR-20a-5p expression. Moreover, miR-20a-5p upregulation facilitated ESCA cell invasiveness and migration by targeting NFIC transcription. METTL3 inhibition suppressed tumor growth and lung metastasis in vivo. Overall, METTL3 promoted m6A modification and the binding of DGCR8 to miR-20a-5p to further elevate the miR-20a-5p expression and inhibit NFIC transcription, thus promoting EMT, invasion and migration.


Asunto(s)
Transición Epitelial-Mesenquimal/genética , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patología , Metiltransferasas/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Animales , Secuencia de Bases , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Metilación de ADN/genética , Regulación hacia Abajo/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Masculino , Metiltransferasas/genética , Ratones Desnudos , MicroARNs/genética , MicroARNs/metabolismo , Persona de Mediana Edad , Modelos Biológicos , Factores de Transcripción NFI/genética , Factores de Transcripción NFI/metabolismo , Invasividad Neoplásica , Metástasis de la Neoplasia , Transcripción Genética , Regulación hacia Arriba/genética
11.
Thorac Cancer ; 11(8): 2306-2315, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32633082

RESUMEN

BACKGROUND: Previous studies have shown that lncRNA LINC00662 plays an important role in pathogenesis of malignancies. The purpose of this study was to elucidate the regulatory mechanism of LINC00662 in esophageal squamous cell carcinoma (ESCC). METHODS: In this study, the regulatory mechanism of LINC00662 was investigated by RT-qPCR. MTT, transwell and dual luciferase reporter assays. RESULTS: Upregulation of LINC00662 was found in ESCC and associated with worse clinical outcomes in ESCC patients. More importantly, knockdown of LINC00662 restrained cell proliferation, migration and invasion in ESCC. In addition, LINC00662 acts as a molecular sponge for miR-340-5p in ESCC, and miR-340-5p directly targets HOXB2. HOXB2 expression can be positively regulated by LINC00662 in ESCC. Furthermore, HOXB2 downregulation or miR-340-5p overexpression weakened the carcinogenesis of LINC00662 in ESCC. CONCLUSIONS: LncRNA LINC00662 promotes the progression of ESCC by upregulating HOXB2 by sponging miR-340-5p.


Asunto(s)
Supervivencia Celular/fisiología , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/metabolismo , Proteínas de Homeodominio/metabolismo , MicroARNs/metabolismo , ARN Largo no Codificante/metabolismo , Factores de Transcripción/metabolismo , Línea Celular Tumoral , Células Cultivadas , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patología , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/patología , Femenino , Proteínas de Homeodominio/genética , Humanos , Masculino , MicroARNs/genética , Persona de Mediana Edad , Metástasis de la Neoplasia , ARN Largo no Codificante/genética , Factores de Transcripción/genética , Transfección , Regulación hacia Arriba
12.
J AOAC Int ; 97(1): 218-24, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24672881

RESUMEN

An ultra-performance LC/tandem MS (UPLC/MS/MS) method for the simultaneous quantification and identification of matrine and berberine, alkaloids widely used in plant fungicides, has been developed and validated. Methanol or 1% ammonia-acetonitrile were selected as extraction solvents, and primary secondary amine sorbent was chosen for cleanup to achieve satisfactory recoveries in accordance with European Union guidelines. The chromatographic separation was carried out on a hydrophilic interaction LC column with a UPLC/MS/MS-based method to improve the retentions and shapes of the peaks. Method validation was performed for linearity, repeatability, interday precision, and sensitivity. Recoveries and RSDs were acceptable (73.1-109.3% recovery, RSD < or = 15.8%). The LODs varied from 0.34 to 1.07 microg/kg for matrine and 0.09 to 0.18 microg/kg for berberine, while the LOQs ranged from 1.12 to 3.58 microg/kg for matrine and 0.31 to 0.60 microg/kg for berberine. This method was successfully and efficiently applied for the analysis of matrine and berberine in real samples.


Asunto(s)
Alcaloides/química , Berberina/química , Cromatografía Liquida , Frutas/química , Quinolizinas/química , Suelo/química , Verduras/química , Análisis de los Alimentos/métodos , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/métodos , Matrinas
13.
J Chromatogr A ; 1299: 71-7, 2013 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-23768534

RESUMEN

A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for the simultaneous determination of spirotetramat and its four metabolites in fruits (apple, peach) and vegetables (cabbage, tomato, potato, cucumber), based on the use of liquid extraction/partition and dispersive solid phase extraction (dispersive-SPE) followed by ultrahigh-performance chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS), was established. Acidified acetonitrile (containing 1% (v/v) acetic acid) as the extraction solvent and simultaneous liquid-liquid partitioning formed by adding anhydrous magnesium sulfate (MgSO4) and anhydrous sodium acetate (NaOAc). The extract was then cleaned up by dispersive-SPE using graphitized carbon black (GCB) as selective sorbent. Further optimization of sample preparation and determination achieved recoveries of between 82 and 110% for all analytes with RSD values lower than 14% in apple, peach, cabbage, tomato, potato and cucumber at three levels (10, 100 and 1000µg/kg). The method showed excellent linearity (R(2)≥0.9895) for all studied analytes. The determination of the target compounds was achieved in less than 6.0min using an electrospray ionization source in positive mode (ESI+). The method is demonstrated to be convenient and reliable for the routine monitoring of spirotetramat and its metabolites in fruits and vegetables.


Asunto(s)
Compuestos Aza/análisis , Cromatografía Liquida/métodos , Frutas/química , Extracción en Fase Sólida/métodos , Compuestos de Espiro/análisis , Espectrometría de Masas en Tándem/métodos , Verduras/química , Compuestos Aza/química , Insecticidas/análisis , Insecticidas/química , Reproducibilidad de los Resultados , Compuestos de Espiro/química
14.
J Hazard Mater ; 250-251: 9-18, 2013 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-23434475

RESUMEN

A novel and sensitive chiral liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed and validated for simultaneous measuring individual enantiomers of 9 pesticides including herbicides, insecticides, and fungicides in soil and water. The separation and determination were performed using reversed-phase chromatography on an amylose chiral stationary phase, a Chiralpak AD-RH column, under gradient elution using a mixture of ACN-2mM ammonium acetate in water as the mobile phase at 0.45 mL/min flow rate. The effects of three cellulose-based columns and three amylose-based columns on the separation were also investigated. The QuEChERS (acronym for Quick, Easy, Cheap, Effective, Rugged and Safe) method and solid-phase extraction (SPE) were used for the extraction and clean-up of the soil and water samples, respectively. Parameters including the matrix effect, linearity, precision, accuracy and stability were undertaken. Under optimal conditions, the mean recoveries for all enantiomers from the soil and water samples were ranged from 77.8% to 106.2% with the relative standard deviations (RSD) less than 14.2%. Good linearity (at least R(2) ≥ 0.9986) was obtained for all studied analytes in the soil and water matrix calibration curves over the range from 2.0 to 125 µg/L. The limits of detection (LOD) for all enantiomers in the soil and water were less than 1.8 µg/kg or µg/L, whereas the limit of quantification (LOQ) did not exceed 5.0 µg/kg or µg/L. The results of the method validation confirm that this proposed method is convenient and reliable for the enantioselective determination of the enantiomers of 9 chiral pesticides in soil and water.


Asunto(s)
Cromatografía Liquida/métodos , Plaguicidas/análisis , Contaminantes del Suelo/análisis , Espectrometría de Masas en Tándem/métodos , Contaminantes Químicos del Agua/análisis , Acetatos/química , Calibración , Celulosa/química , Modelos Químicos , Plaguicidas/aislamiento & purificación , Reproducibilidad de los Resultados , Suelo/análisis , Contaminantes del Suelo/aislamiento & purificación , Estereoisomerismo , Agua/análisis , Contaminantes Químicos del Agua/aislamiento & purificación
15.
Artículo en Inglés | MEDLINE | ID: mdl-23410121

RESUMEN

A QuEChERS procedure for the simultaneous determination of pyrimethanil, cyprodinil, mepanipyrim and its metabolite (M31) in fresh and processed fruit and vegetables was developed using ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). The determination of the four target compounds was achieved in less than 6.0 min using an electrospray ionisation source in positive mode. The limits of detection (LODs) were below 0.4 µg kg⁻¹, while the limits of quantification (LOQs) did not exceed 1.5 µg kg⁻¹ for all studied matrices. Good linearity of the calibration curves was obtained over the range from 0.002 to 2 mg kg⁻¹, with correlation coefficients higher than 0.999. The average recoveries of this method in apple, peach, cabbage and tomato at the five spiked levels (0.002, 0.01, 0.05, 0.20 and 2.0 mg kg⁻¹) ranged from 81.5% to 107.3% with relative standard deviations (RSDs) in the range of 1.5-13.9% (n = 5) for all analytes. Residue levels of anilinopyrimidine fungicides in fresh and home-processed apple, peach, cabbage and tomato were also studied. The results indicate that residue levels are significantly reduced following washing, peeling and boiling, and there is no toxic metabolite of mepanipyrim (M31) which is detected during boiling. This study provides a theoretical basis for China to draw up maximum residue limits (MRLs) and protect consumers from the negative health effects of pesticide residues detected in fruit and vegetables.


Asunto(s)
Cromatografía Liquida/métodos , Frutas/química , Pirimidinas/análisis , Espectrometría de Masas en Tándem/métodos , Verduras/química , Calibración , Límite de Detección , Reproducibilidad de los Resultados
16.
Chirality ; 25(3): 160-9, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23335346

RESUMEN

Chiral pesticide enantiomers often show different bioactivity and toxicity; however, this property is usually ignored when evaluating their environmental and public health risks. Hexaconazole is a chiral fungicide used on a variety of crops for the control of many fungal diseases. This use provides opportunities for the pollution of food and soil. In this study, a sensitive and convenient chiral liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed and validated for measuring hexaconazole enantiomers in tomato, cucumber, and soil. Separation was by a reversed-phase Chiralcel OD-RH column, under isocratic conditions using a mixture of acetonitrile-2 mM ammonium acetate in water (60/40, v/v) as the mobile phase at a flow rate of 0.4 mL/min. Parameters including the matrix effect, linearity, precision, accuracy and stability were undertaken. Then the proposed method was successfully applied to investigate the possible enantioselective degradation of rac-hexaconazole in plants (tomato and cucumber) and soil under field conditions. The degradation of the two enantiomers of hexaconazole proved to be enantioselective and dependent on the media: The (+)-enantiomer showed a faster degradation in plants, while the (-)-enantiomer dissipated faster than the (+)-form in field soil, resulting in relative enrichment of the opposite enantiomer. The results of this work demonstrate that both the environmental media and environmental conditions influenced the direction and rate of enantioselective degradation of hexaconazole.


Asunto(s)
Cromatografía Liquida , Cucumis/química , Fungicidas Industriales/química , Contaminantes del Suelo/análisis , Solanum lycopersicum/química , Espectrometría de Masas en Tándem , Triazoles/química , Fungicidas Industriales/análisis , Límite de Detección , Estructura Molecular , Contaminantes del Suelo/química , Estereoisomerismo
17.
J Chromatogr A ; 1224: 51-60, 2012 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-22209355

RESUMEN

The manuscript concerns the development and validation of a novel and sensitive multi-residue method for simultaneous enantiomeric analysis of 8 triazole fungicides (tetraconazole, fenbuconazole, epoxiconazole, diniconazole, hexaconazole, triadimefon, paclobutrazol, and myclobutanil) in soil and water using chiral liquid chromatography coupled with tandem mass spectrometry. The separation and determination were performed using reversed-phase chromatography on a cellulose chiral stationary phase, a Chiralcel OD-RH (150 mm × 4.6 mm) column, under isocratic conditions using a mixture of ACN-2 mM ammonium acetate in water (55/45, v/v) as the mobile phase at 0.45 mL/min flow rate. The effects of three cellulose-based columns and three amylose-based columns on the separation were also investigated. The QuEChERS (acronym for quick, easy, cheap, effective, rugged and safe) method and solid-phase extraction (SPE) were used for the extraction and clean-up of the soil and water samples, respectively. Parameters including the matrix effect, linearity, precision, accuracy and stability were undertaken. Under optimal conditions, the mean recoveries for all sixteen enantiomers from the soil samples were 76.4-108.1% with 2.6-12.0% intra-day relative standard deviations (RSD) and 4.2-14.1% inter-day RSD at 5, 25 and 50 µg/kg levels; the mean enantiomer recoveries from the water samples were 81.2-106.5% with 2.1-11.5% intra-day RSD and 3.4-13.6% inter-day RSD at 0.25, 0.5 and 2.5 µg/L levels. Coefficients of determination R2 ≥ 0.9989 were achieved for all studied analytes in the soil and water matrix calibration curves within the range of 1.0-125 µg/L. The limits of detection (LOD) (S/N=3) for all enantiomers in the soil and water were less than 1.0 µg/kg or µg/L, whereas the limit of quantification (LOQ) (S/N=10) did not exceed 3.0 µg/kg or µg/L. The results of the method validation confirm that this proposed method is convenient and reliable for the enantioselective determination of the enantiomers of triazole fungicides in soil and water.


Asunto(s)
Fungicidas Industriales/análisis , Residuos de Plaguicidas/análisis , Suelo/química , Triazoles/análisis , Contaminantes Químicos del Agua/química , Cromatografía de Fase Inversa/métodos , Fungicidas Industriales/química , Límite de Detección , Modelos Lineales , Residuos de Plaguicidas/química , Reproducibilidad de los Resultados , Estereoisomerismo , Espectrometría de Masas en Tándem/métodos , Triazoles/química
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