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1.
J Agric Food Chem ; 72(10): 5176-5184, 2024 Mar 13.
Article in English | MEDLINE | ID: mdl-38417018

ABSTRACT

Microbial degradation is a highly efficient and reliable approach for mitigating the contamination of sulfonylurea herbicides, such as chlorimuron-ethyl, in soil and water. In this study, we aimed to assess whether Kj-mhpC plays a pivotal role in the degradation of chlorimuron-ethyl. Kj-mhpC enzyme purified via prokaryotic expression exhibited the highest catalytic activity for chlorimuron-ethyl at 35 °C and pH 7. Bioinformatic analysis and three-dimensional homologous modeling of Kj-mhpC were conducted. Additionally, the presence of Mg+ and Cu2+ ions partially inhibited but Pb2+ ions completely inhibited the enzymatic activity of Kj-mhpC. LC/MS revealed that Kj-mhpC hydrolyzes the ester bond of chlorimuron-ethyl, resulting in the formation of 2-(4-chloro-6-methoxypyrimidine-2-amidoformamidesulfonyl) benzoic acid. Furthermore, the point mutation of serine at position 67 (Ser67) confirmed that it is the key amino acid at the active site for degrading chlorimuron-ethyl. This study enhanced the understanding of how chlorimuron-ethyl is degraded by microorganisms and provided a reference for bioremediation of the environment polluted with chlorimuron-ethyl.


Subject(s)
Herbicides , Pyrimidines , Soil Pollutants , Klebsiella/genetics , Klebsiella/metabolism , Esterification , Soil Pollutants/metabolism , Herbicides/metabolism , Sulfonylurea Compounds/metabolism , Ions
2.
Chemosphere ; 351: 141178, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38218236

ABSTRACT

Excessive or inappropriate applications of imazethapyr cause severe ecological deteriorations and health risks in human. A novel bacterial strain, i.e., Bacillus marcorestinctum YN1, was isolated to efficiently degrade imazethapyr, with the degradation pathways and intermediates predicted. Protein mass spectrometry analysis identified enzymes in strain YN1 potentially involved in imazethapyr biodegradation, including methylenetetrahydrofolate dehydrogenase, carbon-nitrogen family hydrolase, heme degrading monooxygenase, and cytochrome P450. The strain YN1 was further immobilized with biochar (BC600) prepared from mushroom waste (i.e., spent mushroom substrate) by pyrolysis at 600 °C to evaluate its degrading characteristics of imazethapyr. Scanning electron microscope observation showed that strain YN1 was adsorbed in the rich pore structure of BC600 and the adsorption efficiency reached the maximum level of 88.02% in 6 h. Both energy dispersive X-ray and Fourier transform infrared spectroscopy analyses showed that BC600 contained many elements and functional groups. The results of liquid chromatography showed that biochar-immobilized strain YN1 (IBC-YN1) improved the degradation rate of imazethapyr from 79.2% to 87.4%. The degradation rate of imazethapyr by IBC-YN1 could still reach 81.0% in the third recycle, while the bacterial survival rate was 67.73% after 180 d storage at 4 °C. The treatment of IBC-YN1 significantly shortened the half-life of imazethapyr in non-sterilized soil from 35.51 to 11.36 d, and the vegetative growth of imazethapyr sensitive crop plant (i.e., Cucumis sativus L.) was significantly increased in soil remediated, showing that the inhibition rate of root length and fresh weight were decreased by 12.45% and 38.49% respectively. This study exhanced our understanding of microbial catabolism of imazethapyr, and provided a potential in situ remediation strategy for improving the soil environment polluted by imazethapyr.


Subject(s)
Bacillus , Charcoal , Herbicides , Nicotinic Acids , Soil Pollutants , Humans , Herbicides/analysis , Soil/chemistry , Biodegradation, Environmental , Bacteria/metabolism , Soil Pollutants/analysis
3.
Genes Genet Syst ; 97(2): 81-91, 2022 Jul 16.
Article in English | MEDLINE | ID: mdl-35675986

ABSTRACT

Pathogen attacks affect tree health, causing considerable economic losses as well as serious damage to the surrounding environment. Understanding the disease resistance mechanisms of trees is important for tree breeding. In previous studies on birch (Betula platyphylla × B. pendula), we identified a lesion mimic mutant called lmd. We found that reduced expression of BpEIL1 was responsible for the phenotype in lmd. Following cloning, we acquired several BpEIL1 overexpression and suppression lines in birch. In this study, we cloned the BpEIL1 promoter and found that BpEIL1 was primarily expressed in leaves, particularly in veins. We further studied the traits of transgenic lines and the function of BpEIL1 in disease resistance in birch using the BpEIL1 overexpression line OE9, the suppression line SE13 and the non-transgenic line NT. We found that hydrogen peroxide accumulated in SE13 leaves. Ascorbate peroxidase and catalase activity significantly increased in SE13. SE13 was more resistant to the fungal pathogens Alternaria alternata and Rhizoctonia solani than were the OE9 and NT lines. RNA-seq indicated that pathways related to signal transduction, disease resistance and plant immunity were enriched in SE13. BpEIL1 is thus a negative regulatory transcription factor for disease resistance in birch. This study provides a reference for disease resistance of birch and other trees.


Subject(s)
Betula , Disease Resistance , Alternaria/genetics , Betula/genetics , Betula/microbiology , Disease Resistance/genetics , Rhizoctonia
4.
Front Genet ; 13: 841198, 2022.
Article in English | MEDLINE | ID: mdl-35664340

ABSTRACT

Eggplant (Solanum melongena L.; 2n = 24) is one of the most important Solanaceae vegetables and is primarily cultivated in China (approximately 42% of world production) and India (approximately 39%). Thousand-grain weight (TGW) is an important trait that affects eggplant breeding cost and variety promotion. This trait is controlled by quantitative trait loci (QTLs); however, no quantitative trait loci (QTL) has been reported for TGW in eggplant so far, and its potential genetic basis remain unclear. In this study, two eggplant lines, 17C01 (P1, wild resource, small seed) and 17C02 (P2, cultivar, large seed), were crossed to develop F1, F2 (308 lines), BC1P1 (44 lines), and BC1P2 (44 lines) populations for quantitative trait association analysis. The TGWs of P1, P2 and F1 were determined as 3.00, 3.98 and 3.77 g, respectively. The PG-ADI (polygene-controlled additive-dominance-epistasis) genetic model was identified as the optimal model for TGW and the polygene heritability value in the F2 generation was as high as 80.87%. A high-quality genetic linkage bin map was constructed with resequencing analysis. The map contained 3,918 recombination bins on 12 chromosomes, and the total length was 1,384.62 cM. A major QTL (named as TGW9.1) located on chromosome 9 was identified to be strongly associated with eggplant TGW, with a phenotypic variance explanation of 20.51%. A total of 45 annotated genes were identified in the genetic region of TGW9.1. Based on the annotation of Eggplant genome V3 and orthologous genes in Arabidopsis thaliana, one candidate gene SMEL_009g329850 (SmGTS1, encoding a putative ubiquitin ligase) contains 4 SNPs and 2 Indels consecutive intron mutations in the flank of the same exon in P1. SmGTS1 displayed significantly higher expression in P1 and was selected as a potential candidate gene controlling TGW in eggplant. The present results contribute to shed light on the genetic basis of the traits exploitable in future eggplant marker-assisted selection (MAS) breeding.

5.
Exp Ther Med ; 22(4): 1185, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34475975

ABSTRACT

Increased levels of mitochondrial coupling factor 6 (CF6) are present in the peripheral blood of patients with preeclamptic pregnancies, and are particularly evident in cases of early-onset or severe preeclampsia. The present study examined the location and expression levels of CF6 in the placental tissue and its effect on the biological behavior of trophoblast cells. Placental tissue microarrays, including placental villous cytotrophoblast and extravillous cytotrophoblast microarrays, were used to detect the location and relative expression levels of CF6 in the placenta using immunohistochemistry. It was found that CF6 was expressed in both the normal and preeclamptic placenta, but its levels were higher in the preeclamptic tissues. In addition, the effects of the hypoxic environment on the biological behaviors of trophoblast cells were investigated in the JAR and JEG-3 cell lines. Following induction of hypoxia, the expression levels of CF6 were increased. Moreover, exogenous addition of human recombinant CF6 attenuated cell invasion, but exerted no effect on cell proliferation. At the molecular level, the expression levels of MMP-2 were decreased and were accompanied with a reduction in cell invasion following addition of exogenous CF6. In conclusion, the increased expression levels of CF6 and its effects in reducing the invasive abilities of trophoblast cells may be involved in the pathogenesis of severe preeclampsia.

6.
Pestic Biochem Physiol ; 172: 104766, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33518053

ABSTRACT

According to the pharmacophore binding strategy and principle of bioelectronic isobaric, used the sulfonylurea bridge as the parent structure, a series of novel thiourea compounds containing aromatic-substituted pyrimidines were designed and synthesized. The preliminary herbicidal activity tests showed that some compounds had good herbicidal activity against Digitaria adscendens, Amaranthus retroflexus, especially for compound 4d and 4f. The results showed that compound 4d had an inhibition rate of 81.5% on the root growth of Brassica napus L. at the concentration of 100 mg L-1, and compound 4f had an inhibition rate of 81% on the root growth of Digitaria adscendens at the concentration of 100 mg L-1. Compounds 4d and 4f had higher comparative activity on Echinochloa crus-galli than the commercial herbicide bensulfuron-methyl. The preliminary structure-activity relationship (SAR) was also summarized. We also tested the in vivo AHAS enzyme activity inhibition experiment of 14 compounds at 100 mg L-1, and the results showed that they all have inhibitory activity on the enzyme, with the highest inhibition rate reaching 44.4% (compound 4d). Based on the results of molecular docking to yeast acetohydroxyacid synthase (AHAS), the possible herbicidal activity mechanism of these compounds was evaluated.


Subject(s)
Acetolactate Synthase , Herbicides , Acetolactate Synthase/metabolism , Herbicides/pharmacology , Molecular Docking Simulation , Molecular Structure , Pyrimidines/pharmacology , Structure-Activity Relationship , Thiourea/pharmacology
7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(3): 320-324, 2020 May.
Article in Chinese | MEDLINE | ID: mdl-32543136

ABSTRACT

OBJECTIVE: To study the relationship between down-regulated expression of X linked inhibitor of apoptosis protein (XIAP) gene and the reversal effect of taxol-resistance by using siRNA interference technology in the taxol-resistant ovarian cancer. METHODS: Randomly assigned the nude mice into six groups (6 in each group) . Group A: normal saline; Group B: taxol; Group C: siRNA-NC+normal saline; Group D: siRNA-NC+taxol; Group E: siRNA XIAP+normal saline; Group F: siRNA XIAP+taxol. Each group was dealt with the corresponding processing depending on the agreed protocol and the transplanted tumors had a multi-point injection with reagents related siRNA, one time every 3 days, 9 times (27 d) in total. Taxol (2 mg/kg) was used in the intraperitoneal injection, 0.2 mL every time, once a week, for four weeks. After 27 d of siRNA treatment, xenograft volumes and qualities were measured and the inhibitory rate was calculated; RNA expression levels and protein levels of XIAP gene in xenografts were detected respectively by real-time fluorescent quantitative PCR and Western blot. Apoptosis of the transplanted tumor cells was examined by TUNEL method. RESULTS: Among the six groups, the proliferation of transplanted tumor in Group F was the slowest, and the tumor inhibition rate was the highest compared with control Group A, followed by Group E, and the tumor inhibition rate was the lowest in Group C. Group F and E expressed the lowest XIAP mRNA and protein expressions ( P<0.05, vs. the other 4 groups) .The apoptosis rate was highest in Group F, followed by Group E, and lowest in Group A and C ( P<0.05). CONCLUSION: XIAP siRNA has synergy with taxol in taxol-resistant ovarian cancer cells.


Subject(s)
Ovarian Neoplasms , X-Linked Inhibitor of Apoptosis Protein , Animals , Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis , Cell Line, Tumor , Cell Proliferation , Drug Resistance, Neoplasm/genetics , Female , Humans , Mice , Mice, Nude , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/genetics , Paclitaxel/pharmacology , RNA, Small Interfering/genetics , X-Linked Inhibitor of Apoptosis Protein/genetics
8.
BMC Plant Biol ; 19(1): 491, 2019 Nov 12.
Article in English | MEDLINE | ID: mdl-31718548

ABSTRACT

BACKGROUND: Plant architecture, which is mostly determined by shoot branching, plays an important role in plant growth and development. Thus, it is essential to explore the regulatory molecular mechanism of branching patterns based on the economic and ecological importance. In our previous work, a multiple-branches birch mutant br was identified from 19 CINNAMOYL-COENZYME A REDUCTASE 1 (CCR1)-overexpressed transgenic lines, and the expression patterns of differentially expressed genes in br were analyzed. In this study, we further explored some other characteristics of br, including plant architecture, wood properties, photosynthetic characteristics, and IAA and Zeatin contents. Meanwhile, the T-DNA insertion sites caused by the insertion of exogenous BpCCR1 in br were identified to explain the causes of the mutation phenotypes. RESULTS: The mutant br exhibited slower growth, more abundant and weaker branches, and lower wood basic density and lignin content than BpCCR1 transgenic line (OE2) and wild type (WT). Compared to WT and OE2, br had high stomatal conductance (Gs), transpiration rate (Tr), but a low non-photochemical quenching coefficient (NPQ) and chlorophyll content. In addition, br displayed an equal IAA and Zeatin content ratio of main branches' apical buds to lateral branches' apical buds and high ratio of Zeatin to IAA content. Two T-DNA insertion sites caused by the insertion of exogenous BpCCR1 in br genome were found. On one site, chromosome 2 (Chr2), no known gene was detected on the flanking sequence. The other site was on Chr5, with an insertion of 388 bp T-DNA sequence, resulting in deletion of 107 bp 5' untranslated region (UTR) and 264 bp coding sequence (CDS) on CORONATINE INSENSITIVE 1 (BpCOII). In comparison with OE2 and WT, BpCOI1 was down-regulated in br, and the sensitivity of br to Methyl Jasmonate (MeJA) was abnormal. CONCLUSIONS: Plant architecture, wood properties, photosynthetic characteristics, and IAA and Zeatin contents in main and lateral branches' apical buds changed in br over the study's time period. One T-DNA insertion was identified on the first exon of BpCOI1, which resulted in the reduction of BpCOI1 expression and abnormal perception to MeJA in br. These mutation phenotypes might be associated with a partial loss of BpCOI1 in birch.


Subject(s)
Betula/genetics , DNA, Bacterial , Betula/chemistry , Betula/growth & development , Betula/physiology , Indoleacetic Acids/analysis , Mutation , Photosynthesis , Trees/genetics , Trees/growth & development , Trees/physiology , Wood , Zeatin/analysis
9.
J Exp Bot ; 70(12): 3125-3138, 2019 06 28.
Article in English | MEDLINE | ID: mdl-30921458

ABSTRACT

Birch (Betula platyphylla × B. pendula) is an important tree for landscaping due to its attractive white bark and straight trunk. In this study, we characterized a T-DNA yellow-green leaf mutant, yl. We identified six insertion sites (ISs) in the mutant by genome resequencing and found a 40-kb deletion containing BpGLK1 around IS2 on chromosome 2. Complementation experiments with the yl mutant and repression of BpGLK1 in wild-type plants confirmed that BpGLK1 was responsible for the mutated phenotype. Physiological and ultrastructural analyses showed that the leaves of the yl mutant and BpGLK1-repression lines had decreased chlorophyll content and defective chloroplast development compared to the wild-type. Furthermore, the loss function of BpGLK1 also affected photosynthesis in leaves. Transcriptomics, proteomics, and ChIP-PCR analysis revealed that BpGLK1 directly interacted with the promoter of genes related to antenna proteins, chlorophyll biosynthesis, and photosystem subunit synthesis, and regulated their expression. Overall, our research not only provides new insights into the mechanism of chloroplast development and chlorophyll biosynthesis regulated by BpGLK1, but also provides new transgenic birch varieties with various levels of yellowing leaves by repressing BpGLK1 expression.


Subject(s)
Betula/genetics , Chlorophyll/genetics , Chloroplasts/genetics , Plant Proteins/genetics , Transcription Factors/genetics , Betula/metabolism , Chlorophyll/biosynthesis , Chloroplasts/metabolism , Plant Proteins/metabolism , Plants, Genetically Modified/genetics , Plants, Genetically Modified/metabolism , Transcription Factors/metabolism
10.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 49(3): 337-341, 2018 May.
Article in Chinese | MEDLINE | ID: mdl-30014630

ABSTRACT

OBJECTIVE: To research the expression of X-linked inhibitor of apoptosis protein gene (XIAP) on paclitaxel resistance in ovarian cancer. METHODS: A2780 and A2780/T cells were treated with paclitaxel respectively at the concentrations of 5 ng/mL,10 ng/mL,20 ng/mL , 40 ng/mL,80 ng/mL,160 ng/mL,320 ng/mL,then the inhibition rate of cells were detected by MTT assay. The expression of XIAP mRNA and protein among the A2780 and A2780/T cells treated respectively with paclitaxel at the concentration of 100 ng/mL was detected by reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot. The A2780/T cells were divided into blank group,empty group,small interfering RNA (siRNA) XIAP group and siRNA-non-specific group. The expression of XIAP mRNA and protein of four groups were detected by RT-qPCR and Western blot. Apoptotic rate of these groups with addition of paclitaxel at the concentrations of 0 ng/mL,1 000 ng/mL,1 500 ng/mL,2 000 ng/mL and 2 500 ng/mL were detected by flow cytometry. RESULTS: After the treatments on A2780 and A2780/T cells with the different concentrations of paclitaxel,the inhibition rate of A2780 cells were gradually increased with the increased paclitaxel concentrations (P<0.05),while there were no obvious differences in A2780/T cells (P>0.05). After the treatment on these cells with paclitaxel at the concentration of 100 ng/mL,the expression of XIAP mRNA was lower than that non-treatment with paclitaxelin A2780 cells (P<0.05),and the expression of XIAP mRNA in the A2780/T cells were no statistical significance between the treatment group and non-treatment group with paclitaxel (P>0.05). However,the expression of A2780/T cells'XIAP mRNA and protein treated with paclitaxel were higher than A2780 cells' (P<0.05). The expression of XIAP mRNA and protein in siRNA-XIAP group was lower than those of other groups (P<0.05). The apoptotic rate of siRNA-XIAP group was higher than those of other groups treated with the paclitaxel at concentrations of 2 000 ng/mL and 2 500 ng/mL (P<0.05). CONCLUSION: XIAP's high expression on mRNA and protein was correlated with ovarian cancer paclitaxel-resistance,specific siRNA can promote cell apoptosis by reducing the expression of XIAP,and increase the sensitivity of drug-resistant cancer cells to paclitaxel.


Subject(s)
Drug Resistance, Neoplasm/genetics , Ovarian Neoplasms/drug therapy , Ovarian Neoplasms/genetics , Paclitaxel/pharmacology , X-Linked Inhibitor of Apoptosis Protein/genetics , Apoptosis , Cell Line, Tumor , Female , Humans , RNA, Small Interfering
11.
Sci Rep ; 7(1): 11308, 2017 09 12.
Article in English | MEDLINE | ID: mdl-28900274

ABSTRACT

Lesion mimic mutants (LMM) usually show spontaneous cell death and enhanced defence responses similar to hypersensitive response (HR) in plants. Many LMM have been reported in rice, wheat, maize, barley, Arabidopsis, etc., but little was reported in xylophyta. BpGH3.5 is an early auxin-response factor which regulates root elongation in birch. Here, we found a T-DNA insertion mutant in a BpGH3.5 transgenic line named lmd showing typical LMM characters and early leaf senescence in Betula platyphylla × B. pendula. lmd showed H2O2 accumulation, increased SA level and enhanced resistance to Alternaria alternate, compared with oe21 (another BpGH3.5 transgenic line) and NT (non-transgenic line). Cellular structure observation showed that programmed cell death occurred in lmd leaves. Stereomicroscope observation and Evans' blue staining indicated that lmd is a member of initiation class of LMM. Transcriptome analysis indicated that defence response-related pathways were enriched. Southern-blot indicated that there were two insertion sites in lmd genome. Genome re-sequencing and thermal asymmetric interlaced PCR (TAIL-PCR) confirmed the two insertion sites, one of which is a T-DNA insertion in the promoter of BpEIL1 that may account for the lesion mimic phenotype. This study will benefit future research on programmed cell death, HR and disease resistance in woody plants.


Subject(s)
Alternaria , Betula/genetics , Betula/microbiology , Disease Resistance/genetics , Genes, Plant , Host-Pathogen Interactions/genetics , Plant Diseases/genetics , Plant Diseases/microbiology , Betula/ultrastructure , Computational Biology/methods , Gene Expression Regulation, Plant , Gene Ontology , High-Throughput Nucleotide Sequencing , Mutation , Phenotype , Transcriptome
12.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 47(6): 843-847, 2016 Nov.
Article in Chinese | MEDLINE | ID: mdl-28598109

ABSTRACT

OBJECTIVES: To explore the effect of the demethylation drug 5-Aza-CdR on endometrial carcinoma xenografted in nude mice. METHODS: Randomly assigned the mice into decitabine (AZA),cisplatin (DDP),medroxyprogesterone acetate (MPA),AZA+DDP,AZA+MPA,DDP+MPA and model groups (three in each group) after building the models of xenografted tumor by transplanting the HEC-1B cells on nude mice,and dealt them respectively with corresponding drugs (1 µg/g,single or combination) in the experiment groups and normal saline in model group (injected per 3 d,8 injections in total).Then the tumor inhibitory rates in different groups were calculated.The methylation and protein expression of RASSF1A gene was estimated by methylation specific PCR (MSP) and Western blot respectively,and apoptosis situation of carcinoma cell was estimated by tunel. RESULTS: Inhibitory rate in AZA+DDP group was the highest,and the lowest was AZA group.RASSF1A gene promoter region methylation levels of AZA,AZA+DDP and AZA+MPA groups significantly reduced and showed obvious demethylation stripes while other groups mainly showed the methylation stripes.The differences of RASSF1A protein expression between AZA,AZA+DDP and AZA+MPA groups were not statistical significant (P>0.05),but the three were higher than model group (P<0.05);there was no statistically significant difference respectively in the DDP,MPA,DDP+ MPA groups compared with that of model group (P>0.05).In the comparison of apoptosis index,model group was the lowest,followed by the three single medicine groups,and the highest was three combination groups (P<0.05). CONCLUSIONS: Demethylation drug 5-Aza-CdR in endometrial cancer treatment has a great potential clinical application value by reversing the abnormal methylation of RASSF1A gene,restoring biological functions of RASSF1A protein and strengthening the efficacy of DDP and MPA.


Subject(s)
Azacitidine/analogs & derivatives , DNA Methylation , Endometrial Neoplasms/drug therapy , Animals , Apoptosis , Azacitidine/pharmacology , Cell Line, Tumor , Cisplatin , Decitabine , Female , Humans , Medroxyprogesterone Acetate , Mice , Mice, Nude , Promoter Regions, Genetic , RNA, Messenger , Tumor Suppressor Proteins/metabolism , Xenograft Model Antitumor Assays
13.
Anal Chim Acta ; 747: 29-35, 2012 Oct 17.
Article in English | MEDLINE | ID: mdl-22986132

ABSTRACT

A magnetic solid phase extraction (MSPE) method coupled with high-performance liquid chromatography (HPLC) was proposed for the determination of five sulfonylurea herbicides (bensulfuron-methyl, prosulfuron, pyrazosulfuron-ethyl, chlorimuron-ethyl and triflusulfuron-methyl) in environmental water samples. The magnetic adsorbent was prepared by incorporating Fe(3)O(4) nanoparticles and surfactant into a silica matrix according to a sol-gel procedure, which can provide surfactant free extracts during the eluting step to avoid chromatographic interference. The prepared adsorbent was used to extract the sulfonylurea herbicides in several kinds of water samples. The main factors affecting the extraction efficiency, including desorption conditions, extraction time, sample volume, and sample solution pH were optimized. Under the optimum conditions, good linearity was obtained within the range of 0.2-50.0 µg L(-1) for all analytes, with correlation coefficients ranging from 0.9993 to 0.9999. The enrichment factors were between 1200 and 1410, and the limits of detection were between 0.078 and 0.10 µg L(-1). The proposed method was successfully applied in the analysis of sulfonylurea herbicides in environmental samples (tap, reservoir, river, and rice field). The recoveries of the method ranged between 80.4% and 107.1%. This study reported for the first time the use of MSPE procedure in the preconcentration of sulfonylurea herbicides in environmental samples. The procedure proved to be efficient, environmentally friendly, and fast.


Subject(s)
Herbicides/analysis , Magnetite Nanoparticles/chemistry , Silicon Dioxide/chemistry , Solid Phase Extraction/methods , Sulfonylurea Compounds/analysis , Water Pollutants, Chemical/analysis , Adsorption , Benzoates/analysis , Chromatography, High Pressure Liquid/methods , Pyrazoles/analysis , Pyrimidines/analysis , Quaternary Ammonium Compounds/chemistry , Surface-Active Agents/chemistry , Triazines/analysis
14.
J Hazard Mater ; 237-238: 140-6, 2012 Oct 30.
Article in English | MEDLINE | ID: mdl-22964386

ABSTRACT

The dissipation behavior of the two enantiomers of malathion was elucidated in five plant species using enantioselective high performance liquid chromatography (HPLC), and the acute toxicity of the individual enantiomers toward earthworms and honeybees was studied. The calculated LC(50) values of the R-, S- and rac-malathion to earthworms were 0.3869, 25.17, and 19.19 µg/cm(2), respectively, while the calculated LC(50) values of R-, S- and rac-malathion to bees were 2.15, 36.67, and 7.11 µg/mL, respectively. This indicated that the R-enantiomer was more toxic than S-enantiomer. The results of the degradation of racemate in Chinese cabbage and rape showed that the inactive S-(-)-enantiomer degraded faster than the active R-(+)-enantiomer. Inversely, we found a preferential degradation of the R-(+)-enantiomer in sugar beet. However, the degradation of malathion in paddy rice and wheat were nonenantioselectivity. In all plants, malathion was degraded to levels <10% after 5 days, and the calculated t(½) values of the enantiomers ranged from 0.83 to 1.43 days in these five plants. In conclusion, our findings of enantioselectivity in the environmental fate and acute toxicity of the malathion enantiomers may have implications for better environmental and ecological risk assessment for chiral pesticides in general.


Subject(s)
Malathion/chemistry , Malathion/toxicity , Pesticides/chemistry , Pesticides/toxicity , Animals , Bees/drug effects , Lethal Dose 50 , Malathion/metabolism , Oligochaeta/drug effects , Oryza/metabolism , Pesticides/metabolism , Stereoisomerism , Triticum/metabolism , Vegetables/metabolism
15.
Electrophoresis ; 33(14): 2176-83, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22821495

ABSTRACT

A novel method based on the combination of microemulsion electrokinetic chromatography (MEEKC) and vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction (VSLLME) was developed for the determination of five triazine herbicides (simazine, atrazine, ametryn, prometryn, and terbutryn) in water samples. The five triazine herbicides were baseline separated by using the microemulsion buffer containing a 10 mmol/L borate buffer at pH 9.5, 2.5% (w/v) SDS as surfactant, 0.8% (w/v) ethyl acetate as oil phase, and 6.0% (w/v) 1-butanol as cosurfactant. The optimum extraction conditions of VSLLME were as follows: 100 µL chloroform was used as extraction solvent, 5.0 × 10⁻5 mol/L Tween-20 was chosen as the surfactant to enhance the emulsification, and the extraction process was carried out by vortex mixing for 3 min. Under these optimum experimental conditions, the calibration curve was linear in the range of 2.0-200.0 ng/mL, with the correlation coefficients (r²) varying from 0.9927 to 0.9958. The detection limits of the method varied from 0.41 to 0.62 ng/mL. The purposed method was applied to the determination of five triazine herbicides in real water samples, and the recoveries were between 80.6 and 107.3%.


Subject(s)
Chromatography, Micellar Electrokinetic Capillary/methods , Herbicides/isolation & purification , Liquid Phase Microextraction/methods , Surface-Active Agents/chemistry , Triazines/isolation & purification , Water Pollutants, Chemical/isolation & purification , Emulsifying Agents/chemistry , Limit of Detection , Linear Models , Sodium Dodecyl Sulfate/chemistry , Water/analysis
16.
Chirality ; 23(10): 860-6, 2011 Nov.
Article in English | MEDLINE | ID: mdl-25522452

ABSTRACT

We investigated the stereoselective degradation kinetics and toxicity of fluroxypyr methylheptyl ester (FPMH) in rat hepatocytes using a chiral high-performance liquid chromatographic method. The T1/2 of (−)-FPMH was about two times longer than that of (+)-FPMH after the rat hepatocytes were incubated with 10, 20, and 50 µM of rac-FPMH. There was no chiral conversion or transformation during their incubation with the hepatocytes. Toxicity differences were observed among the two enantiomers of FPMH and fluroxypyr (FP) in their EC50 values in rat hepatocytes. Of all the tested compounds, FP was most toxic to the rat hepatocytes. The (−)-FPMH enantiomer showed higher toxicity than the (+)-FPMH, whereas the racemic mixture displayed intermediate toxicity. The data presented here are important for a more thorough understanding of this pesticide and should be useful for its full environmental assessment.


Subject(s)
Glycolates/metabolism , Glycolates/toxicity , Hepatocytes/drug effects , Hepatocytes/metabolism , Herbicides/metabolism , Herbicides/toxicity , Acetates/chemistry , Acetates/metabolism , Acetates/toxicity , Animals , Glycolates/chemistry , Herbicides/chemistry , Male , Pyridines/chemistry , Pyridines/metabolism , Pyridines/toxicity , Rats , Rats, Sprague-Dawley , Reproducibility of Results , Stereoisomerism
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