Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 8.302
Filtrar
1.
Chemosphere ; 286(Pt 2): 131819, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34371354

RESUMO

Seed dressing with fungicide or insecticide is a standard procedure for growing major crops, but very little is known about the leaching risk and the general fate of pesticides from coated seeds. Triazole fungicides are commonly used seed dressing fungicides and recently, there has been increasing concern that 1,2,4-triazole, a major degradation product of several triazole fungicides, may leach to groundwater in concentrations exceeding the 0.1 µg/L threshold limit of the European Union. We therefore carried out a laboratory column experiment with commercial barley seeds coated with the triazole fungicides tebuconazole and prothioconazole to study the fate of the fungicides and their degradation products, especially 1,2,4-triazole. Our experiment showed that the fungicides themselves were relatively immobile in the soil columns, but also that leaching of 1,2,4-triazole will occur no matter if tebuconazole or prothioconazole is used as seed dressing. Relatively high 1,2,4-triazole concentrations (up to 0.8 µg/L) were measured in the column leachates, but when the experiment was terminated after 63 days, a total of only 1 % of the fungicides was recovered as 1,2,4-triazole in the leachate. Our results suggest that seed dressing pesticides should be considered together with spray applications when estimating the total 1,2,4-triazole load from agriculture and that seed dressing pesticides and their degradation products should be included when evaluating leaching risks from pesticide applications in agriculture.


Assuntos
Fungicidas Industriais , Hordeum , Fungicidas Industriais/análise , Sementes/química , Triazóis
2.
Food Chem ; 371: 131209, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34598121

RESUMO

In this study, non-targeted and targeted metabolomics/lipidomics studies based on UPLC-QTOF-MS and UPLC-MS/MS were carried out to clarify the effects of tebuconazole and its different enantiomers on lettuce metabolites and lipids. Slight enantioselective degradation of tebuconazole was observed and six degradation metabolites were tentatively identified. The endogenous metabolites involved in carbohydrate metabolism, amino acid metabolism, nucleic acid metabolism, phenylpropanoid and flavonoid metabolism, vitamins, and lipid metabolism were significantly affected with enantioselectivity by tebuconazole exposure. Nucleotide metabolism and nicotinic acid metabolic network were significantly activated by the stimulation of tebuconazole. Rac- and (-)-R-tebuconazole caused the down-regulation of soluble sugars and subsequent amino acids and organic acids. Overall, lettuce exposed to tebuconazole was shown to have a significant impact on plant metabolism and lipid metabolism, with notable stereoselectivity. The results showed stereoselective toxicity of tebuconazole and provided a better understanding of its metabolomic and lipidomic effects on lettuce.


Assuntos
Fungicidas Industriais , Cromatografia Líquida , Fungicidas Industriais/análise , Fungicidas Industriais/toxicidade , Alface , Lipidômica , Metabolômica , Espectrometria de Massas em Tandem , Triazóis/toxicidade
3.
Food Chem ; 371: 131162, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34600368

RESUMO

The effects of combined treatment (PAL-U) of plasma-activated liquid (PAL) including plasma-activated water (PAW) and plasma-activated buffer solution (PABS) and ultrasound (U) for the degradation of chlorothalonil fungicide on tomato fruit was investigated. Distilled water and buffer solution were activated by radiofrequency plasma jet for durations of 1, 3, 5, and 10 min to obtain PAL1 to PAL10. Fruits were immersed in PAL for 15 min and also in distilled water with sonication for 15 min for individual treatments, and in PAL with sonication for 15 min for combined treatments. The maximum chlorothalonil fungicide residues were reduced by 89.28 and 80.23% for PAW10-U and PABS10-U, respectively. HPLC-MS characterization revealed chlorothalonil degradation pathway and formation of 2,4,5-trichloroisophthalonitrile, 2,4-dichloroisophthalonitrile, 4-chloroisophthalonitrile, isophthalonitrile and phenylacetonitrile as degradation products. Treatments also showed no negative effects on tomato quality. Therefore, PAL and PAL-U treatments could serve as effective methods for degrading pesticides on tomatoes.


Assuntos
Fungicidas Industriais , Lycopersicon esculentum , Resíduos de Praguicidas , Fungicidas Industriais/análise , Nitrilas/análise , Resíduos de Praguicidas/análise
4.
Chemosphere ; 287(Pt 1): 131902, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34438209

RESUMO

Understanding the lethal effects of pesticides nano formulations on the targeted organisms (pathogens) and the non-targeted organisms (fish, earthworms, etc) is essential in assessing the probable impact of new technologies on agriculture and environment. Here we evaluated the bioactivity and the biotoxicity of new type of fungicide smart-delivery formulation based on conjugating carboxymethylated-ß-glucans on the mesoporous silica nanoparticles (MSNs) surface after loading chlorothalonil (CHT) fungicide in the MSNs pores. The obtained formulation has been characterized with FE-SEM, and HR-TEM. The CHT loading efficiency has been measured with TGA. The bioactivity of the obtained formulation (CHT@MSNs-ß-glucans) has been tested against four pathogens, fusarium head blight (Fusarium graminearum), sheath rot (Sarocladium oryzae), rice sheath blight (Rhizoctonia solani), and soyabean anthracnose (Colletotrichum truncatum) compared with CHT WP 75% commercial formulation (CHT-WP) and technical CHT. The environmental biotoxicity of CHT@MSNs-ß-glucans compared with CHT-WP has been tested toward earthworm (Eisenia fetida) and zebra fish (Danio rerio). The results showed that CHT@MSNs-ß-glucans has an excellent bioactivity against the subjected pathogens with better inhabiting effects than CHT-WP. CHT@MSNs-ß-glucans toxicity to Eisenia fetida was found 2.25 times lower than CHT-WP toxicity. The LC50 of CHT@MSNs-ß-glucans to zebra fish after the first 24h was 2.93 times higher than CHT-WP. After 96h of treatment, the LC50 of CHT@MSNs-ß-glucans was 2.66 times higher than CHT-WP. This work highlighted the necessity to increase the mandatory bioassays of nano formulations with the major non-target organisms in the environmental risk assessment of new pesticide formulations.


Assuntos
Fungicidas Industriais , Nanopartículas , beta-Glucanas , Animais , Colletotrichum , Portadores de Fármacos , Fungicidas Industriais/toxicidade , Fusarium , Hypocreales , Nanopartículas/toxicidade , Nitrilas , Porosidade , Rhizoctonia , Dióxido de Silício/toxicidade , beta-Glucanas/toxicidade
5.
Food Chem ; 372: 131267, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34638065

RESUMO

In this study, reduced graphene oxide (rGO) was prepared using a green ultrasonic microwave assisted method and investigated rGO based non-enzymatic electrochemical sensor for detecting a synthetic fungicide as a propamocarb (PM) pesticide. The rGO-based sensor exhibited rapid response within 1 min, low detection limit of 0.6 µM and wide linear range of (1-5) µM with a high sensitivity of 101.1 µAµM-1 cm-2 for PM. Besides this, the sensor detected the propamocarb pesticide on the real cucumber sample with high sensitivity in the concentration range of (1-5) µM within a 1-minute cycle. The sensor is highly selective against propamocarb pesticide. The prepared non-enzymatic electrochemical sensor exhibited high sensitivity, high selectivity, reproducibility, and rapid response.


Assuntos
Fungicidas Industriais , Grafite , Praguicidas , Carbamatos , Técnicas Eletroquímicas , Eletrodos , Reprodutibilidade dos Testes
6.
Environ Pollut ; 292(Pt B): 118477, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34763016

RESUMO

As a common fungicide, tebuconazole are ubiquitous in the natural environment and poses many potential risks. In this study, we examined the effects of exposure to tebuconazole on colitis in mice and explored its underlying mechanism. Specifically, exposure to tebuconazole could cause structural damage and inflammatory cell infiltration in colon tissue, activate the expression of inflammation-related genes, disrupt the expression of barrier function-related genes, and induce the colonic inflammation in mice. Similarly, exposure to tebuconazole could also exacerbate DSS-induced colitis in mice. In addition, we found that tebuconazole also could change the composition of the gut microbiota. In particular, tebuconazole significantly increases the relative abundance of Akkermansia of mice. Moreover, tebuconazole resulted in metabolic profiles disorders of the serum, leading to significant changes in the relative contents of metabolites involving glycolipid metabolism and amino acid metabolism. Particularly, the results of the gut microbiota transplantation experiment showed that exposure to tebuconazole could induced colonic inflammation in mice in a gut microbiota-dependent manner. Taken together, these results indicated that tebuconazole could induce colitis in mice via regulating gut microbiota. Our findings strongly support the concept that the gut microbiota is a key trigger of inflammatory bowel disease caused by pesticide intake.


Assuntos
Colite , Fungicidas Industriais , Microbioma Gastrointestinal , Animais , Colite/induzido quimicamente , Sulfato de Dextrana , Modelos Animais de Doenças , Fungicidas Industriais/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Triazóis
7.
Food Chem ; 371: 131179, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34808762

RESUMO

The challenge of the present comprehensive work was to study, from apple orchards to consumer's plate, the influence of high- and low-temperature thermal treatments on the most frequently occurring fungicides (boscalid, captan, pyraclostrobin) and insecticides (acetamiprid, methoxyfenozide) in apples and processing factor (PF) application for more realistic dietary risk assessment in the new EFSA methodology. Dry pasteurization and canning combined with previous preliminary treatment gave PFs = 0.25-1.8 of the five active substances. Acute exposure (expressed as %ARfD) in the raw commodity was demonstrated to be 168.1% for acetamiprid in the worst case (input - highest residue) and 307.9% for boscalid in the most critical case (input - MRL), and after re-calculation for PF, decreased to 139.5% for acetamiprid in canned product and 203.2% for boscalid in pasteurized apples. These novel data may be helpful in estimating new threshold residue levels significant in food safety especially intended for children.


Assuntos
Fungicidas Industriais , Inseticidas , Malus , Resíduos de Praguicidas , Criança , Contaminação de Alimentos/análise , Frutas/química , Fungicidas Industriais/análise , Humanos , Inseticidas/análise , Pasteurização , Resíduos de Praguicidas/análise , Medição de Risco
8.
Environ Pollut ; 292(Pt A): 118335, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637835

RESUMO

Sown seeds are a key component of many farmland birds' diets due to natural food shortages in autumn and winter. Because these seeds are often treated with pesticides, their ingestion by birds can result in toxic effects. For risk assessment, data on treated seed toxicity should be combined with information about exposure risk for wild birds and the factors that modulate it. We characterized the exposure of red-legged partridges to pesticide-treated seeds through the analysis of digestive contents of birds shot by hunters (n = 194) in an agricultural region in central Spain. We measured the contribution of sown seeds to the partridges' diet and how it related to pesticide exposure. Moreover, we evaluated the influence of landscape composition on the intake of sown seeds and pesticides by partridges. During peak sowing time, seeds constituted half (50.7%) of the fresh biomass ingested by partridges, which consumed mostly winter cereal seeds (42.3% of biomass). Residues of seven fungicides and one insecticide (active ingredients) were detected in 33.0% of birds. The presence of pesticides in digestive contents was linked to the ingestion of cereal sown seeds. Moreover, dietary exposure of birds to pesticides was modulated by landscape characteristics, being lower in areas with heterogeneous landscapes, greater habitat mosaic and more natural vegetation. The estimated dietary intake of pesticides resulting from our field observations, in combination with experimental data on pesticide toxicity, raise concerns about the risks that pesticide-treated cereal seeds pose to granivorous bird populations. Our results highlight the importance of farming landscape composition and diversification, which should be considered as a priority in the agricultural policy to mitigate pesticide risks to farmland birds through the consumption of treated seeds.


Assuntos
Fungicidas Industriais , Galliformes , Inseticidas , Animais , Fungicidas Industriais/toxicidade , Inseticidas/análise , Inseticidas/toxicidade , Sementes/química , Espanha
9.
Sci Total Environ ; 805: 150454, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34818760

RESUMO

Difenoconazole is a commonly used triazole fungicide that consists of four stereoisomers [(2S,4S)-, (2S,4R)-, (2R,4R)-, and (2R,4S)-isomers] with different bioactivity. For example, the toxicity of the (2R,4S)-isomer to fish is approximately seven times higher than that of the (2S,4S)-isomer. However, the stereoselective toxic effects of difenoconazole stereoisomers on mammals have received little attention. In the present study, adult male mice were orally treated with a mixture of the four stereoisomers or each stereoisomer individually (0, 30, or 100 mg/kg/d) by gavage for 28 days. Pathological staining of the liver sections showed that the (2R,4R)-isomer caused lipid droplet accumulation. The mixture or each individual stereoisomers decreased the levels of amino acids and acyl-carnitine in serum. Moreover, the (2S,4R)-, (2R,4R)-, and (2R,4S)-isomers affected intestinal permeability, causing decreases in mucus secretion and tight junction protein expression in colon. Analysis of the gut microbiota composition showed that the stereoisomers caused decreases of OTU numbers and observed species at different levels. Interestingly, difenoconazole and its four stereoisomers reduced the relative abundance of Bacteroidetes at the phylum level and some short-chain fatty acid (SCFA)-producing bacteria. Taking the findings together, 2R-difenoconazole with strong bioactivity against pathogenic fungi also had significant effects in mammals, disrupting hepatic lipid metabolism, intestinal permeability, and gut microbiota. It is concluded that the health risks of the four difenoconazole stereoisomers to mammals should not be overlooked.


Assuntos
Fungicidas Industriais , Microbiota , Animais , Dioxolanos , Fungicidas Industriais/toxicidade , Masculino , Camundongos , Estereoisomerismo , Triazóis
10.
Environ Pollut ; 292(Pt B): 118419, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34751155

RESUMO

Toxicological and epidemiological studies implicate exposure to dithiocarbamate (DTC) fungicides in adverse health outcomes. However, there is limited information about human exposure to these chemicals. This systematic review determined to which extent human populations worldwide, including children, pregnant women, and adults, are exposed environmentally or occupationally to DTC pesticides and how these exposures compare to the NHANES 2003-2008 population, using urinary ETU data as an outcome measure. PubMed, Embase, and SciFinder were searched using the keywords "ethylenethiourea" or CAS No.: 96-45-7, and urine or urinary. Duplicates and irrelevant studies were removed from the search results based on predetermined exclusion criteria. This screening process identified 17 relevant papers. One additional paper was found independent of this search. Data from studies were extracted using a pre-established data collection form. Ten, two, and five manuscripts reported urinary levels in environmentally exposed adults, children, and pregnant women, respectively. Median ETU levels ranged from 0.15 to 4.7 µg/g creatinine in adults (1994-2017), 0.24-0.83 µg/g creatinine in children (2011), and 2.6-5.24 ng/ml in pregnant women (2011). Eight studies reported urinary ETU levels in mostly agriculturally exposed populations, with median ETU levels ranging from 0.42 to 49.6 µg/g creatinine (1999-2011). With one exception, all studies were conducted between 1994 and 2011. ETU levels in the NHANES 2003-2008 population appeared to be generally lower than most studies identified in this review. This finding suggests that, historically, DTC fungicide exposures in the general population of high-income countries, such as the US, were low, whereas agricultural populations may have experienced higher exposure. Unfortunately, more recent exposure data are missing, especially in countries where DTC pesticides are not being phased out.


Assuntos
Etilenotioureia , Fungicidas Industriais , Adulto , Monitoramento Biológico , Biomarcadores , Criança , Etilenotioureia/análise , Feminino , Fungicidas Industriais/análise , Fungicidas Industriais/toxicidade , Humanos , Inquéritos Nutricionais , Gravidez
11.
Sci Total Environ ; 802: 149917, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34525765

RESUMO

The increasing consumption of azole antifungal agents leads to their uncontrolled release into the environment. Therefore, it is crucial to remove their residues from natural ecosystems. This study aimed to examine the biological and chemical degradation of four typical azole fungicides: fluconazole (Fc), clotrimazole (Cl), climbazole (Cb), and epoxiconazole (Ep). The biodegradation was investigated using activated sludge and two novel Gram-negative bacterial strains. The chemical degradation experiments aimed to assess the efficiency of fungicides removal through UV treatment, the Fenton reaction, and a combination of these methods. Transformation products of Cb, Ep, and Cl photocatalytic removal were identified by mass spectrometry. In addition, the AlamarBlue® Assay and the MTT Assay allowed careful evaluation of the toxicity of azole derivatives and their transformation products towards newly isolated strains, Stenotrophomonas maltophilia AsPCl2.3 and Pseudomonas monteilii LB2. Among all azole fungicides, Cb was the most susceptible to biological removal while Fc, Ep, and Cl were basically resistant to biodegradation. Cl and Ep showed a significant biosorption on the activated sludge. Under optimized photolysis conditions, the removal efficiency of Cl, Cb, and Ep was significantly higher than that of biodegradation. The Fenton reaction supported by the UV-irradiation offered the best results of fungicides elimination. After 1 min of the experiment, Cl was almost completely removed while Cb and Ep removal rates reached an average of 60%. The proposed main degradation route of azole fungicides during UV-irradiation includes halogen atoms substitution by hydroxyl moieties. The final degradation product was imidazole or triazole. Azole fungicides and their transformation products differently affected the metabolic activity of Gram-negative bacteria. Cl and Cb intermediates showed lower toxicity than parent compounds. The findings help better understand the environmental impact of azole fungicides, their degradation, and toxicity. They also stress the need for reducing their uncontrolled release to the environment.


Assuntos
Fungicidas Industriais , Poluentes Químicos da Água , Azóis/toxicidade , Ecossistema , Fungicidas Industriais/análise , Fungicidas Industriais/toxicidade , Pseudomonas , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
12.
Food Chem ; 367: 130664, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34343804

RESUMO

Cyclodextrin-based dispersive liquid-liquid microextraction (CD-DLLME) was developed for the determination of triazole and strobilurin fungicides in water, juice, and vinegar samples using high-performance liquid chromatography-diode-array detection (HPLC-DAD). Undecanol, which is a green solvent, was selected as the extraction solvent. A cyclodextrin aqueous solution was chosen as the dispersion solvent and demulsifier to avoid the use of a toxic dispersion solvent and eliminate the centrifugation step. Dispersion and phase separation were completed within 1 and 60 s, respectively. The linear range of this method was 1 to 100 µg L-1. The limits of detection were 0.3 µg L-1 along with the preconcentration factor of 133 and enrichment factor of 124. The recovery was 83.2% to 103.2%. This pretreatment method was fast, simple, and environmentally friendly and was successfully applied to the analysis of triazole and strobilurin fungicide residues in water, juice, and vinegar samples.


Assuntos
Ciclodextrinas , Fungicidas Industriais , Microextração em Fase Líquida , Poluentes Químicos da Água , Ácido Acético , Cromatografia Líquida de Alta Pressão , Fungicidas Industriais/análise , Solventes , Água , Poluentes Químicos da Água/análise
13.
Chemosphere ; 286(Pt 1): 131694, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34346344

RESUMO

Surfactin is a bacterial lipopeptide and an influential biosurfactant mainly known for excellent surfactant ability. The amphiphilic nature of surfactin helps it to sustain under hydrophobic and hydrophilic conditions. In this investigation, a bacterium strain (BTKU3) that produces biosurfactant were isolated from oil-contaminated soil. Based on the blue agar plate (Bap) assay, the BTKU3 strain was found to be promising for biosurfactant production. This strain was later identified as a Lysinibacillus sp. by 16S rRNA sequencing. The characteristics of extracted bacterial surfactin were evidenced by FTIR with the presence of amine, C-H, CO, CC, esters, thiocarbonyl and asymmetric aliphatic C-H stretch molecular structural groups. Further, the extracted bacterial biosurfactant material was subjected to Liquid Chromatography-Mass Spectroscopy (LCMS), and it was identified and confirmed as surfactin with an elution time of 3.1 min and m/z value of 1034. The emulsification and oil displacement tests further proved the surfactin ability with 83% of coconut oil emulsion index and 80 % oil displacement ability with diesel, respectively. Lysinibacillus sp. BTKU3 strain also proved its efficacy in the degradation of difenoconazole by utilizing a capacity of 9.1 µg ml-1. Thus, it is inferred that the Lysinibacillus sp. BTKU3 strain plays a significant role in the production of surfactin, which positively acts as an antimicrobial agent and reduces contaminants in polluted sites.


Assuntos
Anti-Infecciosos , Fungicidas Industriais , Biodegradação Ambiental , Dioxolanos , RNA Ribossômico 16S/genética , Tensoativos , Triazóis
14.
Food Chem ; 368: 130860, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34425340

RESUMO

Two extraction methods based on solid liquid extraction and Quick, Easy, Cheap, Effective, Rugged and Safe procedure were developed for the determination of 21 triazole compounds and 5 metabolites, including triazole derivative metabolites as 1,2,4-triazole and 1,2,4-triazol 1-yl-acetic, in courgette, orange, grape and strawberry. The analysis was performed in 10.5 min, using ultra-high performance liquid chromatography coupled to Q-Orbitrap mass analyser. The proposed method was validated according to SANTE 12682/2019. Limits of quantification were ≤10 µg kg-1 for all the compounds, except for 1,2,4-triazol, 1,2,4-triazol 1-yl-acetic, difenoconazole-alcohol and prothioconazole that were 50 µg kg-1. Finally, the method was successfully applied to the analysis of 30 samples. More than 30% of these samples contained residues of triazole compounds. The fungicide most frequently found was myclobutanil. Furthermore, a suspect screening analysis was carried out to search pesticides present in the samples, detecting some of them at concentrations higher than Maximum Residue Limits.


Assuntos
Fungicidas Industriais , Resíduos de Praguicidas , Cromatografia Líquida de Alta Pressão , Frutas/química , Fungicidas Industriais/análise , Resíduos de Praguicidas/análise , Espectrometria de Massas em Tandem , Triazóis , Verduras
15.
J Agric Food Chem ; 69(45): 13436-13447, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34735141

RESUMO

The environmental risks of prothioconazole (PTC), a popular agricultural fungicide, and its main metabolite, prothioconazole-desthio (PTCd), have attracted more and more attention recently. In this study, the adverse effects of PTC and PTCd on liver function in mice and their underlying mechanisms have been systematically studied from the perspective of gut microbiota. Combining the results of physiological, biochemical, and histopathological analysis showed that PTC and PTCd exposure could cause lipid accumulation and inflammation in the liver of mice. In addition, exposure to PTC and PTCd could also significantly affect the transcriptome of liver tissue, leading to disorders of lipid metabolism of the liver. Particularly, the abundances of bacteria in liver tissues were significantly increased with PTC and PTCd exposure. Further results show that PTC and PTCd could affect the expression of genes related to inflammation and the barrier function in colon tissue, leading to intestinal dysfunction in mice. Last but not least, the results based on 16S rRNA gene sequencing and 1H NMR metabolomics analysis showed that exposure to PTC and PTCd could cause gut microbiota imbalances and cecal content metabolic profile disorders. In short, this study found that PTC and PTCd exposure could cause liver damage in mice by changing the gut microbiota, disrupting the intestinal barrier function and promoting bacterial translocation. These results clarified the key role of gut microbiota in liver damage induced by PTC and PTCd in mice and proposed a new insight into the mechanisms of liver toxicity induced by pesticides through the dialogue of the gut-liver axis.


Assuntos
Fungicidas Industriais , Microbioma Gastrointestinal , Animais , Fungicidas Industriais/toxicidade , Fígado , Camundongos , RNA Ribossômico 16S , Triazóis
16.
J Agric Food Chem ; 69(45): 13373-13385, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34735146

RESUMO

Succinate dehydrogenase (SDH) is known as an ideal target for the investigations of fungicides. To develop novel SDH inhibitors, 30 novel thiophene/furan-1,3,4-oxadiazole carboxamide derivatives were designed and synthesized. In the in vitro antifungal assay, a majority of the target compounds demonstrated fair to potent antifungal activity against seven tested phytopathogenic fungi. Compounds 4b, 4g, 4h, 4i, and 5j showed remarkable antifungal activity against Sclerotinia sclerotiorum, affording EC50 values ranging from 0.1∼1.1 mg/L. In particular, compound 4i displayed the most potent activity against S. sclerotiorum (EC50 = 0.140 ± 0.034 mg/L), which was superior to that of boscalid (EC50 = 0.645 ± 0.023 mg/L). A further morphological investigation revealed the abnormal mycelia and damaged cell structures of compound 4i-treated S. sclerotiorum by scanning electron microscopy. Furthermore, the in vivo antifungal assay against S. sclerotiorum revealed that compounds 4g and 4i were effective for suppressing rape Sclerotinia rot at a dosage of 200 mg/L. In the SDH inhibition assay, compounds 4g and 4i also presented significant inhibitory activity with IC50 values of 1.01 ± 0.21 and 4.53 ± 0.19 µM, respectively, which were superior or equivalent to that of boscalid (3.51 ± 2.02 µM). Molecular docking and molecular dynamics simulation of compound 4g with SDH revealed that compound 4g could form strong interactions with the key residues of the SDH. These results indicated that this class of derivatives could be a promising scaffold for the discovery and development of novel SDH inhibitors.


Assuntos
Fungicidas Industriais , Succinato Desidrogenase , Antifúngicos/farmacologia , Ascomicetos , Inibidores Enzimáticos/farmacologia , Fungicidas Industriais/farmacologia , Furanos/farmacologia , Simulação de Acoplamento Molecular , Oxidiazóis , Relação Estrutura-Atividade , Succinato Desidrogenase/metabolismo , Ácido Succínico , Tiofenos/farmacologia
17.
J Agric Food Chem ; 69(45): 13416-13424, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34738463

RESUMO

Mandipropamid (MDP) is a widely used chiral fungicide to control oomycete pathogens with two enantiomers. In this study, the enantioselective bioactivity, toxicity, and degradation of MDP were investigated for the first time. The bioactivity of S-MDP was 118-592 times higher than that of R-MDP and 1.14-1.67 times higher than that of Rac-MDP against six phytopathogens. Molecular docking found that S-MDP formed a strong halogen bond with HIS 693 of cellulose synthase and possessed a lower binding energy, which validated the results of the bioactivity assay. S-MDP showed lower toxicity toward Spirodela polyrhiza, while it exhibited higher toxicity in Danio rerio embryo and larva. S-MDP preferentially degraded in cowpea and pepper, while R-MDP preferentially degraded in soil. There is no significant difference between the two enantiomers in the toxicity of adult D. rerio and in cucumber degradation. Therefore, the development of the S-enantiomer was considered as a better option to exhibit high efficiency, which could reduce the residual risk of the pesticide and ensure environmental safety.


Assuntos
Fungicidas Industriais , Poluentes do Solo , Amidas , Ácidos Carboxílicos , Fungicidas Industriais/análise , Fungicidas Industriais/toxicidade , Simulação de Acoplamento Molecular , Solo , Poluentes do Solo/análise , Estereoisomerismo , Verduras
18.
J Agric Food Chem ; 69(45): 13448-13459, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34748325

RESUMO

Diversity of pesticide discovery provided a solution to resistance. Here, we presented a strategy of azo-incorporating to promote the diverse developments of fungicide. A series of novel fungicides were synthesized by incorporating azobenzene derivatives into fluxapyroxad. Much better in vitro fungicidal activity increases for compound 9d were observed compared to the positive control, fluxapyroxad against Botrytis cinerea and Rhizoctonia solani. Compound 9d (IC50 = 0.03 µM) also had a great enzyme-inhibiting activity increase toward succinate dehydrogenase in comparison with fluxapyroxad (IC50 = 4.40 µM). A comparatively equivalent biological activity was observed between compounds 8a and 9d. SEM analysis helped us to observe clearly the morphology of the fungi before and after active ingredient delivery. Our results of molecular docking analysis, fluorescence quenching analysis, and enzymatic assays demonstrated that compound 8a and 9d act on SDH. An increase in inhibitory activity could be occurring after incorporation of azobenzene, which provided a new strategy for molecular design in pesticide discovery.


Assuntos
Ascomicetos , Fungicidas Industriais , Ascomicetos/metabolismo , Botrytis , Fungicidas Industriais/farmacologia , Simulação de Acoplamento Molecular , Rhizoctonia/metabolismo , Relação Estrutura-Atividade , Succinato Desidrogenase/metabolismo
19.
Pestic Biochem Physiol ; 179: 104960, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802512

RESUMO

The occurrence of bakanae disease of rice caused by the fungus Fusarium fujikuroi in Zhejiang Province has become increasingly aggravated in recent years, concomitant with the development of resistance to the widely applied fungicides, prochloraz and phenamacril. In this study, the activity of a novel succinate dehydrogenase inhibitor (SDHI) fungicide, penflufen, against different fungi was evaluated in addition to the potential of penflufen in controlling F. fujikuroi infections. Penflufen exhibited good bioactivity against F. fujikuroi, but weak activity against Fusarium spp. and other investigated plant-pathogenic fungi including Colletotrichum spp. In addition to inhibiting mycelial growth, penflufen effectively inhibited F. fujikuroi conidium production. For germination, penflufen could effectively inhibit that of small conidia, but only delay the germination of large conidia. In addition, the sensitivity to penflufen among 100 F. fujikuroi isolates that were collected in areas that were never exposed to SDHIs was determined based on mycelium growth. Sensitivities surprisingly exhibited bimodal distributions, indicating the presence of natural resistance. Cross-resistance was not observed between penflufen in F. fujikuroi and two fungicides that have been extensively applied in field including prochloraz (a DMI) and phenamacril (a 2-cyanoacrylate fungicide), nor with the three SDHIs, fluopyram, benzovindiflupyr, and pydiflumetofen. Additional analysis identified five different point mutations in SDH-A (i.e., at residues 46, 225, 283, 430, and 586) of naturally resistant isolates. These results inform the potential application of the new SDHI fungicide penflufen for managing crop diseases and understanding possible resistance mechanisms among pathogens.


Assuntos
Fungicidas Industriais , Fusarium , Anilidas , Farmacorresistência Fúngica/genética , Fungicidas Industriais/farmacologia , Imunidade Inata , Doenças das Plantas , Pirazóis , Succinato Desidrogenase/genética , Ácido Succínico
20.
Pestic Biochem Physiol ; 179: 104963, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34802513

RESUMO

Glabridin is a natural plant-derived compound that has been widely used in medicine and cosmetic applications. However, the fungicidal mechanism of glabridin against phytopathogens remains unclear. In this study, we determined the biological activity and physiological effects of glabridin against F. graminearum. Then the differentially expressed proteins of F. graminearum were screened. The EC50 values of glabridin in inhibiting the mycelial growth and conidial germination of F. graminearum were 110.70 mg/L and 40.47 mg/L respectively. Glabridin-induced cell membrane damage was indicated by morphological observations, DiBAC4(3) and PI staining, and measurements of relative conductivity, ergosterol content and respiratory rates. These assays revealed that the integrity of the membrane was destroyed, the content of ergosterol decreased, and the respiratory rate was inhibited. A proteomics analysis showed that 186 proteins were up-regulated and 195 proteins were down-regulated. Mechanically sensitive ion channel proteins related to transmembrane transport and ergosterol biosynthesis ERG4/ERG24, related to ergosterol synthesis were blocked. It is speculated that glabridin acts on ergosterol synthesis-related proteins to destroy the integrity of the cell membrane, resulting in abnormal transmembrane transport and an increased membrane potential. Finally, the morphology of mycelia was seriously deformed, growth and development were inhibited. As a result death was even induced.


Assuntos
Fungicidas Industriais , Fusarium , Isoflavonas , Fenóis/farmacologia , Doenças das Plantas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...