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1.
J Agric Food Chem ; 69(23): 6475-6484, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34075747

RESUMO

To improve the effect of pine rosin in plant fungicides, four series of dehydroabietyl-1,3,4-thiadiazole derivatives from the natural product rosin were synthesized. Based on the evaluation of the in vitro antifungal activity against Sclerotinia sclerotiorum, Botrytis cinerea, Fusarium oxysporum, and Magnaporthe oryzae, rosin-based 1,3,4-thiadiazole compounds containing thiophene heterocycles were screened. Notably, compound 3e [dehydroabietyl-(1,3,4-thiadiazol-2-yl)-5-nitrothiophene-2-carboxamide] exhibited excellent antifungal property against F. oxysporum with an EC50 of 0.618 mg/L, which was lower than that of the positive control carbendazim (0.649 mg/L). The in vivo antifungal activity results showed that 3e exerted a protective effect on cucumber plants. Physiological and biochemical studies showed that the primary mechanism of action of compound 3e on F. oxysporum was it changed the mycelial morphology, increased the cell membrane permeability, and inhibited the synthesis of ergosterol in the mycelia. Furthermore, the quantitative structure-activity relationship studies revealed that the frontier orbital energy in the molecule had a key role in the antifungal activity through the conjugation and electrostatic interaction between compound 3e and the receptors of the target. Thus, the present study highlighted the application of rosin-based fungicidal candidates and exploited efficient plant pesticides for sustainable crop production.


Assuntos
Cucumis sativus , Fungicidas Industriais , Fusarium , Antifúngicos/farmacologia , Ascomicetos , Botrytis , Fungicidas Industriais/farmacologia , Recursos Naturais , Resinas Vegetais , Relação Estrutura-Atividade
2.
Int J Mol Sci ; 22(10)2021 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-34068366

RESUMO

Magnaporthe oryzae (M. oryzae) is a typical cause of rice blast in agricultural production. Isobavachalcone (IBC), an active ingredient of Psoralea corylifolia L. extract, is an effective fungicide against rice blast. To determine the mechanism of IBC against M. oryzae, the effect of IBC on the metabolic pathway of M. oryzae was explored by transcriptome profiling. In M. oryzae, the expression of pyruvate dehydrogenase E1 (PDHE1), part of the tricarboxylic acid (TCA cycle), was significantly decreased in response to treatment with IBC, which was verified by qPCR and testing of enzyme activity. To further elucidate the interactions between IBC and PDHE1, the 3D structure model of the PDHE1 from M. oryzae was established based on homology modeling. The model was utilized to analyze the molecular interactions through molecular docking and molecular dynamics simulation, revealing that IBC has π-π stacking interactions with residue TYR139 and undergoes hydrogen bonding with residue ASP217 of PDHE1. Additionally, the nonpolar residues PHE111, MET174, ILE 187, VAL188, and MET250 form strong hydrophobic interactions with IBC. The above results reveal that PDHE1 is a potential target for antifungal agents, which will be of great significance for guiding the design of new fungicides. This research clarified the mechanism of IBC against M. oryzae at the molecular level, which will underpin further studies of the inhibitory mechanism of flavonoids and the discovery of new targets. It also provides theoretical guidance for the field application of IBC.


Assuntos
Chalconas/farmacologia , Proteínas Fúngicas/metabolismo , Magnaporthe/efeitos dos fármacos , Oryza/enzimologia , Doenças das Plantas/imunologia , Piruvato Desidrogenase (Lipoamida)/antagonistas & inibidores , Transcriptoma/efeitos dos fármacos , Proteínas Fúngicas/genética , Fungicidas Industriais/farmacologia , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Magnaporthe/fisiologia , Simulação de Acoplamento Molecular , Oryza/efeitos dos fármacos , Oryza/microbiologia , Doenças das Plantas/microbiologia , Conformação Proteica , Piruvato Desidrogenase (Lipoamida)/genética , Piruvato Desidrogenase (Lipoamida)/metabolismo
3.
J Agric Food Chem ; 69(25): 6958-6967, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34152748

RESUMO

The semisynthesis of 15 new thymol derivatives was achieved through Williamson synthesis and copper-catalyzed azide-alkyne cycloaddition (CuAAC) approaches. The reaction of CuAAC using the "Click Chemistry" strategy, in the presence of an alkynyl thymol derivative and commercial or prepared azides, provided nine thymol derivatives under microwave irradiation. This procedure reduces reaction time and cost. All molecular entities were elucidated by 1H and 13C NMR, IR, and HRMS data. These derivatives were evaluated in vitro for their fungicidal activity against Fusarium solani sp. Among the nine triazolic thymol derivatives obtained, seven of them were found to have moderated antifungal activity. In contrast, naphthoquinone/thymol hybrid ether 2b displayed activity comparable with that of the commercial fungicide thiabendazole. The structure-activity relationship for the most active compound 2b was discussed, and the mode of action was predicted by a possible binding to the fungic ergosterol and interference of osmotic balance of K+ into the extracellular medium.


Assuntos
Fungicidas Industriais , Fusarium , Alcinos , Antifúngicos/farmacologia , Química Click , Fungicidas Industriais/farmacologia , Timol/farmacologia
4.
Pestic Biochem Physiol ; 175: 104834, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33993959

RESUMO

Botrytis cinerea is one of the most destructive fungal pathogens which can cause gray mold diseases of numerous plant species, while the frequent applications of fungicides also result in the fungicide-resistances of B. cinerea. In this study, a new Streptomyces strain FX13 was obtained to show biocontrol potentials against fungicide-resistant B. cinerea B3-4. Its in vitro and in vivo antifungal mechanisms were further investigated. The results showed that the culture extract of strain FX13 could significantly inhibit the mycelia growth of B. cinerea B3-4 with the EC50 value of 5.40 mg L-1, which was greatly lower than those of pyrisoxazole, boscalid and azoxystrobin. Further bioassay-guided isolation of the extract had yielded the antifungal component SA1, which was elucidated as a 26-membered polyene macrolide of oligomycin A. SA1 could inhibit the mycelia growth, spore germination, germ tube elongation and sporogenesis of B. cinerea B3-4 in vitro, and also showed significant curative and protective effects against gray mold on grapes in vivo. Moreover, SA1 could result in the loss of membrane integrity and the leakage of cytoplasmic contents, which might be related to the accumulation of reactive oxygen species (ROS) and membrane lipid peroxidation. Besides, intracellular adenosine triphosphatase (ATPase) activity and adenosine triphosphate (ATP) content of B. cinerea B3-4 decreased after SA1-treatment. Overall, the oligomycin A-producing strain FX13 could inhibit fungicide-resistant B. cinerea B3-4 in vitro and in vivo, also highlighting its biocontrol potential against gray mold.


Assuntos
Fungicidas Industriais , Streptomyces , Botrytis , Fungicidas Industriais/farmacologia , Oligomicinas , Doenças das Plantas
5.
J Agric Food Chem ; 69(20): 5746-5754, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-33988994

RESUMO

To promote the discovery and development of new fungicides, a series of novel pyrazol-5-yl-benzamide derivatives were designed, synthesized by hopping and inversion of amide groups of pyrazole-4-carboxamides, and evaluated for their antifungal activities. The bioassay data revealed that compound 5IIc exhibited an excellent in vitro activity against Sclerotinia sclerotiorum with an EC50 value of 0.20 mg/L, close to that of commercial fungicide Fluxapyroxad (EC50 = 0.12 mg/L) and Boscalid (EC50 = 0.11 mg/L). For Valsa mali, compound 5IIc (EC50 = 3.68 mg/L) showed a significantly higher activity than Fluxapyroxad (EC50 = 12.67 mg/L) and Boscalid (EC50 = 14.83 mg/L). In addition, in vivo experiments proved that compound 5IIc has an excellent protective fungicidal activity with an inhibitory rate of 97.1% against S. sclerotiorum at 50 mg/L, while the positive control Fluxapyroxad showed a 98.6% inhibitory effect. The molecular docking simulation revealed that compound 5IIc interact with TRP173, SER39, and ARG43 of succinate dehydrogenase (SDH) through a hydrogen bond and p-π interaction, which could explain the probable mechanism of the action between compound 5IIc and target protein. Also, the SDH enzymatic inhibition assay was carried out to further validate its mode of action. These results demonstrate that compound 5IIc could be a promising fungicide candidate and provide a valuable reference for further investigation.


Assuntos
Fungicidas Industriais , Succinato Desidrogenase , Ascomicetos , Benzamidas/farmacologia , Fungicidas Industriais/farmacologia , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Succinato Desidrogenase/metabolismo
6.
J Agric Food Chem ; 69(19): 5435-5445, 2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-33945271

RESUMO

In the current work, a series of 1-trifluoromethyl cinnamyl alcohol derivatives were designed and synthesized and their antifungal activities were evaluated. The bioassay result showed that most compounds exhibited excellent antifungal activity in vitro at 10 µg mL-1. Next, photostable and easily synthesized compound 2 with broad-spectrum antifungal activity in vitro was selected as a potential candidate to evaluate its antibacterial and antifungal activities. The EC50 values of compound 2 against eight fungal plant pathogens in vitro ranged from 3.806 to 17.981 µg mL-1; at the same time, compound 2 could effectively control Podosphaera xanthii, Odium heveae Steinm, Puccinia striiformis West, and Puccinia sorghi in pot experiments. In addition, compound 2 exhibited excellent antibacterial activities in vitro and in vivo against Xanthomonas oryzae pv. oryzae. Furthermore, the absorption and translocation of compound 2 in wheat plants were determined by the high-performance liquid chromatography method. The result showed that compound 2 could be translocated acropetally as well as basipetally in wheat plants. Finally, it was found that compound 2 had no cross-resistance with carbendazim, azoxystrobin, and boscalid.


Assuntos
Fungicidas Industriais , Antibacterianos/farmacologia , Ascomicetos , Fungicidas Industriais/farmacologia , Testes de Sensibilidade Microbiana , Doenças das Plantas , Propanóis , Relação Estrutura-Atividade , Xanthomonas
7.
J Agric Food Chem ; 69(14): 4253-4262, 2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33792298

RESUMO

Natural products are one of the resources for discovering novel fungicidal leads. As a natural fungicide, osthole was used as a coumarin-based lead compound for the development of novel fungicides. Here, a series of 3,4-dichloroisothiazole-containing 7-hydroxycoumarins were rationally designed, synthesized, and characterized by introducing a bioactive substructure, 3,4-dichloroisothiazole, into the coumarin skeleton. In vitro bioassay indicated that compound 7g displayed good activity against Rhizoctonia solani, Physalospora piricola, Sclerotinia sclerotiorum, and Botrytis cinerea. Its median effective concentration (EC50) value against each of these fungi fell between 0.88 and 2.50 µg/mL, which was much lower than that of osthole against the corresponding pathogen (between 7.38 and 74.59 µg/mL). In vivo screening validated that 7k exhibited 100%, 60%, and 20% efficacy against R. solani Kühn at 200, 100, and 50 µg/mL, respectively. RNA sequence analysis implied that growth inhibition of R. solani by 7k might result from potential disruptions of fungal membrane formation and intracellular metabolism. Furthermore, a field experiment with cucumber plants indicated that 7b showed 62.73% and 74.03% efficacy against Pseudoperonospora cubensis (Berk. & Curt.) Rostov. at rates of 12.5 g a.i./ha and 25 g a.i./ha, respectively, which showed no significant difference between 7b and osthole at 30 g a.i./ha. Our studies suggested that 7b, 7g, and 7k might be used as fungicidal leads for further optimization.


Assuntos
Fungicidas Industriais , Ascomicetos , Botrytis , Cumarínicos/farmacologia , Fungicidas Industriais/farmacologia , Rhizoctonia , Relação Estrutura-Atividade
8.
Toxins (Basel) ; 13(3)2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803254

RESUMO

Photosensitization is a novel environmentally friendly technology with promising applications in the food industry to extend food shelf life. In this study, the natural food dye curcumin, when combined with visible light (430 nm), was shown to be an effective photosensitizer against the common phytopathogenic fungi Botrytis cinerea (the cause of grey mould). Production of the associated phytotoxic metabolites botrydial and dihydrobotrydial was measured by our newly developed and validated HRAM UPLC-MS/MS method, and was also shown to be reduced by this treatment. With a light dose of 120 J/cm2, the reduction in spore viability was directly proportional to curcumin concentrations, and the overall concentration of both botrydial and dihydrobotrydial also decreased with increasing curcumin concentration above 200 µM. With curcumin concentrations above 600 µM, the percentage reduction in fungal spores was close to 100%. When the dye concentration was increased to 800 µM, the spores were completely inactive and neither botrydial nor dihydrobotrydial could be detected. These results suggest that curcumin-mediated photosensitization is a potentially effective method to control B. cinerea spoilage, and also to reduce the formation of these phytotoxic botryane secondary metabolites.


Assuntos
Botrytis/efeitos dos fármacos , Curcumina/farmacologia , Fragaria/microbiologia , Frutas/microbiologia , Fungicidas Industriais/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Esporos Fúngicos/efeitos dos fármacos , Aldeídos/metabolismo , Aldeídos/toxicidade , Botrytis/crescimento & desenvolvimento , Botrytis/metabolismo , Compostos Bicíclicos com Pontes/metabolismo , Compostos Bicíclicos com Pontes/toxicidade , Cromatografia Líquida , Microbiologia de Alimentos , Conservação de Alimentos , Metabolismo Secundário , Espectrometria de Massas por Ionização por Electrospray , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo , Espectrometria de Massas em Tandem
9.
Int J Mol Sci ; 22(9)2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33926042

RESUMO

The control of the fungal contamination on crops is considered a priority by the sanitary authorities of an increasing number of countries, and this is also due to the fact that the geographic areas interested in mycotoxin outbreaks are widening. Among the different pre- and post-harvest strategies that may be applied to prevent fungal and/or aflatoxin contamination, fungicides still play a prominent role; however, despite of countless efforts, to date the problem of food and feed contamination remains unsolved, since the essential factors that affect aflatoxins production are various and hardly to handle as a whole. In this scenario, the exploitation of bioactive natural sources to obtain new agents presenting novel mechanisms of action may represent a successful strategy to minimize, at the same time, aflatoxin contamination and the use of toxic pesticides. The Aflatox® Project was aimed at the development of new-generation inhibitors of aflatoxigenic Aspergillus spp. proliferation and toxin production, through the modification of naturally occurring molecules: a panel of 177 compounds, belonging to the thiosemicarbazones class, have been synthesized and screened for their antifungal and anti-aflatoxigenic potential. The most effective compounds, selected as the best candidates as aflatoxin containment agents, were also evaluated in terms of cytotoxicity, genotoxicity and epi-genotoxicity to exclude potential harmful effect on the human health, the plants on which fungi grow and the whole ecosystem.


Assuntos
Aflatoxinas/química , Aflatoxinas/isolamento & purificação , Aspergillus flavus/química , Aflatoxinas/toxicidade , Antifúngicos/farmacologia , Aspergillus/metabolismo , Aspergillus/patogenicidade , Aspergillus flavus/isolamento & purificação , Aspergillus flavus/metabolismo , Aspergillus flavus/patogenicidade , Produtos Agrícolas/microbiologia , Ecossistema , Contaminação de Alimentos/prevenção & controle , Fungos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Humanos , Micotoxinas/toxicidade , Tiossemicarbazonas/química
10.
Mar Drugs ; 19(4)2021 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-33923448

RESUMO

Phlorotannins are secondary metabolites produced by brown seaweeds with antiviral, antibacterial, antifungal, and larvicidal activities. Phlorotannins' structures are formed by dibenzodioxin, ether and phenyl, ether, or phenyl linkages. The polymerization of phlorotannins is used to classify and characterize. The structural diversity of phlorotannins grows as polymerization increases. They have been characterized extensively with respect to chemical properties and functionality. However, review papers of the biological activities of phlorotannins have focused on their antibacterial and antiviral effects, and reviews of their broad antifungal and larvicidal effects are lacking. Accordingly, evidence for the effectiveness of phlorotannins as antifungal and larvicidal agents is discussed in this review. Online databases (ScienceDirect, PubMed, MEDLINE, and Web of Science) were used to identify relevant articles. In total, 11 articles were retrieved after duplicates were removed and exclusion criteria were applied. Phlorotannins from brown seaweeds show antifungal activity against dermal and plant fungi, and larvicidal activity against mosquitos and marine invertebrate larvae. However, further studies of the biological activity of phlorotannins against fungal and parasitic infections in aquaculture fish, livestock, and companion animals are needed for systematic analyses of their effectiveness. The research described in this review emphasizes the potential applications of phlorotannins as pharmaceutical, functional food, pesticide, and antifouling agents.


Assuntos
Antifúngicos/farmacologia , Culicidae/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Inseticidas/farmacologia , Controle de Mosquitos , Feófitas/metabolismo , Alga Marinha/metabolismo , Taninos/farmacologia , Animais , Antifúngicos/isolamento & purificação , Culicidae/embriologia , Fungicidas Industriais/isolamento & purificação , Inseticidas/isolamento & purificação , Larva/efeitos dos fármacos , Estrutura Molecular , Relação Estrutura-Atividade , Taninos/isolamento & purificação
11.
Molecules ; 26(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802719

RESUMO

Plant diseases reduce crop yield and quality, hampering the development of agriculture. Fungicides, which restrict chemical synthesis in fungi, are the strongest controls for plant diseases. However, the harmful effects on the environment due to continued and uncontrolled utilization of fungicides have become a major challenge in recent years. Plant-sourced fungicides are a class of plant antibacterial substances or compounds that induce plant defenses. They can kill or inhibit the growth of target pathogens efficiently with no or low toxicity, they degrade readily, and do not prompt development of resistance, which has led to their widespread use. In this study, the growth inhibition effect of 24 plant-sourced ethanol extracts on rice sprigs was studied. Ethanol extract of gallnuts and cloves inhibited the growth of bacteria by up to 100%. Indoor toxicity measurement results showed that the gallnut and glove constituents inhibition reached 39.23 µg/mL and 18.82 µg/mL, respectively. Extract treated rice sprigs were dry and wrinkled. Gallnut caused intracellular swelling and breakage of mitochondria, disintegration of nuclei, aggregation of protoplasts, and complete degradation of organelles in hyphae and aggregation of cellular contents. Protection of Rhizoctonia solani viability reached 46.8% for gallnut and 37.88% for clove in water emulsions of 1000 µg/mL gallnut and clove in the presence of 0.1% Tween 80. The protection by gallnut was significantly stronger than that of clove. The data could inform the choice of plant-sourced fungicides for the comprehensive treatment of rice sprig disease. The studied extract effectively protected rice sprigs and could be a suitable alternative to commercially available chemical fungicides. Further optimized field trials are needed to effectively sterilize rice paddies.


Assuntos
Misturas Complexas/farmacologia , Oryza/efeitos dos fármacos , Extratos Vegetais/farmacologia , Rhizoctonia/efeitos dos fármacos , Rhus/química , Syzygium/química , Cromatografia por Troca Iônica , Misturas Complexas/toxicidade , Etanol/química , Eugenol/análise , Fungicidas Industriais/farmacologia , Ácidos Láuricos/análise , Espectrometria de Massas , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Micélio/efeitos dos fármacos , Micélio/ultraestrutura , Oryza/microbiologia , Doenças das Plantas/microbiologia , Extratos Vegetais/toxicidade
13.
Ecotoxicol Environ Saf ; 217: 112251, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33905983

RESUMO

Pollinators and other insects are experiencing an ongoing worldwide decline. While various environmental stressors have been implicated, including pesticide exposure, the causes of these declines are complex and highly debated. Fungicides may constitute a particularly prevalent threat to pollinator health due to their application on many crops during bloom, and because pollinators such as bees may consume fungicide-tainted pollen or nectar. In a previous study, consumption of pollen containing the fungicide Pristine® at field-relevant concentrations by honey bee colonies increased pollen foraging, caused earlier foraging, lowered worker survival, and reduced colony population size. Because most pollen is consumed by young adults, we hypothesized that Pristine® (25.2% boscalid, 12.8% pyraclostrobin) in pollen exerts its negative effects on honey bee colonies primarily on the adult stage. To rigorously test this hypothesis, we used a cross-fostering experimental design, with bees reared in colonies provided Pristine® incorporated into pollen patties at a supra-field concentration (230 mg/kg), only in the larvae, only in the adult, or both stages. In contrast to our predictions, exposure to Pristine® in either the larval or adult stage reduced survival relative to control bees not exposed to Pristine®, and exposure to the fungicide at both larval and adult stages further reduced survival. Adult exposure caused precocious foraging, while larval exposure increased the tendency to forage for pollen. These results demonstrate that pollen containing Pristine® can induce significant negative effects on both larvae and adults in a hive, though the magnitude of such effects may be smaller at field-realistic doses. To further test the potential negative effects of direct consumption of Pristine® on larvae, we reared them in vitro on food containing Pristine® at a range of concentrations. Consumption of Pristine® reduced survival rates of larvae at all concentrations tested. Larval and adult weights were only reduced at a supra-field concentration. We conclude that consumption of pollen containing Pristine® by field honey bee colonies likely exerts impacts on colony population size and foraging behavior by affecting both larvae and adults.


Assuntos
Abelhas/fisiologia , Compostos de Bifenilo/toxicidade , Fungicidas Industriais/toxicidade , Niacinamida/análogos & derivados , Estrobilurinas/toxicidade , Animais , Fungicidas Industriais/farmacologia , Insetos , Larva/efeitos dos fármacos , Niacinamida/toxicidade , Praguicidas/toxicidade , Néctar de Plantas , Pólen/efeitos dos fármacos , Polinização
14.
Pest Manag Sci ; 77(7): 3419-3426, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33797181

RESUMO

BACKGROUND: Pydiflumetofen, as a new succinate dehydrogenase inhibitor (SDHI) chiral fungicide, has been used in crop production because of its broad-spectrum and high-efficiency antifungal activity. However, little is known about pydiflumetofen at the chiral level. The stereoselective bioactivity and degradation of pydiflumetofen enantiomers were therefore investigated. RESULTS: Pydiflumetofen presented effective bioactivity against the eight tested phytopathogens, and its enantiomers showed significant differences in activity. The bioactivity of R-pydiflumetofen was 9.0-958.8 times higher than that of the S enantiomer. Treatment with R-pydiflumetofen increased the cell membrane permeability of Sclerotinia sclerotiorum and decreased exopolysaccharide and oxalic acid production more than treatment with S-pydiflumetofen. Furthermore, R-pydflumetofen exhibited better inhibitory activity against the succinate dehydrogenase enzyme of S. sclerotiorum than S-pydiflumetofen by 584-fold. According to homology modeling and molecular docking studies, the binding affinities of the R and S enantiomers were -7.0 and -5.3 kcal mol-1 , respectively. Additionally, the degradation half-lives of S- and R-pydiflumetofen in three vegetables (cucumber, eggplant, and cowpea) under field conditions were 2.56-3.12 days and 2.48-2.76 days, respectively, which reveals that R-pydiflumetofen degrades faster than S-pydiflumetofen. CONCLUSION: Based on the results obtained, R-pydiflumetofen not only exhibited a higher bactericidal activity, but also posed fewer residual risks in the environment. The mechanism of the stereoselective bioactivity was correlated with the stereoselective inhibition activity of the target enzyme and affected the cell membrane permeability and the production of exopolysaccharide and oxalic acid. This research could provide a foundation for the systematic evaluation of pydiflumetofen from an enantiomeric view. © 2021 Society of Chemical Industry.


Assuntos
Fungicidas Industriais , Ascomicetos , Fungicidas Industriais/farmacologia , Simulação de Acoplamento Molecular , Pirazóis , Estereoisomerismo
15.
Pest Manag Sci ; 77(7): 3049-3056, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33821561

RESUMO

Herbicides are the largest category of pesticides used in global agriculture, which is reflected in the rate of increase in the number of unique cases of herbicide-resistant weed biotypes since the late 1950s. Recommended herbicide resistance management strategies and tactics have evolved over the past 50 years through cumulative research and experience and have been regularly reviewed. Nevertheless, new perspectives may be gained by viewing current recommended strategies through the lens of insecticide, fungicide, and antibiotic resistance management. What commonalities exist and what is the basis for disparate strategies? Although pesticide and antibiotic mixtures (or combinations) are generally more effective than rotations (or alternations) in mitigating or managing resistance, the latter strategy is often employed because of greater ease of implementation and other reasons. We conclude that there are more common than different strategies for mitigating or managing pesticide and antibiotic resistance. Overall, a reduction in selection pressure for resistance evolution through diverse multi-tactic management programmes, and disruption or mitigation of the dispersal or transmission of problematic genotypes are needed to sustain the longevity of current and future mode-of-action products for crop and human health protection. © 2021 Society of Chemical Industry. © 2021 Society of Chemical Industry.


Assuntos
Fungicidas Industriais , Herbicidas , Inseticidas , Antibacterianos/farmacologia , Fungicidas Industriais/farmacologia , Resistência a Herbicidas , Herbicidas/farmacologia , Humanos , Plantas Daninhas , Controle de Plantas Daninhas
16.
Pest Manag Sci ; 77(7): 3529-3537, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33837653

RESUMO

BACKGROUND: To promote the discovery and development of new fungicide with novel scaffolds or modes of action, a series of novel 5-(2-chloroethyl)-1-phenyl-6-(pyridin-4-yl)-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one derivatives were synthesized, and evaluated for their antifungal activities. RESULTS: The bioassay data showed that compound 8IIId (EC50  = 1.93 mg L-1 ) is superior to boscalid (EC50  = 6.71 mg L-1 ) against Valsa mali. We introduced chiral groups on the structure of 8IIId, and two chiral configurations were respectively synthesized, which are 8Vc and 8Vd. Surprisingly, 8Vc showed significant antifungal activities against Valsa mali and Physalospora piricola with EC50 values of 0.22 and 0.55 mg L-1 . Physiological and biochemical studies showed that the primary action mechanism of compound 8Vc on Valsa mali may involve changing mycelial morphology and increasing cell membrane permeability. CONCLUSION: These results demonstrated that 8Vc could be further modified as fungicide and provided a valuable reference for antifungal agents with pyrazolo[3,4-d]pyrimidin-4-one skeleton. © 2021 Society of Chemical Industry.


Assuntos
Ascomicetos , Fungicidas Industriais , Antifúngicos/farmacologia , Fungicidas Industriais/farmacologia , Relação Estrutura-Atividade
17.
J Agric Food Chem ; 69(16): 4604-4614, 2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33872004

RESUMO

Plant diseases caused by phytopathogenic fungi reduce the yield and quality of crops. To develop novel antifungal agents, we designed and synthesized eight series of quinazolinone derivatives and evaluated their anti-phytopathogenic fungal activity. The bioassay results revealed that compounds KZL-15, KZL-22, 5b, 6b, 6c, 8e, and 8f exhibited remarkable antifungal activity in vitro. Especially, compound 6c displayed the highest bioactivity against Sclerotinia sclerotiorum, Pellicularia sasakii, Fusarium graminearum, and Fusarium oxysporum, displaying appreciable IC50 values (50% inhibitory concentration) of 2.46, 2.94, 6.03, and 11.9 µg/mL, respectively. A further mechanism interrogation revealed abnormal mycelia, damaged organelles, and changed permeability of cell membranes in S. sclerotiorum treated with compound 6c. In addition, the in vivo bioassay indicated that compound 6c possessed comparable curative and protective effects (87.3 and 90.7%, respectively) to the positive control azoxystrobin (89.5 and 91.2%, respectively) at 100 µg/mL concentration against S. sclerotiorum. This work validated the potential of compound 6c as a new and promising fungicide candidate, contributing to the exploration of potent antifungal agents.


Assuntos
Fungicidas Industriais , Antifúngicos/farmacologia , Ascomicetos , Fungicidas Industriais/farmacologia , Fusarium , Quinazolinonas/farmacologia , Relação Estrutura-Atividade
18.
Molecules ; 26(8)2021 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-33919567

RESUMO

Essential oils are gaining interest as environmentally friendly alternatives to synthetic fungicides for management of seedborne pathogens. Here, seven essential oils were initially tested in vivo for disinfection of squash seeds (Cucurbita maxima) naturally contaminated by Stagonosporopsis cucurbitacearum, Alternaria alternata, Fusarium fujikuro, Fusarium solani, Paramyrothecium roridum, Albifimbria verrucaria, Curvularia spicifera, and Rhizopus stolonifer. The seeds were treated with essential oils from Cymbopogon citratus, Lavandula dentata, Lavandula hybrida, Melaleuca alternifolia, Laurus nobilis, and Origanum majorana (#1 and #2). Incidence of S. cucurbitacearum was reduced, representing a range between 67.0% in L. nobilis to 84.4% in O. majorana #2. Treatments at 0.5 mg/mL essential oils did not affect seed germination, although radicles were shorter than controls, except with C. citratus and O. majorana #1 essential oils. Four days after seeding, seedling emergence was 20%, 30%, and 10% for control seeds and seeds treated with C. citratus essential oil (0.5 mg/mL) and fungicides (25 g/L difenoconazole plus 25 g/L fludioxonil). S. cucurbitacearum incidence was reduced by ~40% for plantlets from seeds treated with C. citratus essential oil. These data show the effectiveness of this essential oil to control the transmission of S. cucurbitacearum from seeds to plantlets, and thus define their potential use for seed decontamination in integrated pest management and organic agriculture.


Assuntos
Cucurbita/microbiologia , Óleos Voláteis/farmacologia , Óleos Vegetais/farmacologia , Sementes/efeitos dos fármacos , Alternaria/efeitos dos fármacos , Alternaria/patogenicidade , Ascomicetos/patogenicidade , Cucurbita/efeitos dos fármacos , Curvularia/efeitos dos fármacos , Curvularia/patogenicidade , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Fusarium/efeitos dos fármacos , Fusarium/patogenicidade , Hypocreales/efeitos dos fármacos , Hypocreales/patogenicidade , Óleos Voláteis/química , Doenças das Plantas/microbiologia , Doenças das Plantas/prevenção & controle , Óleos Vegetais/química , Rhizopus/efeitos dos fármacos , Rhizopus/patogenicidade , Sementes/microbiologia
19.
Food Chem ; 355: 129551, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33799235

RESUMO

Hops contain a variety of compounds possessing antioxidant capacity including phenolic and polyphenolic compounds as well as α- and ß- acids. These compounds may contribute to the oxidative stability of beer during brewing and storage. Hop plants may be treated with copper-based fungicides (CBFs) which have been shown to increase the total copper content of harvested hop cones; however, copper ions are well known to catalyze the generation of reactive oxygen species production in beer and may negatively impact its oxidative stability. Increased copper content in CBF-treated hops has been previously shown to have deleterious effects on the aroma quality of hops and beer. The impact of CBFs on the antioxidant content and quality of hops has not been previously investigated. In this study, ethanolic extracts of CBF-treated hops are evaluated for their metal content and antioxidant quality in order to determine whether excess copper from CBF treatment negatively impacts their antioxidant capacity.


Assuntos
Antioxidantes/análise , Cannabaceae/química , Cannabaceae/efeitos dos fármacos , Cobre/química , Cobre/farmacologia , Etanol/química , Extratos Vegetais/química , Cerveja/análise , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Humulus , Oxirredução
20.
Molecules ; 26(6)2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33810162

RESUMO

Wheat is one of the global strategic crops and ranks third in terms of cereals production. Wheat crops are exposed to many fungal infections during their cultivation stages, some of which have the ability to secrete a number of toxic secondary metabolites that threaten the quality of the grains, consumer health, producer economics, and global trade exchange. Fifty-four random samples were collected from wheat which originated from different countries. The samples included 14 types of soft wheat to study the extent of their contamination with deoxynivalenol (DON) and T-2 toxin by auto-ELISA technology and r-biopharm microtiter plate. All samples were contaminated with DON toxin except one sample, and the values ranged between 40.7 and 1018.8 µg/kg-1. The highest contamination rates were in Lithuanian wheat and the lowest was in Indian wheat. Meanwhile, the highest average level of T-2 toxin contamination was in Lithuanian wheat grains with 377.4 µg/kg-1, and the lowest average was 115.3 µg/kg-1 in Polish wheat. GC-MS/MS and multiple reaction monitoring mode (MRM) were used to detect 15 triazole derivatives in the collected samples, which may be used to combat fungal diseases on wheat during the growing season. Only 9 derivatives were found: simeconazole, penconazole, hexaconazole, cyproconazole, diniconazole, tebuconazole, metconazole, fenbuconazole, and difenoconazole. These derivatives varied according to the origin of the wheat samples as well as their concentration, whereas another 6 derivatives were not detected in any samples. A direct inverse relationship was found between the DON concentration in the samples and the residues of simeconazole, penconazole, diniconazole, tebuconazole, metconazole, fenbuconazole, and difenoconazole, and the T-2 toxin showed the same relationship except for tebuconazole. The safe and rational use of some triazole derivatives may be a new approach and a promising strategy to not only reduce plant diseases and their problems, but also to get rid of some mycotoxins as grain contaminants.


Assuntos
Fungicidas Industriais/farmacologia , Doenças das Plantas/microbiologia , Triazóis/farmacologia , Tricotecenos/análise , Triticum , Grãos Integrais , Triticum/química , Triticum/microbiologia , Grãos Integrais/química , Grãos Integrais/microbiologia
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