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1.
J Agric Food Chem ; 68(3): 826-837, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31895558

RESUMO

A total of five strains of nicosulfuron-degrading bacteria were isolated from a continuously cultivated microbial consortium using culturomics. Among them, a novel Pseudomonas strain, LAM1902, with the highest degradation efficiency was investigated in detail. The characteristics of nicosulfuron-degradation by LAM1902 were investigated and optimized by response surface analysis. Furthermore, non-targeted metabolomic analysis of extracellular and intracellular biodegradation of nicosulfuron by LAM1902 was carried out by liquid chromatography/mass spectroscopy (LC-MS) and gas chromatography-time-of-flight/mass spectroscopy (GC-TOF/MS). It was found that nicosulfuron was degraded by LAM1902 mainly via breaking the sulfonylurea bridge, and this degradation might be attributed to oxalate accumulation. The results of GC-TOF/MS also showed that the intracellular degradation of nicosulfuron did not occur. However, nicosulfuron exerted a significant influence on the metabolism of inositol phosphate, pyrimidine, arginine/proline, glyoxylate, and dicarboxylate metabolism and streptomycin biosynthesis. The changes of myo-inositol, trehalose, and 3-aminoisobutanoic acid were proposed as a mechanism of self-protection against nicosulfuron stress.


Assuntos
Herbicidas/metabolismo , Pseudomonas/metabolismo , Piridinas/metabolismo , Compostos de Sulfonilureia/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Herbicidas/química , Concentração de Íons de Hidrogênio , Metabolômica , Filogenia , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Piridinas/química , Compostos de Sulfonilureia/química
2.
J Agric Food Chem ; 68(1): 17-32, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31809036

RESUMO

Weeds had caused significant loss for crop production in the process of agriculture. Herbicides have played an important role in securing crop production. However, the high reliance on herbicides has led to environmental issues as well as the evolution of herbicide resistance. Thus, there is an urgent need for new herbicides with safer toxicological profiles and novel modes of action. Actinomycetes produce very diverse bioactive compounds, of which some show potent biopesticidal activity. The herbicidal secondary metabolites from actinomycetes can be classified into several groups, such as amino acids, peptides, nucleosides, macrolides, lactones, amide, amines, etc., some of which have been successfully developed as commercial herbicides. The structure diversity and evolved biological activity of secondary metabolites from actinomycetes can offer opportunities for the development of both directly used bioherbicides and synthetic herbicides with new target sites, and thus, this review focuses on the structure, herbicidal activity, and modes of action of secondary metabolites from actinomycetes.


Assuntos
Actinobacteria/química , Herbicidas/química , Herbicidas/farmacologia , Actinobacteria/metabolismo , Descoberta de Drogas , Herbicidas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Metabolismo Secundário , Controle de Plantas Daninhas
3.
J Sci Food Agric ; 100(3): 1185-1194, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31680262

RESUMO

BACKGROUND: Ludwigia hyssopifolia (G. Don) Exell, one of the problem weeds in some rice-producing countries, was studied to determine its allelopathic potential based on the effects of aqueous extracts of its tissues (leaves, roots and stem) on seedling growth of selected weeds and rice. The major phenolic compound of its leaves was also isolated and characterized. RESULTS: L. hyssopifolia aqueous leaf extract showed significant inhibition of shoot growth and biomass accumulation of weeds (Amaranthus spinosus L., Dactyloctenium aegyptium L., Cyperus iria L.) while maintaining less adverse effects on rice (crop) compared to other aqueous extracts of roots and stem. Phytochemical screening showed that phenols, tannins, flavonoids, terpenoids, saponins and coumarins are found in its leaf aqueous extract. The Folin-Ciocalteu method revealed that its leaves contain 26.66 ± 0.30 mg GAE g-1 leaf. The extract was then acid-hydrolyzed to liberate the phenolics (25 mg phenolics g-1 leaf). The major compound was isolated via preparative thin-layer chromatography using formic acid-ethyl acetate-n-hexane (0.05:4:6) solvent system. It had maximum UV absorption at 272 nm while its Fourier transform infrared spectrum revealed phenol, carboxylic acid and ether functionalities. This also had similar chromatographic mobility when run together with syringic acid in two-dimensional paper chromatography and thin-layer chromatography. CONCLUSIONS: L. hyssopifolia has potential allelopathic activity and its leaf aqueous extract showed the highest phytotoxic activity (P ≤ 0.05) indicating its potential as a bioherbicide. The most probable identity of the major phenolic compound is syringic acid. © 2019 Society of Chemical Industry.


Assuntos
Herbicidas/química , Onagraceae/química , Extratos Vegetais/química , Amaranthus/efeitos dos fármacos , Amaranthus/crescimento & desenvolvimento , Flavonoides/química , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Herbicidas/isolamento & purificação , Herbicidas/farmacologia , Fenóis/química , Fenóis/isolamento & purificação , Fenóis/farmacologia , Compostos Fitoquímicos/química , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Folhas de Planta/química , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Taninos/química , Taninos/farmacologia
4.
Chemosphere ; 239: 124801, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31520969

RESUMO

The maintenance of public swimming pools requires numerous technological steps. One of the most important issues involves microbiological safety. Benzalkonium chloride (BAC) encompasses homologous alkylbenzyldimethylammonium chlorides with various alkyl chains, in particular C12 and C14, and is known as a popular algaecide for keeping water clean. In addition to BAC, NaOCl and UV-irradiation are also used to treat pool water as additional technological steps. Therefore, BAC itself can become a precursor of disinfection byproducts (DBPs). High-performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS), with accurate mass measurements, has allowed the discovery of several groups of DBPs that are related to BAC in public pool water in Arkhangelsk (Russia). These DBPs include numerous isomeric monochlorinated derivatives ([C21H37ClN]+ and [C23H41ClN]+), hydroxyl derivatives ([C21H38NO]+ and [C23H42NO]), carbonyl ([C21H36NO]+ and [C23H40NO]+), and dicarbonyl derivatives ([C21H34NO2]+ and [C23H38NO2]+). In addition, chlorinated alcohols, ketones and ketoalcohols of BAC were also detected, including [C21H35ClNO]+, [C21H37ClNO]+ and [C21H35ClNO2]+ for BAC-12; and [C23H39ClNO]+, [C23H41ClNO]+ and [C23H39ClNO2]+ for BAC-14. MS/MS allowed reliable elucidation of the structures of novel DBPs, proving that chlorination starts via radical substitution in the long aliphatic chains of BAC. UV-irradiation dramatically accelerates the reaction completely destroying the original compounds in less than an hour, while the array of the intermediate products remains the same as in the dark. The formation of other DBPs proceeds due to further reactions of these primary products. The concentrations of novel DBPs in pool water reach µg L-1 levels. These conclusions were proved by conducting model reactions of BAC with NaOCl.


Assuntos
Compostos de Benzalcônio/química , Desinfecção , Herbicidas/química , Piscinas , Poluentes Químicos da Água/análise , Água/química , Desinfetantes/química , Halogenação , Federação Russa , Espectrometria de Massas em Tandem , Raios Ultravioleta
5.
Chemosphere ; 238: 124550, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31425868

RESUMO

Large volumes of contaminated water are produced via intentional and unintentional incidents, including terrorist attacks, natural disasters and accidental spills. Contaminated waters could contain harmful chemicals, which present management and disposal challenges. This study investigates three Advanced Oxidation Processes (AOPs) - UV/H2O2, O3/H2O2, and electrochemical oxidation using a boron-doped diamond (BDD) anode - to treat eleven contaminants including herbicides, pesticides, pharmaceuticals, and flame retardant compounds. To address treatment and toxicity concerns, this study focuses on the resulting microbial toxicity via Microtox® toxicity and Nitrification Inhibition tests. The results suggest four functional Microtox® toxicity categories upon AOP treatment, which are useful for streamlining AOP selection for specific applications. Except for one compound, the O3/H2O2 and UV/H2O2 AOPs achieved, within experimental error, 100% parent compound degradation during 2 h of treatment for all contaminants, as well as Microtox® toxicities that declined below 10% by the end of the treatment. In addition, anodic oxidation with a BDD electrode exhibited slower degradation and some increases in Microtox® toxicity. Only one compound exhibited above 50% Nitrification Inhibition, indicating the robustness of activated sludge to many contaminated and AOP-treated waters. These results indicate that AOP pre-treatment can be a viable strategy to facilitate drain disposal of contaminated waters, but that eco-toxicity may remain a concern.


Assuntos
Reatores Biológicos , Diamante/química , Eletrodos , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Poluição da Água/análise , Boro/química , Herbicidas/análise , Herbicidas/química , Herbicidas/toxicidade , Peróxido de Hidrogênio/química , Oxirredução , Praguicidas/análise , Praguicidas/química , Praguicidas/toxicidade , Microbiologia da Água , Poluentes Químicos da Água/análise , Purificação da Água/métodos
6.
J Agric Food Chem ; 67(47): 13040-13050, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31670962

RESUMO

Two new natural 10-membered macrolides (1, 2) and one chromene-4,5-dione derivative (3), named stagonolides J and K and stagochromene A, respectively, were isolated from the phytopathogenic fungus Stagonospora cirsii S-47, together with two known compounds, stagonolide A (4) and herbarumin I (5). Stagonolides J and K and stagochromene A were characterized as (5E,7R*,8S*,9R*)-7,8-dihydroxy-9-propyl-5-nonen-9-olide, (5E,7R,9S)-7-hydroxy-9-propyl-5-nonen-9-olide, and (2R*,3R*)-3-hydroxy-2-propyltetrahydro-2H-chromene-4,5(3H,4aH)-dione, respectively, by spectroscopic (mostly by NMR and ESIMS) data. Compounds 1-5 showed different rates of phytotoxic activity on punctured leaf discs of Sonchus arvensis. The antimicrobial, cytotoxic, and antiprotozoal activity of isolated compounds was also evaluated. Based on our data, stagonolide K and herbarumin I can be proposed as a potential scaffold for the development of a new natural herbicide and estimated as possible selection/quality markers of a bioherbicide based on S. cirsii, while stagonolide A can be considered as a mycotoxin.


Assuntos
Ascomicetos/química , Benzopiranos/química , Herbicidas/química , Compostos Heterocíclicos com 1 Anel/química , Lactonas/química , Macrolídeos/química , Sonchus/efeitos dos fármacos , Benzopiranos/farmacologia , Herbicidas/farmacologia , Compostos Heterocíclicos com 1 Anel/farmacologia , Lactonas/farmacologia , Macrolídeos/farmacologia , Estrutura Molecular , Micotoxinas/química , Micotoxinas/farmacologia , Sonchus/crescimento & desenvolvimento
7.
J Agric Food Chem ; 67(46): 12816-12823, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31675231

RESUMO

Microbial degradation plays a major role in the dissipation of pendimethalin, and nitroreduction is an initial and detoxicating step. Previously, a pendimethalin nitroreductase, PNR, was identified in Bacillus subtilis Y3. Here, another pendimethalin nitroreductase from strain Y3, LNR, was identified. LNR shares only 40% identity with PNR and reduces the aromatic ring C-6 nitro group of pendimethalin and both nitro groups of trifluralin, butralin, and oryzalin. The catalytic activities against the four dinitroanilines were much higher for LNR than for PNR. lnr deletion significantly reduced the pendimethalin-reduction activity (60% activity loss), while pnr deletion led to only 30% activity loss, indicating that both LNR and PNR were involved in pendimethalin nitroreduction in strain Y3; however, LNR played the major role. This study facilitates the elucidation of pendimethalin catabolism and provides degrading enzyme resources for the removal of dinitroaniline herbicide residues in environment and agricultural products.


Assuntos
Compostos de Anilina/metabolismo , Bacillus subtilis/enzimologia , Proteínas de Bactérias/metabolismo , Herbicidas/metabolismo , Nitrorredutases/metabolismo , Sequência de Aminoácidos , Compostos de Anilina/química , Bacillus subtilis/classificação , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Biodegradação Ambiental , Herbicidas/química , Nitrorredutases/química , Nitrorredutases/genética , Filogenia , Alinhamento de Sequência
8.
J Agric Food Chem ; 67(45): 12382-12392, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31635461

RESUMO

Protoporphyrinogen oxidase (PPO, EC 1.3.3.4) is a promising target for herbicide discovery. Search for new compounds with novel chemotypes is a key objective for agrochemists. Here, we describe the discovery and systematic SAR-based structure optimization of novel N-isoxazolinylphenyltriazinones 5-9 as PPO inhibitors. The in vivo herbicidal activity and in vitro Nicotiana tabacum PPO (NtPPO) inhibitory activity were explored in detail. A number of the new synthetic compounds displayed strong PPO inhibitory activity with Ki values in the nanomolar range. Some compounds exhibited excellent and broad-spectrum weed control at the rate of 9.375-37.5 g ai/ha by postemergence application and showed improved monocotyledonous weed control compared to saflufenacil. Most promisingly, ethyl 3-(2-chloro-5-(3,5-dimethyl-2,6-dioxo-4-thioxo-1,3,5-triazinan-1-yl)-4-fluorophenyl)-5-methyl-4,5-dihydroisoxazole-5-carboxylate, 5a, with a Ki value of 4.9 nM, displayed over 2- and 6-fold higher potency than saflufenacil (Ki = 10 nM) and trifludimoxazin (Ki = 31 nM), respectively. Moreover, 5a showed excellent and broad-spectrum weed control against 32 kinds of weeds at 37.5-75 g ai/ha. Rice exhibited relative tolerance to 5a at 150 g ai/ha by postemergence application, indicating that 5a could be a potential herbicide candidate for weed control in paddy fields.


Assuntos
Inibidores Enzimáticos/farmacologia , Herbicidas/química , Herbicidas/farmacologia , Proteínas de Plantas/antagonistas & inibidores , Protoporfirinogênio Oxidase/antagonistas & inibidores , Descoberta de Drogas , Inibidores Enzimáticos/química , Cinética , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Daninhas/química , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Protoporfirinogênio Oxidase/química , Protoporfirinogênio Oxidase/metabolismo , Relação Quantitativa Estrutura-Atividade , Tabaco/química , Tabaco/efeitos dos fármacos , Tabaco/enzimologia , Controle de Plantas Daninhas
9.
Ecotoxicol Environ Saf ; 185: 109702, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31585394

RESUMO

The purpose of our work was to determine the acute and chronic toxicity of three of the EU's most common herbicides - mesotrione, S-metolachlor, terbuthylazine - and their mixtures by Aliivibrio fischeri ecotoxicological assays. While comparing the sensitivity of the acute (30 min) Microtox® standard assay with the chronic (25 h) test adapted to microtiter plate, joint effects (antagonism, additive effect and synergism) to the bioluminescence inhibition (consequently the metabolic damage) in A. fischeri were also determined by Combination Index (CI) method. 30 min of exposure to mesotrione and S-metolachlor resulted in a relatively low acute toxicity (EC50 values were 118 and 265 mg/L), while terbuthylazine did not cause bioluminescence inhibition at all. Results showed that the chronic toxicity of S-metolachlor and terbuthylazine to A. fischeri (EC5010h = 59.2 and 4.9 mg/L and EC5015h = 54.0 and 9.6 mg/L, respectively) is larger by at least one order of magnitude than that after 30 min of contact time. Considering mesotrione no significant difference was experienced in toxicity. Regarding the EC50 values, all of the mixtures had synergistic joint effects in the acute assay. However, in the chronic test all the mixtures showed antagonistic responses with the exception of mesotrione and S-metolachlor (ratio 1:1) combination, which also had additive and synergistic effects after 10 and 15 h of exposure, similarly to the short-term test. This is also the first report of the joint effects of these herbicides. The chronic test is a more sensitive indicator to the active ingredients; both acute and chronic assays supply valuable data of the toxic properties of the pesticides. Moreover, the short- and long-term joint effects of their mixtures supporting a more accurate and reliable risk assessment.


Assuntos
Acetamidas/toxicidade , Aliivibrio fischeri/efeitos dos fármacos , Cicloexanonas/toxicidade , Herbicidas/toxicidade , Triazinas/toxicidade , Poluentes Químicos da Água/toxicidade , Acetamidas/química , Bioensaio , Cicloexanonas/química , Relação Dose-Resposta a Droga , Ecotoxicologia , Herbicidas/química , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Triazinas/química , Poluentes Químicos da Água/química
10.
J Agric Food Chem ; 67(45): 12558-12564, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31609622

RESUMO

All four stereoisomers of naturally occurring 6-(2-hydroxy-6-phenylhex-1-yl)-5,6-dihydro-2H-pyran-2-one (1) were synthesized by employing yeast-reduction products with high optical purity [from 95% enantiomeric excess (ee) to more than 99% ee], and then their phytotoxicities against lettuce and Italian ryegrass were evaluated. In the Italian ryegrass seedlings test, (6S,2'R)-1 showed the most potent and stereospecific activity against the shoots (IC50 = 260 µM) and roots (IC50 = 43.2 µM), with a significant difference from other stereoisomers. The highest seed germination inhibitory activity against Italian ryegrass seed was also observed in (6S,2'R)-1, showing a 53% germination ratio from the control at 1000 µM. This advantageous (6S,2'R) stereochemistry was employed in the syntheses of α,ß-dihydro, 2'-dehydroxy, and 2'-methoxy derivatives 13-15. By the test using these derivatives, the importance of the α,ß-unsaturated double bond and hydroxy group bonding to a chiral center on the 6-alkyl chain of 5,6-dihydro-α-pyrone for phytotoxicity was determined. In the test against lettuce, the 6S configuration and (6S,2'S) configuration were necessary for growth inhibition (IC50 = ca. 60 µM) and germination inhibition (63% germination ratio at 1000 µM), respectively.


Assuntos
Carbono/química , Herbicidas/farmacologia , Piranos/química , Carbono/farmacologia , Germinação/efeitos dos fármacos , Herbicidas/síntese química , Herbicidas/química , Alface/efeitos dos fármacos , Alface/crescimento & desenvolvimento , Lolium/efeitos dos fármacos , Lolium/crescimento & desenvolvimento , Estrutura Molecular , Piranos/farmacologia , Estereoisomerismo , Relação Estrutura-Atividade
11.
J Agric Food Chem ; 67(43): 11839-11847, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31589436

RESUMO

4-Hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) is an important target site for discovering new bleaching herbicides. To explore novel HPPD inhibitors with excellent herbicidal activity, a series of novel N-aroyl diketone/triketone derivatives were rationally designed by splicing active groups and bioisosterism. Bioassays revealed that most of these derivatives displayed preferable herbicidal activity against Echinochloa crus-galli (EC) at 0.045 mmol/m2 and Abutilon juncea (AJ) at 0.090 mmol/m2. In particular, compound I-f was more potent compared to the commercialized compound mesotrione. Molecular docking indicated that the corresponding active molecules of target compounds and mesotrione shared similar interplay with surrounding residues, which led to a perfect interaction with the active site of Arabidopsis thaliana HPPD.


Assuntos
4-Hidroxifenilpiruvato Dioxigenase/antagonistas & inibidores , Inibidores Enzimáticos/química , Herbicidas/química , Cetonas/química , Proteínas de Plantas/antagonistas & inibidores , 4-Hidroxifenilpiruvato Dioxigenase/química , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Domínio Catalítico , Echinochloa/efeitos dos fármacos , Echinochloa/enzimologia , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Herbicidas/síntese química , Herbicidas/farmacologia , Cetonas/farmacologia , Malvaceae/efeitos dos fármacos , Malvaceae/enzimologia , Simulação de Acoplamento Molecular , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/enzimologia , Relação Estrutura-Atividade
12.
J Agric Food Chem ; 67(45): 12538-12546, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31638796

RESUMO

Cyanobacteria harmful algal blooms are of global concern, but all currently available algicides in the market are nonselective and have potential side effects on nontarget species. In the present work, two series of compounds (4 and 6) comprising 16 novel 1,2,3-triazole aminopyrimidines were rationally designed and synthesized as control agent for cyanobacteria. Our design focus was the inhibiting cyanobacteria by inhibition against pyruvate dehydrogenase complex E1 (PDHc-E1). Compounds 4 and 6 showed potent inhibition against Escherichia coli PDHc-E1 (IC50 = 4.13-23.76 µM) and also strong algicidal activities against Synechocystis sp. PCC 6803 (EC50 = 1.7-8.1 µM) and Microcystis sp. FACHB905 (EC50 = 2.1-11.8 µM). In particular, the algicidal activities of 6d against four algal species were not only higher than that of prometryn; they were also comparable to or higher than that of copper sulfate. The analogues 4c, 4d, 6d, and 6e displayed potent algicidal activities and inhibition of E. coli PDHc-E1 but exhibited negligible inhibition of porcine PDHc-E1. As revealed by molecular docking, site-directed mutagenesis, enzymatic assays, and an inhibition kinetic analysis, 4c and 6d inhibited PDHc-E1 in a competitive manner. Our results suggest that highly selective, effective algicides can be developed by rationally designing competitive PDHc-E1 inhibitors.


Assuntos
Proteínas de Bactérias/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Herbicidas/farmacologia , Microcystis/efeitos dos fármacos , Pirimidinas/farmacologia , Piruvato Desidrogenase (Lipoamida)/antagonistas & inibidores , Synechocystis/efeitos dos fármacos , Triazóis/farmacologia , Proteínas de Bactérias/química , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Herbicidas/síntese química , Herbicidas/química , Cinética , Microcystis/química , Microcystis/enzimologia , Simulação de Acoplamento Molecular , Pirimidinas/química , Piruvato Desidrogenase (Lipoamida)/química , Relação Estrutura-Atividade , Synechocystis/química , Synechocystis/enzimologia , Triazóis/química
13.
Environ Pollut ; 255(Pt 1): 113150, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31541823

RESUMO

Excessive pesticide residues in the environment have caused more and more serious social problems. In this article, the polymer materials and graphene oxide were smoothly grafted together through surface-initiated atom-transfer radical polymerization. A temperature and pH dual-sensitive adsorbent was successfully obtained, which was used for the removal of six sulfonylurea herbicides in the aquatic environment. Experiment results showed that the adsorbent could efficiently remove the tested pesticides in aqueous solution rapidly (only 1 min). The adsorption process was in consist with the pseudo-second-order kinetics equation and Freundlich model, and the thermodynamic parameters were also calculated. Furthermore, the mechanism for removal performance was judged as n-π, π-π, hydrogen bonding, hydrophobic and electrostatic interaction verdict. Exhilaratingly, the material showed no significant toxicity to Daphnia magna on risk assessment.


Assuntos
Grafite/química , Herbicidas/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Animais , Daphnia/efeitos dos fármacos , Herbicidas/química , Herbicidas/toxicidade , Concentração de Íons de Hidrogênio , Cinética , Temperatura Ambiente , Termodinâmica , Poluentes Químicos da Água/química
14.
J Agric Food Chem ; 67(39): 10844-10852, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31525997

RESUMO

The discovery of 4-hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) inhibitors has been an active area of research due to their great potential as herbicides for weed control. Starting from the binding mode of known inhibitors of HPPD, a series of HPPD inhibitors with new molecular scaffolds were designed and synthesized by hybridizing 2-benzoylethen-1-ol and isoindoline-1,3-dione fragments. The results of the in vitro tests indicated that the newly synthesized compounds showed good HPPD inhibitory activity with IC50 values against the recombinant Arabidopsis thaliana HPPD (AtHPPD) ranging from 0.0039 µM to over 1 µM. Most promisingly, compound 4ae, 2-benzyl-5-(5-hydroxy-1,3-dimethyl-1H-pyrazole-4- carbonyl)isoindoline-1,3-dione, showed the highest AtHPPD inhibitory activity with a Ki value of 3.92 nM, making it approximately 10 times more potent than pyrasulfotole (Ki = 44 nM) and slightly more potent than mesotrione (Ki = 4.56 nM). In addition, the cocrystal structure of the AtHPPD-4ae complex was successfully resolved at a resolution of 1.8 Å. The X-ray diffraction analysis indicated that the two carbonyl groups of 2-benzoylethen-1-ol formed a bidentate chelating interaction with the metal ion, while the isoindoline-1,3-dione moiety formed pronounced π-π stacking interactions with Phe381 and Phe424. Moreover, water-mediated hydrogen bonding interactions were observed between Asn282 and the nitrogen atoms of the pyrazole ring of 4ae. The above results showed that the pyrazole-isoindoline-1,3-dione hybrid is a promising scaffold for developing HPPD inhibitors.


Assuntos
4-Hidroxifenilpiruvato Dioxigenase/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Herbicidas/farmacologia , Isoindóis/farmacologia , Proteínas de Plantas/antagonistas & inibidores , Pirazóis/farmacologia , 4-Hidroxifenilpiruvato Dioxigenase/química , 4-Hidroxifenilpiruvato Dioxigenase/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/crescimento & desenvolvimento , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Herbicidas/síntese química , Herbicidas/química , Isoindóis/química , Cinética , Estrutura Molecular , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Daninhas/efeitos dos fármacos , Plantas Daninhas/crescimento & desenvolvimento , Pirazóis/química , Relação Estrutura-Atividade
15.
Sci Total Environ ; 692: 723-731, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31539980

RESUMO

The enantioselective effects of imazethapyr (IM) enantiomers on wheat seedlings in a hydroponic medium were studied. R-IM at 0.05mg/L exerted a stronger inhibitory effect on shoot weight and root weight than 0.05mg/L S-IM, suggesting that R-IM more severely inhibited growth. Oxidative damage, based on the anthocyanin content, malondialdehyde (MDA) content, antioxidant enzyme activities and transcript levels of antioxidant enzyme genes, were studied together with the cellular ultrastructure of wheat leaves. The anthocyanin and MDA contents in the R-IM treatment group were significantly increased compared with those in the control group, but no significant changes were observed in the S-IM treatment group. The antioxidant enzyme activities of CAT and SOD were inhibited by 0.32- and 0.73-fold, respectively, in the 14day R-IM treatment group compared to those in the control. However, the transcript levels of antioxidant enzyme genes, including CuZnSOD, POD and CAT, were downregulated in the 14day R-IM exposure group, but those of DHAR were not. The number and size of starch granules increased and chloroplast swelling was observed in wheat leaf cells after R-IM exposure, which showed that photosynthetic functions were potentially disturbed. These results directly or indirectly imply that R-IM exposure causes more oxidative stress and exerts a stronger negative effect on wheat than S-IM. A metabolomics approach revealed that the tricarboxylic acid cycle was heavily suppressed by R-IM treatment. Some amino acids (proline, threonine, lysine, valine) were increased by only the R-IM treatment, indicating the activation of antioxidant pathways. The decrease in a series of fatty acids implied that the cell membrane composition changed in response to R-IM. These results provide a deeper understanding of the enantioselective effects of IM enantiomers on the molecular and metabolic responses in wheat seedlings.


Assuntos
Herbicidas/efeitos adversos , Ácidos Nicotínicos/efeitos adversos , Triticum/efeitos dos fármacos , Herbicidas/química , Ácidos Nicotínicos/química , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/metabolismo , Estereoisomerismo , Triticum/genética , Triticum/metabolismo
16.
Artigo em Inglês | MEDLINE | ID: mdl-31479387

RESUMO

An extraction method based on metal-organic framework has been developed and applied to acetanilide herbicides, including metazachlor, propanil, pretilachlor, and butachlor, in black beans, red beans, and kidney beans. The acetanilide herbicides are extracted with a mixture of ethyl acetate and n-hexane. The extract solution is absorbed and purified with metal-organic framework MIL-101 (Zn). The separation and determination of four acetanilide herbicides were implemented by high-performance liquid chromatography. The experimental parameters were evaluated by a univariate method and orthogonal experiments. The presented method can obtain effective extraction and purification. The detection limits for metazachlor, propanil, pretilachlor, and butachlor were 0.58, 0.90, 1.78 and 1.18 µg/kg, respectively. The average recoveries of the acetanilide herbicides at spiked concentrations of 10, 50, and 100 µg/kg ranged from 86.9% to 119.0%, and relative standard deviations were equal to or lower than 2.80%.


Assuntos
Acetanilidas/isolamento & purificação , Herbicidas/isolamento & purificação , Estruturas Metalorgânicas/química , Acetanilidas/química , Acetatos/química , Adsorção , Animais , Canavalia/química , Herbicidas/química , Hexanos/química , Tamanho da Partícula , Phaseolus/química
17.
Molecules ; 24(17)2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31484319

RESUMO

A novel synthetic strategy for obtainment of (±)-3-deoxyradicinin (2) is reported. This synthetic methodology is more efficient than those previously reported in the literature and also shows higher versatility towards the introduction of different side-chains at both C-7 and C-2. The obtained compound (±)-2 shows phytotoxicity against the grass-weed buffelgrass comparable to that of the natural phytotoxin radicinin (1). Therefore, (±)-2 can constitute a more practical synthetic alternative to 1 as bioherbicide for buffelgrass control.


Assuntos
Cenchrus/efeitos dos fármacos , Herbicidas/síntese química , Herbicidas/farmacologia , Pironas/metabolismo , Herbicidas/química
18.
J Environ Sci (China) ; 85: 66-73, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471032

RESUMO

Arsenic (As) mobilization in soils is a fundamental step controlling its transport and fate, especially in the presence of the co-existing components. In this study, the effect of two commonly used herbicides, glyphosate (PMG) and dicamba, and two competing ions including phosphate and humic acid, on As desorption and release was investigated using batch and column experiments. The batch kinetics results showed that As desorption in the presence of competing factors conformed to the pseudo-second order kinetics at pH range of 5-9. The impact of phosphate on desorption was greatest, followed by PMG. The competitive effect of dicamba and humic acid was at the same level with electrolyte solution. In situ flow cell ATR-FTIR analysis was performed to explore the mechanism of phosphate and PMG impact on As mobilization. The results showed that PMG promoted As(III) desorption by competiting for available adsorption sites with no change in As(III) complexing structure. On the other hand, phophate changed As(III) surface complexes from bidentate to monodentate structures, exhibiting the most siginficant effect on As(III) desorption. As(V) surface complexes remained unchanged in the presence of PMG and phosphate, implying that the competitive effect for As(V) desorption was primarily determined by the available adsorption sites. Long-term (10 days) soil column experiments suggested that the effect of humic acid on As mobilization became pronounced from 3 days (18 PVs). The insights of this study help us understand the transport and fate of As due to herbicides application.


Assuntos
Arsênico/química , Herbicidas/química , Poluentes do Solo/química , Adsorção , Substâncias Húmicas , Cinética , Solo/química
19.
Chemosphere ; 237: 124513, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31401429

RESUMO

The ability of contaminated farmland soils reclaimed by remediation to dissipate pesticides and thus to mitigate their unwanted environmental effects, i.e., leaching and run-off, was studied. Novel EDTA-based soil washing technology (EDTA and process waters recycling; no toxic emissions) removed 79 and 73% of Pb from acidic and calcareous soil with 740 and 2179 mg kg-1 Pb, respectively. The dissipation kinetics of four herbicides: mecoprop-P, isoproturon, bentazon and S-metolachlor was investigated under field conditions in beds with maize (Zea mays) and barley (Hordeum vulgare). The biphasic First-Order Multi-Compartment (FOMC) model was used to fit experimental data and calculate the herbicides' half-life (DT50) in soil. Remediation significantly (up to 64%) decreased dehydrogenase activity assessed as a marker of soil microbial activity and prolonged the DT50 of herbicides in acidic soils from 16% (isoproturon) to 111% (S-metachlor). Remediation had a less significant effect on herbicide dissipation in calcareous soils; i.e., mecoprop-P DT50 increased by 3%, while isoproturon and S-metachlor DT50 decreased by 29%. Overall, the dissipation from remediated soils was faster than the average DT50 of tested herbicides published in the Pesticides Properties DataBase. Results demonstrate that EDTA-based remediation of the studied soils does not pose any threat of extended herbicide persistence.


Assuntos
Ácido Edético/química , Herbicidas/análise , Metais Pesados/análise , Poluentes do Solo/análise , Ácido 2-Metil-4-clorofenoxiacético/análogos & derivados , Ácido 2-Metil-4-clorofenoxiacético/análise , Ácido 2-Metil-4-clorofenoxiacético/química , Acetamidas/análise , Acetamidas/química , Benzotiadiazinas/análise , Benzotiadiazinas/química , Recuperação e Remediação Ambiental , Herbicidas/química , Metais Pesados/química , Compostos de Fenilureia/análise , Compostos de Fenilureia/química , Solo/química , Microbiologia do Solo , Poluentes do Solo/química , Zea mays
20.
J Environ Sci Health B ; 54(8): 681-692, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31403392

RESUMO

Although there are many reports on the dangers posed by glyphosate, this herbicide is still one of the most popular and widely used total weed killers. Therefore, great effort should be made to minimize exposure to this herbicide and limit its losses into the environment. The aim of this study was to prepare a new formulation consisted of various molecular weight chitosans with glyphosate and their evaluation toward active substance release, phytotoxicity, and preliminary herbicidal efficiency. The phytotoxicity study of the obtained chitosan/glyphosate formulations was determined based on the Organisation for Economic Co-operation and Development 208 guideline. Among all tested formulations evaluated for phytotoxicity, that containing the highest molecular weight of chitosan was found to be the least toxic, showing simultaneously the most effective herbicidal activity against selected weeds. The release rate of glyphosate from the obtained formulations was dependent on the molecular weight and viscosity of chitosan.


Assuntos
Quitosana/química , Glicina/análogos & derivados , Herbicidas/química , Herbicidas/farmacologia , Quitosana/farmacologia , Glicina/química , Glicina/farmacocinética , Glicina/farmacologia , Herbicidas/farmacocinética , Peso Molecular , Plantas Daninhas/efeitos dos fármacos
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