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1.
BMC Microbiol ; 24(1): 231, 2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-38951812

RESUMO

BACKGROUND: Natural products are important sources for the discovery of new biopesticides to control the worldwide destructive pests Acyrthosiphon pisum Harris. Here, insecticidal substances were discovered and characterized from the secondary metabolites of the bio-control microorganism Bacillus velezensis strain ZLP-101, as informed by whole-genome sequencing and analysis. RESULTS: The genome was annotated, revealing the presence of four potentially novel gene clusters and eight known secondary metabolite synthetic gene clusters. Crude extracts, prepared through ammonium sulfate precipitation, were used to evaluate the effects of strain ZLP-101 on Acyrthosiphon pisum Harris aphid pests via exposure experiments. The half lethal concentration (LC50) of the crude extract from strain ZLP-101 against aphids was 411.535 mg/L. Preliminary exploration of the insecticidal mechanism revealed that the crude extract affected aphids to a greater extent through gastric poisoning than through contact. Further, the extracts affected enzymatic activities, causing holes to form in internal organs along with deformation, such that normal physiological activities could not be maintained, eventually leading to death. Isolation and purification of extracellular secondary metabolites were conducted in combination with mass spectrometry analysis to further identify the insecticidal components of the crude extracts. A total of 15 insecticidal active compounds were identified including iturins, fengycins, surfactins, and spergualins. Further insecticidal experimentation revealed that surfactin, iturin, and fengycin all exhibited certain aphidicidal activities, and the three exerted synergistic lethal effects. CONCLUSIONS: This study improved the available genomic resources for B. velezensis and serves as a foundation for comprehensive studies of the insecticidal mechanism by Bacillus velezensis ZLP-101 in addition to the active components within biological control strains.


Assuntos
Afídeos , Bacillus , Inseticidas , Lipopeptídeos , Animais , Afídeos/efeitos dos fármacos , Bacillus/genética , Bacillus/metabolismo , Lipopeptídeos/farmacologia , Lipopeptídeos/química , Lipopeptídeos/metabolismo , Lipopeptídeos/isolamento & purificação , Inseticidas/farmacologia , Inseticidas/metabolismo , Inseticidas/química , Família Multigênica , Metabolismo Secundário , Controle Biológico de Vetores , Sequenciamento Completo do Genoma , Genoma Bacteriano/genética
2.
Molecules ; 29(12)2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38930942

RESUMO

Naturally occurring substances and their derivatives function as vital resources for pesticides that can be used in fields, such as insecticide production and fungicide development. As a botanical entity displaying multifaceted biological functions, wormwood has received thorough scrutiny across multiple sectors. The insect repellency potency combined with antibacterial and antifungal activities of wormwood position it as a potential candidate for prospective development into eco-friendly chemical pesticides. In this research, Wormwood essential oil was procured via ethanol water under ultrasonic scenarios and subsequently diluted with PEG 400 to formulate green chemical pesticides. The defensive efficacy of this green pesticide on plants was validated through 2 weeks of clustered plant growth experiments. Active constituents that exerted their effects were scrutinized by GC-MS. Furthermore, this green pesticide also displays efficacious effects on the prevention and management of aphids, exhibiting a dose-dependent relationship. 4-terpenol, eucalyptol, carvacrol, and L-borneol were identified by GC-MS as the predominant active constituents in this green chemical pesticide. Wormwood can be leveraged to develop green chemical pesticides, which can protect plants without contaminating the environment.


Assuntos
Inseticidas , Óleos Voláteis , Inseticidas/química , Inseticidas/farmacologia , Animais , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Cimenos/química , Cimenos/farmacologia , Química Verde/métodos , Afídeos/efeitos dos fármacos , Eucaliptol/química , Eucaliptol/farmacologia , Canfanos
3.
Pestic Biochem Physiol ; 202: 105958, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38879340

RESUMO

The wheat aphid Sitobion miscanthi is a dominant and destructive pest in agricultural production. Insecticides are the main substances used for effective control of wheat aphids. However, their extensive application has caused severe resistance of wheat aphids to some insecticides; therefore, exploring resistance mechanisms is essential for wheat aphid management. In the present study, CYP6CY2, a new P450 gene, was isolated and overexpressed in the imidacloprid-resistant strain (SM-R) compared to the imidacloprid-susceptible strain (SM-S). The increased sensitivity of S. miscanthi to imidacloprid after knockdown of CYP6CY2 indicates that it could be associated with imidacloprid resistance. Subsequently, the posttranscriptional regulation of CYP6CY2 in the 3' UTR by miR-3037 was confirmed, and CYP6CY2 participated in imidacloprid resistance. This finding is critical for determining the role of P450 in relation to the resistance of S. miscanthi to imidacloprid. It is of great significance to understand this regulatory mechanism of P450 expression in the resistance of S. miscanthi to neonicotinoids.


Assuntos
Afídeos , Sistema Enzimático do Citocromo P-450 , Resistência a Inseticidas , Inseticidas , MicroRNAs , Neonicotinoides , Nitrocompostos , Neonicotinoides/farmacologia , Nitrocompostos/farmacologia , Animais , Inseticidas/farmacologia , Resistência a Inseticidas/genética , Afídeos/genética , Afídeos/efeitos dos fármacos , MicroRNAs/genética , MicroRNAs/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Imidazóis/farmacologia
4.
J Agric Food Chem ; 72(25): 14141-14151, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38864686

RESUMO

The cotton aphid, Aphis gossypii, is a polyphagous pest that stunts host plant growth via direct feeding or transmitting plant virus. Due to the long-term application of insecticides, A. gossypii has developed different levels of resistance to numerous insecticides. We found that five field populations had evolved multiple resistances to neonicotinoids. To explore the resistance mechanism mediated by uridine diphosphate glycosyltransferases (UGTs), two upregulated UGT genes in these five strains, UGT350C3 and UGT344L7, were selected for functional analysis of their roles in neonicotinoid detoxification. Transgenic Drosophila bioassay results indicated that compared with the control lines, the UGT350C3 and UGT344L7 overexpression lines were more tolerant to thiamethoxam, imidacloprid, and dinotefuran. Knockdown of UGT350C3 and UGT344L7 significantly increased A. gossypii sensitivity to thiamethoxam, imidacloprid, and dinotefuran. Molecular docking analysis demonstrated that these neonicotinoids could bind to the active pockets of UGT350C3 and UGT344L7. This study provides functional evidence of neonicotinoid detoxification mediated by UGTs and will facilitate further work to identify strategies for preventing the development of neonicotinoid resistance in insects.


Assuntos
Afídeos , Glicosiltransferases , Resistência a Inseticidas , Inseticidas , Neonicotinoides , Nitrocompostos , Animais , Afídeos/genética , Afídeos/enzimologia , Afídeos/efeitos dos fármacos , Neonicotinoides/farmacologia , Neonicotinoides/metabolismo , Neonicotinoides/química , Inseticidas/farmacologia , Inseticidas/química , Inseticidas/metabolismo , Resistência a Inseticidas/genética , Glicosiltransferases/genética , Glicosiltransferases/metabolismo , Glicosiltransferases/química , Nitrocompostos/farmacologia , Nitrocompostos/metabolismo , Simulação de Acoplamento Molecular , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Proteínas de Insetos/química , Tiametoxam , Drosophila/genética , Drosophila/enzimologia , Drosophila/efeitos dos fármacos , Drosophila/metabolismo , Guanidinas
5.
Pestic Biochem Physiol ; 202: 105957, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38879339

RESUMO

Sitobion miscanthi is a destructive wheat pest responsible for significant wheat yield losses. Pirimicarb, one of the most important representatives of N, N-dimethylcarbamate insecticides, is widely used to control wheat aphids. In present work, heterozygous S431F mutation of acetylcholinesterase 1 (AChE1) was identified and verified in three pirimicarb-resistant S. miscanthi populations (two field populations (HA and HS, >955.8-fold) and one lab-selected population (PirR, 486.1-fold)), which has not been reported in S. miscanthi yet. The molecular docking results revealed that AChE1 containing the S431F mutation of S. miscanthi (SmAChE1S431F) showed higher free binding energy to three insecticides (pirimicarb, omethoate, and methomyl) than wild-type AChE1 of S. miscanthi (SmAChE1). Enzyme kinetic and inhibition experiments showed that the recombinant SmAChE1S431F was more insensitive to pirimicarb and omethoate than the recombinant SmAChE1. Furthermore, two overexpression P450 genes (CYP6K1 and CYP6A14) associated with pirimicarb resistance of S. miscanthi were verified by RNAi. These results suggested both target alteration and enhanced metabolism contributed to high pirimicarb resistance of S. miscanthi in the field and laboratory. These findings lay a foundation for further elucidating the mechanism of pirimicarb resistance in S. miscanthi, and have important implications for the resistance management of S. miscanthi control.


Assuntos
Acetilcolinesterase , Afídeos , Carbamatos , Sistema Enzimático do Citocromo P-450 , Resistência a Inseticidas , Inseticidas , Mutação , Acetilcolinesterase/genética , Acetilcolinesterase/metabolismo , Animais , Resistência a Inseticidas/genética , Afídeos/genética , Afídeos/efeitos dos fármacos , Inseticidas/farmacologia , Carbamatos/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Pirimidinas/farmacologia , Simulação de Acoplamento Molecular , Triticum/genética , Dimetoato/análogos & derivados
6.
J Agric Food Chem ; 72(27): 15142-15150, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38926152

RESUMO

Celangulin V is a novel botanical insecticide with significant bioactivity and a unique molecular target, but its complex polyol ester structure hinders its broader application in agriculture. To discover new analogues of celangulin V with a simpler structure and enhanced biological activities, we initiated a research project aimed at simplifying its structure and assessing insecticidal efficacy. In this study, a series of novel 1-tetralone derivatives were designed via a structure-based rational design approach and synthesized by a facile method. The biological activities of the target compounds were determined against Mythimna separata (M. separata), Plutella xylostella, and Rhopalosiphum padi. The results revealed that most of the synthesized compounds exhibited superior activities compared to celangulin V. Remarkably, the insecticidal activity of compound 6.16 demonstrated 102-fold greater stomach toxicity than celangulin V against M. separata. In addition, certain compounds showed significant contact toxicity against M. separata, a finding not reported previously in the structural optimization studies of celangulin V. Molecular docking analysis illustrated that the binding pocket of compound 6.16 with the H subunit of V-ATPase was the same as celangulin V. This study presents novel insights into the structural optimization of botanical pesticides.


Assuntos
Desenho de Fármacos , Inseticidas , Simulação de Acoplamento Molecular , Mariposas , Inseticidas/química , Inseticidas/farmacologia , Inseticidas/síntese química , Animais , Mariposas/efeitos dos fármacos , Relação Estrutura-Atividade , Afídeos/efeitos dos fármacos , Estrutura Molecular , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Proteínas de Insetos/química , Haptenos
7.
J Agric Food Chem ; 72(27): 15276-15283, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38943575

RESUMO

Using nicofluprole as the lead compound, we designed and synthesized a series of new phenylpyrazole analogues through substituting the methyl group on the nitrogen atom of the amide with an acyl group. Bioassay results showed that compounds A12-A17 with a 1-cyanocyclopropimide group exhibited outstanding insecticidal activity. The LC50 values for compounds A12-A17 against Tetranychus cinnabarinus ranged from 0.58 to 0.91 mg/L. Compound A15 showed an LC50 value of 0.29 and 3.10 mg/L against Plutella xylostella and Myzus persicae, respectively. Molecular docking indicated the potential binding interactions of compound A15 with a gamma-aminobutyric acid receptor. Additionally, density functional theory calculations implied that the 1-cyanocyclopropimide structure might be essential for its biological activity. Phenylpyrazole derivatives, containing a 1-cyanocyclopropimide fragment, have the potential for further development as potential insecticides.


Assuntos
Acaricidas , Desenho de Fármacos , Inseticidas , Simulação de Acoplamento Molecular , Pirazóis , Animais , Pirazóis/química , Pirazóis/farmacologia , Pirazóis/síntese química , Acaricidas/química , Acaricidas/farmacologia , Acaricidas/síntese química , Inseticidas/química , Inseticidas/farmacologia , Inseticidas/síntese química , Relação Estrutura-Atividade , Imidas/química , Imidas/farmacologia , Imidas/síntese química , Afídeos/efeitos dos fármacos , Mariposas/efeitos dos fármacos , Tetranychidae/efeitos dos fármacos , Estrutura Molecular
8.
J Agric Food Chem ; 72(21): 11949-11957, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38757770

RESUMO

As the first marketed phenylpyrazole insecticide, fipronil exhibited remarkable broad-spectrum insecticidal activity. However, it poses a significant threat to aquatic organisms and bees due to its high toxicity. Herein, 35 phenylpyrazole derivatives containing a trifluoroethylthio group on the 4 position of the pyrazole ring were designed and synthesized. The predicted physicochemical properties of all of the compounds were within a reasonable range. The biological assay results revealed that compound 7 showed 69.7% lethality against Aedes albopictus (A. albopictus) at the concentration of 0.125 mg/L. Compounds 7, 7g, 8d, and 10j showed superior insecticidal activity for the control of Plutella xylostella (P. xylostella). Notably, compound 7 showed similar insecticidal activity against Aphis craccivora (A. craccivora) compared with fipronil. Potential surface calculation and molecular docking suggested that different lipophilicity and binding models to the Musca domestica (M. domestica) gamma-aminobutyric acid receptors may be responsible for the decreased activity of the tested derivatives. Toxicity tests indicated that compound 8d (LC50 = 14.28 mg/L) induced obviously 14-fold lower toxicity than fipronil (LC50 = 1.05 mg/L) on embryonic-juvenile zebrafish development.


Assuntos
Aedes , Desenho de Fármacos , Moscas Domésticas , Inseticidas , Simulação de Acoplamento Molecular , Pirazóis , Animais , Inseticidas/química , Inseticidas/síntese química , Inseticidas/farmacologia , Pirazóis/química , Pirazóis/farmacologia , Pirazóis/síntese química , Aedes/efeitos dos fármacos , Aedes/crescimento & desenvolvimento , Relação Estrutura-Atividade , Moscas Domésticas/efeitos dos fármacos , Moscas Domésticas/crescimento & desenvolvimento , Afídeos/efeitos dos fármacos , Afídeos/crescimento & desenvolvimento , Mariposas/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Estrutura Molecular , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Peixe-Zebra/embriologia
9.
J Agric Food Chem ; 72(21): 11968-11979, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38759145

RESUMO

With the aim of identifying novel neonicotinoid insecticides with low bee toxicity, a series of compounds bearing thiazolidine moiety, which has been shown to be low bee toxic, were rationally designed through substructure splicing strategy and evaluated insecticidal activities. The optimal compounds A24 and A29 exhibited LC50 values of 30.01 and 17.08 mg/L against Aphis craccivora, respectively. Electrophysiological studies performed on Xenopus oocytes indicated that compound A29 acted on insect nAChR, with EC50 value of 50.11 µM. Docking binding mode analysis demonstrated that A29 bound to Lymnaea stagnalis acetylcholine binding protein through H-bonds with the residues of D_Arg55, D_Leu102, and D_Val114. Quantum mechanics calculation showed that A29 had a higher highest occupied molecular orbit (HOMO) energy and lower vertical ionization potential (IP) value compared to the high bee toxic imidacloprid, showing potentially low bee toxicity. Bee toxicity predictive model also indicated that A29 was nontoxic to honeybees. Our present work identified an innovative insecticidal scaffold and might facilitate the further exploration of low bee toxic neonicotinoid insecticides.


Assuntos
Inseticidas , Neonicotinoides , Tiazolidinas , Animais , Inseticidas/química , Inseticidas/toxicidade , Abelhas/efeitos dos fármacos , Neonicotinoides/química , Neonicotinoides/toxicidade , Tiazolidinas/química , Tiazolidinas/toxicidade , Simulação de Acoplamento Molecular , Proteínas de Insetos/genética , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Proteínas de Insetos/toxicidade , Afídeos/efeitos dos fármacos , Afídeos/genética , Relação Estrutura-Atividade , Estrutura Molecular , Receptores Nicotínicos/genética , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/química
10.
J Agric Food Chem ; 72(20): 11331-11340, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38721769

RESUMO

Research on mesoionic structures in pesticide design has gained significant attention in recent years. However, the 1-position of pyridino[1,2-a]pyrimidine is usually designed with 2-chlorothiazole, 2-chloropyridine, or cyano moieties commonly found in neonicotinoid insecticides. In order to enrich the available pharmacophore library, here, we disclose a series of new pyridino[1,2-a]pyrimidine mesoionics bearing indole-containing substituents at the 1-position. Most of these target compounds are confirmed to have good insecticidal activity against aphids through bioevaluation. In addition, a three-dimensional structure-activity relationship model is established to allow access to optimal compound F45 with an LC50 value of 2.97 mg/L. This value is comparable to the property achieved by the positive control triflumezopyrim (LC50 = 2.94 mg/L). Proteomics and molecular docking analysis suggest that compound F45 has the potential to modulate the functioning of the aphid nervous system through its interaction with neuronal nicotinic acetylcholine receptors. This study expands the existing pharmacophore library for the future development of new mesoionic insecticides based on 1-position modifications of the pyridino[1,2-a]pyrimidine scaffold.


Assuntos
Afídeos , Desenho de Fármacos , Indóis , Inseticidas , Simulação de Acoplamento Molecular , Pirimidinas , Inseticidas/química , Inseticidas/síntese química , Inseticidas/farmacologia , Animais , Pirimidinas/química , Pirimidinas/farmacologia , Pirimidinas/síntese química , Afídeos/efeitos dos fármacos , Indóis/química , Indóis/farmacologia , Indóis/síntese química , Relação Estrutura-Atividade , Estrutura Molecular , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/química , Receptores Nicotínicos/efeitos dos fármacos
11.
J Agric Food Chem ; 72(23): 12925-12934, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38809684

RESUMO

Potato virus Y (PVY) relies on aphids and tubers to spread in the field and causes serious economic losses in the potato industry. Here, we found that pyrido[1,2-α] pyrimidinone mesoionic compounds with insecticidal activity against aphids possessed a good inhibitory effect on PVY. Among them, compound 35 had the best inhibitory activity against PVY (EC50 = 104 µg/mL), even superior to that of ningnanmycin (125 µg/mL). The fluorescence and qPCR results confirmed that compound 35 could inhibit the proliferation of PVY in Nicotiana benthamiana. Preliminary experiments on the mechanism of action indicated that compound 35 had good binding affinity with the coat protein (CP), which plays an essential role in aphid-PVY interactions. Molecular docking revealed that compound 35 could bind to the pocket of CP formed by Ser52, Glu204, and Arg208. Compound 35 had substantially lower binding affinity (Kd) values with CPS52A (219 µM), CPE204A (231 µM), and CPR208A (189 µM) than those with CPWT (5.80 µM). A luciferase assay confirmed that mutating Ser52, Glu204, and Arg208 significantly affected the expression level of CP and further reduced virus proliferation. Therefore, the broad-spectrum activity of compound 35 provides a unique strategy for the prevention and treatment of PVY.


Assuntos
Antivirais , Afídeos , Simulação de Acoplamento Molecular , Nicotiana , Doenças das Plantas , Potyvirus , Afídeos/efeitos dos fármacos , Antivirais/farmacologia , Antivirais/química , Animais , Doenças das Plantas/virologia , Doenças das Plantas/prevenção & controle , Potyvirus/efeitos dos fármacos , Potyvirus/genética , Potyvirus/química , Nicotiana/virologia , Pirimidinonas/farmacologia , Pirimidinonas/química , Inseticidas/química , Inseticidas/farmacologia , Solanum tuberosum/química , Solanum tuberosum/virologia , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/química , Relação Estrutura-Atividade
12.
J Agric Food Chem ; 72(23): 12956-12966, 2024 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-38820064

RESUMO

Bees, one of the most vital pollinators in the ecosystem and agriculture, are currently threatened by neonicotinoids. To explore the molecular mechanisms of neonicotinoid toxicity to bees, the different binding modes of imidacloprid, thiacloprid, and flupyradifurone with nicotinic acetylcholine receptor (nAChR) α1ß1 and cytochrome P450 9Q3 (CYP9Q3) were studied using homology modeling and molecular dynamics simulations. These mechanisms provided a basis for the design of compounds with a potential low bee toxicity. Consequently, we designed and synthesized a series of triazinone derivatives and assessed their bioassays. Among them, compound 5a not only displayed substantially insecticidal activities against Aphis glycines (LC50 = 4.40 mg/L) and Myzus persicae (LC50 = 6.44 mg/L) but also had low toxicity to Apis mellifera. Two-electrode voltage clamp recordings further confirmed that compound 5a interacted with the M. persicae nAChR α1 subunit but not with the A. mellifera nAChR α1 subunit. This work provides a paradigm for applying molecular toxic mechanisms to the design of compounds with low bee toxicity, thereby aiding the future rational design of eco-friendly nicotinic insecticides.


Assuntos
Proteínas de Insetos , Inseticidas , Neonicotinoides , Receptores Nicotínicos , Abelhas/efeitos dos fármacos , Animais , Inseticidas/química , Inseticidas/toxicidade , Neonicotinoides/química , Neonicotinoides/toxicidade , Neonicotinoides/metabolismo , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/química , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Afídeos/efeitos dos fármacos , Nitrocompostos/química , Nitrocompostos/toxicidade , Desenho de Fármacos , Sistema Enzimático do Citocromo P-450/metabolismo , Sistema Enzimático do Citocromo P-450/química , Simulação de Dinâmica Molecular , Ligação Proteica , Tiazinas
13.
Int J Mol Sci ; 25(9)2024 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-38732039

RESUMO

Hesperidin is a highly bioactive natural flavonoid whose role in ecological interactions is poorly known. In particular, the effects of hesperidin on herbivores are rarely reported. Flavonoids have been considered as prospective biopesticides; therefore, the aim of the present study was to examine the influence of hesperidin on the host plant selection behavior of three aphid (Hemiptera: Aphididae) species: Acyrthosiphon pisum Harrris, Rhopalosiphum padi (L.), and Myzus persicae (Sulz.). The aphid host plants were treated with 0.1% and 0.5% ethanolic solutions of hesperidin. Aphid probing behavior in the no-choice experiment was monitored using electropenetrography and aphid settling on plants in the choice experiment was recorded. The results demonstrated that hesperidin can be applied as a pre-ingestive, ingestive, and post-ingestive deterrent against A. pisum, as an ingestive deterrent against R. padi, and as a post-ingestive deterrent against M. persicae using the relatively low 0.1% concentration. While in A. pisum the deterrent effects of hesperidin were manifested as early as during aphid probing in peripheral plant tissues, in M. persicae, the avoidance of plants was probably the consequence of consuming the hesperidin-containing phloem sap.


Assuntos
Afídeos , Hesperidina , Afídeos/efeitos dos fármacos , Afídeos/fisiologia , Animais , Hesperidina/farmacologia , Hesperidina/química , Especificidade da Espécie , Comportamento Alimentar/efeitos dos fármacos , Herbivoria/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos
14.
Sci Rep ; 14(1): 9392, 2024 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658769

RESUMO

A series of arecoline derivatives with amino acid moieties were designed and synthesised using an acylamide condensation strategy, taking arecoline as the foundational structure. The insecticidal efficacy of these compounds against Aphis craccivora and Tetranychus cinnabarinus was evaluated. Notably, derivatives 3h and 3i demonstrated superior insecticidal activity compared with arecoline. Additionally, 3h and 3i showed good fungicidal effectiveness against two types of plant fungi. Moreover, molecular docking analyses suggested that 3h and 3i could affect the nervous systems of A. craccivora and T. cinnabarinus by binding to neuronal nicotinic acetylcholine receptors. These findings suggest that compounds 3h and 3i represent promising leads for further development in insecticide and fungicide research.


Assuntos
Aminoácidos , Antifúngicos , Desenho de Fármacos , Inseticidas , Simulação de Acoplamento Molecular , Inseticidas/farmacologia , Inseticidas/síntese química , Inseticidas/química , Animais , Antifúngicos/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Aminoácidos/química , Afídeos/efeitos dos fármacos , Tetranychidae/efeitos dos fármacos , Relação Estrutura-Atividade , Receptores Nicotínicos/metabolismo , Receptores Nicotínicos/química , Testes de Sensibilidade Microbiana
15.
Arch Insect Biochem Physiol ; 115(4): e22112, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38605672

RESUMO

Insect trehalases have been identified as promising new targets for pest control. These key enzymes are involved in trehalose hydrolysis and plays an important role in insect growth and development. In this contribution, plant and microbial compounds, namely validamycin A, amygdalin, and phloridzin, were evaluated for their effect, through trehalase inhibition, on Acyrthosiphon pisum aphid. The latter is part of the Aphididae family, main pests as phytovirus vectors and being very harmful for crops. Validamycin A was confirmed as an excellent trehalase inhibitor with an half maximal inhibitory concentration and inhibitor constant of 2.2 × 10-7 and 5 × 10-8 M, respectively, with a mortality rate of ~80% on a A. pisum population. Unlike validamycin A, the insect lethal efficacy of amygdalin and phloridzin did not correspond to their trehalase inhibition, probably due to their hydrolysis by insect ß-glucosidases. Our docking studies showed that none of the three compounds can bind to the trehalase active site, unlike their hydrolyzed counterparts, that is, validoxylamine A, phloretin, and prunasin. Validoxylamine A would be by far the best trehalase binder, followed by phloretin and prunasin.


Assuntos
Afídeos , Trealase , Animais , Amigdalina , Afídeos/efeitos dos fármacos , Afídeos/enzimologia , Inositol/análogos & derivados , Nitrilas , Floretina , Florizina , Trealase/antagonistas & inibidores
16.
Ecotoxicol Environ Saf ; 276: 116291, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38581910

RESUMO

Myzus persicae is an important pest that has developed resistance to nearly all currently used insecticidal products. The employment of insecticide synergists is one of the effective strategies that need to be developed for the management of this resistance. Our study showed that treatment with a combination of the antibiotic, rifampicin, with imidacloprid, cyantraniliprole, or clothianidin significantly increased their toxicities against M. persicae, by 2.72, 3.59, and 2.41 folds, respectively. Rifampicin treatment led to a noteworthy reduction in the activities of multifunctional oxidases (by 32.64%) and esterases (by 23.80%), along with a decrease in the expression of the CYP6CY3 gene (by 58.57%) in M. persicae. It also negatively impacted the fitness of the aphids, including weight, life span, number of offspring, and elongation of developmental duration. In addition, bioassays showed that the combination of rifampicin and a detoxification enzyme inhibitor, piperonyl butoxide, or dsRNA of CYP6CY3 further significantly improved the toxicity of imidacloprid against M. persicae, by 6.19- and 7.55-fold, respectively. The present study suggests that development of active ingredients such as rifampicin as candidate synergists, show promise to overcome metabolic resistance to insecticides in aphids.


Assuntos
Afídeos , Guanidinas , Inseticidas , Neonicotinoides , Nitrocompostos , Butóxido de Piperonila , Rifampina , Tiazóis , Animais , Rifampina/toxicidade , Rifampina/farmacologia , Afídeos/efeitos dos fármacos , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Tiazóis/toxicidade , Guanidinas/toxicidade , Butóxido de Piperonila/toxicidade , Pirazóis/toxicidade , Sinergismo Farmacológico , Resistência a Inseticidas/genética , Sinergistas de Praguicidas/toxicidade , ortoaminobenzoatos/toxicidade , Esterases/metabolismo
17.
Pestic Biochem Physiol ; 201: 105894, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38685221

RESUMO

Rhopalosiphum padi is a global pest that poses a significant threat to wheat crops and has developed resistance to various insecticides. G protein-coupled receptors (GPCRs), known for their crucial role in signaling and biological processes across insect species, have recently gained attention as a potential target for insecticides. GPCR has the potential to contribute to insect resistance through the regulation of P450 gene expression. However, GPCRs in R. padi remained unexplored until this study. We identified a total of 102 GPCRs in R. padi, including 81 receptors from family A, 10 receptors from family B, 8 receptors from family C, and 3 receptors from family D. Among these GPCR genes, 16 were up-regulated in both lambda-cyhalothrin and bifenthrin-resistant strains of R. padi (LC-R and BIF-R). A relaxin receptor gene, RpGPCR41, showed the highest up-regulated expression in both the resistant strains, with a significant increase of 14.3-fold and 22.7-fold compared to the susceptible strain (SS). RNA interference (RNAi) experiments targeting the relaxin receptor significantly increase the mortality of R. padi when exposed to the LC50 concentration of lambda-cyhalothrin and bifenthrin. The expression levels of five P450 genes (RpCYP6CY8, RpCYP6DC1, RpCYP380B1, RpCYP4CH2, and RpCYP4C1) were significantly down-regulated following knockdown of RpGPCR41 in LC-R and BIF-R strains. Our results highlight the involvement of GPCR gene overexpression in the resistance of R. padi to pyrethroids, providing valuable insights into the mechanisms underlying aphid resistance and a potential target for aphid control.


Assuntos
Afídeos , Resistência a Inseticidas , Inseticidas , Piretrinas , Receptores Acoplados a Proteínas G , Animais , Afídeos/efeitos dos fármacos , Afídeos/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Inseticidas/toxicidade , Nitrilas/farmacologia , Nitrilas/toxicidade , Piretrinas/farmacologia , Piretrinas/toxicidade , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Interferência de RNA
18.
Chem Biodivers ; 21(7): e202400823, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38687255

RESUMO

The design of novel agrochemicals starting from bioactive natural products is one of the most effective ways in the discovery and development of new pesticidal agents. In this paper, a series of novel butenolide-containing methylxanthine derivatives (Ia-Ir) were designed based on natural methylxanthine caffeine and stemofoline, and the derivatized insecticide flupyradifurone of the latter. The structures of the synthesized compounds were confirmed via 1H-NMR, 13C NMR, HRMS and X-ray single crystal diffraction analyses. The biological activities of the compounds were evaluated against a variety of agricultural pests including oriental armyworm, bean aphid, diamondback moth, fall armyworm, cotton bollworm, and corn borer; the results indicated that some of them have favorable insecticidal potentials, particularly toward diamondback moth. Among others, Ic and Iq against diamondback moth possessed LC50 values of 6.187 mg ⋅ L-1 and 3.269 mg ⋅ L-1, respectively, - 2.5- and 4.8-fold of relative insecticidal activity respectively to that of flupyradifurone (LC50=15.743 mg ⋅ L-1). Additionally, both the DFT theoretical calculation and molecular docking with acetylcholine binding protein were conducted for the highly bioactive compound (Ic). Ic and Iq derived from the integration of caffeine (natural methylxanthine) and butenolide motifs can serve as novel leading insecticidal compounds for further optimization.


Assuntos
4-Butirolactona , Teoria da Densidade Funcional , Inseticidas , Simulação de Acoplamento Molecular , Mariposas , Inseticidas/química , Inseticidas/farmacologia , Inseticidas/síntese química , Animais , 4-Butirolactona/análogos & derivados , 4-Butirolactona/química , 4-Butirolactona/farmacologia , 4-Butirolactona/síntese química , Mariposas/efeitos dos fármacos , Cristalografia por Raios X , Estrutura Molecular , Xantinas/farmacologia , Xantinas/química , Xantinas/síntese química , Afídeos/efeitos dos fármacos , Relação Estrutura-Atividade
19.
Chem Biodivers ; 21(6): e202400451, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38556464

RESUMO

Five types of heterocyclic compounds containing trifloromethylpyridine scaffold namely; 3-cyano-2-(N-phenyl)carbamoylmethylthio-6-(thiophen-2-yl)-4-trifluoromethyl-pyridine (6a), thieno[2,3-b]pyridines 3-5 and 7a-c, pyrido[3',2':4,5]thieno[3,2-d] pyrimidines 8-13 and 15a-c, pyrido[3',2':4,5]thieno[3,2-d][1,2,3]triazines 16a,b, and 9-(thiophen-2-yl)-7-(trifluoromethyl) pyrido [3',2':4,5]thieno[2,3-e][1,2,4]triazolo[1,5-c]pyrimidine (14) were synthesized in excellent yields and very pure state. The structures of these compounds were confirmed by elemental and spectral analyses. Most of the synthesized compounds were evaluated as insecticidal agents toward Aphis gossypii insects and promising results obtained. Among all tested compounds, only 6, 7a, 7c and 15c being the most potent compounds against nymphs and adults of Aphis gossypii and their activities are nearly to that of acetamiprid as a reference. The effect of 6a compounds 7a, 7c and 15c on the Aphis digestive system from histological point of view was also included.


Assuntos
Afídeos , Compostos Heterocíclicos , Inseticidas , Piridinas , Animais , Inseticidas/química , Inseticidas/farmacologia , Inseticidas/síntese química , Piridinas/química , Piridinas/síntese química , Compostos Heterocíclicos/química , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/farmacologia , Afídeos/efeitos dos fármacos , Relação Estrutura-Atividade , Estrutura Molecular
20.
Pest Manag Sci ; 80(8): 3893-3900, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38511881

RESUMO

BACKGROUND: Afidopyropen is a novel insecticide with high selectivity between sucking insects such as the peach aphids Myzus persicae and natural enemies like the seven-spotted lady beetle Coccinella septempunctata. However, the mechanisms of selective action for afidopyropen remain unknown. RESULTS: The LC50 values of afidopyropen to the 1st-4th instar larvae and adult C. septempunctata were 372- to more than 7267-fold higher than that to adult M. persicae. Though the activity of cytochrome P450s in M. persicae was 6.1- to 7.5-fold higher than that in C. septempunctata, the latter has much higher activities of carboxylesterase (CarEs) and glutathione S-transferases (GSTs), and the crude enzyme of C. septempunctata and M. persicae showed similar metabolism efficiency to afidopyropen. Molecular docking results demonstrated that afdopyropen showed higher binding affinity to the vanilloid-type transient receptor potential (TRPV) channel of M. persicae (-9.1 kcal/mol) than to that of C. septempunctata (-8.2 kcal/mol). And the EC50 value of afdopyropen to the TRPV channel of C. septempunctata (41 360 nM) was 19 885-fold higher than that in M. persicae (2.08 nM). CONCLUSIONS: Our results demonstrated that the significantly different sensitivity of M. persicae and C. septempunctata TRPV channel to afidopyropen play a key role in the high selectivity of afidopyropen. These findings provide new insights into the selective mechanisms of afidopyropen against insect pests and natural enemies as well as the theory support for coordinated application of chemical control and biological control. © 2024 Society of Chemical Industry.


Assuntos
Afídeos , Besouros , Inseticidas , Larva , Simulação de Acoplamento Molecular , Animais , Afídeos/metabolismo , Afídeos/efeitos dos fármacos , Afídeos/enzimologia , Inseticidas/farmacologia , Larva/crescimento & desenvolvimento , Proteínas de Insetos/metabolismo , Proteínas de Insetos/química , Sistema Enzimático do Citocromo P-450/metabolismo
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