First report of field resistance to cyantraniliprole, a new anthranilic diamide insecticide, on Bemisia tabaciMED in China

The Bemisia tabaci （Gennadius） cryptic species complex comprises important insect pests that cause devastating damage to agricultural crops worldwide. In China, the B. tabaci Mediterranean （MED） （or biotype Q） species is threatening agricul- tural production all over the country as resistance to commonly used insecticides has increased. This situation highlights the need for alternative pest control measures. Cyantraniliprole, a novel anthraniiic diamide insecticide, has been widely employed to control Hemipteran pests. To monitor the levels of resistance to cyantraniliprole in B. tabaci field populations in China, bioassays were conducted for 18 field samples from nine provinces over two years. Compared with median lethal concentration （LC^0） for the MED susceptible strain, all field samples had significantly higher resistance to cyantraniliprole. Furthermore, resistance factors （RFs） increased significantly in samples from Shanxi （from 5.62 in 2015 to 25.81 in 2016）, Hunan （3.30 in 2015 to 20.97 in 2016） and Hubei （from 9.81 in 2015 to 23.91 in 2016） provinces. This study indicates a considerable decrease in the efficacy of cyantraniliprole against B. tabaci and establishes a baseline of susceptibility that could serve as a reference for future monitoring and management of B. tabaci resistance to cyantraniliprole.

Diamide derivatives containing a trifluoromethylpyridine skeleton:Design,synthesis,and insecticidal activity

Diamide derivatives are biologically active molecules that have been widely applied in recent years in research on pesticides,especially insecticides.Using a simple and environmentally friendly scheme,a series of new diamide derivatives containing a trifluoromethylpyridine skeleton was designed,synthesized,and confirmed by^(1)H,^(19)F and^(13)C NMR,and HR-MS.Their insecticidal activities against Plutella xylostella and Helicoverpa armigera were measured and the relationship between structure and activity was investigated.Eight of the title compounds(D2,D5,D10,D21,D28,D29,D30 and D33)showed 100%activity against P.xylostella at 500 mg L^(-1).One compound,D33,still showed 100%activity against P.xylostella at 100 mg L^(-1)and had the lowest LC_(50)(lethal concentration 50%,3.7 mg L^(-1))among the synthesized compounds.Molecular docking analysis revealed that D33 could be thoroughly embedded in the active pocket of the ryanodine receptor via hydrogen bonding in a manner similar to the commercial insecticide chlorantraniliprole.

Expression of Macrophage Inflammatory Protein 1α in the Endothelial Cells Exposed to Diamide

In order to study whether the endothelial cells (ECs) with lipid peroxidation induced by diamide can express and secrete macrophage inflammatory protein 1α (MIP-1α), the expression of MIP-1α protein in the cells was detected by cell enzyme-linked immunosorbent assay (ELISA) and that of MIP-1α mRNA was determined by cell in situ hybridization and nuclease S1 protection assay after the ECs were exposed to different concentrations of diamide for 4 h. The chemotactic activity of MIP-1α was tested by micropore filter method using modified Boyden chambers. Cell ELISA showed that the expression of MIP-1α protein in endothelial cells exposed to 1 μmol/L, 5 μmol/L and 10 μmol/L diamide was 1.9-fold, 2.3-fold and 1.7-fold respectively as much as that in the control cells, which was statistically significant by analysis of variance. In situ hybridization revealed that the mRNA expression of ECs treated with 1 μmol/L, 5 μmol/L and 10 μmol/L diamide was 1 3-fold, 3.0-fold and 1.7-fold as much as that in the control group, which had statistical significance ( F =188.93, P <0.01). The mRNA expression in 5 μmol/L dimide treated ECs, measured by nuclease S1 protection assay, was 3.4-fold as much as that in the control group( t =8 70, P <0 05). Chemotactic response(99.50±4.31 μm) to the culture medium conditioned by 5 μmol/L diamide treated ECs , which was stronger than that(66.47±3.25 μm) conditioned by the ECs ( F =404.31, P <0.05), was significantly decreased ( F =192.25, P <0.05) after adding MIP-1α antibody. It suggests that diamide, a lipid peroxidation inducer, could stimulate ECs to produce high level of MIP-1α, and might play an important role in atherogenesis by promoting the migration of peripheral blood monocytes into arterial intima.

Discovery of Novel Anthranilic Diamide Derivatives Bearing Sulfoximine Group as Potent Insecticide Candidates

The fall armyworm,Spodoptera frugiperda(S.frugiperda),represents the most resistant insect species and poses serious threat to grain yield.Chlorantraniliprole(CHL),which targets the ryanodine receptors(RyRs)in insects,has demonstrated the efficacy in controlling S.frugiperda.Nevertheless,this has led to emerging resistance in several countries.To counter this resistance,a viable approach involves the development of novel compounds that bind against RyRs via distinct binding sites or modes.In this study,a series of 22 novel anthranilic diamide derivatives was designed and synthesized,and their insecticidal activities were evaluated.Most of these derivatives showed moderate to good insecticidal activity against S.frugiperda and Mythimna separata.Time-lapse fluorescence measurements of endoplasmic reticulum luminal calcium revealed that most derivatives elicited cellular responses similar as CHL when assessed on HEK293 cells expressing S.frugiperda ryanodine receptors(SfRyRs).The mode of action of compound 13a was studied and verified on the isolated neurons by calcium imaging technique.Finally,molecular docking analysis was employed to predict the binding mechanism of compound 13a against SfRyRs.Overall,these novel diamide derivatives hold promise as a valuable resource for guiding the future design of insecticidal compounds targeting RyRs.

Efficacious selective separation of U(Ⅵ) over Mo(Ⅵ) using novel 2,9-diamide-1,10-phenanthroline ligands: Liquid-liquid extraction and coordination chemistry

Uranium and molybdenum are important strategic elements. The production of ^(99)Mo and the hydrometallurgical process of uranium ore face difficult problems of separation of uranium and molybdenum.In this study, the four phenanthroline diamide ligands were synthesized, and extraction and stripping experiments were performed under different conditions to evaluate the potential application of these ligands for separation of U(Ⅵ) over Mo(Ⅵ). With the growth of alkyl chain, the solubility of ligands could be greatly improved, and the separation effect of U(Ⅵ) over Mo(Ⅵ) gradually increased. The SF_(U/Mo) were around 10,000 at 4 mol/L HNO3. Three stripping agents were tested with the stripping efficiency of Na_(2)CO_(3)(5%) > H_(2)O > HNO_(3)(0.01 mol/L). The stripping percentages of the three stripping agents were all close to unity, indicating that the ligands had the potential to be recycled. The chemical stoichiometry of U(Ⅵ) complexes with ligands was evaluated as 1:1 using electrospray ionization mass spectrometry,ultraviolet visible spectroscopy and single-crystal X-ray diffraction. The consistency between theoretical calculation and experimental results further explains the coordination mechanism.

Substituted diamides of dipicolinic acid as extractants and ionophores for rare earth metals

The variety of newly synthesized diamides of dipicolinic acid(DPA)bearing methyl-and oxymethyl substituents in various positions of phenyl ring was investigated as potential ligands for liquid-liquid extraction of rare earth metal ions and as membrane active compounds in plasticized polymeric membranes of potentiometric sensors.It is found that scandium is extracted with 2,6-pyridinedicarboxylic acid diamides similarly to heavy lanthanides,while yttrium is extracted together with light group lanthanides.DPA shows high selectivity for the separation of cadmium/zinc,lead/nickel or copper/nickel pairs.The four out of six studied ligands demonstrate significant potentiometric sensitivity towards scandium,yttrium and lanthanides in 10^(-7)-10^(-3)mol/L concentration range in nitric acid solutions.The trends in sensitivity values vary depending on a ligand structure and the highest values are observed for Sc^(3+)and heavy lanthanides.According to the evaluated selectivity Sm^(3+)is the most preferred ion,while La^(3+)is the most discriminated.The differences in sensor behavior in rare earth metal solutions assume that such devices can be applied in sensor arrays for potentiometric analysis of lanthanide mixtures.

Detection of ryanodine receptor target-site mutations in diamide insecticide-resistant Spodoptera frugiperda in China

Spodoptera frugiperda(Lepidoptera:Noctuidae)is a widely distributed pest of corn.Since it invaded China in 2018,it has caused serious damage to local corn production.Chlorantraniliprole,an anthranilic diamide insecticide,has been widely used to control lepidopteran pests.Tetrachloropyramid is a new allosteric modulator insecticide devel-oped based on chlorantraniliprole,so it has a similar mechanism and insecticidal effect.In this study,we investigated resistance levels to chlorantraniliprole and tetrachloropyramid in S.frugiperda from 13 populations in China.Among the populations tested,the relative highest resistance to chlorantraniliprole occurred in the Guangzhou population,and the most susceptible to chlorantraniliprole was found in the Wuhan population.The lethal dosage LD50 value of the Guangzhou population against chlorantraniliprole was 27.8-fold higher than that of the Wuhan population.Minimal differences were observed among 5".frugiperda populations in terms of sensitivity to tetrachloropyramid.Heterozygous mutations at the 14734 site of the ryanodine receptor(RyR)were found,while no mutations were found in the G4891 site.The mutations were detected in only two of the 786 individuals analyzed one from the Qinzhou population and other from the Anshun population(frequency below 2%in both cases).There were no significant differences in the expression levels of RyR between Guangzhou and Wuhan populations.In summary,our results indicate that:(i)S.frugiperda has low resistance levels to diamide insecticides in China;and(ii)the differences in relative resistance among the 13 populations analyzed are not caused by the mutations in RyR or the expression of RyR.

Identification of the ryanodine receptor mutation I4743M and its contribution to diamide insecticide resistance in Spodoptera exigua (Lepidoptera: Noctuidae)

Insect ryanodine receptors(RyRs)are the targets of diamide insecticides.Two point mutations G4946E and I4790M(numbering according to Plutella xylostella,PxRyR)in the transmembrane domain of the insect RyRs associated with diamide resistance have so far been identified in three lepidopteran pests,P.xylostella,Tuta absoluta and Chilo suppressalis.In this study,we identified one of the known RyR target site resistance mutations(I4790M)in a field-collected population of Spodoptera exigua.The field-collected WF population of S.exigua exhibited 154 fold resistance to chlorantraniliprole when compared with the susceptible WH-S strain.Sequencing the transmembrane domains of S.exigua RyR(SeRyR)revealed that the resistant WF strain was homozygous for the 14743M mutation(corresponding to I4790M in PxRyR),whereas the G4900E allele(corresponding to G4946E of PxRyR)was not detected.The 4743M allele was introgressed into the susceptible WH-S strain by crossing WF with WH-S,followed by three rounds of backcrossing with WH-S.The introgressed strain 4743M was homozygous for the mutant 4743M allele and shared about 94%of its genetic background with that of the recipient WH-S strain.Compared with WH-S,the near-isogenic 4743M strain showed moderate levels of resistance to chlorantraniliprole(21 fold),cyantraniliprole(25 fold)and flubendiamide(22 fold),suggesting that the I4743M mutation confers medium levels of resistance to all three diamides.Genetic analysis showed diamide resistance in the 4743M strain was inherited as an autosomal and recessive trait.Results from this study have direct implications for the design of appropriate resistance monitoring and management practices to sustainably control S.exigua.

Synthesis, bioactivity, action mode and 3D-QSAR of novel anthranilic diamide derivatives

To study the pesticide effect, action mode, structure-activity relationships (SARs) of anthranilic diamide insecticide and screen highly active pesticides, novel anthranilic diamide derivatives were synthesized.Bioassays indicated that all of the title compounds displayed 100% mortality against diamondback moth and oriental armyworm at 100 mg/L, among which 12 v and 12 w showed 100% insecticidal acitvity at 5 mg/L. Surprisingly compound 12 w exhibited better insecticidal acitvity than commercialized chlorantraniliprole against Pyrausta nubilalis (0.1 mg/L) and Cnaphalocrocis Medinalis (2 mg/L). 3 D-QSAR and SARs statistical analysis revealed that title compounds with R^2 fixed as methoxy had the highest probability possessing high activity. The calcium fluorescence measurements on neurons revealed that E series compounds containing pyrazinyl may have a molecular target different from caffeine on ryanodine receptors rather than the voltage-gated calcium channel present on cytomembran.

Design, Synthesis and Insecticidal Activity of Novel Anthranilic Diamides Containing Oxime Ester and Diacylhydrazine Moieties

Two series of novel anthranilic diamides containing oxime ester and diacylhydrazine moieties were designed and synthesized.Their structures were characterized by melting points,1H NMR,13C NMR and high resolution mass spectrometry（HRMS）.The single crystal structure of compound 7e was determined by X-ray diffraction and their evaluated insecticidal activity against oriental armyworm（Mythimna separata） indicates that some of the compounds exhibited moderate insecticidal activities.Among the 20 compounds,6a and 6b show 100％ larvicidal activity against Mythimna separate Walker at the test concentration of 100 mg/L.

Design, Syntheses and Biological Activities of Novel Anthranilic Diamide Insecticides Containing N-Pyridylpyrazole

In search of environmentally benign insecticides with high activity, low toxicity and low residue, a series of novel anthranilic diamide derivatives containing N-pyridylpyrazole was designed and synthesized. All the compounds were characterized by H NMR spectroscopy and elemental analysis. The single crystal structure of com pound 8j was determined by X-ray diffraction. The insecticidal activities of the new compounds were evaluated. The results show that some compounds exhibited moderate insecticidal activities against Lepidoptera pests. Among this series of compounds, compounds 80 and 8p showed 100% larvicidal activity against Mythimna separate Walker, Plutella xylostella Linnaeus and Laphygma exigua Hubner at a test concentration of 200 mg/kg, which is equal to the commercial chlorantraniliprole.

Synthesis and Biological Activities of Novel Anthranilic Diamides Analogues Containing Benzo[b]thiophene

A series of novel anthranilic diamides analogues containing benzo[b]thiophenyl ring was designed and synthesized. Their structures were characterized by melting points, 1H nuclear magnetic resonance（IH NMR） and high-resolution mass spectrometry（HRMS）. The bioassay tests indicate that their insecticidal activities were weak to moderate. Antibacterial tests indicate that some of the compounds showed favourable activity in vitro against Physa- lospora piricola, Alternaria solani, Cercospora arachidicola, Gibberella sanbinetti and Phytophthora infestans at a dosage of 50 mg/L.

Synthesis and Insecticidal Evaluation of Novel Anthranilic Diamides Derivatives Containing 4-Chlorine Substituted N-Pyridylpyrazole

To search for potent insecticides targeting at ryanodine receptors(RyRs),a series of novel anthranilic diamides analogs containing 4-chlorine N-pyridylpyrazole were designed and synthesized.Their insecticidal activities were evaluated and the preliminary struc ture-activity relationships(SARs)were discussed.The insecticidal results showed that some of the compounds(8a-8h,8m,8n)exhibited good larvicidal activities against oriental armyworm at 2.5 mg·L^(-1),and compound 8m possessed 60%insecticidal activityat 0.5 mg·L^(-1).For diamondback moth,8m exhibited better activity than Chlorantraniliprole at a hundred fold preference.

Synthesis, insecticidal activities and SAR studies of novel anthranilic diamides containing trifluoroethoxyl substituent and chiral amino acid moieties

Ryanodine receptors（RyRs） activator has become one class of popular insecticide because of its unique mode of action. In order to find more new RyRs activators as insecticidal agents, a series of 18 novel chiral anthranilic diamides were designed by introducing the D-alanine acid and D-serine acid esters as well as trifluoroethoxyl group into the anthranilic diamide skeleton and synthesized successfully based on anthranilic diamide and FKI-1033 structures. The structures of the title compounds Ia–i and IIa–i were confirmed by melting points,~1H NMR,^（13）C NMR, elemental analysis and specific optical rotation analysis.The preliminary bioassay results indicated that most of the title compounds exhibited considerable larvicidal activities against oriental armyworm at 10 mg/L, especially Ib, Ie and IIh showed remarkable insecticidal activities at 0.5 mg/L. The larvicidal activity against diamondback moth of Ia and IId were 80%and 90% respectively at 0.0001 mg/L, which was similar to that of chlorantraniliprole. The relationship between structure and insecticidal activity was analyzed to reveal a possible co-regulated effect of the chiral amino acid ester, halogen atom or cyano group, and trifluoroethyloxyl group of the skeleton structures of the title compounds, which will provide useful information for guiding the design and discovery of new RyRs activators and insecticidal agrochemicals.

Design,synthesis and insecticidal activity of novel anthranilic diamides with benzyl sulfide scaffold

A series of novel anthranilic diamides with benzyl sulfide scaffold were synthesized,in which N-pyridylpyrazole moiety generally regarded as key pharmacophore was abandoned.The target compounds were characterized by ~1H NMR,^（13）C NMR,^（19）F NMR and HRMS.The preliminary bioassays indicated that half of the title compounds were endowed with good insecticidal activities against armyworm（Mythimna sepatara） at the concentration of 500 mg/L,Exhilaratingly,the synthesized compound 3a was also active against Tetranychus cinnabarinus at 100 mg/L.The difference in activities between the target compounds was influenced by the substituents,which provided some hints for further investigation on structure modifications.

Synthesis and Insecticidal Evaluation of Novel Phthalic Diamides Containing 1,2,3-Triazoles via Click Reaction

A series of novel phthalic diamide derivatives containing 1,2,3-triazole moiety were synthesized using one-pot click chemistry approach and characterized by ^(1)H NMR and HRMS.The insecticidal activity against armyworm(Mythimna separata),Tetranychus cinnabarinus and cowpea aphid(Aphis craccivora)was evaluated.Compounds 4Ⅱ-a and 4Ⅱ-i showed 50%insecticidal activity against armyworm(Mythimna separata)at the concentration of 4 mg/L and one-third of the compounds had moderate activity against Tetranychus cinnabarinus at 500 mg/L.

Synthesis and Bioactivities Evaluation of Novel Anthranilic Diamides Containing N-(tert-Butyl)benzohydrazide Moiety as Potent Ryanodine Receptor Activator

Anthranilic diamides have been proven to be a class of efficacious and safe insecticides targeting ryanodine receptors (RyRs) during the last decade. In order to develop innovative scaffolds with high insecticidal activity, two series of N-pyridylpyrazole derivatives containing N-(tert-butyl)benzohydrazide substructures were designed and synthesized. Their insecticidal activities against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella) were evaluated. Preliminary bioassay results revealed that some of the new compounds exhibited good insecticidal activity against the oriental armyworm and diamondback moth. The mode of action of these compounds were verified using calcium-imaging technique and the results showed that some new compounds could effectively modulate the insect cytosolic Ca^2+ level, and break the cellular calcium homeostasis, indicating some of these compounds were potent activators of the RyRs.

An efficient synthesis of imidodicarbonic diamides from 1,3-thiazetidin-2-ones with NH_2OH·HCl via ring-opening reaction

A ring-opening process of 4-imino-1,3-thiazetidin-2-ones with NH2OH.HCI was described for the first time. Two different scaffolds of imidodicarbonic diamide were obtained selectively in good yields in the presence of organic base. The obtained imidodicarbonic diamides were demonstrated by X-ray diffraction analysis.

Design, synthesis and insecticidal activity of biphenyl-diamide derivatives

Diamides acting on insect ryanodine receptors are an intensive research area now. In order to search for novel candidates, a series of diamides containing biphenyl substructure were designed and synthesized.Their insecticidal activities against armyworms（Mythimna sepatara） and aphis（Aphis craccivora） were screened. The compounds with 3,5-dichloro-4-（1,1,2,2-tetrafluoroethoxy）phenyl substituent were found to be insecticidal to armyworms with the similar symptoms to poisoning by flubendiamide. In this research, we presented a novel type of diamide insecticide as a lead compound for further optimization.

Bioactive conformation analysis of anthranilic diamide insecticides:DFT-based potential energy surface scanning and 3D-QSAR investigations

Anthranilic diamides are fasting growing class insecticides in modern crop protection for their high activity, low ecotoxicity, and broad insecticidal spectra. However. the bioactive conformations of anthranilic diamides are still unclear until now. In the present study, DFT-based potential energy surface scanning was used to detect the low energy conformations of chlorantraniliprole, then were used respectively in the structure alignment for a series of anthranilic diamide compounds followed by detailed CoMFA and CoMSIA analyses. Finally, the bioactive conformations of anthranilic diamide insecticides were revealed from a series of low energy conformations, which might provide some clues for future insecticide design.