Good Insecticidal Activity Research Articles

Self-assembled pentagonal bipyramidal and skew trapezoidal organotin(IV) complexes of substituted benzoic acids: Their antibacterial, antifungal, cytotoxic, insecticidal and urease inhibition activities

Fourteen di- and triorganotin(IV) derivatives with pentagonal bipyramidal and skew trapezoidal geometries have been synthesized and characterized. Dimethylstannyl bis[3-amino-4-chlorophenylcarboxylate] ( 1), bis[3-amino-4-chlorophenylcarboxylato] tetraethyldistannoxane] ( 2) and bis[3,5-dinitro-4-chlorophenylcarboxylato] tetra- n-butyldistannoxane ( 10) are dinuclear and tetranuclear complexes of bidentate ligands. The crystal structure of ( 1) is dimeric in which each Sn atom is seven coordinated. Study of weak intramolecular Sn⋯O interactions is very important to decide geometry around tin. Furthermore, it has been investigated that these compounds exhibit fairly good antibacterial, antifungal, cytotoxic, insecticidal and antiurease activities.

Synthesis and insecticidal activity of 1,2,4-oxadiazole and 1,2,4-thiadiazole derivatives

A series of 5-substituted 1,2,4-oxadiazoles and 1,2,4-thiadiazoles were prepared as muscarinic acetylcholine receptor agonists and evaluated for their insecticidal activity. These derivatives were synthesized through sequential reactions consisting of the condensation of pyridinecarboamides or pyridinecarbothioamides with N,N-dimethylacetamide dimethyl acetal, cyclization with hydroxylamine, quaternization by alkyl halide and reaction with sodium borohydride. All 1,2,4-oxadiazoles and 1,2,4-thiadiazoles synthesized were evaluated for insecticidal activity and their structure-activity relationships are discussed. It was discovered that many compounds were active against representative insects such as Nilaparvata lugens, Nephotettix cincticeps and Aphis craccivora. In particular, it was also found that 3-pyridyl-substituted derivatives of 1,2,4-oxadiazole and 1,2,4-thiadiazole exhibited good insecticidal activity against all the insects tested. Among the compounds evaluated, 3-methyl-5-(1,2,5,6-tetrahydropyridin-3-yl)-1,2,4-thiadiazole (9m-2) showed the highest activity against Nilaparvata lugens, and provided a high level of activity against the imidacloprid-resistant strain. Based on the preliminary binding assay using the binding inhibition of mAChR antagonist [3H]NMS to the nerve-cord membranes as an index of the binding activity, 9m-2 exhibited a range of potencies for the insect muscarinic receptor.

Synthesis and Insecticidal Activity of N-tert-Butyl-N,N′-diacylhydrazines Containing 1,2,3-Thiadiazoles

N-tert-Butyl-N,N'-diacylhydrazines are nonsteroidal ecdysone agonists used as environmental benign pest regulators. In this paper, two series of new N-tert-butyl-N,N'-diacylhydrazine derivatives containing 1,2,3-thiadiazole were designed and synthesized. All structures of the synthesized compounds were confirmed by proton nuclear magnetic resonance ((1)H NMR), infrared spectroscopy (IR), and high-resolution mass spectrometry (HRMS). Bioasssay results indicated that most of the synthesized compounds possessed good insecticidal activities against Plutella xylostella L. and Culex pipiens pallens as compared with the positive control, tebufenozide. The results of this study indicated that 1,2,3-thiadiazoles, as an important active substructure, could improve or maintain the activity of the dicylhydrazines and favor novel pesticide development.

ChemInform Abstract: Synthesis, Antimicrobial and Insecticidal Activity of Some New Cinnoline Based Chalcones and Cinnoline Based Pyrazoline Derivatives.

AbstractThe title compounds (IV) and (V) exhibit good antibacterial, antifungal and insecticidal activities.

Spirodiclofen Analogues as Potential Lipid Biosynthesis Inhibitors: A Convenient Synthesis, Biological Evaluation, and Structure-Activity Relationship

Twenty spirodiclofen analogues have been designed and conveniently synthesized via three steps including esterification, one-pot heterocyclization, and acylation reactions. The target molecules have been identified on the basis of analytical spectra (<TEX>$^1H$</TEX> NMR, <TEX>$^{13}C$</TEX> NMR and ESI-MS) data. All newly synthesized compounds have been screened for their potential insecticidal and herbicidal activity by standard method. The preliminary assays indicated that some of analogues displayed moderate to good insecticidal activity against Plutella xylostella compared with spirodiclofen, and some compounds showed obvious activity against Brassica chinensis. Structure-activity relationship (SAR) is also discussed based on the experimental data.

Effects of monoterpenoid insecticides on [ 3H]-TBOB binding in house fly GABA receptor and 36Cl − uptake in American cockroach ventral nerve cord

Monoterpenoids and their derivatives from plant essential oils showed good insecticidal activities in previous studies, but the mechanisms of their action as natural insecticides are not known yet. In the present work, we evaluated the pharmacological action of five monoterpenoids (α-terpineol, carvacrol, linalool, pulegone, and thymol) on native insect GABA receptors from house flies and American cockroaches using radiotracer methods. In the [ 3H]-TBOB binding assay, carvacrol, pulegone, and thymol all enhanced the [ 3H]-TBOB binding to membrane preparation of house fly heads with EC 50 values of 48 μM, 432 μM, and 6 mM, respectively. Moreover, these three monoterpenoids at concentrations of 500 μM and 1 mM also significantly increased the 36Cl − uptake induced by GABA in membrane microsacs prepared from American cockroach ventral nerve cords. These results revealed that carvacrol, pulegone, and thymol are all positive allosteric modulators at insect GABA receptors. The other two monoterpenoids that were tested, α-terpineol and linalool, showed little or no effect in both the [ 3H]-TBOB binding and 36Cl − uptake assays.

Toxicity and repellency of origanum essential oil and its components against Tribolium castaneum (Coleoptera: Tenebrionidae) adults

The components of Origanum vulgare L. essential oil showing insecticidal activity and repellency against red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae), adults were analysed by GC-MS. All constituents were identified, and the main components were carvacrol (67.2%), p-cymene (16.2%), γ-terpinene (5.5%), thymol (4.9%), and linalool (2.1%). In a vapor phase fumigant assay, the origanum oil was more effective in closed conditions (LD 50 = 0.055 mg/cm 3) than in open conditions (LD 50 > 0.353 mg/cm 3). This suggests that toxicity is exerted largely in the vapor phase. Based on 24-h LD 50 values, the toxicity of caryophyllene oxide (0.00018 mg/cm 3) was comparable with that of dichlorvos (0.00007 mg/cm 3). In addition, thymol, camphene, α-pinene, p-cymene, and γ-terpinene showed good insecticidal activity (LD 50 = 0.012–0.195 mg/cm 3). In repellency tests using 9 constituents of origanum oil, caryophyllene oxide showed complete repellency at 0.03 mg/cm 2. Hydrogenated monoterpenoids, such as thymol, α-pinene, carvacrol, and myrcene, elicited strong repellency at 0.03 and 0.006 mg/cm 2. Repellency depended on both time and concentration. These results indicate that origanum oil and its components could be potential candidates as a fumigant and repellent for managing T. castaneum adults.

Synthesis and Bioactivity of N-Benzoyl-N'-[5-(2'-substituted phenyl)-2-furoyl] Semicarbazide Derivatives

In order to find novel chitin synthesis inhibitors (CSIs) with good activity, benzoylphenylurea, a typical kind of CSIs, was chosen as the lead compound and 15 novel derivatives containing furan moieties were designed by converting the urea linkage of benzoylphenylureas into a semicarbazide and changing the aniline part into furoyl groups. The title compounds were synthesized by the reaction of substituted benzoyl isocyanates with 5-(substituted phenyl)-2-furoyl hydrazine, and the structures were confirmed by IR, 1H-NMR, elemental analysis and single crystal X-ray diffraction analyses (compound E2). The bioassay results indicated that the title compounds exhibit good insecticidal activity, especially towards Plutella xylostella L., but had lower fungicidal activity. Inspiringly, the title compounds possessed obvious anticancer activity against human promyelocytic leukemic cell line (HL-60), and some of the title compounds also had activity against human hepatocellular carcinoma cell line (Bel-7402), human gastric carcinoma cell line (BGC-823), and human nasopharyngeal carcinoma cell line (KB). The results indicated that the linkage in the lead compounds was important to the bioactivity and spectra. The modification on the urea linkage is an effective strategy to discover new pesticide and drug candidates.

Natural products-based insecticidal agents 6. Design, semisynthesis, and insecticidal activity of novel monomethyl phthalate derivatives of podophyllotoxin against Mythimna separata Walker in vivo

To discover the more potent analogs, 12 novel monomethyl phthalate derivatives of podophyllotoxin were synthesized and preliminarily tested against the pre-third-instar larvae of Mythimna separata Walker in vivo at the concentration of 1mg/mL. Compounds 8e–i showed the higher insecticidal activity than podophyllotoxin. Especially 8g exhibited the most potent insecticidal activity compared with toosendanin, a commercially available insecticide derived from Melia azedarach. The structure–activity relationships demonstrated that trans-lactone, 4β-substitution, 2β-chlorine substitution, and 4′-methoxy group were the important structural properties of podophyllotoxins for good insecticidal activity.

Discovery of bis-aromatic ring neonicotinoid analogues fixed as cis-configuration: Synthesis, insecticidal activities, and molecular docking studies

A novel series of bis-aromatic ring neonicotinoid analogues (1a–1l, 2a–2c), were designed and prepared by introducing a new substituted aromatic ring into nitenpyram and forming a tetrahydropyrimidine ring, with the cis-configuration confirmed by X-ray diffraction. Preliminary bioassays showed most analogues exhibited good insecticidal activities at 100mg/L, and compound 1d and 2a were highly potent even at 10mg/L. Modeling the ligand–receptor complexes by molecular docking study explained the structure–activity relationships observed in vitro, which may provide some useful information for future design of new insecticides.

Synthesis and biological activities of O‐(E)‐(arylmethyl) 1‐[1‐(arylmethyl)‐5‐methyl‐1H‐1,2,3‐triazol‐4‐yl] ethanone oxime ethers

Abstract magnified image A series of novel O‐(E)‐(arylmethyl) 1‐[1‐(arylmethyl)‐5‐methyl‐1H‐1,2,3‐triazol‐4‐yl] ethanone oxime ethers were synthesized by the O‐alkylation of 1‐[1‐(arylmethyl)‐5‐methyl‐1H‐1,2,3‐triazol‐4‐yl] ethanone oximes with various arylmethyl chlorides in the basic condition. Their structures were confirmed by IR, 1H NMR, mass spectroscopy, and elemental analyses. The preliminary bioassay indicated that some of the target compounds (4a, 4b, 4c, 4d, 4e, 4f) displayed good insecticidal and moderate fungicidal activity. For example, compounds 4c and 4g showed 100% and 90.6% death rates against aphides at the concentration of 250 mg/L, respectively, and compounds 4f and 4g displayed 67% and 78.4% inhibitory rates against Rhizoctonia solani at the dosage of 100 mg/L, respectively. J. Heterocyclic Chem., (2009).

Synthesis, Structure and Biological Activities of Some Novel Anthranilic Acid Esters Containing N‐Pyridylpyrazole

AbstractIn search of environmentally benign insecticides with high activity, low toxicity and low residue, a novel series of anthranilic acid esters containing N‐pyridylpyrazole were designed and synthesized. All of the compounds were characterized and confirmed by IR, 1H NMR, MS and elemental analysis. The single crystal structure of 14d was determined by X‐ray diffraction. The bioassay tests showed that the synthesized compounds exhibited good insecticidal activities against Mythimna separata Walker and Culex pipiens pallens.

Toxicity of Cassia and Cinnamon Oil Compounds and Cinnamaldehyde-Related Compounds to &lt;I&gt;Sitophilus oryzae&lt;/I&gt; (Coleoptera: Curculionidae)

The toxicity to adult Sitophilus oryzae (L.) (Coleoptera: Curculionidae) of two cassia oils (Especial and true), four cinnamon oils (technical, #500, bark, and green leaf), and (E)-cinnamaldehyde and its 41 structurally related compounds was examined by residual and vapor-phase toxicity bioassays. Results were compared with those of dichlorvos. In residual bioassays, cassia and cinnamon oils exhibited good insecticidal activity. Based on 48-h LD50 values, the toxicity of allyl cinnmate (0.0003 mg/cm2) was comparable with that of dichlorvos (0.00025 mg/cm2). Potent insecticidal activity also was observed with benzaldehyde, beta-caryophyllene, cinnamonitrile, hydrocinnamyl acetate, (E)-4-hydroxycinnamic acid, and alpha-terpineol (LD50 = 0.003-0.009 mg/cm2). Structure-activity relationships indicate that types of functional groups rather than hydrophobicity or vapor pressure parameters seem to play a role in determining the toxicities to adult S. oryzae. In vapor-phase toxicity tests with weevils, these compounds were more effective in closed containers than in open ones. These results indicate that the effect of the compounds was largely a result of action in the vapor phase. Cassia and cinnamon oils and test compounds described merit further study as potential fumigants for the control of S. oryzae because of their greater activity as a fumigant.

Synthesis and Insecticidal Activity of N-Substituted (1,3-Thiazole)alkyl Sulfoximine Derivatives

The N-substituted alkyl sulfoximine derivatives are a new chemical family of neonicotinoid insecticides. We have designed and synthesized 10 (1,3-thiazole)alkyl sulfoximine derivatives. All compounds were identified by (1)H and (13)C nuclear magnetic resonance (NMR), IR, and elemental analyses. Preliminary bioassays indicated that some title compounds exhibited good insecticidal activities at 10 mg/L against Myzus persicae . The relationship between structure and biological activity was also discussed.

Synthesis and Biological Activities of Novel Pyrazole Oxime Derivatives Containing a 2-Chloro-5-thiazolyl Moiety

A series of novel pyrazole oxime derivatives containing a 2-chloro-5-thiazolyl moiety were synthesized. Their structures were confirmed by (1)H NMR, (13)C NMR, and elemental analysis. The preliminary bioassays showed that all of the title compounds had low acaricidal activity against Tetranychus cinnabarinus . However, most of them exhibited excellent insecticidal activity against Aphis medicagini at the dosage of 0.5 mg/mL, and some compounds still showed good insecticidal activity against A. medicagini even at the dosage of 0.2 mg/mL. Meanwhile, some title compounds displayed fungicidal and plant growth regulatory activities.

Insecticidal Activity of Some New Amidophosphoric Acid Esters Containing Substituted Pyridine Moieties

Some new amidophosphoric acid esters containing substituted pyridine moieties were synthesized by the reaction of O-aryl, O-ethyl phosphoryl chlorides with 3-(aminomethyl)pyridine and 5-(aminomethyl)-2-chloropyridine. Characterization was done by 1H NMR, 31P{1H} NMR, IR, MS, and elemental analyses. The results of preliminary bioassay showed that the new compounds possess good insecticidal activity against aphides.

Development of chamaejasmin microemulsion and its biological activity against Aphis craccivora and Culex pipiens pallens

AbstractChamaejasmin is the mixture of many natural insecticidal ingredients from the ethanol extract of Stellera chamaejasme root. 1,5‐Diphenyl‐1‐pentanone is one of major insecticidal components. Chamaejasmin microemulsion was prepared and its insecticidal activity against Aphis craccivora and Culex pipiens pallens and its stability were evaluated. The results showed that it had good insecticidal activity and good stability. Its median lethal concentration (LC50) values (24 h after treatment) were 47.93 mg/l and 31.78 mg/l, respectively. Results of analysis of variance (ANOVA) indicated that after the prepared microemulsion was stored at 54 ±2 ˚C for 14 days or at room temperature for 12 months, its insecticidal activity had no significant changes. The content of 1,5‐diphenyl‐1‐pentanone in the microemulsion was 0.27%. This is the first report of insecticidal activity of Stellera chamaejasme against Culex pipiens pallens. Copyright © 2008 John Wiley &amp; Sons, Ltd.

Synthesis, crystal structure, insecticidal activity and DFT study on the geometry and vibration of O-( E)-1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1 H-1,2,3-triazol-4-yl}ethyleneamino- O-ethyl- O-phenylphosphorothioate

The title compound, O-( E)-1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1 H-1,2,3-triazol-4-yl}ethyleneamino- O-ethyl- O-phenylphosphorothioate, has been synthesized via the condensation reaction of 1-{1-[(6-chloropyridin-3-yl)methyl]-5-methyl-1 H-1,2,3-triazol-4-yl}ethanone oxime and O-ethyl- O-phenylphosphorochloridothioate in the presence of NaOH powder in refluxing EtOH. Its structure was characterized by 1H NMR, FTIR, Raman, elemental analysis and X-ray single crystal diffraction. The results of preliminary bioassays indicated that the title compound displays good insecticidal activity. Density functional (DFT) calculations have been carried out for the title compound by using the Becke-Lee-Yang-Parr's three-parameter hybrid functional (B3LYP) method at 6-31G** and 6-31G* basis sets. The calculated results show that the predicted geometry can well reproduce the structural parameters. The vibrational wave numbers of the title compound were calculated at same level. Predicted vibrational frequencies have been assigned and compared with experimental IR and Raman spectra and they are supported each other.

Separation and identification of botanical insecticide 7-hydroxycoumarin and its biological activity against Aphis craccivora and Culex pipiens pallens

The root powder of Stellera chamaejasme was extracted with chloroform. The crude extract obtained was chromatographed with silica gel columns many times. One pure natural product was obtained. It was identified as 7-hydroxycoumarin. Laboratory bioassay showed that it had a good insecticidal activity against Aphis craccivora and Culex pipiens pallens. Its median lethal concentrations (LC50) (24 h after treatment) were 19.56 and 0.435 mg L−1, respectively. The results of regressive and correlative analysis demonstrated that the correlations were very significant between concentration and efficacy. The corresponding correlative coefficients were 0.9686 and 0.9712, respectively. This is the first report of the insecticidal activity of 7-hydroxycoumarin. It may represent a new class of insecticides.

Toxicity of Plant Essential Oils and Their Components Against &lt;I&gt;Lycoriella ingenua&lt;/I&gt; (Diptera: Sciaridae)

Plant essential oils from 20 plant species were tested for their insecticidal activity against larvae of Lycoriella ingenua (Dufour) (Diptera: Sciaridae) by using a fumigation bioassay. Good insecticidal activity (>90%) against larvae of L. ingenua was achieved with essential oils of caraway seed Carum carvi (L.)], lemongrass [Cymbopogon citratus (D.C.) Stapf.], mandarine (Citrus reticulate Blanco), nutmeg (Myristica fragrans Houtt), cade (Juniperus oxycedrus L.), spearmint (Mentha spicata L.), cumin (Cuminum cyminum L.), and thyme red [Thymus vulgaris (L.)] oils at 30 X 10-3 mg/1 air. Among them, caraway seed, spearmint, cumin, and thyme red essential oils were highly effective against L. ingenua at 20 x 10(-3) mg/ml air. Analysis by gas chromatography-mass spectrometry led to identification of 4, 9, 8, and 17 compounds from caraway seed, spearmint, cumin, and thyme red oils, respectively. These compounds were tested individually for their insecticidal activities against larvae of L. ingenua, and compared with the toxicity of dichlorvos. Carvacrol, thymol, linalool, cuminaldehyde, p-cymen, terpinen-4-ol, and carvone was effective at 10 x 10(-3) mg/l. The insecticidal activity of dichlorvos was 60% at 10 x 10(-3) mg/ml. Effects of four selected plant essential oils on growth of oyster mushroom, Pleurotus ostreatus, also were investigated.