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1.
A series of novel 2-(2,4,6-trisubstituted phenyl)-1,3,4-oxadiazolin-5-one derivatives and 3-(2,4,6-trichlorophenyl)pyrazolin-5-one derivatives were synthesized and evaluated for insecticidal activity. It was found that a moderately bulky alkyl group, such as a tert-butyl group, on the heterocyclic ring, and a trifluoromethyl group on the benzene ring were optimal substituents on the molecule. The oxygen atom in the oxadiazoline ring was essential for insecticidal activity. Of the compounds assayed, 4-tert-butyl-2-(2,6-dichloro-4-trifluoromethylphenyl)-1,3,4-oxadiazolin-5-one gave the highest activity against Nephtotettix cincticeps, with an LC50 value of 0.51 mg litre−1. © 1999 Society of Chemical Industry  相似文献   

2.
A series of novel 4,5-dihydropyrazole-5-thiones (DHPs) was synthesised by treating the corresponding dihydropyrazolones with ‘Lawesson’s reagent and evaluated for miticidal activity against two-spotted spider mites (Tetranychus urticae Koch). Of these, 3-(4-chlorophenyl)-4,4-dimethyl-1-phenyl-4,5-dihydropyrazole-5-thione, 3-(4-chlorophenyl)-4-ethyl-4-methyl-1-phenyl-4,5-dihydropyrazole-5-thione, 3-(4-chlorophenyl)-1-phenyl-4,5-dihydropyrazole-5-thione-4-spirocyclopentane and 4,4-dimethyl-1-phenyl-3-(4-trifluoromethyl-phenyl)-4,5-dihydropyrazole-5-thione were highly active (pEC50>4·0) and were more effective than the miticide dicofol (pEC50=3·879), which has traditionally been used for the control of phytophagous mites. Structure–activity relationship (SAR) studies were performed on each position of the pyrazole ring of DHPs. The results indicated that the unsubstituted phenyl, 4-substituted phenyl and thioxo groups on the 1-, 3- and 5-positions of DHPs respectively were required for activity. Quantitative SAR studies using physicochemical parameters of substituents and the capacity factor k′ as a hydrophobicity index suggested that: (a) the activities of all types of DHPs examined were mainly dominated by hydrophobicity, (b) the bulkiness of 4-substituents of the 3-phenyl ring favoured the activity and (c) the log k′ optimum for all DHPs was 1·675, equivalent to a log Pow value of c. 5·0.  相似文献   

3.
A series of compounds with structures based on insecticidal/acaricidal naphthoquinones isolated from Calceolaria andina has been synthesised. A feature of the series is the lack of resistance shown by strains resistant to established classes of pesticides. The importance for activity of the tetra-substituted carbon atom in the side-chain, as observed in the natural products, has been investigated. In analogues with acyclic side-chains the position of the tetra-substituted carbon for optimum activity was dependent on the length of the side-chain. With cyclic side-chains, activity was dependent on the size of the ring, the number and position of the substituents therein. Activity of the compounds examined was particularly high against Bemisia tabaci and Tetranychus urticae in direct-contact tests, but was much lower than expected in leaf-dip tests. A partial improvement based on formulation has been demonstrated. © 1997 SCI  相似文献   

4.
BACKGROUND: Phthalic acid diamide derivatives are among the most important classes of synthetic insecticides. In this study, a 3,3‐dichloro‐2‐propenyloxy group, the essential active group of pyridalyl derivatives, was incorporated into phthalic acid diamide derivatives with the aim of combining the active groups to generate more potent insecticides. RESULTS: Thirty‐one new phthalic acid diamides were obtained, and these were characterised by 1H and 13C NMR. The structure of N2‐[1,1‐dimethyl‐2‐(methoxy)ethyl]‐3‐iodo‐N1‐[4‐(3,3‐dichloro‐2‐propenyloxy)‐3‐(trifluoromethyl)phenyl]‐1,2‐benzenedicarboxamide was determined by X‐ray diffraction crystallography. The insecticidal activities of the compounds against Plutella xylostella were evaluated. The title compounds exhibited excellent larvicidal activities against P. xylostella. Structure‐activity relationships revealed that varying the combination of aliphatic amide and aromatic amide moieties, or the nature and position of substituent Y on the aniline ring, could aid the design of structures with superior performance. CONCLUSION: A series of novel phthalic acid diamides containing a 3,3‐dichloro‐2‐propenyloxy group at the 4‐position of the aniline ring were designed and synthesised. Structure‐activity relationships with the parent structure provided information that could direct further investigation on structure modification. Copyright © 2012 Society of Chemical Industry  相似文献   

5.
Novel types of mitochondrial respiration inhibitors at complex I, with emphasis on acaricidal activity, have been designed and prepared. The synthetic approach to these 4‐pyrimidinylphenyl ethyl ethers and amines with a specific ketal or oxime function in the phenyl side chain is outlined. Bioassays demonstrate their high potential against important spider mites, like Tetranychus urticae and Panonychus ulmi. Structure–activity relationship studies and several biological parameters are discussed. © 2000 Society of Chemical Industry  相似文献   

6.
The quantitative relationship between the structure of 2-methoxy-5-(substituted-phenyl)-1, 3, 2-oxazaphospholidine 2-sulfides (5-PMOS) and their insecticidal activity against the house fly. Musca domestica L., was analyzed using reported physicochemical parameters and regression analysis. The electronic nature of the substituent on the phenyl group of 5-PMOS has the most significant effect on the activity, followed by hydrophobic and steric effects; the optimum value of Σρ is zero and the more hydrophobic the substituents on the phenyl group, the higher the insecticidal activity. The plots of observed pLD50, values against calculated pLD50 values for compounds having substituents in the ortho-position deviated downwards from those of compounds having substituents at the meta and/or para positions. This ortho-effect, which reduces the insecticidal activity of compounds having substituents at the ortho-position, was expressed by a dummy parameter D, which has the value 2 for di-ortho-substituted derivatives, 1 for mono-ortho-substituted derivatives and zero for others. Thus, the highest activity was obtained for 2-methoxy-5-phenyl-1, 3, 2-oxazaphospholidine 2-sulfide, and the activity was decreased by the introduction of any substituents on the phenyl group.  相似文献   

7.
Quaternary organosilicon pyrethroid‐like ethers (five compounds) and alkanes (three compounds) were used for neurophysiological tests. Their activities in inducing repetitive firing in the central nervous cord of the American cockroach (Periplaneta americana) were evaluated by an extra‐cellular recording method. The ethers were more active than the corresponding alkanes. The ability of the compounds to cause conduction blockage was also measured using the same nerve preparations, but the effects were too weak to allow definitive activity values to be determined. The compounds prolonged the sodium tail‐current in the crayfish giant axon under voltage clamp conditions. The rate of decay of the tail‐current changed in parallel with the reported insecticidal activity against P americana. These findings indicated that tail‐current activity was the most useful nerve parameter in predicting insecticidal activity. Regression analysis of the numerical data together with those reported for other alkanes revealed that the higher the tail‐current activity, the higher the insecticidal activity when a structural feature and the hydrophobicity were considered separately. The insecticidal activity of the ethers was about seven‐fold higher than that of the alkanes with equivalent tail‐current activity and hydrophobicity. Variations in insecticidal activity were parabolically correlated with the hydrophobicity [(log P)opt = 9.1] when other factors were similar. © 2001 Society of Chemical Industry  相似文献   

8.

BACKGROUND

1,3,4‐Oxadiazole and imidazolidine rings are important heterocyclic compounds exhibiting a variety of biological activities. In this study, novel compounds with oxadiazole and imidazolidine rings were synthesized from 3‐(methylsulfonyl)‐2‐oxoimidazolidine‐1‐carbonyl chloride and screened for insecticidal activities. The proposed structures of the 17 synthesized compounds were confirmed using elemental analysis, infrared (IR), proton nuclear magnetic resonance (1H‐NMR), and mass spectroscopy.

RESULTS

None of the compounds showed larvicidal activity at the tested concentrations against first‐instar Aedes aegypti larvae. However, nine compounds exhibited promising adulticidal activity, with mortality rates of ≥80% at 5 µg per mosquito. Further dose–response bioassays were undertaken to determine median lethal dose (LD50) values. Compounds 1 , 2b , 2c , 2d , 2 g , 3b , 3c , 3 g, and 3 h were effective, with typical LD50 values of about 5 ? 10 µg per mosquito against female Ae. aegypti. Compounds 2c (bearing a nitro group on the aromatic ring; LD50 = 2.80 ± 0.54 µg per mosquito) and 3 h ( double halogen groups at 2,4 position on the phenyl ring; LD50 = 2.80 ± 0.54 µg per mosquito) were the most promising compounds.

CONCLUSION

Preliminary mode of action studies failed to show consistent evidence of either neurotoxic or mitochondria‐directed effects. Further chemical synthesis within this series may lead to the development of new effective insecticides. © 2017 Society of Chemical Industry
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9.
Insecticidal activity against the Colorado potato beetle, Leptinotarsa decemlineata, was measured for a series of substituted N-tert-butyl-dibenzoylhydrazines, in which one of the benzoyl moieties closer to the tert-butyl group was fixed as being 2-chloro-substitued and the other variously substituted singly or doubly. The effects of substituents on the activity were quantitatively analysed using the classical quantitative structure–activity relationship (QSAR) procedure. The activity against the Colorado potato beetle increases with the molecular hydrophobicity. In addition, various types of steric effect are at work, depending upon the positions. Hydrogen-bonding acceptor substituents at the para position enhance the activity. There seem to be threshold (or optimum) values, albeit position-dependent, in the molecular hydrophobicity, above which the activity starts to decrease. This biphasic contribution of the molecular hydrophobicity to activity against coleopterous larvae is the most conspicuous difference in substituent effects from those found for similar compounds against lepidopterous pest insects, and may be the basis of the variations in the activity spectrum for certain compounds in this series. The introduction of bulkier substituents into the meta- and para-positions of the benzene ring, apart from the tert-butyl group, is unfavorable to activity. LD50 values against Colorado potato beetle larvae of methoxyfenozide (RH-2485) and tebufenozide (RH-5992) were in the order of 10−7 mol per insect, whereas those of RH-5849, and halofenozide (RH-0345) were very low, 10−9–10−10 mol per insect being selective to the coleopterous larvae. © 1999 Society of Chemical Industry  相似文献   

10.
The insecticidal activities against houseflies (Musca domestica L.) and mustard beetles (Phaedon cochleariae Fab.) of the chrysanthemate bioresmethrin, and of 31 related 5-benzyl-3-furylmethyl 2,2-dimethylcyclopropanecarboxylates with alkenyl, alkadienyl or alkoxycarbonylalkenyl substituents at position 3 of the cyclopropane ring are compared to determine the relative influence of the isobutenyl sidechain (as in chrysanthemates) and of the other side chains. Several substituents, in particular (E)- or (Z)-butadienyl or -pentadienyl, give considerably greater activity than isobutenyl but alkoxycarbonyl compounds are less potent.  相似文献   

11.
BACKGROUND: 4‐(3‐Trifluoromethylphenyl)pyridazine represents a new series of compounds with bleaching and herbicidal activities. RESULTS: A total of 43 novel 3‐(substituted benzyloxy or phenoxy)‐6‐methyl‐4‐(3‐trifluoromethylphenyl)pyridazine derivatives were synthesised, and their bleaching and herbicidal activities were evaluated through Spirodela polyrrhiza and greenhouse tests. Some compounds exhibited excellent herbicidal activities, even at a dose of 7.5 g ha?1. CONCLUSION: The results showed that a substituted phenoxy group at the 3‐position of the pyridazine ring and the electron‐withdrawing group at the para ‐position on the benzene ring were essential for high herbicidal activity. Copyright © 2011 Society of Chemical Industry  相似文献   

12.
A series of substituted aryltriazolinones, known to inhibit protoporphyrinogen oxidase, were prepared and their structure–activity requirements at positions 4 and 5 of the aromatic ring investigated. A QSAR equation obtained for substituents at the 5 position identified the hydrophobicity term π and the Sterimol minimum width B1 as the two parameters affecting in-vitro biological activity. Greenhouse pre-emergence activity correlated with in-vitro activity and the hydrophobicity term π of the substituent at that position. It was found that the phenoxy-4-oxyacetate group at aromatic position 5 was an outlier and had to be considered separately. SAR analysis of substituents at aromatic position 4 revealed that two different models were required to explain all observed substituent effects. In the first model, where the 5 position was occupied by hydrogen, the 4-chlorobenzyloxy group at aromatic position 4 gave the best compound. The second model, where the 5 position of the aromatic ring was occupied by a group other than hydrogen, resulted in a QSAR equation, previously derived, which links substituent effects at position 4 with π and with the electronic para inductive term Fp. In this model the chloro group provides optimum biological activity. The need to separate the aryltriazolinone herbicides into several different classes in order to explain their substituent effects at aromatic positions 4 and 5 could be rationalized if more than one binding conformation, within the same binding site, is possible. © 1997 SCI  相似文献   

13.
BACKGROUND: Although more than ten strobilurin analogues have been commercialized since 1996 as fungicides, only one was available as an acaricide as of 2003. To search for novel strobilurin analogues with unique biological activities, a synthetic screening programme was carried out. RESULTS: Syntheses of compounds analogous to the commercialized fungicide metominostrobin and the acaricide fluacrypyrim led to the discovery of a lead compound, (E)‐2‐{2‐[[3,5‐bis(trifluoromethyl)phenoxy]methyl]phenyl}‐2‐(methoxyimino)‐N‐methylacetamide (3b), that showed moderate acaricidal activity against Tetranychus urticae Koch. Compound 3b has a 3,5‐(CF3)2‐phenoxymethyl group instead of the unsubstituted phenoxy substituent in metominostrobin. Optimization of compound 3b was achieved by introducing an oxime ether bridge along with an alkylthio(alkyl) branch in place of the oxymethylene chain between two aromatic moieties, as well as by replacing the methoxyiminoacetamide group with a methoxyacrylate structure, leading to (E)‐ methyl 2‐{2‐[[[(Z)[1‐(3,5‐bis(trifluoromethyl)phenyl)‐2‐methylthioethylidene]amino]oxy] methyl]phenyl}‐3‐methoxyacrylate (6c) and (E)‐ methyl 2‐{2‐[[[(Z)[1‐(3,5‐bis(trifluoromethyl)phenyl)‐1‐methylthiomethylidene]amino]oxy]methyl]phenyl}‐3‐methoxyacrylate (9a, HNPC‐A3066). CONCLUSION: The above two compounds (6c, 9a) were shown to exhibit potent acaricidal and fungicidal activity. Compound 9a (HNPC‐A3066) also exhibits larvicidal and ovicidal activities against various acarids. The acaricidal potency is comparable with those of commercial acaricides such as fluacrypyrim, tebufenpyrad and chlorfenapyr. Copyright © 2008 Society of Chemical Industry  相似文献   

14.
1,5‐Diphenyl‐1‐pentanone (A) and 1,5‐diphenyl‐2‐penten‐1‐one (B) are natural products extracted for the first time from Stellera chamaejasme. Laboratory bioassay showed that the two products have strong contact activity and very good anti‐feedant activity against Aphis gossypii and Schizaphis graminum. Both products showed dose‐dependent relationships for both forms of activity against the two aphids, the contact activity of B being about twice that of A. Both products were inferior to methomyl in contact activity but superior in anti‐feedant activity against the two aphids. This is the first report of aphicidal activity in these two compounds, which may represent a new class of aphicide. © 2001 Society of Chemical Industry  相似文献   

15.
The insecticidal activities against houseflies (Musca domestica L.) and mustard beetles (Phaedon cochleariae Fab.) of 29 new 5-benzyl-3-furylmethyl 2,2-dimethyl-cyclopropane-carboxylates are compared with those of the corresponding chrysanthe-mate (bioresmethrin) to assess the influence of non-ethylenic and isobutenyl substituents at position 3 of the cyclopropane ring. Of the new groups investigated, only 3-methoxyiminomethyl gives equal or enhanced activity; 3-(2-furyl) esters are moderately effective, but 3-phenyl and 3-alkoxycarbonyl compounds show weak activity. A 3-(2,2,2-trihaloethyl) compound was more active than compounds with other saturated groups, such as isobutyl.  相似文献   

16.
BACKGROUND: Pyrazole and hydrazone derivatives possess good insecticidal activities; their substructural units are widely used in pesticide design. In an effort to discover new molecules with good insecticidal activities, a series of pyrazole amide derivatives containing hydrazone substructures were synthesised and bioassayed. RESULTS: Bioassays demonstrated that some of the title compounds exhibited notable control of Plutella xylostella (Linnaeus), Helicoverpa armigera (Hübner), Culex pipiens pallens, Laphygma exigua (Hübner), Spodoptera litura (Fabricius), Nilaparvata lugens (Stål) and Rhopalosiphum maidis (Fitch) at 5, 10, 0.25, 200, 20, 100 and 500 mg L?1 respectively. Comparative molecular field analysis (CoMFA) based on the bioactivities for P. xylostella was studied; the values of q2 and r2 for the CoMFA model were 0.701 and 0.964 respectively. CONCLUSION: Some of the title compounds displayed good and broad‐spectrum insecticidal activities against different insect species; the CoMFA model revealed that a bulky and negatively charged group at the 4‐position of benzene could enhance insecticidal activity. These results could provide useful information for the design of novel insecticide containing substructural units of pyrazole amide and hydrazone. Copyright © 2011 Society of Chemical Industry  相似文献   

17.
N-Arylcarbamoylpyrazolines with various substituents at the para position of the carbamoyl benzene ring inhibited ATP-dependent Ca2+-uptake in synaptosomes prepared from the rat brain. The activity of these compounds was evaluated as log(1/I50), the reciprocal logarithm of half inhibitory concentration, I50 (m ), from the concentration–response curve for the inhibition of Ca2+-uptake. Among the compounds tested, methyl 3-(4-chlorophenyl)-4-methyl-1-[N-(4-trifluoromethylphenyl)carbamoyl]-2-pyrazoline-4-carboxylate was the most potent, the I50 value of which as 9·12×10−7 m . Variations in the activity in terms of log(1/I50) were quantitatively analysed using a substituent parameter, showing that the higher the electron-withdrawing effect of the substituent, the higher was the activity. The substituent effects were similar to those on insecticidal activity against the Americal cockroach. The higher the inhibitory activity against Ca2+ uptake, the higher seemed to be the insecticidal activity. Methyl(4S) - 3 - (4 - chlorophenyl) - 4 - methyl - 1 - [N - (4 - chlorophenyl)carbamoyl] - 2 - pyrazoline -4-carboxylate had higher inhibitory activity against Ca2+-uptake and higher in-secticidal activity than the R-isomer, but the difference was greater in theCa2+-uptake system.  相似文献   

18.
Variously substituted benzyl derivatives of chloronicotinyl insecticides were synthesized with a wide range of substituents including halogens, NO2, CN, CF3 and small alkyl and alkoxy groups at the ortho, meta and para positions, as well as multiple‐substituted benzyl analogues. Their binding activity to the α‐bungarotoxin binding site in housefly (Musca domestica) head membrane preparations was measured. Among the compounds tested, the activity of the meta‐CN derivative was the highest, being 20–100 times higher than those of imidacloprid, acetamiprid and nitenpyram. The synergized insecticidal activity against houseflies was also measured for selected compounds with the metabolic inhibitor, NIA16388 (propargyl propyl phenylphosphonate). For the nitromethylene analogues, including both benzyl and pyridylmethyl analogues, higher binding activity usually resulted in higher insecticidal activity. © 2000 Society of Chemical Industry  相似文献   

19.
Effects of DDT-type compounds including 1,1-bis(para-substituted phenyl)-2,2-dichlorocyclopropanes (DCC-series compounds) on sodium currents in crayfish giant axons were measured under voltage-clamp conditions. Variations in the activity to prolong the tail-current that was observed upon step repolarization of the membrane were quantitatively analysed by use of physicochemical parameters of aromatic substituents and regression analysis. Introduction of lengthy and narrow substituents was favourable to the activity. Variations in the activity were parabolically related to the hydrophobicity, optimum value being around that of H. DDT- and prolan-series compounds were 2–3 times more active than DCC-series compounds when other structural factors were the same. Insecticidal activity of the compounds was linearly correlated with the tail-current activity when the hydrophobic factor was separately considered. The insecticidal activity of DDT-series compounds was 2·5 times higher than that of others when the other factors were the same. © 1997 SCI.  相似文献   

20.
The variations in the light-dependent herbicidal activity against Echinochloa oryzicola of a number of 4-pyridone-3-carboxanilides with various substituents on the anilide and pyridone rings have been examined by use of physicochemical substituent parameters and regression analysis. The effects of substituents of the anilide ring were such that the activity was related parabolically not only with the substituent hydrophobicity (π) but also with the steric bulk parameter (Es) of the bulkier ortho substituent. The effect of substituents at the 1-position of the pyridone ring was analysed with steric(STERIMOL L and B5) and electronic(γ1) parameters. That of substituents at the 5-position of the pyridone ring was explained by a parabolic function of a steric (MR) parameter. Analyses of the activity of 105 analogs confirmed that our previous selection of a candidate compound in this series for field trials was indeed appropriate in terms of physicochemical substituent effects.  相似文献   

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