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1.
The effect of 2,4-dichlorophenoxyacetic acid (2,4-D), 4-chloro-2-methylphenoxyacetic acid (MCPA), and their derivatives: phenol, 2,4-dichlorophenol (2,4-DCP), 2,4-dimethylphenol (2,4-DMP), and catechol on the activity of acetylcholinesterase (AChE, EC 3.1.1.7) in human erythrocytes was studied. Phenol, MCPA, and 2,4-DMP did not significantly change AChE activity in human erythrocytes (in vitro). Decrease of AChE activity was observed under the highest applied dose of 2,4-D—500 and 1000 ppm. Decrease of AChE activity exposed to 2,4-DCP and catechol was noted and depended on the doses of applied compounds. The relationship between activities and substrate concentrations (curves) was analyzed for reactions of acetylcholinesterase. Catalytic constants Km and Vmax were calculated from the Michaelis curve. Statistically significant decrease of Vmax and Km was observed in the activity of AChE incubated with 2,4-DCP and catechol, revealing mixed inhibition type of AChE inhibition (this compound may affect not only on enzyme but also on complex ES as well). 2,4-D decreases Vmax but do not change Km value, what reveals non-competitive type of AChE inhibition by this compounds. Non-competitive inhibition does not depend on the substrate concentrations but only on the inhibitor concentration and its Ki value, characterizes the affinity of inhibitors towards enzyme. In conclusion, changes of AChE activity upon 2,4-D, 2,4-DCP, and catechol are the consequences of direct interactions between compounds and the enzyme and indirect via membrane modification and increase of Reactive Oxygen Species. 相似文献
2.
Christoph Dingler Wolfgang Ladner Georg A. Krei Bryan Cooper Bernhard Hauer 《Pest management science》1996,46(1):33-35
With Beauveria bassiana Lu 700 as biocatalyst an ecologically beneficial process has been developed for the production of (R)-2-(4-hydroxyphenoxy) propionic acid. The fungal strain used in this process, B. bassiana Lu 700, is also a very suitable catalyst for the selective monohydroxylation of other aromatic carboxylic acids. 相似文献
3.
Paul H. Smith Keith Chamberlain Jane M. Sugars Richard H. Bromilow 《Pest management science》1995,44(3):219-224
More than 20 N-(2-cyano-2-methoximinoacetyl)amino acids and derivatives were synthesised and tested for antifungal activity against grape downy mildew, caused by Plasmopara viticola (de Bary) Berl. & de Toni, and rape downy mildew, Peronospora parasitica Fr. Two of the compounds containing a free carboxylic acid group, a moiety which has been shown to confer phloem mobility on compounds, showed high activity, especially against P. parasitica, in protectant tests. These results indicate that there is no incompatibility between the acid function and fungicidal activity. A number of the esters showed activity comparable with that of cymoxanil in the protectant tests, and the tert-butyl esters of the methionine derivative and its sulfone were more than ten times as active as the commercial compound. 相似文献
4.
Nobuyoshi Mikami Naohiro Takahashi Hirohiko Yamada Junshi Miyamoto 《Pest management science》1985,16(2):101-112
Using a spin-trap reagent 3-nitrosodurene (1,2,4,5-tetramethyl-3-nitrosobenzene), the short-lived free radicals generated by ultraviolet irradiation of fenvalerate [(RS)-α-cyano-3-phenoxybenzyl (RS)-2-(4-chlorophenyl)-3-methylbutyrate] in degassed benzene or dichloromethane, were scavenged as the more stable nitroxide radicals. These radicals were separated by high-performance liquid chromatography and identified individually by electron-spin resonance spectroscopy, as well as by gas chromatography/mass spectrometry. As a result, they were found to be the spin adduct mixtures of the 4-chloro-α-isopropylbenzyl and α-cyano-3-phenoxybenzyl radicals, which are involved in the photo-induced decarboxylation process of fenvalerate. Discrimination of the radicals was also performed by the isotope-labelling method whereby the benzylic proton in the acid moiety was deuteriated. The spin numbers of the nitroxides decreased by about five-fold when photolysis was carried out in oxygenated benzene solution. N-Benzylidene-tert-butylamine N-oxide trapped both radicals but much less efficiently. The nitroxide of the 4-chloro-α-isopropylbenzyl radical was predominant at 25°C or –40°C, but the proportion of the α-cyano-3-phenoxybenzyl nitroxide radical increased at the lower temperature. 相似文献
5.
以对叔丁基氯苄为起始原料,经氰化、酯化、酯交换和酰基化4步反应合成了新化合物2-酰基氰基乙酸酯类衍生物 SYP-10898 ,其化学结构经核磁共振氢谱和元素分析确证。室内生物活性测试结果表明, SYP-10898 对朱砂叶螨Tetranychus cinnabarinus成螨的LC50值为3.67 mg/L,优于对照药剂丁氟螨酯(cyflumetofen)。田间试验结果表明,在50 mg/L剂量下, SYP-10898 对柑桔红蜘蛛Panonychus citri表现了良好的速效性和持效性,3 d后的防效在93%以上,30 d后的防效在79%以上。 相似文献
6.
David A. Pulman Ian H. Smith John P. Larkin John E. Casida 《Pest management science》1996,46(3):237-245
5-tert-Butyl-2-(4-ethynylphenyl)pyrimidine and the corresponding 2,5-disubstituted-4H-1,3-thiazine block the GABA-gated chloride channel at c.20and c.200 nm , respectively, measured as 50% inhibition of the binding of 1-(4-ethynylphenyl)-4-[3H]propyl-2,6,7-trioxabicyclo[2.2.2]octane (4′-ethynyl-4-n-[3H]propylbicycloorthobenzoate; [3H]EBOB) in house fly and mouse brain membranes, and they are also toxic to topically-treated flies with LD50 values of 6–27 μg g−1 alone and 2–6 μg g−1 with piperonyl butoxide (PB) as synergist. In the pyrimidine series, the general pattern of effectiveness of substituents in the 5-position is tert-butyl>isopropyl≈cyclohexyl≈cyclopropyl>methyl, phenyl and 3- and 4-fluorophenyl, and in the 2-position is 4-ethynylphenyl≪4-bromophenyl. These planar pyrimidines and nearly-planar 4H-1,3-thiazines with 2-ethynylphenyl or 2-bromophenyl and 5-tert-butyl or 5-isopropyl substituents are more effective than the corresponding 6H-1,3-thiazine, 6-oxo-1,3-thiazines and 4,6-dioxo-1,3-thiazine examined, but they are less active than the analogous conformationally flexible trans-1,3-dioxanes and -1,3-dithianes. The heterocyclic moiety confers a region of high electron density and positions the 2- and 5-substituents in a linear or parallel relationship for optimal affinity at the receptor. Two observations indicate that the new pyrimidines and thiazines probably act as chloride channel blockers. First, the poisoning signs are identical to those of EBOB in both mice and house flies. Second, each of the pyrimidines, thiazines and dioxanes falls on the same correlation line for inhibition of [3H]EBOB binding and toxicity to house flies (with PB) as that obtained earlier for EBOB analogs, dithianes and polychlorocycloalkanes, suggesting that they all act at the same or closely coupled binding sites in the GABA-gated chloride channel. 相似文献
7.
Synthesis and insecticidal activity of novel 1,3,4-oxadiazolin-5-one and pyrazolin-5-one derivatives
Kazuo Yagi Akira Numata Norihiko Mimori Toshiro Miyake Kazutaka Arai Shigeru Ishii 《Pest management science》1999,55(2):161-165
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
8.
2,6,7-Trioxa-1-phosphabicyclo[2.2.2]octane 1-sulfides (bicyclophosphorothionates) with various C1–4 alkyl groups at the 3- and 4-positions were synthesized and tested for their ability to compete with [3H]4′-ethynyl-4-n-propylbicycloorthobenzoate (EBOB), a non-competitive antagonist of γ-aminobutyric acid (GABA) receptors, for specific binding to rat-brain and housefly-head membranes, and for their insecticidal activity against houseflies. Among the 3,4-substituted analogues, 20 compounds were selectively active for housefly GABA receptors versus rat GABA receptors. The 3-alkyl groups of C3 length and the 4-alkyl groups of C4 length were tolerated in housefly receptors, whereas such bulky substituents were deleterious in rat receptors. The 4-isobutyl-3-isopropyl analogue was the most potent in housefly receptors (IC50 = 45.2 nM ), and tert-butylbicyclophosphorothionate (TBPS), with the 4-tert-butyl group and no 3-substituent, was the most potent in rat receptors (IC50 = 62.2 nM ). Their receptor selectivities (rat IC50/housefly IC50) were 52 and 0.038, respectively. The insecticidal activity (LD50) of 20 active analogues was well correlated with their potency (IC50) in inhibiting [3H]EBOB binding to housefly-head membranes (r = 0.93). The results obtained in the present study indicate that the introduction of appropriate alkyl groups into the 3- and 4-positions of bicyclophosphorothionate leads to non-competitive antagonists with increased affinity and selectivity for housefly ionotropic GABA receptors versus rat GABAA receptors. © 1999 Society of Chemical Industry 相似文献
9.
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
10.
首次以氯甲基化交联聚苯乙烯树脂(CMCPS)为载体和大分子引发剂、2,4-二氯苯氧乙酸(2,4-D)为模板、丙烯酰胺(AM)为单体、乙二醇二甲基丙烯酸酯(EDMA)为交联剂、溴化铜/2,2'-联吡啶(CuBr/Bpy)为催化剂,采用表面引发原子转移自由基聚合(SI-ATRP)技术,制备了2,4-二氯苯氧乙酸分子印迹聚合物(2,4-D MIPs),并研究了模板分子与功能单体比例对该印迹聚合物吸附量的影响。通过动态、静态及竞争试验考察了该印迹聚合物对2,4-D的吸附性能。结果表明:2,4-D MIPs对模板分子2,4-D具有良好的特异性识别作用;与2,4-二氯苯酚和2,4-二氯苯甲醛相比,2,4-D MIPs对2,4-D的选择性系数分别为2.84和3.75,相对选择性系数分别为2.31和2.29。采用Scatchard模型分析,可以得到两类结合位点,计算得到最大表观吸附量(Qmax)分别为76.92和142.91 mg/g,离解常数Kd分别为632.91和2 309.47 mg/L。将2,4-D MIPs作为固相萃取剂,对豆芽样品进行添加回收试验,回收率为86%~104%,相对标准偏差(RSD)为1.9%~10%,方法的检出限为20 ng/g。该印迹聚合物可以富集分离测定2,4-D,稳定性好,并且能重复使用。 相似文献
11.
Peter Babczinski 《Pest management science》1999,55(6):671-674
Plant cell cultures have been used to study the metabolic degradation of 4-amino-5-methyl-2-(tert-butylaminocarbonyl)-1,2,4-triazolin-3-one. The biochemical basis of selectivity was shown to reside in effective metabolic conjugation. The herbicide was eliminated from cell cultures of beet (which is tolerant to it) by conjugation (N-glycolisation), but this occured to only a limited extent with cell cultures of non-target plants such as soybean. 相似文献
12.
Michel Couderchet Pierre F. Bocion Reynold Chollet Karl Seckinger Peter Bger 《Pest management science》1997,50(3):221-227
Due to the presence of an asymmetrically substituted C atom, dimethenamid [2-chloro-N-(2,4-dimethyl-3-thienyl)-N-(2-methoxy-1-methylethyl)acetamide], a recently introduced N-thienyl chloroacetamide herbicide, exists as two stereoisomers (S and R) having differing herbicidal activities as demonstrated with a selection of weeds and Lemna minor. The activity of the two isomers was investigated in greater detail with the green alga Scenedesmus acutus and compared to that of alachlor [2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide]. As with alachlor, the S isomer (5 μM ) strongly inhibited algal growth and fatty acid desaturation while the R isomer had no effect. In short-term experiments (up to 5·5 h), the S isomer and alachlor (100 μM ) inhibited [14C]acetate uptake and its incorporation into fatty acids in the same manner, while the R isomer did not. Incorporation of [14C]acetate into a non-lipid fraction of the algae was strongly inhibited by alachlor and the S isomer (100 μM ) and only slightly by the R isomer. A 50% inhibition of incorporation of [14C]oleic acid into the same non-lipid fraction was attained with less than 10-7 M of the S isomer while 10-5 M of the R form of dimethenamid achieved only a 40% inhibition. The same stereospecificity of the compound on growth, fatty acid desaturation, acetate uptake and oleic acid incorporation provides strong evidence that dimethenamid may act upon a primary, specific target in lipid metabolism. Furthermore, the comparable biological activities of dimethenamid and alachlor indicate that this target is common to both N-phenyl and N-thienyl chloroacetamide herbicides. © 1997 SCI. 相似文献
13.
The compounds tested were isopropyl (±)-(E,E)-11 -methoxy-3,7,11-trimethyl-dodeca-2,4-dienoate (ZR 515) and 6,7-epoxy-3-ethyl-7-methylnonyl 4-ethylphenyl ether (R 20458) (two juvenile hormone mimics); 2,6-di-tert-butyl-4-(αα-dimethyl-benzyl)phenol (MON 0585) (which inhibits melanisation during pupation); diflubenzuron and 1-(4-chlorophenyl)-3-(2,6-dichlorobenzoyl)urea (PH 60:38) (which affect chitinisation during moulting); and (E)-oct-2-enoic acid and (E)-non-2-enoic acid (all of which are claimed to have “teratogenic” effects on insects). The relative potencies of these chemicals were assessed on eggs, larvae and pupae of several mosquito species. Their characteristic delayed harmful effects are described and related to various stages of metamorphosis. 相似文献
14.
天然产物吩嗪-1-羧酸（PCA）作为重要的微生物代谢产物,在假单胞菌属（Pseudomonads）和链霉菌属（Streptomycetes）等微生物分泌物中广泛存在,具有医用抗肺癌活性及抗水稻纹枯病、西瓜枯萎病、辣椒疫病、小麦全蚀病、西瓜炭疽病和油菜菌核病等病原菌的广谱性农用抗菌活性,对人畜和环境无害,并具有独特的化学结构,是研发绿色农药的理想化合物。文章综述了吩嗪-1-羧酸及其类似物在微生物发酵及化学合成方面的研究进展,分析了各合成路线中的关键反应,讨论了各合成方法的优缺点。 相似文献
15.
Effect of humic acid on Meloidogyne incognita (Kofoid & White) Chitwood infecting banana (Musa spp.)
Humic acid, a natural by-product from lignite coals, was evaluated for its potential to control root-knot nematode, Meloidogyne incogntia infecting banana. Hatching of M. incognita eggs was inhibited 50%–100% following incubation in 0.08%-2.0% humic acid in vitro. Exposure of juveniles (J2) of M. incognita to different humic acid concentrations significantly affected the mobility of J2 in vitro. The percent immobility of J2 increased with concentrations of humic acid up to 0.08%. In pot experiments, soil treatment with humic acid reduced the root galling in banana plantlets. All the humic acid tested concentrations (0.04%, 0.08%, 0.2% and 0.4%) significantly reduced the nematode soil density by 53.5%–56.7%, root infection by 61.9%–63.8%, egg population by 61.9%–63.8% and reproduction rate by 55.7%–56.6%. A significant improvement of growth of banana plantlets in terms of number of leaves, pseudostem height, girth, weight, root length and weight was noticed in humic acid treated pots. Humic acid did not suppress growth of the biocontrol agents Pseudomonas fluorescens and Trichoderma viride in vitro. Results suggest that soil treatment with humic acid at 0.04% not only offers significant nematode control but also improves growth of banana. 相似文献
16.
为明确以天然产物阿魏酸为母体进行化学结构改造得到的化合物4-羟基-3-甲氧基肉桂酸乙酯的生物活性及其除草机制,利用茎叶喷雾法和小杯法测定其对马唐和反枝苋的生物活性,基于生理生化指标及功能基因表达量对其除草作用机制进行研究。结果表明:4-羟基-3-甲氧基肉桂酸乙酯对马唐茎叶鲜重抑制中浓度IC50为46.27 mg/L;对反枝苋胚根和芽的IC50分别为129.94 mg/L和147.33 mg/L,且在500 mg/L浓度处理时可抑制反枝苋种子萌发;对拟南芥根长的IC50为43.82 mg/L,在160 mg/L浓度处理时拟南芥几乎停止生长、叶片发黄、根毛堆积。该化合物以1 000 mg/L浓度处理马唐叶片2、3、8 h后,电导率较对照组分别增加了22.70%、18.46%和25.62%;1 000 mg/L浓度处理下叶绿素a/b为2.43,较对照的3.62显著下降;处理后叶表微观结构观察发现化合物浓度越大,植物叶片表皮毛倒伏和褶皱越严重;拟南芥AT4G04820基因表达量显著下降,在处理45 min时下降最显著,与对照组相差42.52倍,微管蛋白含量下降,造成微管解离,从而抑制植物生长。表明4-羟基-3-甲氧基肉桂酸乙酯具有较强的除草活性,可能通过破坏细胞结构、抑制光合作用及阻止根生长等途径使杂草生长受到抑制甚至死亡。 相似文献
17.
Late blight caused by Phytophthora infestans is one of the most devastating diseases of the potato crop. Resistance breeding and current fungicides are unable to control the rapidly evolving P. infestans and new control strategies are urgently needed. This study examined mechanisms of dl ‐β‐aminobutyric acid (BABA)‐induced resistance (IR) in the potato–P. infestans system. Leaves from two cultivars that differ in their degree of resistance, Bintje and Ovatio, were analysed after foliar treatment with BABA. Rapid activation of various defence responses and a significant reduction in P. infestans growth were observed in leaves treated with BABA. In the more resistant cultivar, Ovatio, the activation was both faster and stronger than in Bintje. Microscopic analysis of leaves treated with BABA revealed induction of small hypersensitive response (HR)‐like lesions surrounded by callose, as well as production of hydrogen peroxide (H2O2). Molecular and chemical analyses revealed soluble phenols such as arbutin and chlorogenic acid and activation of PR‐1. These results show a direct activation of defence responses in potato, rather than priming as reported for other plant species. They also show that the efficiency of BABA‐IR differs between cultivars, which highlights the importance of taking all aspects into consideration when establishing new methods for disease management. 相似文献
18.
19.
Vivian I. Knight Hong Wang James E. Lincoln Edward C. Lulai David G. Gilchrist Richard M. Bostock 《Physiological and Molecular Plant Pathology》2001,59(6):277
Arachidonic acid (AA) is a fatty acid elicitor abundant in the glycerolipids of the late blight pathogen Phytophthora infestans and related Oomycete species. Lipoxygenases (LOX), which catalyze the addition of molecular oxygen to the 1 or 5 position of a cis, cis -1,4- Z, Z -pentadiene system in polyunsaturated fatty acids, is induced in host plants such as tomato and potato during infection by P. infestans. Here it is reported that AA, the LOX metabolites of AA, 5- and 15-hydroperoxyeicosatetraenioc acid (5- and 15-HpETE), and the LOX metabolite of linoleic acid, 9-hydroperoxyoctadecadienoic acid (9-HpODE), are potent inducers of programmed cell death (PCD) in tomato protoplasts. 5- and 15-HpETE increased DNA fragmentation as detected by t erminal deoxynucleotidyl transferase-mediated d U TP-X n ick e nd l abeling (TUNEL) and increased DNA laddering as visualized by ligation-mediated PCR. Background levels of DNA laddering were decreased in intensity by Zn2+ and increased by Ca2+, effects that are consistent with the reported action of these cations on PCD-associated endonucleases in other systems. H2O2, methyl jasmonate, and linoleic and linolenic acids were not toxic to tomato protoplasts at concentrations up to 350 μ
, and lipid peroxides (LD100 = 80 μ
) were far more potent inducers of death than free AA within this same concentration range. These results indicate the potential of fatty acid peroxides and LOX-related metabolism to engage an apoptotic type of PCD in higher plant cells. 相似文献
20.
Bacterial wilt, caused by Ralstonia solanacearum, is a devastating soilborne disease in plants that limits the production of many crops worldwide. Although management of bacterial wilt has so far been unsuccessful, enhancing host resistance to the pathogen may be an effective control strategy. Recently, magnesium oxide (MgO) was found to induce defence responses against R. solanacearum in tomato plants. Here, the mechanisms underlying MgO-induced defence responses against R. solanacearum (MgO-i DARS) were investigated using Arabidopsis thaliana as a host plant. MgO-i DARS was confirmed in A. thaliana mutants deficient in jasmonic acid or ethylene signalling pathways as well as in the wildtype (Col-0) plants. In contrast, no MgO-i DARS was found in A. thaliana mutants deficient in the salicylic acid (SA) production (sid2-2) and signalling pathways (tga1-1 and npr-1). MgO treatment led to significant accumulation of SA in both roots and shoots of Col-0. The SA biosynthesis gene isochorismate synthase 1 (ICS1) was induced in roots and shoots of A. thaliana treated with MgO. An NADPH oxidase gene respiratory burst oxidase homolog D (AtRbohD) was up-regulated in both roots and shoots of Col-0 treated with MgO. No MgO-i DARS was observed in A. thaliana mutants deficient in AtRbohD. These results suggest that SA and RBOHD-mediated ROS are pivotal for MgO-i DARS in A. thaliana. 相似文献