Identification of novel inhibitors of calling and in vitro [14C]acetate incorporation by pheromone glands of Plodia interpunctella

Some octopamine agonists were found to suppress in vitro biosynthesis of the calling pheromone of the Indian meal moth, Plodia interpunctella. Isolated pheromone-gland preparations incorporated sodium [14C]acetate at a linear rate for 3 h when incubated with the pheromone biosynthesis activating neuropeptide (PBAN). This incorporation was dependent on the dose of PBAN (up to 0.5 microM). Thin-layer chromatography of a pheromone-gland extract revealed quantitative incorporation of radioactivity into a product exhibiting the same mobility as (Z,E)-9,12-tetradecadienyl acetate, the main component of the calling pheromone of P interpunctella. Twenty-seven octopamine agonists were initially screened using a calling behaviour bioassay of female P interpunctella. Four derivatives with activity in the nanomolar range were identified which were, in order of decreasing pheromonostatic activity: 2-(2,6-diethylphenylimino)thiazolidine > 2-(2,6-diethylphenylimino)oxazolidine > 2-(2,6-dimethylphenylimino)thiazolidine > 2-(2-ethylphenylimino)oxazolidine. These compounds also showed in vitro inhibitory activity in intracellular de novo pheromone biosynthesis. The results of the present study indicate that these derivatives could provide useful information in the characterization and differentiation of octopaminergic receptor types and subtypes.     

杀虫剂对蛾类昆虫生殖行为影响的研究进展

综述了近年来国内外关于杀虫剂对蛾类昆虫求偶、性信息素合成及释放、定向行为、交配和产卵等生殖行为影响的研究进展。经杀虫剂处理后,许多雌蛾的求偶行为受到抑制、性信息素含量降低,雄蛾对性信息素的反应和交配成功率下降,但药剂对产卵量和卵孵化率没有明显影响。而部分药剂可增强雄蛾对性信息素的反应,刺激雌蛾信息素含量异常增高和使活性组的比例发生漂移。     

A comparative molecular field analysis study of obtusifoliol 14α-methyl demethylase inhibitors

This report describes the development of a Comparative Molecular Field Analysis (CoMFA) model from a set of obtusifoliol 14α-methyl demethylase (DM) inhibitors to aid in the design of herbicides targeting sterol biosynthesis. CoMFA is a three-dimensional (3-D) quantitative structure–activity relationship (QSAR) method that is useful in the probing of receptor binding sites when experimental structure data are unavailable. Conformational analysis and SAR of some rigid and active analogs were used to build the initial model using the active analog hypothesis. The model was subsequently used to design compounds that retain the active site shape requirements, but incorporate physical properties that favor soil-applied herbicidal action. In addition, a second-generation CoMFA model incorporating the newly designed inhibitors was developed and represents the current understanding of the DM binding site. This model was derived from a pharmacophore developed from two methods, the active analog approach as well as from the Catalyst program. The fact that two independent methods produced a similar pharmacophore strengthens the validity of the model. © 1999 Society of Chemical Industry     

噁唑烷类安全剂的三维定量构效关系研究

针对25个噁唑烷类化合物,以玉米根部GST活性为衡量标准,运用三维定量构效关系中的比较分子力场分析(CoMFA)和比较分子相似性指数分析(CoMSIA)两种方法进行研究;应用20个化合物作为训练集,分别建立相应的模型,并对其进行结构和活性关系的分析。CoMFA模型的交叉验证系数q2为0.647,非交叉验证系数r2为0.999;CoMSIA模型交叉验证系数q2为0.527,非交叉验证系数r2为0.949。使用训练集以外的5个化合物进行了验证,两种模型预测值与实测值偏差较小,都显示出了较好的预测性和稳定性。研究结果可为设计新的噁唑烷类潜在的除草剂安全剂提供可靠信息。     

外源注射PBAN对甜菜夜蛾求偶、交配与产卵作用初步研究

在光期对甜菜夜蛾雌蛾注射人工合成的小分子性信息素合成激活肽PBAN,并观察其求偶、交配与产卵行为。结果表明,人工合成甜菜夜蛾PBAN适宜的注射浓度为3.5 pmol/μL。与注射蒸馏水对照相比,注射PBAN能够有效促进雌蛾提前发生求偶行为,且持续交配时间显著延长,单雌产卵量也显著增加。但与空白对照(未注射)相比,尽管注射PBAN的雌蛾求偶行为有所提前,但交配率和产卵量均明显低于对照组。初步说明外源注射PBAN对甜菜夜蛾求偶、交配与产卵行为均有重要的影响作用,特别是引起雌蛾求偶行为明显提前,甚至在光期观察到注射PBAN的雌蛾出现求偶行为。这为验证甜菜夜蛾PBAN的功能提供了依据,也为遗传改造PBAN基因干扰成虫交配达到无公害防治开拓了思路。     

Inhibitors of juvenile hormone biosynthesis in corpora allata of the cockroach Periplaneta americana (L.) in vitro

The spontaneous biosynthesis of methyl (2E,6E)-(10R)-10,11-epoxy-3,7,11-trimethyldodeca-2,6-dienoate (juvenile hormone III; JH III) in excised corpora allata of Periplaneta americana was inhibited by a number of synthetic prop-2-ynyl ethers and 1,3-benzodioxole derivatives. One structurally diverse group of compounds inhibited only the final biosynthetic enzyme methyl farnesoate epoxidase (EC.1.14.14.–) at low to moderate concentrations, but at higher concentrations, also inhibited methyl farnesoate (MF) formation, causing an accumulation of MF in the concentration range 10 to 100 μM. For a second, more limited, group of compounds, there was close congruence between the inhibition of JH III biosynthesis and that of total ester (MF plus JH III) biosynthesis over their effective inhibitory concentration ranges. In contrast to the first group, there was no accumulation of MF and these compounds evidently inhibited JH III biosynthesis, at the level of either farnesoic acid esterification by O-methyl transferase (EC.2.1.1.–), or at an earlier step in the biosynthetic pathway that remains to be elucidated.     

我国昆虫性信息素技术的研发与应用进展

昆虫性信息素是昆虫性成熟后求偶时所分泌的能引诱同种异性个体以进行交尾的微量挥发性化学物质,具有种的特异性,因此广泛应用于害虫的监测与防治。近年来,我国在昆虫性信息素的工业化合成、纯化、稳定,缓释生产工艺的改进和完善,各种干式诱捕器的开发研制,智能化性诱测报技术研发,以及多种害虫田间性诱实用技术试验示范方面取得了一系列进展,极大地促进了重大害虫的监测预报和绿色防控。本文详细介绍和比较了群集诱杀技术的诱芯、诱捕器种类及其应用特点,交配干扰技术的释放器及其智能化的原理、种类和应用特点;系统总结了求偶与交配之间的关系、性信息素引诱力和专一性,以及生物和非生物因子对群集诱杀和交配干扰效果的影响;总结了群集诱杀和交配干扰技术在水稻、玉米、蔬菜、果树、棉花等作物重要害虫中的应用进展。最后,分析了当前性信息素技术研发与推广应用中仍存在的问题,并提出了改进对策及建议。     

两种亚致死剂量的农药对亚洲玉米螟化学通讯系统的干扰作用

采用胸部点滴法研究马拉硫磷、溴氰菊酯在亚致死剂量(100h-LD30)下对亚洲玉米螟Ostrinia furnacalis雌蛾性信息素通讯系统的干扰作用。试验结果表明：①点滴当天雌蛾的求偶百分率分别下降为对照的50％、33％，但求偶高峰期出现的时间未受影响。②点滴这两种药剂后求偶百分率的恢复过程相当缓慢。③亚致死剂量的马拉硫磷使性信息素的量下降1／2左右，亚致死剂量的溴氰菊酯使性信息素量下降为不足对照的1／4，但性信息素顺反异构体比例均不受影响。④马拉硫磷点滴后第4天性信息素量能完全恢复，但溴氰菊酯点滴后，到第4天仍几乎不能恢复。     

Synthesis of allylic trifluoromethyl ketones and their activity as inhibitors of the sex pheromone of the leopard moth, Zeuzera pyrina L. (Lepidoptera: Cossidae)

BACKGROUND: Trifluoromethyl ketones (TFMKs), structurally related to the pheromones, are good inhibitors of pheromone communication in insects. To determine their activity on Zeuzera pyrina L. (Lepidoptera: Cossidae), a polyphagous pest, the authors have prepared two diunsaturated TFMK analogues of the major (3) and the minor (4) pheromone components, and two monounsaturated ones (5, 6). Their biological activity in electroantennogram (EAG), wind tunnel and field tests is presented. RESULTS: The synthetic strategy to obtain the allylic TFMKs 3 and 5 is based on the reactions of diene 10 and 1‐octadecene with trifluoroacetaldehyde ethyl hemiacetal, followed by Dess–Martin oxidation of the resulting homoallylic trifluoromethyl alcohols. In EAG, topical application of analogues 3 and 4 on male antennae significantly reduced the pheromone response. In the wind tunnel, compound 4 reduced the number of contacts with the pheromone source. In the field, traps baited with mixtures of pheromone and inhibitors captured significantly fewer males than the pheromone alone. CONCLUSION: An efficient synthesis of allylic TFMKs is reported, with good overall yield, regiospecificity and diastereoselectivity. These compounds are good inhibitors of the pheromone in electrophysiology, wind tunnel and field tests. The results show the importance of two unsaturations at positions 2 and 13 of the trifluoroacyl group in the structure of the analogues, the latter being critical for inhibitory activity. Copyright © 2011 Society of Chemical Industry     

Insect peptide hormones: a selective review of their physiology and potential application for pest control

Our knowledge on primary structure, synthesis, release, receptor binding, structure-activity relationships, mode of action and degradation of, mainly, neuropeptides from insects has increased dramatically during the last 10 years or so. Here, five case studies are presented, which deal selectively with effects on: reproduction (trypsin modulating oostatic factor in mosquito); energy metabolism, locomotion and the immune system (adipokinetic hormones); water and ion balance, and feeding behaviour (diuretic hormones, kinins, sulfakinins); sex attraction (pheromone biosynthesis activating neuropeptide); and growth and development, and muscle activity (allatostatins). The literature is reviewed in the context of how the knowledge on neuropeptides has been and can be used for the design of novel, safe and selective compounds to control pest insects in the foreseeable future.     

杀虫剂亚致死剂量对昆虫性信息素通讯系统影响的研究进展

杀虫剂亚致死剂量对昆虫生理和行为的影响日益受到人们的关注.亚致死剂量杀虫剂影响雄虫嗅觉感受能力,使其不能准确识别性信息素信号,导致对信号的错误整合;对雌虫则影响性信息素各组分的滴度、比例及求偶和交配行为.短期作用可降低两性间的交配率及下一代种群发生量,长期作用则可能使性信息素通讯系统发生漂移.作者综述了菊酯和有机磷两类杀虫剂在这方面的研究进展,并对一些值得深入研究的问题进行了讨论.     

吡啶甲基亚氨基噻(噁)唑烷的合成及生物活性

根据天然海藻糖酶抑制剂的结构设计了一类吡啶甲基亚氨基噻(噁)唑烷化合物, 通过吡啶甲基异硫氰酸酯和相应的胺反应, 然后在盐酸或黄色氧化汞条件下关环,合成了吡啶甲基亚氨基噻唑烷和噁唑烷,其结构得到IR、1H NMR、HRMS的确证。测试了化合物对昆虫(家蝇)飞行的抑制能力。对影响合成反应的因素以及生测结果进行了讨论。     

Harelish负向调控棉铃虫性信息素生物合成机制的初步研究

性信息素是蛾类昆虫通讯的关键信号分子,其生物合成机制已在家蚕Bombyx mori、棉铃虫Helicoverpa armigera和亚洲玉米螟Ostrinia furnacalis等蛾类中明确了,但其负向调控机制尚不明确。本文探索了Harelish基因在棉铃虫雌蛾性信息素生物合成中的作用。结果发现,Harelish基因在棉铃虫雌蛾中肠、表皮、脑、触角、脂肪体、肌肉和性信息素腺体等7个组织中均有表达,且在羽化后随着性信息素生物的合成和释放而高丰度表达。基于RNAi降低Harelish基因转录水平的表达量后,其性信息素含量和钙调磷酸酶活性均显著上升,表明Harelish通过抑制钙调磷酸酶活性负向调控了性信息素的生物合成。该研究为利用性信息素生物合成的终止信号为分子靶标来防控害虫奠定理论基础。     

Use of insect antifeedants against aphid vectors of plant virus disease

The probing and feeding behaviour of aphids can result in uptake of viruses from infected plants and subsequent transmission to healthy plants. It is possible to interfere with virus acquisition and transmission by influencing aphid host-selection and feeding behaviour with antifeedant chemicals. Published work is reviewed and new work is presented in this paper. The two most successful classes of antifeedants against aphids are (a) compounds derived from the aphid alarm pheromone and (b) plant-derived antifeedants such as the sesquiterpene (-)-polygodial. Results with these and other compounds are discussed in terms of antifeedant activity against Myzus persicae, their effects on resistant aphids and the evidence for dec?ease in virus spread by aphids in laboratory and field.     

Sublethal effects of azadirachtin on lipid metabolism and sex pheromone biosynthesis of the Asian corn borer Ostrinia furnacalis

Azadirachtin has remarkable toxic and growth inhibitory effects on Ostrinia furnacalis (Guenée) (Lepidoptera: Pyralidae). In this study, sublethal effects of azadirachtin on fatty acid metabolism and sex pheromone biosynthesis in O. furnacalis were investigated. Quantities of fatty acids were significantly reduced when larvae were fed a diet containing azadirachtin at 0.1?C10?ppm. After 10?days, fatty acids were reduced by 50% on a diet treated with 10?ppm azadirachtin; the relative composition of fatty acids was also affected. The relative proportion of C18:2 fatty acid decreased significantly in adult survivors, correlating with decreased fecundity. Furthermore, sex pheromone titers in adults were inversely proportional to dietary azadirachtin concentration, and reduced by 50% relative to controls when larvae were fed a diet containing 10?ppm azadirachtin. However, there were no effects of azadirachtin on pheromone blend ratios. Our results suggest that reductions in fecundity and pheromone titer in O. furnacalis are associated with alterations in lipid metabolism by azadirachtin, although these effects are not linked to a reduction in consumption.     

Impact of sub-lethal residues of azinphos-methyl on the pheromone-communication systems of insecticide-susceptible and insecticide-resistant obliquebanded leafrollers Choristoneura rosaceana (Lepidoptera: Tortricidae)

The effects of sub-lethal residues of azinphos-methyl on pheromone production, calling, female attractiveness and the ability of males to locate sources of natural and synthetic pheromone were compared in azinphos-methyl-susceptible (susceptible) and azinphos-methyl-resistant (resistant) obliquebanded leafrollers, Choristoneura rosaceana (Harris). The amount of pheromone in susceptible females was reduced by 29-33% after exposure to azinphos-methyl; this treatment did not affect the pheromone content of resistant females. Azinphos-methyl-treated resistant females contained 39-43% less pheromone than azinphos-methyl-treated susceptible females. Resistant females that were not treated with azinphos-methyl contained 35-56% less pheromone than susceptible females that were not treated with insecticide. The incidence of calling was reduced by 67-100% in azinphos-methyl-treated susceptible females; the incidence of calling by resistant females was not affected by exposure to azinphos-methyl. The incidence of calling by azinphos-methyl-treated susceptible females was 58-100% lower than that of azinphos-methyl-treated resistant females. There was no difference in the incidence of calling between susceptible and resistant females that had not been treated with insecticide. In a flight tunnel, treatment with insecticide reduced the attractiveness of susceptible females by 38%; treatment with insecticide did not affect the attractiveness of resistant females. There was no difference in the proportion of males attracted to susceptible and resistant females that had, or had not been treated with insecticide. In an apple orchard, the attractiveness of susceptible and resistant females treated with azinphos-methyl was reduced by 84 and 12%, respectively. The proportion of males attracted to azinphos-methyl-treated susceptible females was 58% lower than the proportion attracted to azinphos-methyl-treated resistant females, whereas, if females were not treated with insecticide, the proportion attracted to resistant females was 57% lower than the proportion attracted to susceptible females. In a flight tunnel, azinphos-methyl did not affect the ability of susceptible or resistant males to locate a source of pheromone gland extract. Likewise, in an apple orchard, the insecticide treatment had no effect on the ability of susceptible or resistant males to locate a source of synthetic pheromone. In a flight tunnel, there was no difference in the proportion of azinphos-methyl-treated susceptible and resistant males locating a source of pheromone gland extract; however, in the orchard, 39% fewer azinphos-methyl-treated resistant males located a source of synthetic pheromone than azinphos-methyl-treated susceptible males. A similar proportion of susceptible and resistant males that had not been treated with insecticide located a source of pheromone gland extract in the flight tunnel, but in the orchard, the proportion of resistant males not treated with azinphos-methyl that located the source of synthetic pheromone was 32% lower than the proportion of susceptible males not treated with this insecticide. The implications of the differences in the effect of sub-lethal residues of azinphos-methyl on the pheromone communication system of susceptible and resistant moths are discussed in relation to the theory of the development of insecticide resistance, the detection of resistance in feral populations of moths using sex pheromone-baited traps, and the control of moths using sex pheromone-mediated mating disruption.     

Chitin biosynthesis inhibition and fungicidal effect of thiosemicarbazones of 2-formyl- and 2-acetylpyridine,their hydrogenated derivatives and copper complexes thereof

Several thiosemicarbazones of 2-formyl- and 2-acetylpyridine dialkylated on N⁴ and non-alkylated on N² were found to be broad-spectrum protectant fungicides with activity particularly against oomycetes. The effect of some of the compounds on chitin biosynthesis was studied, but the low inhibitory activity observed combined with the fungicidal activity spectrum—particularly the high activity against oomycetes—excludes this as their main mode of action. Attempts at enhancing the systemic properties of the compounds by chemical modifications failed.     

银锭夜蛾性信息素拮抗剂的合成及活性研究

银锭夜蛾Macdunnoughia crassisigna Warren是豆类作物和十字花科蔬菜上重要的食叶性害虫。因其具有暴食性，迁飞性等特点，逐渐成为东北、华北地区重要的农业害虫。由于缺乏有效的绿色防控技术，目前化学农药仍是防控银锭夜蛾有效的方法之一。为提高银锭夜蛾的防治效果，以银锭夜蛾性信息素主要成分顺-7-十二碳烯乙酸酯（Z7-12：Ac）、顺-9-十四碳烯乙酸酯（Z9-14：Ac）为母体结构，通过酯化反应得到结构新颖的类似物14个，结构经GC-MS、¹H NMR、¹³C NMR和HR-MS确证。触角电生理试验（EAG）表明，有11个类似物具有较好的EAG反应。EAG抑制试验发现，类似物4、13和14具有明显的抑制效果。在100 μg剂量下，类似物4对Z7-12：Ac的抑制率达50.2%。风洞试验表明，当添加1500 μg的类似物4时，对银锭夜蛾的干扰尤为显著，没有成虫到达诱芯。田间试验表明，类似物4具有潜在的抑制活性，当添加150、1500 μg的类似物4时，平均诱捕量与性信息素存在显著性差异，抑制率分别为56.90%、59.34%。研究结果有助于揭示性信息素拮抗剂对银锭夜蛾种内化学通讯调控方式，为银锭夜蛾绿色防控技术提供新的思路与手段。     

1-[2-苄氧基-2-(2,4-二氟苯基)乙基]-1H-1,2,4-三唑衍生物的合成及杀菌活性

以抗真菌药物益康唑为先导化合物，设计合成了17个1-((2-取代苄基) 氧基)-2-(2,4-二氟苯基) 乙基)-1H-1,2,4-三唑类目标化合物，其中14个为首次报道，其结构均经 1H NMR、13C NMR和HRMS确认。采用菌丝生长速率法测定了目标化合物对7种植物病原菌的抑制效果，并对毒力较高的化合物进行了其对水稻纹枯病和小麦条锈病的盆栽和田间药效试验，而且测定了其对水稻纹枯病菌麦角甾醇生物合成的抑制作用。结果表明:大多数目标化合物对测试病原菌菌丝生长有较强的抑制作用，尤其对水稻纹枯病菌和番茄早疫病菌的抑制作用最好，其中对水稻纹枯病菌的EC₅₀值均低于3 μmol/L，明显高于对照药剂苯醚甲环唑和益康唑；化合物 4a 、 4b 、 4c 、 4g 、 4i 和 4l 对番茄早疫病菌的EC₅₀值均低于10 μmol/L。在浓度为250 μmol/L时，化合物 4b 和 4i 对小麦条锈病的盆栽防效均超过70%，在有效剂量为240 g/hm2时，化合物 4b 对小麦条锈病的田间防效达到81.93%。而且，化合物 4b 和 4i 在100 μmol/L时可有效抑制水稻纹枯病菌麦角甾醇的生物合成，抑制效果在80%左右。     

Quantitative structure-activity studies of benzoylphenylurea larvicides: II. Effect of benzyloxy substituents at aniline moiety against Chilo suppressalis Walker

The larvicidal activity of a series of N-2,6-difluorobenzoyl-N′-[4-(substituted benzyloxy)-phenyl]-ureas against nondiapause larvae of the rice stem borer, Chilo suppressalis Walker, was measured by a topical application method under conditions in which oxidative metabolism was inhibited by piperonyl butoxide. The effects of the substituted-benzyloxy moiety on variations in the activity were analyzed quantitatively using physicochemical substituent parameters and regression analysis. Results were compared with those found previously for N-2,6-difluorobenzoyl-N′-(4-substituted phenyl)-ureas, indicating that the electron-withdrawing property of the anilide substituents participates in determining the activity through the inductive effect. The hydrophobicity of the total anilide substituents favors activity, whereas the steric dimension in terms of the width lowers it. Although inhibition of new cuticle formation on cultured integument of diapausing larva could not be determined accurately for most of the compounds because of their limited solubility in the assay medium, inhibitory activity seemed related to larvicidal activity, as was the case for previously investigated simpler congeners.