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1.
Natural products that have been used commercially as crop protection agents   总被引：4，自引：0，他引：4  
Many compounds derived from living organisms have found a use in crop protection. These compounds have formed the basis of chemical synthesis programmes to derive new chemical products; they have been used to identify new biochemical modes of action that can be exploited by industry-led discovery programmes; some have been used as starting materials for semi-synthetic derivatives; and many have been used or continue to be used directly as crop protection agents. This review examines only those compounds derived from living organisms that are currently used as pesticides. Plant growth regulators and semiochemicals have been excluded from the review, as have living organisms that exert their effects by the production of biologically active secondary metabolites.  相似文献   

2.
Over the last 20 years the share of the crop protection market attributable to the leading markets (North America, EU‐15 and Japan) that are the major focus of new active ingredient research and development (R&D) has declined. Greater growth has been recorded in developing markets, questioning the focus of current R&D strategy. R&D budgets within the major companies have seen a shift toward genetically modified (GM) trait development away from agrochemicals, such that the rate of new active ingredients entering development and subsequently being introduced has declined. As a result, the industry has become more reliant on older, off‐patent chemistry, although the availability of older products has been affected by re‐registration requirements, particularly in the EU. Current criteria often preclude the registration of broad‐spectrum agrochemicals, resulting in many new active ingredients being single site active, which is perceived to increase the potential for resistance development, particularly for herbicides, although this is not always the case. © 2019 The Author. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

3.
Scaffold hopping, the exchange of a specific portion of a potential active ingredient with another substructure with the aim of finding isofunctional molecular structures with significantly different molecular backbones, often offers the chance in lead discovery or optimization to mitigate problems related to toxicity, intellectual property, and insufficient potency or stability. Scaffold hopping tools such as isosteric ring replacement including 1,3 nitrogen shift and cyclic imine–amide isosterism, but also ring opening and ring closure approaches, functional group isosterism, reversion of functional groups, chain shortening, chain lengthening, and scaffolds delivered by natural products, have become a permanent fixture of the innovation and optimization process in crop protection research. Their appropriate use will be explained through examples of success stories in the field of agrochemistry. Analogies to, but also differences from, the main categories of scaffold hopping in medicinal drug discovery are discussed. © 2017 Society of Chemical Industry  相似文献   

4.
Herbicides inhibiting branched-chain amino acid biosynthesis represent a signal advance in crop protection chemistry, with implications for both practical weed control and basic agricultural science. In practical terms, at least 20 different active ingredients are currently marketed or are in development, and more may be expected. They offer selectivity in virtually every major crop, unprecedented low use rates, and inherently selective toxicity to plants. In scientific terms, the research behind these compounds shows modern agricultural chemistry at its best. Synthesis has been integrated with other disciplines to understand and rapidly optimize properties. In the process, basic knowledge has been gained in chemistry, biochemistry, and strategies for finding new agrochemicals. This issue provides the first unified, interdisciplinary overview of the three major classes of inhibitors–sulfonylureas, imidazolinones, and triazolopyrimidines. The following introductory note explores some implications of this research.  相似文献   

5.
The past 30 years have witnessed a period of significant expansion in the use of halogenated compounds in the field of agrochemical research and development. The introduction of halogens into active ingredients has become an important concept in the quest for a modern agrochemical with optimal efficacy, environmental safety, user friendliness and economic viability. Outstanding progress has been made, especially in synthetic methods for particular halogen‐substituted key intermediates that were previously prohibitively expensive. Interestingly, there has been a rise in the number of commercial products containing ‘mixed’ halogens, e.g. one or more fluorine, chlorine, bromine or iodine atoms in addition to one or more further halogen atoms. Extrapolation of the current trend indicates that a definite growth is to be expected in fluorine‐substituted agrochemicals throughout the twenty‐first century. A number of these recently developed agrochemical candidates containing halogen substituents represent novel classes of chemical compounds with new modes of action. However, the complex structure–activity relationships associated with biologically active molecules mean that the introduction of halogens can lead to either an increase or a decrease in the efficacy of a compound, depending on its changed mode of action, physicochemical properties, target interaction or metabolic susceptibility and transformation. In spite of modern design concepts, it is still difficult to predict the sites in a molecule at which halogen substitution will result in optimal desired effects. This review describes comprehensively the successful utilisation of halogens and their unique role in the design of modern agrochemicals, exemplified by various commercial products from Bayer CropScience coming from different agrochemical areas. Copyright © 2009 Society of Chemical Industry  相似文献   

6.
Although proactive or reactive herbicide‐resistant weed management (HRWM) practices have been recommended to growers in different agroecoregions globally, there is a need to identify and prioritise those having the most impact in mitigating or managing herbicide selection pressure in the northern Great Plains of North America. Our perspective on this issue is based on collaborative research, extension activities and dialogue with growers or farming experience (cereal, oilseed and pulse crop production) during the past 30 years. We list our top 10 HRWM practices, concluding with the number 1 practice which is the foundation of the other nine practices: crop diversity. Although our top 10 HRWM practices have broad applicability across agroecoregions, their ranking may vary widely. © 2017 Society of Chemical Industry  相似文献   

7.
Agriculture is confronted with enormous challenges, from production of enough high‐quality food to water use, environmental impacts and issues combined with a continually growing world population. Modern agricultural chemistry has to support farmers by providing innovative agrichemicals, used in applied agriculture. In this context, the introduction of halogen atoms into an active ingredient is still an important tool to modulate the properties of new crop protection compounds. Since 2010, around 96% of the launched products (herbicides, fungicides, insecticides/acaricides and nematicides) contain halogen atoms. The launched nematicides contain the largest number of halogen atoms, followed by insecticides/acaricides, herbicides and fungicides. In this context, fungicides and herbicides contain in most cases fluorine atoms, whereas nematicides and insecticides contain in most cases ‘mixed’ halogen atoms, for example chlorine and fluorine. This review gives an overview of the latest generation of halogen‐containing pesticides launched over the past 6 years and describes current halogen‐containing development candidates. © 2017 Society of Chemical Industry  相似文献   

8.
Mechanisms of herbicide resistance include (1) modified target site, (2) enhanced detoxification or delayed activation, and (3) alterations in the uptake, translocation, or compartmentalization of a herbicide. The first two mechanisms have mainly been identified in plants. Herbicide resistance genes were isolated for several herbicides of different modes of action. Genes that coded for herbicide target or detoxification enzymes were transferred into crop plants. The transgenic plants expressing these genes were tolerant of the active ingredients of herbicides. Before commercialization, the transgenic plants were tested in the field for risk assessment. In the case of crops with herbicide detoxification enzymes, including cytochrome-P450-species-metabolizing xenobiotics, the substrate specificity of the enzymes as well as the toxicological properties of the herbicide metabolites and the pattern of secondary metabolites in plants must be evaluated. © 1999 Society of Chemical Industry  相似文献   

9.
The well-established evaporation rate method for determining the vapour pressure of active ingredients in crop protection down to the order of 10-12 mbar can be supplemented by the new sample preparation technique of Solid Phase MicroExtraction (SPME). With this technique, it is possible to identify evaporating substances by analysis after partitioning into the polymer coating of a thin fibre in the outlet-gas flow of thermogravimetric equipment. The active ingredients fenpropimorph, kresoxim-methyl, metolachlor, clomazone and (Z)-9-dodecenyl acetate were used in this study, which showed that, despite the relatively small amount of collected material, an analytical identification of the evaporating compound by SPME/GC can be successfully achieved. In particular, the experiments have demonstrated a clear correlation between the linearity of the weight loss curve and the evaporation process of a pure compound. In the case of organic compounds that are unstable to heat, the SPME method can also be utilized to show whether, and at what temperatures, decomposition of the sample into fragments of higher volatility occurs. For example, the insecticide dimethoate showed a clear temperature dependence of both evaporation behaviour and in the SPME/GC analysis. © 1998 SCI  相似文献   

10.
In this review, it is demonstrated that zeolites have a potential to be used as crop protection agents. Similarly to kaolin, zeolites can be applied as particle films against pests and diseases. Their honeycomb framework, together with their carbon dioxide sorption capacity and their heat stress reduction capacity, makes them suitable as a leaf coating product. Furthermore, their water sorption capacity and their smaller particle sizes make them effective against fungal diseases and insect pests. Finally, these properties also ensure that zeolites can act as carriers of different active substances, which makes it possible to use zeolites for slow‐release applications. Based on the literature, a general overview is provided of the different basic properties of zeolites as promising products in crop protection. © 2015 Society of Chemical Industry  相似文献   

11.
Applied aspects of neonicotinoid uses in crop protection   总被引：2，自引：0，他引：2  
Neonicotinoid insecticides comprise seven commercially marketed active ingredients: imidacloprid, acetamiprid, nitenpyram, thiamethoxam, thiacloprid, clothianidin and dinotefuran. The technical profiles and main differences between neonicotinoid insecticides, including their spectrum of efficacy, are described: use for vector control, systemic properties and versatile application forms, especially seed treatment. New formulations have been developed to optimize the bioavailability of neonicotinoids through improved rain fastness, better retention and spreading of the spray deposit on the leaf surface, combined with higher leaf penetration. Combined formulations with pyrethroids and other insecticides are also being developed with the aim of broadening the insecticidal spectrum of neonicotinoids and to replace WHO Class I products from older chemical classes. These innovative developments for life-cycle management, jointly with the introduction of generic products, will, within the next few years, turn neonicotinoids into the most important chemical class in crop protection.  相似文献   

12.
The structure of the imidazolinone herbicides consists of three distinct moieties: the imidazolinone ring, the carboxylic acid and the backbone. The effect of changes in each of these on herbicidal activity, crop selectivity and AHAS enzyme inhibition has been studied. Though both whole-plant and enzyme activity were drastically affected by changes in the carboxylic acid or imidazolinone ring portions of the molecule, a variety of backbones and of substituents on the backbones afforded good activity. Methyl-isopropyl was found to be the best combination of substituents on the imidazolinone ring. While pyridine backbones generally gave the most active herbicides, benzene backbones led to the strongest enzyme inhibition. A QSAR study in the pyridine series generated two equations which proved useful for guiding the analog program toward the synthesis of potent heteropyridyl compounds. Selectivity in wheat is dependent upon differences in the rate of metabolism of key groups. Rapid metabolism of either the imidazolinone ring or backbone alkyl groups occurs rapidly in soybeans compared with susceptible weeds.  相似文献   

13.
With the anticipated population growth in the coming decades, the changing regulatory environment, and the continued emergence of resistance to commercial pesticides, there is a constant need to discover new lead chemistries with novel modes of action. We have established a portfolio of approaches to accelerate lead generation. One of these approaches capitalizes on the rich bioactivity of natural products (NPs), highlighted by the numerous examples of NP‐based crop protection compounds. Within Corteva Agriscience and the affiliated preceding companies, NPs have been a fruitful approach, for nearly three decades, to identifying and bringing to the market crop protection products inspired by or originating from NPs, . Included in these NP‐based crop protection products are the spinosyns family of insecticides, and those from more recent areas of NP‐based fungicidal chemistry, as highlighted in this perspective. © 2019 Society of Chemical Industry  相似文献   

14.
Azole resistance in human fungal pathogens has increased over the past twenty years, especially in immunocompromised patients. Similarities between medical and agricultural azoles, and extensive azole (14α‐demethylase inhibitor, DMI) use in crop protection, prompted speculation that resistance in patients with aspergillosis originated in the environment. Aspergillus species, and especially Aspergillus fumigatus, are the largest cause of patient deaths from fungi. Azole levels in soils following crop spraying, and differences in sensitivity between medical and agricultural azoles (DMIs), indicate weaker selection in cropping systems than in patients receiving azole therapy. Most fungi have just one CYP51 paralogue (isozyme CYP51B), but in Aspergillus sp. mutations conferring azole resistance are largely confined to a second paralogue, CYP51A. Binding within the active centre is similar for medical and agricultural azoles but differences elsewhere between the two paralogues may ensure selection depends on the DMI used on crops. Two imidazoles, imazalil and prochloraz, have been widely used since the early 1970s, yet unlike triazoles they have not been linked to resistance in patients. Evidence that DMIs are the origin, or increase the frequency, of azole resistance in human fungal pathogens is lacking. Limiting DMI use would have serious impacts on disease control in many crops, and remove key tools in anti‐resistance strategies. © 2017 Society of Chemical Industry  相似文献   

15.
阐述了近年世界农药的发展趋势。化学农药仍然是全球植物保护的主体;生物农药前景看好;全球转基因作物(GMC)持续发展,不断改变世界农药市场格局;种子处理剂已成为当今农药开发的重点之一;世界农药市场继续高度集中、垄断。重点介绍了16个重点专利农药的发展潜力。  相似文献   

16.
Synthesis of new moth-proofing agents is necessary to overcome the damage caused by clothes moths and carpet beetles to hosiery and upholstery. In the present paper substituted benzyl 2-methyl-2-phenylpropyl ethers were synthesised and evaluated for moth-proofing activity. Two compounds were found to provide protection against larvae of Anthrenus fasciatus at levels of 1.0 and 10 g kg−1 respectively. The introduction of a methyl group in the para position of the benzene ring attached to C2 of the 2-methylpropyl chain (ring A) increased moth-proofing activity. The introduction of a phenoxy ring at the meta position of the benzyl nucleus (ring B) also increased activity, while the presence of a nitro group on the benzyl nucleus (ring B) decreased activity. © 1999 Society of Chemical Industry  相似文献   

17.
Scientists have made significant progress in understanding and unraveling several aspects of double‐stranded RNA (dsRNA)‐mediated gene silencing during the last two decades. Now that the RNA interference (RNAi) mechanism is well understood, it is time to consider how to apply the acquired knowledge to agriculture and crop protection. Some RNAi‐based products are already available for farmers and more are expected to reach the market soon. Tailor‐made dsRNA as an active ingredient for biopesticide formulations is considered a raw material that can be used for diverse purposes, from pest control and bee protection against viruses to pesticide resistance management. The RNAi mechanism works at the messenger RNA (mRNA) level, exploiting a sequence‐dependent mode of action, which makes it unique in potency and selectivity compared with conventional agrochemicals. Furthermore, the use of RNAi in crop protection can be achieved by employing plant‐incorporated protectants through plant transformation, but also by non‐transformative strategies such as the use of formulations of sprayable RNAs as direct control agents, resistance factor repressors or developmental disruptors. In this review, RNAi is presented in an agricultural context (discussing products that have been launched on the market or will soon be available), and we go beyond the classical presentation of successful examples of RNAi in pest‐insect control and comprehensively explore its potential for the control of plant pathogens, nematodes and mites, and to fight against diseases and parasites in beneficial insects. Moreover, we also discuss its use as a repressor for the management of pesticide‐resistant weeds and insects. Finally, this review reports on the advances in non‐transformative dsRNA delivery and the production costs of dsRNA, and discusses environmental considerations. © 2017 Society of Chemical Industry  相似文献   

18.
阐述了近年世界农药的发展趋势。化学农药仍然是全球植物保护的主体;生物农药前景看好;全球转基因作物(GMC)持续发展,不断改变世界农药市场格局;种子处理剂已成为当今农药开发的重点之一;世界农药市场继续高度集中、垄断。重点介绍了16个重点专利农药的发展潜力。  相似文献   

19.
Genomics, and especially functional genomics, will prove to be one of the major keys in capturing the promising benefits of crop biotechnology. The world will need more food, and better quality food, than can be provided by the old crops of the 20th century. Genetic manipulation (alias plant breeding) has produced excellent results over the past 50 years. However, improvements have been linear and have often been limited to higher yields rather than improved nutritional quality. The use of new tools in crop breeding will allow more precise, more easily measured and more beneficial traits to be added to crops around the world. The application of genomics and use of transgenics must be regulated by sound scientific principles and not by amorphous ideological misinformation. Given a fair chance, genomics will improve crop production, crop protection and enhance the quality of life for billions of people. © 2000 Society of Chemical Industry  相似文献   

20.
Natural compounds and living organisms continue to play a limited role in crop protection, and few of them have reached the market, despite their attractiveness and the efforts made in research. Very often these products have negative characteristics compared to synthetic compounds, e.g., higher costs of production, lower effectiveness, lack of persistence, and inability to reach and penetrate the target plant. Conversely, nanotechnologies are having an enormous impact on all human activities, including agriculture, even if the production of some nanomaterials is not environmentally friendly or could have adverse effects on agriculture and the environment. Thus, certain nanomaterials could facilitate the development of formulated natural pesticides, making them more effective and more environmentally friendly. Nanoformulations can improve efficacy, reduce effective doses, and increase shelf‐life and persistence. Such controlled‐release products can improve delivery to the target pest. This review considers certain available nanomaterials and nanotechnologies for use in agriculture, discussing their properties and the feasibility of their use in sustainable crop protection, in particular, in improving the effectiveness of natural bio‐based agrochemicals. © 2019 Society of Chemical Industry  相似文献   

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