Organic pesticides. XV. Synthesis and insecticidal activity of some compounds containing phosphorus and fluorine

Forty new organofluorine compounds, containing phosphorus, have been synthesised as potential pesticides. The compounds include esters of O,O-dialkyl phosphoramidic acids of the type (RO)₂P(O)NHAr; thioesters of O,O-dialkyl thiophosphoramidic acids of the type (RO)₂P(S)NHAr; esters of O,O-dialkyl phosphonic acid of the type (RO)₂P(O)Ar and esters of O,O-dialkyl thiophosphonic acid (RO)₂P(S)OAr. All the compounds have been screened for their insecticidal activity against adult cockroaches (Periplanata americana) and a few show appreciable activity.     

分子电性作用矢量用于芳香族化合物的 定量结构-生物降解性相关研究

基于定量结构-生物降解性相关(QSBR)研究芳香族类化合物的性质具有重要意义。采用分子电性作用矢量(MEIV)表征芳香族有机物的分子结构,运用多元线性回归建立定量QSBR模型,同时采用逐步回归结合统计检测筛选模型变量,建立了60个芳香族化合物生物降解最大去除率(QTOD)与其结构间的回归方程。另外采用内部及外部双重验证的办法深入分析和检验模型的稳定性。建模的复相关系数(Rcum)、留一法(LOO)交互校验复相关系数(Qcum)和外部样本校验复相关系数(Qext)分别为0.891、0.809和0.877。表明用MEIV表征芳香族有机物分子结构信息较好,所建QSBR模型的稳定性和预测能力良好。     

含氟昆虫性信息素的研究进展及应用前景

以氟原子取代性信息素上的氢原子,能够影响天然性信息素的化学、生物学和物理性质。氟原子的取代位点一般分为烷基链取代、双键取代和极性基团取代3类。含氟昆虫性信息素或类似物具有增效、激活、拮抗、抑制等多种生物活性,在害虫的预报和综合防治上具有着良好的应用前景。本文就国内外学者对昆虫性信息素含氟取代物的研究进展展开综述,并预测了其应用前景。     

The application of granular pesticides

Three basic processes are involved in the application of granular pesticides—metering, transporting and distributing. Metering may be simply dependent upon flow through an orifice under gravity but preferably force-feed mechanisms, usually driven in relation to forward speed are used. Transport may be effected merely under gravity, but pneumatics is also an accepted method particularly for large swath widths. Kinetic energy is also an agency in transporting granules as in “throwing” type distributors and this also achieves the distribution element. With gravity and pneumatic transport the final distribution is usually by spreaders or by nozzles at each outlet. Assessment of performance is rendered difficult by the very small size of the particles to be detected and the very low rates of application usually employed. Data are required on the appropriate sampling areas which should be used in assessing uniformity of distribution and the significance of the variations measured. Cooperation between all the disciplines of workers in the field is necessary for further development of the technique and in particular in the field of formulation a valuable contribution would be in the reduction in the diversity of physical properties of all the granular materials in use or projected.     

Human food flavor additives as bird repellents: I. Conjugated aromatic compounds

Avian repellents derived from natural products and human food flavorants may be less expensive to register under United States environmental pesticide registration requirements. However, one difficulty faced by workers attempting to target repellents for development is the need to screen large numbers of compounds for activity, as well as consideration of formulation and environmental constraints. In this study, we compare the bird repellent activity of aldehyde-based human food additives and compare the levels of activity with our previously elucidated model for structure–activity relationships (SAR) for bird repellents. We find that a previously elucidated SAR model for identifying acetophenone and anthranilate bird repellents is applicable to predicting the activity of aromatic aldehyde flavorants as well. In particular, of the nine flavorants tested, four, benzaldehyde, cinnamaldehyde, o-tolualdehyde, and o-anisaldehyde, warrant further consideration as bird repellents. L© 1999 Society of Chemical Industry     

农药在植物中的内吸和传导行为与施药技术研究进展

农药的施用方式和施用效果与其在植物中的内吸和传导行为密切相关.农药在植物表面和内部的内吸和传导行为,不仅与其自身理化性质有关,还受植物种类、生长期、生长条件及施药方式等因素的影响.研究农药在植物体内的内吸和传导行为及其影响因素,对于选择合适的施药技术及提高农药利用率具有重要的指导意义.本文综述了农药在植物体内的内吸和传...     

Phosphorothiolate pesticides and related compounds: Oxidative bioactivation and aging of the inhibited acetylcholinesterase

Several phosphorothiolates with a C₂ to C₆ S-alkyl substituent (i.e., ethyl, n-propyl, isopropyl, n-butyl, t-butyl, n-pentyl, or cyclohexyl) undergo microsomal oxidase activation to more potent acetylcholinesterase (AChE) inhibitors. Profenofos is activated by both mouse liver and house fly abdomen microsomes. The phosphorothiolates examined having S-methyl, S-benzyl, S-phenyl, and a variety of other thiol substituents and the phosphoramidothiolates were not converted to more potent AChE inhibitors. The microsomal oxidese system cleaves (±)-profenofos predominantly at the P-S-propyl linkage probably via initial sulfoxidation. (−)-Profenofos and O,S-diethyl O-phenyl phosphorothioate undergo in vivo oxidative activation as evidenced by lessened chick brain AChE inhibition after pretreatment with piperonyl butoxide. AChE inhibited in vitro by several bioactivated phosphorothiolates quickly becomes refractory to oxime reactivation, i.e., it undergoes aging. Thus, the toxicological properties of some S-propyl, S-butyl, and related phosphorothiolates are determined in part by their bioactivation and AChE-aging reactions.     

矿物油类农药的使用现状和发展方向

1矿物油类农药的使用现状早在1865年,即世界上第一口油井开采后的第6年,未经乳化的煤油就开始用于控制柑橘树上的介壳虫;20世纪20年代,润滑油加乳化剂开始应用于柑橘树和落叶果树,并成为果园冬季清园的主要药剂。20世纪70～80年代,碳21-碳25窄溜程喷淋油已经广泛应用在多种害虫的常年控制上。从20世纪90年代起,农用喷淋油开始使用高度精炼的白油做有效成分,使得农用喷淋油达到食品级。目前,喷淋油已在世界许多国家的蔬菜、花卉、果树和棉花等作物上使用,以控制害虫和害螨。     

园林生物农药及其使用技术浅谈

随着人们绿色环保意识的逐渐增强,利用生物农药控制病虫、杂草将成为今后园林绿地有害生物可持续控制的重要手段之一,应用会越来越广泛。本文结合园林管理实际,对生物农药从分类、特点及其使用技术等几个不同的角度作了较为系统的阐述,供广大园林绿化工作者参考。     

Organochlorine pesticides and polycyclic aromatic hydrocarbons in water and sediment of the Bosten Lake,Northwest China

We evaluated organic pollution in Bosten Lake, Xinjiang, China, by measuring the concentrations and distributions of organochlorine pesticides(OCPs) and polycyclic aromatic hydrocarbons(PAHs). Water and sediment samples were collected from 19 sites(B1–B19) in the lake for analysis. Our analytical results show that the concentrations of total OCPs in water ranges from 30.3 to 91.6 ng/L and the concentrations of PAHs ranges from undetectable(ND) to 368.7 ng/L. The concentrations of total OCPs in surface(i.e., lake bottom) sediment ranges from 6.9 to 16.7 ng/g and the concentrations of PAHs ranges from 25.2 to 491.0 ng/g. Hexachlorocyclohexanes(HCHs) and dichlorodiphenyltrichloroethanes(DDTs) account for large proportions of the OCPs. Low α- to γ-HCH ratios in both water and sediment samples indicate possible contributions from both industrial products and lindane. DDTs in water are probably from historical input, whereas DDTs in sediments are from both historical and recent inputs. Moreover, DDT products in both water and sediments were from multiple sources in the northwestern part of the lake(B11, B12, B13, and B14). Fugacity ratios for DDT isomers(p,p′-DDE and p,p′-DDT) at these sites were generally higher than equilibrium values. These results suggest that the input from the Kaidu River and diffusion of DDTs from the sediment to the water are responsible for DDT pollution in the water. Lower-molecular-weight PAHs, which originate primarily from wood and coal combustion and petroleum sources, represent the major fraction of the PAHs in both water and sediment samples. Our findings indicate that OCPs and PAHs in Bosten Lake can be attributed primarily to human activities. A risk assessment of OCPs and PAHs in water and sediment from Bosten Lake, however, suggests that concentrations are not yet high enough to cause adverse biological effects on the aquatic ecosystem.     

Natural cyclopeptides as leads for novel pesticides: tentoxin and destruxin

Difficulties in synthesis make natural cyclopeptides challenging targets for chemists. Our interest focused on two natural toxic cyclopeptide series produced by pathogenic fungi: tentoxin, [cyclo-(N-MeAla¹-Leu²-N-Meδ^zPhe³-Gly⁴)] and the destruxins [cyclo-(Pro¹-Ile²-N-MeVal³-N-MeAla⁴-β-Ala⁵-HA⁶)]. The total syntheses of these two bioactive series were optimised, and several analogues were designed and synthesised to establish structure–activity relationships. The importance of synthetic analogues in the identification of molecular targets and the explanation of mechanisms of action was demonstrated. Such systematic investigations can determine the crucial features responsible for the activity of the natural compound and help the design of more powerful or more selective products. © 1998 SCI.     

药剂诱导稻飞虱再猖獗及科学用药

稻飞虱是典型的再猖獗型重大害虫。害虫再猖獗包括生态再猖獗和生理再猖獗,前者主要由药剂杀伤天敌使天敌功能崩溃引起,后者指药剂刺激害虫生殖导致害虫增殖倍数显著增加。刺激稻飞虱生殖的药剂包括大部分有机磷、菊酯类、氨基甲酸酯类杀虫剂,及一些除草剂和杀菌剂(如井冈霉素、多菌灵)等。通过蛋白质组学、转录组学、基因表达谱分析及基因沉默试验证实化学药剂刺激稻飞虱生殖主要涉及与生殖和代谢相关基因的上调表达,但同一药剂对稻飞虱组团物种产生物种间基因功能生态位分离。这就需要在深入理解化学农药对生态系统中组团物种的正负效应和生殖影响的基础上进行精准用药技术设计。本文综述了一些农药对稻田害虫天敌行为、生殖、捕食功能及稻飞虱生殖影响的机理,并基于同种药剂对稻飞虱组团内不同物种生殖的相反效应,提出稻飞虱多物种共存时的科学用药技术。     

Anaerobic microbial degradation of selected 3,4-dihalogenated aromatic compounds

Anaerobic microbial degradation of selected 3,4-dihalogenated aromatic compounds was studied in medium inoculated with pond sediment. Sediment samples were collected from a diuron-treated pond. Diuron was dehalogenated at the para position, forming CPDMU as the sole degradation product. DCPU was similarly dehalogenated at the para position, forming MCPU as the only degradation product. Linuron degradation resulted in four products: one, CPMMU, was the result of biological dehalogenation at the para position; another, DCPMU, was the result of chemical degradation; and the other two products were unidentified. Chlorbromuron degradation formed three unidentified products. Stam, an acylanilide, was degraded, forming two products, one of which was possibly 3-chloropropioanilide. CIPC and an unidentified compound were formed from DCIP. No degradation of parent compounds or appearance of degradation products were detected in mixtures of each test compound and sterile sediment except linuron.     

农药的科学使用问题与农药应用工艺学

农药应用工艺学是研究提高农药利用率和施药效率,减轻或消除农药对环境的污染和对人、畜及有益生物危害风险的一门综合性学科。近20年来,中国在农药的吸收传导、控制释放、剂型研发、省力化施药、雾滴运动、高效装备及智能精准施药等方面取得了长足的进步：建立了药剂吸收量与种子包衣剂量之间的关系模型;阐明了农药控制释放的动力学规律,揭示了缓释农药提高作物安全性的生物学机制;研发了超低容量制剂、烟雾剂、粉尘剂、展膜油剂、缓释颗粒剂等省力化农药剂型和与之匹配的省力化施药技术;探明了农药雾滴在作物冠层的沉积流失规律,建立了农药利用率模型;建立了农药施用定量分析计算理论,提出了农药雾滴“杀伤半径”概念,推动了农药低容量喷雾技术发展;建立了植保无人飞机低容量喷雾技术体系,开启了人工智能 (AI) 施药技术的研究和应用,初步建立人工智能精准喷雾技术。中国农药应用已逐步实现从简单、粗放向科学、安全、智能精准的转变,为农药减施增效提供理论依据和技术支撑。     

Microscopy and image analysis in the study of plant pathogens and the application of pesticides

Problems associated with the preparation of diseased plant material for transmission electron microscopy (TEM) and the uses of TEM to meet the specific needs of plant virologists are discussed. Methods of collecting spray droplets for analysis by an image-analysing computer method are described.     

浅析农药产品超范围使用问题频发的原因及应对对策

农药产品超范围使用（即在其未登记的作物上使用）是《农药管理条例》等法律法规明令禁止的行为，但目前该问题发生比较普遍、频繁，是导致我国大量农产品农约残留量超标、品质不佳以及使作物遭受药害（以除草剂药害为主）的主要原因之一。仔细分析，农药产品超范围使用问题频发，既有农药生产企业、销售商的原因，也有农药使用者的原因，还有农药科研、推广单位的原因，