Insecticidal activity of the pyrimidine nucleoside analogue (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU)

The insecticidal activity of the antiherpetic agent (E)-5-(2-bromovinyl)-2'-deoxyuridine (BVDU) was assessed in in vivo assays against the fall armyworm, Spodoptera frugiperda (JE Smith) (Lepidoptera, Noctuidae). BVDU, mixed into an artificial diet, caused a variety of effects, depending on the concentration used. Compared with controls, food intake was lower, larval growth was retarded and larval development was prolonged. The treated larvae formed smaller pupae and the hatching moths often showed morphogenetic defects. A higher mortality could be found in larval and pupal stages and was generally caused by moult disruption. A choice assay showed that BVDU has very slight feeding-deterrent properties, which only partly explain the toxic effects. The agent most probably acts through its cytostatic activity that has been described previously using cell lines of different insect species.     

Preparation of (R)-2-(4-hydroxyphenoxy) propionic acid by biotransformation

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.     

3-[2-(4-氯-苯基)-1-(3,3-二甲基-氧代-丁基)-乙烯基]-2-氰基亚胺-1,3-噻唑的合成研究

本文研究了3-[2-(4-氯-苯基)-1-(3,3-二甲基-氧代-丁基)-乙烯基]-2-氰基亚胺-1,3-噻唑的合成方法,对反应的各个步骤中的投料摩尔比、溶剂、温度和催化剂进行了对比,优化了反应步骤,总结出了产率较高的合成路径。设计合成了未见报道的新型噻唑衍生物类化合物。其结构经红外光谱、氢核磁共振和气质联用谱图确认,总收率为37.3%。该合成技术降低了成本,减轻了对环境的污染,具有很好的发展前景和市场竞争力。     

1(R)-(2,6-cis-dimethylmorpholino)- 3(S)-(p-tert-butylphenyl)cyclopentane: A representative of a novel,potent class of bio-rationally designed fungicides

Inhibition of the Δ⁸-Δ⁷ sterol isomerase in the ergosterol biosynthesis pathway is known to lead to fungistatic or even fungicidal effects. Our approach to the rational design of new putative inhibitors of the enzyme was based on the assumed mechanism of the enzymic transformation and in particular on the structure of the unstable carbocationic intermediate, i.e. the ‘transition-state-analogue’ principle. The synthesis and the biological properties of 1(R)-(2,6-cis- dimethylmorpholino)-3(S)-(p-tert-butylphenyl)cyclopentane, a representative of a novel, potent class of rationally designed fungicides, as well as the synthesis and biological activities of several other related compounds are described and discussed.     

Effects of ametryn [2-(ethylamino)-4-(isopropylamino)-6-(methylthio)-s-triazine] on nitrate reductase activity and nitrite content of wheat (Triticum aestivum L.)

The objectives of this study were to show that: (a) a herbicide, such as ametryn, which interferes with the photosynthetic electron transport system, causes nitrite to accumulate in illuminated leaves and (b) that nitrite is toxic and contributes to the herbicidal damage and death of the plant. Tests were conducted on wheat seedlings grown on 5 mM nitrate, 5 mM ammonia, and zero nitrogen. Ametryn treatment decreased in vivo and in vitro nitrate reductase activity (NRA) within a 26-hr period. In vivo NRA decreased more rapidly than in vitro NRA. Compared with control tissue, only 3% in vivo NRA remained at the end of 26 hr. The in vivo assay conducted in light confirmed the inhibition of photosynthetic electron flow by ametryn within the leaf tissue. Nitrate-grown, ametryn-treated plants accumulated nitrite and, after 10 days were the only plants that were completely desiccated and dead. Ammonia- and zero-nitrogen, ametryn-treated plants did not accumulate nitrite, were only partially chlorotic after the 10-day period, and were still living. Low levels of NO_(X) (NO₂ and/or NO) emissions were demonstrated by nitrate-grown ametryn-treated plants.     

新型除草剂1-(4-甲基嘧啶-2-基)-3-(2-硝基苯磺酰)脲的溶液构象研究

应用系统构象搜索及分子动力学模拟方法,研究了新型超高效、"对环境友好"的除草剂1-(4-甲基嘧啶-2-基)-3-(2-硝基苯磺酰)脲分子在常态以及溶液中的构象特征。在极性溶剂水形成的溶液中,分子呈现伸展形和卷曲形,而在非极性溶剂CCl4形成的溶液中则只呈现伸展形。通过计算协同旋转的各势能面,得到不同构象相互转换所需克服的能垒为21 kJ/mol。分子在溶液中很容易转换到活性构象与乙酰乳酸合成酶作用。     

吡啶衍生物研究(II)3-(4-吡啶基)-4-烃基-1,2,4-三唑啉-5-硫酮的合成及生物活性

本文研究合成了十七个 3- (4-吡啶基 ) - 4 -烃基 - 1,2 ,4 -三唑啉 - 5-硫酮化合物 ,并归属了它们的1HNMR和 13 CNMR。生物活性测定结果表明 ,合成化合物均具有一定的杀菌和除草活性 ,但植物生长促进活性较差     

Base-catalysed hydrolysis of (E)- and (Z)-mevinphos

The rates at which (E)- and (Z)-mevinphos are hydrolysed in aqueous solutions in the pH range 8.7–11.5, and in the temperature range 30–50°C, have been measured. The overall activation parameters have been calculated, and equations to allow calculation of the rates in any basic conditions are given. The complicated routes by which (E)- and (Z)-mevinphos are hydrolysed to simple molecules have been deduced. The rates for the individual steps in each route have been either measured experimentally, or have been calculated through analogue simulation of all the reactions, by matching the calculated to the observed ultraviolet spectral changes during hydrolysis. It is proposed that (Z)-2-carboxyl-1-methylvinyl dimethyl phosphate is not observed as a hydrolysis product of (Z)-mevinphos because it decomposes by an extremely fast intramolecular reaction. The reasons for the greater lability of (E)-mevinphos are also discussed.     

2-氰基-3-取代胺基(或甲硫基)-3-(2-氯-5-吡啶甲胺基)-丙烯酸酯类化合物的合成及生物活性

作者曾模拟新烟碱类杀虫剂的化学结构,合成了一系列含2-氯-5-吡啶甲基的双氰基取代烯酮缩胺类化合物,并对其进行了生物活性测定,发现部分化合物显示了较好的杀虫和除草活性[1],特别是除草活性引起我们的兴趣。为进一步研究此结构类型的化合物的合成及生物活性,我们以酯基替代前文所述化合物中的一个氰基,并保留新烟碱杀虫剂nitenpyram类似物的骨架[2]。由于这种结构与作为光合作用光系统II(PSII)电子传递抑制剂的氰基丙烯酸酯类化合物很相似[3],该类化合物可能会有更好的除草效果。我们依此设计,合成了2-氰基-3-(2-氯-5-吡啶甲胺基)-3-甲…     

Determination of residues of 1-(2-cyano-2- methoxyiminoacetyl)-3-ethylurea (DPX-3217) by gas-liquid chromatography

Residues of the fungicide 1-(2-cyano-2-methoxyiminoacetyl)-3-ethylurea (DPX-3217) in grapes, potatoes, tomatoes and wine were determined by initial extraction with ethyl acetate, clean-up by liquid-liquid partitioning and adsorption chromatography, and final determination by gas-liquid chromatography with a nitrogen-selective detector. The sensitivity of the method was 0.04 mg kg^?1 based on 50-g samples. Recoveries of the compound added to untreated substrates averaged approximately 92% in the range of 0.04-5.0 mg kg^?1.     

The degradation of (Z)- and (E)-1,3-dichloropropenes and 1,2-dichloropropane in soil

The degradation in soil of the major constituents of a 1,3-dichloropropene-1,2-dich-loropropane nematicide has been studied under laboratory and outdoor conditions. In sealed glass containers, ( Z)- and ( E)-1,3-dichloropene- 2-¹⁴C were converted in soil into the corresponding 3-chloroallyl alcohols and these alcohols were in part strongly bound to the soil. The ( Z)- and ( E)-3-chloroacrylic acids were also found as minor products. More polar products were detected and these released the chloroacrylic acids in 20–30% yield upon hydrolysis. Although the 1,3-dichloropropenes were lost by volatilisation from soil stored in open glass jars outdoors, they also underwent degradation to the same products that were detected in sealed containers. There was evidence of only slight degradation of 1,2-dichloropropane- 2-¹⁴C (4 % or less of the applied radioactivity remained unextracted from a loam soil after 5 months). When soil treated with the 1,2-dichloropropane was stored outdoors in an open glass container, less than 1 % of the original radiolabel remained in the soil after 10 days under these conditions due to volatilisation of the applied material. In a separate experiment potatoes were grown in soil 6 months after treatment with a mixture of both ( Z)- and ( E)-1,3-dichloropropene- 2-¹⁴C and 1,2-dichloropropane- 2-¹⁴C. Although 5 % of the applied radiolabel remained in the soil at potato harvest the potato tubers contained only a very small residue (0.007 mg/kg).     

Stereochemical and chiral aspects in the synthesis of 3-(2,2- dihalovinyl)-2,2-dimethylcyclopropanecarboxylic acids

The synthesis of (1RS)-cis,trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid by dehydrohalogenation of 4,6,6,6-tetrahalohexanoates has been modified to produce stereo-selectively the cis-isomer. A new stereospecific synthesis of cis-3-(2,2-dihalovinyl)-2,2-dimethylcyclopropanecarboxylic acids using a bicyclic lactone and its extension to the preparation of the optically active (1R)-cis acid are described.     

Design, synthesis and anticoccidial activity of a series of 3-(2-(2-methoxyphenyl)-2-oxoethyl) quinazolinone derivatives

A series of 3-(2-(2-methoxyphenyl)-2-oxoethyl) quinazolinone derivatives were designed and synthesized as anticoccidial agents by modifying the quinazoline ring of febrifugine. All the compounds were biologically evaluated according to the ACI method, and four of them exhibited anticoccidial activity against Eimeria tenella in the chicken at a dose of 9 mg/kg. Compound 5e shows ACI value at 173.2 and is as potent as decoquinate. These data suggest that 5e possesses high anticoccidial activity and may serve as a lead compound for the development of anticoccidial drugs in the future.     

Photochemical behaviour of dichlorprop [(+/-)-2-(2,4-dichlorophenoxy)propanoic acid] in aqueous solution

Aqueous solutions of dichlorprop were irradiated under different conditions of pH, wavelength and oxygenation. The photochemical behaviour was found to be complex and many photoproducts were formed. However, at low concentrations the main photoproducts were 4-chloropyrocatechol, 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol. Some other photoproducts were identified, namely 2-(4-chloro-2-hydroxyphenoxy)propanoic acid, 2-(3,5-dichloro-2-hydroxyphenyl)propanoic acid and 2,4-dichlorophenyl acetate. From comparison with results previously obtained with mecoprop [2-(4-chloro-2-methylphenoxy)propanoic acid] it appears that the presence of a chlorine atom in position 2 on the ring strongly modifies the photochemical behaviour.     

Synthesis and herbicidal activities of novel 3-(substituted benzyloxy or phenoxy)-6-methyl-4-(3-trifluoromethylphenyl)pyridazine derivatives

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     

丹皮酚衍生物——3-羟基-1-(2-羟基-4-甲氧基苯)-3-(2'-溴苯)-1-丙酮的合成及其抗菌活性

从牡丹根皮中提取丹皮酚,将丹皮酚精制后与2-溴苯甲醛在室温及碱催化下发生亲核加成反应,生成一种丹皮酚衍生物——3-羟基-1-(2-羟基-4-甲氧基苯)-3-(2'-溴苯)-1-丙酮,产率为78.6%,其结构用紫外光谱(UV)、红外光谱(IR)、质谱(MS)及核磁共振谱(NMR),结合元素分析等进行表征。单晶X-衍射(X-ray diffraction)测定结果表明:该晶体属单斜晶系;P2(1)/n空间群;晶胞参数:a=0.99380(15) nm,b=0.80617(12) nm,c=1.9251(3) nm,α=90.0(2)°,β=103.287(2)°,γ=90(2)°,V=1.5010(4) nm3,Dc=1.554 mg/cm3, μ=2.751 mm-1,F(000)=712,Z=4,R1=0.0290,ωR2=0.0660,R(int)=0.0322。该丹皮酚衍生物具有抗菌活性,对植物源真菌油菜菌核病菌Sclerotinia sclerotiorum和番茄灰霉病菌Botrytis cinerea的最小抑菌浓度(MIC)分别为0.36和0.48 g/L,对病源细菌福氏志贺菌Shigella flexneri 51065和金黄色葡萄球菌Staphylococcus aureus ATTCC25925的MIC分别为0.02和0.06 g/L。     

Synthesis and Insecticidal Activity of Some New 3-[4(3H)-Quinazolinone-2-(yl)thiomethyl]-1,2,4- triazole-5-thiols

A series of 14 new 3-[4(3H)-quinazolinone-2-(yl)thiomethyl]-1,2,4-triazoles were prepared and characterized by elemental analyses, IR, [¹H] NMR and mass spectral data. Four of the compounds showed insecticidal activity equivalent to that of malathion against the adult stage of the blow fly (Chrysomyia albiceps). However, their activity against the larval stages of this insect species was considerably weaker.