Interference of benomyl and methyl-2-benzimidazolecarbamate (MBC) with DNA metabolism and nuclear divisions in Fusarium oxysporum

Methyl-1-(butylcarbamoyl)-2-benzimidazolecarbamate (benomyl) severely decreased DNA synthesis when applied at 3.5 × 10^?6M during the G1 phase of germinating conidia of Fusarium oxysporum; nuclear divisions were completely inhibited at a fungicide concentration of 10 × 10^?6M. The same concentration applied only after the S phase also completely inhibited the nuclear divisions. This dual interference of benomyl with DNA formation and mitosis might be related to a disturbed phosphorus metabolism.     

The cytokinin-like action of methyl-2-benzimidazolecarbamate on oat leaves and protoplasts

Chlorophyll breakdown in excised oat leaves is retarded by methyl-2-benzimidazolecarbamate, benzimidazole, and kinetin. Protoplasts derived from treated leaves showed lower nuclease activity, increased leucine incorporation, and decreased uridine and thymidine incorporation into trichloroacetic acid-insoluble materials relative to water-treated controls. Methyl-2-benzimidazolecarbamate is more active than benzimidazole in affecting macromolecular synthesis, and both compounds resemble kinetin in their effects on host-plant physiology. Protoplasts can be useful tools in the analysis of the action of pesticides.     

Benomyl and methyl-2-benzimidazolecarbamate (MBC): Biochemical,cytological and chemical aspects of toxicity to Ustilago maydis and Saccharomyces cerevesiae

Action of methyl-2-benzimidazolecarbamate (MBC), a breakdown product of benomyl, was studied in synchronous cultures of Ustilago maydis and Saccharomyces cerevesiae. Cells treated with MBC developed similarly to control cells until the two portions of the doublets (joined mother and daughter “cells”) were morphologically equivalent. At this point development of the treated cells ceased but control doublets separated to form two new cells. The compound did not prevent DNA synthesis during the first cell cycle of synchronized S. cerevesiae cells but did prevent completion of cell division, as it did also in synchronized U. maydis sporidia which already contained the DNA complement needed for completion of the first division. Mitosis did not go to completion in MBC-treated cells so the doublets formed contained only a single compact nucleus. The effect of MBC markedly resembles mitotic arrest caused by colchicine and isopropyl N-phenylcarbamate in higher plants and griseofulvin in the fungus Aspergillus nidulans. Inhibition of DNA synthesis in U. maydis and inhibition of cytokinesis in both organisms studied are secondary effects attributable to mitotic failure.A volatile compound toxic to U. maydis and S. cerevesiae was demonstrated in air over moistened benomyl. Hexane, through which such air samples were passed, or hexane extracts of aqueous suspensions of benomyl contained a substance having the same ir spectrum and retention time in two gas chromatographic systems as butyl isocyanate (BIC).BIC inhibited respiration of U. maydis and S. cerevesiae in a manner similar to benomyl. Benomyl partially inhibited respiration of subcellular particles from both organisms. MBC had essentially no effect on whole cell or subcellular particle respiration of either organism. Toxicity of benomyl preparations is not attributed to “benomyl” as such, but to two breakdown products, MBC and BIC. Therefore, differential effects of benomyl preparations and of MBC on growth and metabolism in fungi should be ascribed to BIC.     

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.     

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。     

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…     

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.     

农药中间体环氧化合物的液相色谱分析

本文叙述了采用以甲醇 水(80 20)为流动相,用C18柱和紫外检测器分离测定2-(4-氯苯基乙基)-2-叔丁基-环氧乙烷的反相高效液相色谱法。结果表明,该方法的标准偏差为0.1417;变异系数为0.1463%;平均回收率为99.70%;线性相关系数为0.9992。     

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.     

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.     

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。     

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。     

2-(4-芳基噻唑-2-基)-3-羟基丙烯腈类化合物的合成及其生物活性

为了寻找新的含2-噻唑基丙烯腈结构的先导化合物,利用2-(4-芳基噻唑-2-基)乙腈与酰氯在吡啶或氢化钠存在下反应,合成了9个2-(4-芳基噻唑-2-基)-3-羟基丙烯腈类化合物,其中8个为新化合物,利用1H NMR、MS和元素分析对其结构进行了表征。初步的生物活性测定结果表明,部分化合物在供试浓度下具有一定的杀虫、杀菌活性,其中化合物 5f 在100 mg/L下对棉花枯萎病菌Fusarium oxysporium的抑制率超过90%,化合物 5e 在250 mg/L下对蚕豆蚜Aphis fabae的致死率达95%。毒力测定结果表明, 5e 对蚕豆蚜的活性优于对照化合物2- -3-羟基-3- 丙烯腈( 6 )。     

N-(2,5-二氯苯基)-6-氯-2-(4,6-二甲氧基-2-嘧啶氧基)胺的合成及除草活性

以2,5-二氯苯胺、6-氯水杨醛和4,6-二甲氧基-2-甲砜基嘧啶为原料,设计并合成了2-嘧啶氧基-N-芳基苄胺类化合物N-(2,5-二氯苯基)-6-氯-2-(4,6-二甲氧基-2-嘧啶氧基)苄胺,其化学结构经核磁共振氢谱和质谱分析确证。室内生物测定结果显示,该化合物对单子叶杂草稗草、马唐、狗尾草以及双子叶杂草反枝苋、芥菜具有较好的芽后除草活性,在有效剂量75 g/hm2下其抑制率达到80% ~100%;对棉花安全,在有效剂量225 g/hm2下未产生明显药害,在棉花和棉田杂草反枝苋之间的选择性系数为24.93。初步表明该化合物在棉田具有一定开发应用价值。     

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.     

5-(2-乙基亚环己基)-2-取代氨基咪唑啉酮类化合物的合成及其杀菌活性

以2-乙基环己酮和2-硫代乙内酰脲为起始原料,经Knoevenagel缩合反应制得5-(2-乙基亚环己基)-2-硫代咪唑啉-4-酮(1),化合物1在乙醇钠-乙醇体系中与碘甲烷反应得到5-(2-乙基亚环己基)-2-甲硫基咪唑啉-4-酮(2),化合物2再与相应的取代苄胺在冰醋酸体系中回流制得新化合物3a～3f,其化学结构均经1H NMR、IR和MS确证。初步生物活性测定结果表明:在50 μg/mL下,部分目标化合物对油菜菌核病菌Sclerotinia scleotiorum显示出良好的抑制活性,其中3a、3c、3e和3f的EC50值分别为12.10、8.73、10.11和7.67 μg/mL。     

A new general method of resolving racemic alcohols and its application to (rs)-2-hydroxy-2-(3-phenoxyphenyl)acetonitrile and (rs)-allethrolone

The preparation is described of pure (S)-2-hydroxy-2-(3-phenoxyphenyl)acetonitrile (the alcohol component of some very active pyrethroids) from the racemic form of this 2-hydroxyacetonitrile. The new resolution process is based on differences in physical properties of two diastereoisomeric ethers. The resolving agents used are chiral hemiacetal compounds; one of these, 4-hydroxy-6,6-dimethyl-3-oxabicyclo[3.1.0]hexan-2-one, is available from an industrial synthesis of chrysanthemic acid, and appears specially useful for a two-step resolution of many racemic alcohols, even base-sensitive types.     

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.     

2-(4-羟基苯氧基)-6-氯-喹喔啉的合成新方法

以2,6-二氯喹喔啉、对苯二酚、液碱为原料,优化操作过程,于三元体系中合成2-(4-羟基苯氧基)-6-氯喹喔啉,收率达到96％以上.