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1.
A series of compounds containing fluorine atoms in place of hydrogen in olefinic non-ester pyrethroids has been synthesised using a route based on novel intermediates, ie 2-fluoroallyl acetates, which are coupled with aryl Grignard reagents, and tested against several insect species. In most cases, after introduction of fluorine at the olefinic position, the activity remains high in both the 1-aryl-1-(3-arylprop-2-enyl)cyclopropane and the (1-aryl-4-arylbut-2-enyl)cyclopropane series. In particular, the former series have potential as soil insecticides, because in tests against Diabrotica balteata, activities were high, and dose-transferability factors were increased by the introduction of fluorine. © 1999 Society of Chemical Industry  相似文献   

2.
The insecticidal activities against houseflies (Musca domestica L.) and mustard beetles (Phaedon cochleariae Fab.) of 29 new 5-benzyl-3-furylmethyl 2,2-dimethyl-cyclopropane-carboxylates are compared with those of the corresponding chrysanthe-mate (bioresmethrin) to assess the influence of non-ethylenic and isobutenyl substituents at position 3 of the cyclopropane ring. Of the new groups investigated, only 3-methoxyiminomethyl gives equal or enhanced activity; 3-(2-furyl) esters are moderately effective, but 3-phenyl and 3-alkoxycarbonyl compounds show weak activity. A 3-(2,2,2-trihaloethyl) compound was more active than compounds with other saturated groups, such as isobutyl.  相似文献   

3.
The insecticidal activities against houseflies (Musca domestica L.) and mustard beetles (Phaedon cochleariae Fab.) of the chrysanthemate bioresmethrin, and of 31 related 5-benzyl-3-furylmethyl 2,2-dimethylcyclopropanecarboxylates with alkenyl, alkadienyl or alkoxycarbonylalkenyl substituents at position 3 of the cyclopropane ring are compared to determine the relative influence of the isobutenyl sidechain (as in chrysanthemates) and of the other side chains. Several substituents, in particular (E)- or (Z)-butadienyl or -pentadienyl, give considerably greater activity than isobutenyl but alkoxycarbonyl compounds are less potent.  相似文献   

4.
New 2,2-dimethylcyclopropanecarboxylic acids bearing halogenated 1,3-alkadienyl substituents at position 3 of the cyclopropane ring were synthesised and the insecticidial activities of their 3-phenoxybenzyl and α-cyano-3-phenoxybenzyl esters against housefly (Musca domestica), Colorado potato beetle (Leptinotarsa decemlineata) and Egyptian cotton leafworm (Spodoptera littoralis) were determined. The activity of these compounds varied according to the relative position of the halogen substituents on the diene chain. The observed changes of activity with the structure of the side chain are discussed in terms of the coplanarity of the conjugated double bonds.  相似文献   

5.
2-氧代和2-羟基环烷基磺酰胺对14种病原真菌的杀菌活性   总被引：4，自引：4，他引：0  
为了研究2-氧代和2-羟基环烷基磺酰胺类化合物的杀菌谱,选择N-(2-三氟甲基-4-氯苯基)-2-氧代和2-羟基环戊、己、庚、辛、十二烷基磺酰胺(A1～A5和B1～B5)共10个化合物,采用菌丝生长速率法测试了其对14种病原真菌的杀菌活性,并进行了初步的构效关系分析。在质量浓度50 mg/L下,2-氧代环庚、环辛烷基衍生物(A3、A4)和2-羟基环庚、环辛烷基衍生物(B3、B4)的杀菌谱接近或宽于对照药剂百菌清。精密毒力测定结果表明,化合物A3和B3对小麦赤霉病菌Gibberella zeae (Schw.) Petch、棉花黄萎病菌Verticillium dahliae等8种病原菌的EC50值均在20 mg/L以内。2-氧代和2-羟基对该类化合物杀菌活性的影响基本一致,7、8员环化合物的活性明显高于5、6员环和12员环化合物。  相似文献   

6.
The fungicidal activity of a series of 2-(1-alkenyl)-3-hydroxy-1,4-naphthoquinones and their acetates has been assessed against various fungi in vitro and against others, notably powdery mildews, in vivo, and the activity compared with that of analogous compounds bearing saturated side chains. Several of the compounds demonstrated a broad spectrum of activity in vitro. Whereas the presence of α-unsaturation in the side chain is essential for the in-vitro activity against the non-obligate fungi tested, it is of virtually no importance for the curative effect against Erysiphe graminis on barley. Only the corresponding acetates had activity against the latter pathogen.  相似文献   

7.
Fifty-three heterocyclic sulphonyl derivatives including eight sulphonamides, three sulphonyl azides, nine sulphonohydrazides and twenty sulphonohydrazones of substituted thiophenes, and a smaller range of analogous isoxazoles pryazoles and thiazoles, were tested as potential fungicides in a simple screening procedure against Mucor mucedo, Septoria nodorum, Trichoderma viride, Chaetomium globosum and Aspergillus niger. Several thiophene-2-sulphonyl based compounds exhibited a high level of antifungal activity at 100 mg litre?1 against the five test species, especially the mono-halogen-substituted sulphonamides and sulphonohydrazines, in which a single chlorine or bromine atom was substituted in the para position of an attached phenyl ring. The most active compound, against all five species of fungus was N-(4-chlorophenyl)-N-(trichloromethylthio) thiophene-2-sulphonamide which had average MIC50 and MIC100 values of 86 and 180 μmol respectively. (MIC50 and MIC100 values are, respectively, the concentrations required to inhibit fungal growth by 50% and to inhibit it totally.) In general, the isoxazole analogues of the thiophene-2-sulphonyl compounds exhibited a much lower fungitoxic activity, whilst the pyrazole and thiazole based compounds had little or no activity. Compared with the other results, the considerable activity shown by 4-[2′-(3,4-dichlorobenzylidene)hydrazinosulphonyl]thiophene-2-carboxylic acid was unexpected.  相似文献   

8.
A report by Staudinger and Ruzicka of the insecticidal activity of an ester of pulegenic acid with mixed naturally derived alcohols had not been examined further, and had been misinterpreted in a review. Therefore, two isomeric pulegenic and nine related acids were synthesised, characterised and esterified with modern, more effective, pyrethroidal alcohols. The pulegenic esters were inactive, but low activity was found in esters of acids in which the 5-membered ring was additional to, rather than a replacement for, the cyclopropane ring.  相似文献   

9.
Three 2,4‐diaminopyrimidines were tested against several insect species. They were active against lepidopteran pests with LC50 values <3 mg liter−1 for most species tested. They were also active against two‐spotted spider mite, Tetranychus urticae, (LC50 10–40 mg liter−1). Folinate, but not hypoxanthine or thymidine was found to be an effective rescue agent, requiring a concentration of 100 mg liter−1 diet to rescue half of the intoxicated larvae. The results confirm dihydrofolate reductase to be the site of action for these insecticides and are consistent with the mode of action of folinate rescue in mammals. © 2000 Society of Chemical Industry  相似文献   

10.
Various methanesulfonates, notably of 3-isoxazolols, exhibit interesting insecticidal activity, especially against Musca domestica and Locusta migratoria. Although the symptoms of poisoning are very similar to those caused by parathion, no correlation between in-vitro inhibition of acetylcholinesterase and insecticidal activity was observed. This is also true for several methanesulfonates of hydroxy-heterocycles and phenols included in this study for comparison.  相似文献   

11.
We investigated the synthesis and herbicidal activity of 23 toxoflavin analogs, 1a–w, in which aromatic rings (R) were introduced into the C-3 position. In paddy field conditions, 1k (R=2-CF3–C6H4) and 1w (R=2-thienyl) showed excellent herbicidal activity. Under upland field conditions, we found that toxoflavin analogs 1a (R=C6H5), 1n (R=2-CH3O–C6H4), and 1p (R=4-CH3O–C6H4) exhibited wide herbicidal spectrum against Echinochloa crus-galli (L) var. crus-galli (ECHCG), Chenopodium album, and Amaranthus viridis (AMAVI). The analog with the 2-fluoro group on benzene ring 1b also showed high herbicidal activity against both ECHCG and AMAVI.  相似文献   

12.
Conversion of chrysanthemates to their cyclopropane, episulfide, and epoxide derivatives by addition of methylene, sulfur, or oxygen, respectively, to the 2-methyl-1-propenyl double bond yields products generally of reduced toxicity but enhanced neurophysiological activity and photostability. The reduced toxicity is established with cis-cyphenothrin derivatives administered intracerebrally to mice and topically to house flies and with cis-phenothrin derivatives applied topically to American cockroaches and house flies, even in the presence of piperonyl butoxide for the house flies. In contrast, cyclopropane, episulfide, and epoxide derivatives of phenothrin are more potent than the parent compound in eliciting repetitive firing following stimulation of a cercal sensory nerve of the American cockroach in vitro. The individual 1′R and 1′S isomers of epoxides derived from (1R,cis,αS)cyphenothrin, (1R,cis)phenothrin, and (1R,trans)tetramethrin differ in potency by up to 20-fold for insecticidal activity, >30-fold for intracerebral toxicity to mice, and ～100,000-fold in the cercal sensory nerve assay. In each case the epoxide isomer of higher Rf is more potent than that of lower Rf when derived from a trans-chrysanthemate and vice versa from a cis-chrysanthemate.  相似文献   

13.
Eleven sesquiterpene lactone derivatives of parthenin ( 1 ), obtained from wild feverfew, Parthenium hysterophorus, were prepared by chemical and photochemical transformations. The compounds tested were a pyrazoline adduct ( 2 ) of parthenin, its cyclopropyl ( 3 ) and propenyl ( 4 ) derivatives, anhydroparthenin ( 5 ), a dihydro‐deoxygenated product ( 6 ), a formate ( 7 ) and its corresponding alcohol ( 8 ) and acetate ( 9 ), a rearranged product ( 10 ), lactone ( 11 ) and hemiacetal ( 12 ). All these derivatives, along with parthenin, were tried for their antifeedant action against sixth‐instar larvae of Spodoptera litura, for insecticidal activity against the adults of store grain pest Callosobruchus maculatus, for phytotoxic activity against Cassia tora, and for nematicidal activity against the juvenile stage‐II (J2) of the root knot nematode Meloidogyne incognita. Antifeedent bioassay revealed that parthenin is moderately antifeedant. Among the derivatives, the saturated lactone ( 11 ) was found to be about 2.25 times more active than parthenin. The pyrazoline adduct ( 2 ) was found to be the most effective as an insecticide, with LC50 values after 24, 48 and 72 h of 96, 43 and 32 mg litre−1, respectively, which are comparable with neem extract. Compound 4 was found to be the most effective inhibitor of germination and seedling growth of C tora, with ID50 values for germination, plumule length and radicle length of 136, 326 and 172 compared with 364, 738 and 427 mg litre−1, respectively, for parthenin. Compound 10 was found to be the most effective in terms of nematicidal activity. The LC50 values for this compound were 273 and 104 mg litre−1, respectively, after 48 and 72 h compared with 862 and 512 mg litre−1 observed for parthenin after 48 and 72 h. © 2001 Society of Chemical Industry  相似文献   

14.
Twenty substituted quinoxalines based on the structure of 6 (or 7)-methyl-3-phenyl-1, 2-dihydroquinoxalin-2-one, a fungicidally active photodegradation product of quinomethionate, were synthesised. Eleven of these compounds had ED50 values, as protectant sprays against Podosphaera leucotricha, of 0.1 mmol or less; these compounds had an aromatic substituent at the 3-position of the quinoxaline ring. They were less active as protectant leaf dips against Erysiphe graminis f. sp. hordei than against Podosphaera leucotricha; none showed any systemic activity as a soil-applied treatment against Podosphaera leucotricha. One compound was more active than quinomethionate as an eradicant spray. In spore germination tests on fungi from different taxonomic groups, the quinoxaline derivatives were active against only one basidiomycete (Uromyces fabae), whereas quinomethionate showed a broad spectrum of activity. The possible significance of this difference in spectrum of activity with respect to the mode of action is discussed.  相似文献   

15.

BACKGROUND

Aedes aegypti is an important mosquito species that can transmit several arboviruses such as dengue fever, yellow fever, chikungunya and zika. Because these mosquitoes are becoming resistant to most chemical insecticides used around the world, studies with new larvicides should be prioritized. Based on the known biological profile of imidazolium salts (IS), the objective of this study was to evaluate the potential of six IS as larvicides against Ae. aegypti, as tested against Ae. aegypti larvae. Larval mortality was measured after 24 and 48 h, and residual larvicidal activity was also evaluated.

RESULTS

Promising results were obtained with aqueous solutions of two IS: 1‐n‐octadecyl‐3‐methylimidazolium chloride ( C 18 MImCl ) and 1‐n‐hexadecyl‐3‐methylimidazolium methanesulfonate ( C 16 MImMeS ), showing up to 90% larval mortality after 48 h exposure. C 18 MImCl was more effective than C 16 mIMeS , causing mortality until day 15 after exposure. An application of C 18 MImCl left to dry under ambient conditions for at least 2 months and then dissolved in water showed a more pronounced residual effect (36 days with 95% mortality and 80% mortality up to 78 days).

CONCLUSION

This is the first study to show the potential of IS in the control of Ae. aegypti. Further studies are needed to understand the mode of action of these compounds in the biological development of this mosquito species. © 2017 Society of Chemical Industry
  相似文献   

16.
松油烯-4-醇具有较高的生物活性,在前期研究基础上,以松油烯-4-醇为原料,对其羟基进行改造,合成了12个松油烯-4-醇酯类衍生物 Z1~Z12,其中Z3、Z4、Z8、Z9、Z10、Z11、Z12为新化合物。所有化合物的结构均经核磁共振氢谱、碳谱及质谱确证。初步杀虫活性测定结果表明:各化合物对粘虫均有一定的触杀作用,其中Z5 活性最高,其LD50值为0.072 8 mg/头,为松油烯-4-醇的1.32倍;除 Z9 外,其余11个化合物对家蝇均具有一定的熏蒸作用,但其毒力均低于松油烯-4-醇。  相似文献   

17.
BACKGROUND: Triterpenic saponins from Sapindus mukorossi Gaertn. and Diploknema butyracea JF Gmelin were evaluated for in vitro antifungal activity against four phytopathogenic fungi. The study of the structure–antifungal activity relationships of protobassic acid saponins was widened by including semi‐synthetic derivatives. RESULTS: Diploknema butyracea saponins exhibited significant antifungal activity against three fungi (ED50 230–455 µg mL?1), whereas S. mukorossi saponin was effective against two fungi (ED50 181–407 µg mL?1). The n‐butanol extract after preparative HPLC separation provided two saponins from D. butyracea saponin mixture: 3‐O‐[β‐D ‐glucopyarnosyl‐β‐D ‐glucopyranosyl]‐16‐α‐hydroxyprotobassic acid‐28‐O‐[arabinopyranosyl‐glucopyranosyl‐xylopyranosyl]‐arabinopyranoside (MI‐I), and 3‐O‐β‐D ‐glucopyranosyl‐glucopyranosyl‐glucopyranosyl‐16‐α‐hydroxyprotobassic acid‐28‐O‐[arabinopyranosyl‐xylopyranosyl‐arabinopyranosyl]‐apiofuranoside (MI‐III). The single saponin extracted from S. mukorossi saponin mixture was identified as 3‐O‐[O‐acetyl‐β‐D ‐xylopyranosyl‐β‐D ‐arabinopyranosyl‐β‐D ‐rhamnopyranosyl] hederagenin‐28‐O[β‐D ‐glucopyranosyl‐β‐D ‐glucopyranosyl‐β‐D ‐rhamnopyranosyl] ester (SM‐I). Monodesmosides resulting from the partial degradation of hederagenin and hydroxyprotobassic acid bisdesmosides exhibited significant reduction in antifungal effect. Further removal of sugar moiety yielded complete loss in activity. The antifungal activity of the triterpenic saponins was associated with their aglycone moieties, and esterification of the hydroxyl group led to change in antifungal activity. CONCLUSION: Sapindus mukorossi saponin, which is effective against Rhizoctonia bataticola (Taub.) Briton Jones and Sclerotium rolfsii Sacc., can be exploited for the development of a natural fungicide. A sugar moiety is a prerequisite for the antifungal activity of triterpenic saponin. Copyright © 2010 Society of Chemical Industry  相似文献   

18.
The activity of a number of O-(4,6-dimethoxypyrimidin-2-yl)salicylic acids and their thio analogs inhibiting acetolactate synthase (ALS) preparation was measured. The effects of substituents on the salicylic-benzene ring on the inhibitory activity were analyzed quantitatively with physicochemical substituent parameters. For 6-substituted (thio)salicylic acids, the activity was shown to vary parabolically with the ‘intramolecular’ steric parameter ( Es ). In addition, the higher steric dimension of substituents in terms of the STERIMOL width or length parameter lowered the activity. The field-inductive electron-withdrawing property of the 6-substituents in terms of the Swain–Lupton–Hansch F was favorable for the activity of salicylic acid series. In 5-substituted salicylic acids, the activity was increased by electron-donating substituents with smaller size. The relationships between ALS inhibitory and herbicidal activities were also analyzed with some weed species. Both pre- and post-emergence activities against barnyard grass, Echinochloa crus-galli, were linearly related to the ALS inhibitory activity after allowing for the hydrophobic factor that may contribute to the transport processes. Those against two broad-leaved weed species, Polygonum convolvulus and Abutilon theophrasti were linearly related to the in-vitro activity with no significant participation of the hydrophobic factor. © 1998 SCI  相似文献   

19.
Isothiocyanates are biotoxic degradation products formed as a result of enzymatic hydrolysis of glucosinolates present in Brassica species. The application of biofumigant Brassica crops, as an alternative crop protection method for soilborne pathogens and pests is increasingly gaining interest. However, little is known of the potential of biofumigation to reduce the inoculum of Fusarium species affecting cereals. The aim of this study was to evaluate the antifungal activity of five isothiocyanates, namely allyl, benzyl, ethyl, 2-phenylethyl and methyl isothiocyanates, against germination and growth of Fusarium graminearum under in vitro conditions. Aromatic isothiocyanates were more inhibitory than the aliphatic isothiocyanates against mycelial growth, whereas the reverse was observed for conidial germination. Among the tested isothiocyanates, allyl and methyl isothiocyanates were more efficient overall, showing lower ED50 values (35–150 mg/L) for conidial germination and mycelial radial growth. The findings suggest that Brassica plants containing allyl and methyl glucosinolates could have a suppressive effect, reducing the inoculum of F. graminearum in soil prior to cereal production.  相似文献   

20.
2-吡啶酰氨基环己烷基磺酰胺的合成与杀菌活性   总被引：2，自引：2，他引：0  
为了进一步研究环烷基磺酰胺类化合物的杀菌活性与构效关系,在前期工作基础上,对先导化合物进一步展开研究,合成了15个未见文献报道的2-吡啶酰氨基环己烷基磺酰胺类化合物。首先以2-氧代环己烷基磺酰胺为原料,经过还原胺化后得到2-氨基环己烷基磺酰胺;再与取代吡啶甲酰氯反应,得到目标化合物。分别通过菌丝生长速率法与黄瓜活体叶片法测定了目标化合物对番茄灰霉病菌Botrytis cinerea及其他5种植物病原菌的杀菌活性。结果表明:目标化合物对番茄灰霉病菌表现出较好的抑制活性,其中化合物V-8在离体条件下对番茄灰霉病菌的EC50值为1.41 mg/L,在500 mg/L下的活体防效为79.17%;此外,部分目标化合物在50 mg/L下,对水稻纹枯病菌、水稻稻瘟病菌、大豆根腐病菌、黄瓜绵腐病菌和辣椒疫霉的抑制率高于60%,其中,化合物V-7对黄瓜绵腐病菌的EC50值为2.7 mg/L,其活性高于对照药剂多菌灵（EC50值为4.4 mg/L）,有进一步研究的价值。  相似文献   

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