bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of juvenile hormone biosynthesis and methyl farnesoate epoxidase activity by 1,5‐disubstituted imidazoles in the cockroach, Diploptera punctata
Authors: Unnithan Gopalan C. , Andersen John F. , Hisano Tomomi , Kuwano Eiichi , Feyereisen René 
Published: November 2006

AbstractSeventeen substituted imidazoles were tested as inhibitors of juvenile hormone (JH) III synthesis by cockroach corpora allata in an in‐vitro radio‐chemical assay. Most of these 1,5‐disubstituted imidazoles were highly potent, with IC50 values of less than 100nM. The compounds differed in their ability to cause an accumulation of the precursor methyl farnesoate in the glands. Four of the imidazoles were tested by topical application to previtellogenic adult females, and all caused a significant inhibition of JH synthesis and an accumulation of intraglandular methyl farnesoate for at least three days after treatment. Methyl farnesoate epoxidase activity of homogenates of corpora allata was inhibited by the compounds TH‐14 and TH‐27. This P450‐dependent epoxidase activity was inhibited at less than 10 nM. The results show that the 1,5‐disubstituted imidazoles are powerful inhibitors of the last step of juvenile synthesis in this cockroach.
Xenobiotic glucosyltransferase activity from suspension‐cultured Glycine max cells
Authors: Gallandt Eric R. , Balke Nelson E. 
Published: November 2006

AbstractProteins extracted from suspension‐cultured soybean (Glycine max (L.) Merr. Corsoy 79) cells contained O‐ and N‐glucosyltransferases (GTs; EC 2.4.1) that catalyzed glucosylation of several xenobiotic compounds including (a) the hydroxylated herbicide metabolites 6‐hydroxybentazone (B‐6‐OH), 8‐hydroxybentazone and 5‐hydroxydiclofop (b) the herbicide chloramben and (c) the environmental contaminants 2,4‐dichlorophenol and 3,4‐dichloroaniline. The O‐GT that catalyzes B‐6‐OH glucosylation, UDP‐glucose: B‐6‐OH glucosyltransferase (B6GT), was chosen for further study. A rapid and sensitive B6GT assay was developed that uses ethyl acetate extraction to separate the product 6‐O‐[14C]glucosylbentazone from the glucose donor uridine[5′]diphospho‐[1]‐α‐D‐[U‐14C]glucose. B6GT, recovered in the soluble protein fraction, was extracted in consistently high amounts from Corsoy 79 cells cultured for one to seven days. 2‐Mercaptoethanol in the extraction buffer increased B6GT activity as did sodium, potassium, calcium, magnesium or manganese(II) chlorides in the assay buffer. B6GT activity in an ammonium sulfate fraction (30–50% saturation pellet) displayed two pH optima, one at pH 5.5 and another at pH 10 to 11. Apparent Km values for UDP‐glucose and B‐6‐OH in the ammonium sulfate fraction were 90 and 4.5μM, respectively. Thus, we have partially characterized glucosylation of B‐6‐OH, one example of the several xenobiotic GT activities present in Corsoy 79 soybean.
Anticoagulant resistance in Europe: Appraisal of the data from the 1992 EPPO questionnaire
Authors: Myllymäki Arvo 
Published: November 2006

AbstractResistance to the first successful anticoagulant rodenticide, warfarin, was detected in the Norway rat (Rattus norvegicus Berk.) in 1958, and it has since expanded to cover other commensal rodent species (R. rattus L., Mus musculus L.) and the majority of later‐developed anticoagulant compounds. The purpose of this paper is to give an up‐to‐date picture of the current distribution of anticoagulant resistance in Europe, as revealed by the questionnaire dispatched by EPPO (European and Mediterranean Plant Protection Organization) to its member countries in 1992. Replies were received from 13 countries (43% of EPPO members), and it was found that broad‐spectrum resistance occurred in practically all those countries that reported testing activity. A likely conclusion based on this finding is that true distribution of resistance is certainly more extensive than documented by the questionnaire replies. Another conclusion drawn by the EPPO Rodent Control Panel was that the existing resistance detection protocols were no longer adequate to cover the whole array of existing anticoagulant rodenticides. Consequently, a new guideline including novel methods particularly for detecting resistance to single‐dose anticoagulant compounds was urgently needed. This guideline is currently under review.
Interaction of benzimidazole‐N‐sulfonamides with the cytochrome b/c1 complex of Pythium aphanidermatum
Authors: Pillonel Christian 
Published: November 2006

AbstractExperiments with intact cells and submitochondrial fractions of Pythium aphanidermatum (Edson) Fitz. indicated an interference of benzimidazole‐N‐sulfonamides with the NADH‐ or succinate‐driven electron transport system between cytochromes b and c. Comparison with Ustilago maydis (DC) Corda and Botrytis cinerea Pers. ex Fr. revealed that this effect is Oomycetes specific. The molecular interaction between benzimidazole‐N‐sulfonamides and the mitochondrial cytochrome b/c1 complex from P. aphanidermatum has been investigated. Binding assays with [14C]52232 RP (dimefluazole) indicated a time‐ and dose‐dependent labelling of two proteins. The molecular mass of one labelled protein and the competition of the binding with antimycin A suggest that benzimidazole‐N‐sulfonamides interact with the Q1‐centre of cytochrome b. Furthermore, experiments with doubly labelled [3H][14C]CGA 323103 revealed a possible irreversible inactivation of the b/c1 complex leading to covalent linkage of the dimethylsulfonamoyl moiety to the target site.
The determination of abamectin from soil and animal tissue by supercritical fluid extraction and fluorescence detection
Authors: Brooks Matthew W. , Uden Peter C. 
Published: November 2006

AbstractThe insecticide abamectin is extracted from soil and animal tissue by supercritical fluid extraction. Supercritical carbon dioxide modified with 9% 2‐methoxyethanol extracted abamectin from soil samples at levels up to 11 ng g−1 with greater than 80% efficiency. Recovery at fortification levels of 5 ng g−1 were obtainable without the need for clean‐up. Abamectin was also easily extracted from animal tissue at levels of 22ng g−1 without interfering coextractives. Extracted abamectin was determined by liquid chromatography of a fluorescent derivative.
Reinvestigating adjuvants for the wild oat herbicide, flamprop‐M‐isopropyl. I: Glasshouse trials
Authors: Grayson B. Terence , Boyd Sarah L. , Walter David 
Published: November 2006

AbstractCommercial formulations of flamprop‐M‐isopropyl and formulations of other members of this class of herbicide have always contained an oil adjuvant to increase herbicidal performance. Further increases of performance could be obtained by following the label recommendations to add further quantities of a commercial emulsifiable oil (e.g. ‘Swirl’). Nevertheless it was judged that, in view of current advances in adjuvant research, even greater improvements in herbicidal performance could be obtained with different types of adjuvants.Experimental trials using a cultivated oat (Avena sativa L.) assay under glasshouse conditions to test ranges of surfactants (alkyl aryl, alkyl saccharide, alkylamine and alcohol ethoxylates) and emulsifiable oils (paraffinic/naphthenic, rape seed, transmethylated rape seed) showed that all of these adjuvants were capable of increasing flamprop‐M‐isopropyl activity compared with that of an emulsifiable concentrate formulation containing no adjuvant. Alkylamine and alcohol ethoxylates, with no particular preference for the length of the alkyl chain, but optimum ethylene oxide content of 5 moles and 7–10 moles respectively, were the most efficacious and better than the current emulsifiable oil system. There was no additional benefit from mixture of these two types of adjuvant and an alcohol ethoxylate (‘Dobanol’ 25‐7) was preferred on cost grounds. This adjuvant also gave substantial activity to the otherwise inactive suspension concentrate formulation. Final trials determined that the optimum application rate of ‘Dobanol’ 25–7 was in the range 1000–1500 g ha−1, and this information guided the design of subsequent field trials.
Reinvestigating adjuvants for the wild oat herbicide, flamprop‐M‐isopropyl. II: Field performance
Authors: Murphy Michael W. , Craven Matthew L. , Grayson B. Terence 
Published: November 2006

AbstractA field trials programme was conducted in which the performance of a new emulsifiable concentrate formulation (ECI) of flamprop‐M‐isopropyl containing the adjuvant, ‘Dobanol’ 25‐7, in a ratio of 2:1 (by weight) with the AI, was compared with the current commercial formulation of ‘Commando’, in combination with its recommended adjuvant, ‘Swirl’, for the control of wild oat (Avena fatua L.) in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). A further treatment, in which the ‘Dobanol’ 25‐7: AI ratio was increased to 4:1 by the spray tank addition of the former, was also included.The mean results from six trials (five wheat, one barley) showed that the addition of ‘Swirl’ to ‘Commando’ was beneficial, increasing wild oat floret control from a mean value of 80% to 92% at current recommended rates (flamprop‐M‐isopropyl, 600 g ha−1; ‘Swirl’, 2.5 litre ha−1). However, combinations of flamprop‐M‐isopropyl and ‘Dobanol’ 25‐7 gave superior levels of control even at lower AI application rates. For example, a mean level of 96% control of Avena spp. was obtained at 300 g AI ha−1 with 1200 g ha−1 ‘Dobanol’ 25–7; with even better control at higher rates of application of both components.This improvement in performance was accompanied by a higher risk of crop phytotoxicity than observed with the ‘Commando’/‘Swirl’ mixtures. Symptoms initially were scorch and subsequently growth depression, particularly of tillers. None of the mean values in the six ‘efficacy’ trials reached commercially unacceptable levels, but in a further six ‘crop effects’ trials (three wheat, three barley), in which double rates were applied, the levels of phytotoxicity did become unacceptable and subsequently reduced grain yields. In contrast, two barley ‘crop effects’ trials gave yields higher than the control plots, possibly through the effects of reducing stem length and lodging thereby enabling more efficient harvesting.Nevertheless, there were rates of application of flamprop‐M‐isopropyl in the range 300–400 g ha−1 with ratios of ‘Dobanol’ 25‐7 in the range 2:1 to 4:1 that would achieve high levels of control of Avena spp. without undue risk of crop phytotoxicity and further trials are planned to support this new adjuvant system.
Polymerase chain reaction‐based monitoring techniques for the detection of insecticide resistance‐associated point mutations and their potential applications
Authors: Ffrench‐Constant Richard , Aronstein Kate , Anthony Nicola , Coustau Christine 
Published: November 2006

AbstractThe design of three PCR‐based monitoring techniques for the genotyping of cyclodiene‐resistant insects are described: (1) PCR followed by a diagnostic restriction enzyme digest or PCR/REN, (2) PCR amplification of specific alleles or PASA and (3) single‐stranded conformational polymorphism analysis of PCR‐amplified DNA or SSCP. The relative disadvantages and potential applications of each of these techniques are discussed and compared to the use of insecticide bioassays. It is concluded that, although such techniques will probably never replace bioassays for routine monitoring, they can more readily address several fundamental questions relating to the evolution and spread of specific resistance alleles in insect populations.
Alterations in phytosterol profiles of Galium aparine following treatment with BAS 480F
Authors: Benton Joanne M. , Cobb Andrew H. , Loeffler R. Thomas 
Published: November 2006

AbstractThe following are extended summaries based on posters presented at the 8th International Congress of Pesticide Chemistry (IUPAC), held in Washington, DC, USA 4–9 July 1994. They are entirely the responsibility of the authors, and do not necessarily reflect the views of the Editorial Board of Pesticide Science.
Characterization of new photosynthesis‐inhibiting imidazolidine derivatives. 2. Interpretation of pre‐emergence herbicidal performance from photosyghesis‐inhibiting activity and soil adsorption coefficient
Authors: Chiba Misako , Yanase Daisuke , Andoh Akihide , Gotoh Takeshi 
Published: November 2006

AbstractRuling factors governing pre‐emergence herbicidal activity were analysed for 16 photosynthesis‐inhibiting 5‐hydroxy‐3‐methyl‐2–oxo‐imidazolidine‐1‐carboxamide derivatives. Herbicidal performance was quantified by the reduction in area of experimental weed vegetation, measured by a computer‐aided image analysis system. A system for fluorometric estimation of photosynthesis inhibitor concentration in aqueous solution greatly facilitated determination of the soil adsorption coefficients (Kd). Maximum herbicidal performance was found for N‐sec‐butyl‐5‐hydroxy‐3‐methyl‐2‐oxo‐imidazolidine‐1‐carboxamide, a compound with the second lowest soil adsorptivity and average photosynthesis‐inhibiting activity. A multiple regression analysis suggested that herbicidal performance of the soil‐applied imidazolidine derivatives was determined by a balance between Kd and photosynthesis‐inhibiting activity. In the present experimental system, however, the main influence was attributed to Kd.
Disappearance of carbosulfan residues in peaches
Authors: Barba A. , García S. Navarro , Cámara M. A. , Molina R. , Buendia J. 
Published: November 2006

AbstractThe disappearance kinetics of the carbamate insecticide, carbosulfan, applied at 2 kg AI ha−1 (‘Marshal’ 250 g litre−1 EC) in peaches was studied. Degradation took place in two consecutive stages (0–28 and 28–57 days), with half‐lives of 7.4 and 17.5 days, respectively. The residues obtained 57 days after treatment did not exceed 0.2 mg kg−1. When treatments were carried out 30, 21 and 14 days before the probable date of harvest (date of fruit maturation) with two doses (1.0 and 2.0 g formulated product litre−1) and two volumes applied (750 and 1500 litre ha−1), the residual levels detected were between 0.122 mg kg−1 (30 days before harvest) and 0.4 mg kg−1 (14 days before harvest). The major metabolite, carbofuran, was never detected above its determination limit of 0.004 mg kg−1 throughout the whole study.
Synergism of insecticidal action and effects on detoxifying enzymes in vivo of lambda‐cyhalothrin and malathion by some nitrogen heterocycles in resistant and susceptible strains of Tribolium castaneum
Authors: Wilkins Richard M. , Saleem Mushtaq A. , Rajendran Candasamy 
Published: November 2006

AbstractThe interactions of the synthetic pyrethroid, lambda‐cyhalothrin and malathion were studied with purines, pyrimidines, caffeine and some other related nitrogenous compounds in resistant and susceptible strains of Triboliurn castaneum (Herbst.) The results were compared with those obtained with a known synergist, piperonyl butoxide (PBO) and precocene I. Adenine, cytosine, guanine, thymine and uracil synergised lambda‐cyhalothrin, especially in the susceptible strain, with maximum effect at a 1:1 mass ratio, with the effect decreasing with increasing proportion of the heterocycle. The order of synergism of lambda‐cyhalothrin was; precocene I > PBO > the nitrogenous compounds, in both resistant and susceptible strains. On the other hand, caffeine (lethal effect increased about twice), barbital (about twice), isobarbituric acid (less than twice) and bromacil (up to eight times) synergised malathion in malathion‐resistant strains and antagonised in the susceptible strains. Total in‐vivo esterases, carbox‐ylesterases and cytochrome P450 of susceptible and resistant strains showed significantly increased activity or content when treated with either insecticide plus a heterocyclic compound. Exceptions were with bromacil and malathion and for the malathion‐specific strain, Kano‐C with malathion and the N‐heterocycles.
Quantitative structure—activity studies of insect growth regulators. XI. Stimulation and inhibition of N‐acetylglucosamine incorporation in a cultured integument system by substituted N‐tert‐butyl‐N,N′‐dibenzoylhydrazines
Authors: Nakagawa Yoshiaki , Soya Yoshihiro , Nakai Katsumi , Oikawa Nobuhiro , Nishimura Keiichiro , Ueno Tamio , Fujita Toshio , Kurihara Norio 
Published: November 2006

AbstractThe ability to stimulate N‐acetylglucosamine (GluNAc) incorporation in‐vitro of a number of N‐tert‐butyl‐N,N′‐dibenzoylhydrazines having various substituents on both phenyl rings was measured in cultured integument excised from the rice stem borer (Chilo suppressalis Walker). The relationship between in‐vitro and larvicidal potency was approximately linear. The substituent effects on variations in the potency were similar between in‐vitro and larvicidal activities. An inhibitor of oxidative detoxication, piperonyl butoxide, had no synergistic effects on the in‐vitro potency. The ability of some dibenzoylhydrazines to inhibit GluNAc incorporation at exposure periods longer than the optimum for stimulation was also measured in a similar cultured integument system. The relationship between the inhibitory and stimulatory potency indices was linear, indicating that the larvicidal activity of dibenzoylhydrazines is closely related to its ability to stimulate as well as to inhibit GluNAc incorporation into the larval cuticle.
Multiple actions of dieldrin and lindane on the GABAA receptor‐chloride channel complex of rat dorsal root ganglion neurons
Authors: Nagata Keiichi , Narahashi Toshio 
Published: November 2006

AbstractThe GABAA receptor‐chloride channel complex is known to be the target of cyclodiene insecticides and of γ‐hexachlorocyclohexane (γ‐HCH, lindane). Dieldrin first enhances, then suppresses, γ‐aminobutyric acid (GABA)‐induced chloride currents, and the latter action results from the acceleration of desensitization. We now report more detailed analyses of the action of dieldrin and γ‐HCH on the GABAA receptor‐chloride channel complex of rat dorsal root ganglion, using whole‐cell and single‐channel patch clamp techniques. Pre‐application of dieldrin suppressed GABA‐induced chloride currents in a time‐and dose‐dependent manner. No enhancement of current was observed under these conditions, because the enhancing action of dieldrin, which is transient in nature, had ceased by the time GABA‐induced currents were recorded. Both transient and sustained components of chloride currents were suppressed by dieldrin. The effect was almost irreversible, and the current did not recover after 30 min of washout with dieldrin‐free solution. The currents activated by higher concentrations of GABA were more strongly suppressed by dieldrin. Co‐application of γ‐HCH with GABA caused an enhancement of the GABA‐induced chloride currents, which was followed by suppression. Single‐channel currents induced by 1 μM GABA were completely suppressed by 1 μM γ‐HCH. Hyper‐excitation of the nervous system and whole animal caused by dieldrin and γ‐HCH is the result of suppression of the GABA receptor‐chloride channel complex.
Phloem mobility of xenobiotics VI. A phloem‐mobile pro‐nematicide based on oxamyl exhibiting root‐specific activation in transgenic tobacco
Authors: Hsu Francis C. , Sun Kingmo , Kleier Daniel A. , Fielding Max J. 
Published: November 2006

AbstractPhloem mobility is a desirable attribute for pesticides in many applications, and the physicochemical properties necessary for phloem mobility are now well understood. However, attempts to derivatize pesticides to make them phloem mobile are often frustrated by a concomitant loss of activity. This study describes a phloem‐mobile pro‐nematicide, a hydroxymethyloxamyl glucuronide (JR522) coupled with an in‐situ activation mechanism in transgenic tobacco expressing Escherichia coli β‐glucuronidase in its root tips. When applied foliarly to the transgenic tobacco, JR522 and its methyl ester (JM775) showed greater nematicidal activity than oxamyl against root‐knot nematodes. This example of combining pro‐pesticide chemistry with crop genetic engineering for site‐specific activation provides a model system for demonstrating how to circumvent the often mutual exclusivity of phloem mobility and pesticidal activity. Additional advantages of this scheme include the potential mammalian safety of the propesticide, as exhibited by JR522 in this study, and a high degree of site‐specific release of xenobiotics in plants.
Investigation of azole resistance in the Ustilago maydis sterol demethylase mutant erg 40
Authors: Joseph‐Horne Timothy , Carelli Angelina , Hollomon Derek , Kelly Steven L. 
Published: November 2006

AbstractResistance to azole fungicides in Ustilago maydis (DC) Corda has been examined using the mutant erg 40, a newly isolated mutant TriR‐1 and erg 40 revertants. Azole‐induced growth arrest of the wild type did not support an obvious role for 3,6‐diol in the mode of action has is clear for Saccharomyces cerevisiae Meyer ex Hansen. The level of microsomal P450 of erg 40 was identical to that of the parent, and reversion analysis showed no evidence of mutation in the sterol Δ5(6) desaturase, as would be expected for a S. cerevisiae mutant accumulating 14α‐methylfecosterol. Resistance appeared to be due to a single mutation in P450 14αdm. It is proposed that the orthologous forms of fungal sterol Δ5(6) desaturases have varied responses when attempting to utilise 14α‐methylated substrates.
Structure—activity relationships of pyridylcarbamates active against both benzimidazole‐sensitive and ‐resistant isolates of Botrytis cinerea
Authors: Akagi Toshio , Mitani Shigeru , Ito Keiichiro , Shigehara Itaru , Komyoji Terumasa , Matsuo Norifusa 
Published: November 2006

AbstractA series of pyridylcarbamates showed high potency against cucumber gray mould (Botrytis cinerea Pers.). The most potent compound, propargyl‐N‐(6‐ethyl‐5‐iodo‐2‐pyridyl)carbamate was effective against an isolate sensitive to benzimidazole and dicarboximide fungicides as well as against an isolate resistant to both types of compound. QSAR analyses and molecular modelling studies were carried out to investigate the structural requirements for highly active compounds and the structural feature of the binding site of each strain. Significantly different QSAR equations were obtained only for substituents at the 6‐position of the pyridine ring. An ethyl‐sized pocket or an ethyl terminal recognition was suggested in the case of the sensitive or resistant isolate respectively. These results could explain the phenomenon of negatively correlated cross‐resistance between benzimidazoles and N‐phenylcarbamate fungicides. Substituent effects at the 5‐ or 2‐position were governed by steric factors. Substituent effects at the 3‐position were explained by steric hindrance or by conformational effects. The propargyl‐substituted compound above was the most desirable one from the viewpoint of QSAR.
Insecticidal isomers of 4‐tert‐butyl‐1‐(4‐ethynylcyclohexyl)‐2,6,7‐trioxabicyclo [2.2.2] octane and 5‐tert‐butyl‐2‐(4‐ethynylcyclohexyl)‐1,3‐dithiane
Authors: Weston John B. , Larkin John P. , Pulman David A. , Holden Ian , Casida John E. 
Published: November 2006

Abstract4‐tert‐Butyl‐2,6,7‐trioxabicyclo[2.2.2]octanes and 5‐tert‐butyl‐1,3‐dithianes with the 4‐ethynylcyclohexyl substituent in the 1‐ and 2‐positions, respectively, are potent insecticides modeled on their 4‐ethynylphenyl and hex‐5‐ynyl analogs. The compounds were prepared from dimethyl 1,4‐cyclohexanedicarboxylate, 4‐(2,2‐dibromovinyl)cyclohexanecarboxylic acid, methyl 4‐(1‐chlorovinyl)cyclohexanecarboxylate, and 4‐ethynylcyclohexylmethanol by wellestablished chemistry. The cis and trans isomers of the 1‐cyclohexyl‐trioxabicyclooctane and all four geometric isomers of the 2‐cyclohexyl‐1,3‐dithiane were separated by chromatography of the final products or suitable intermediates. High levels of insecticidal activity were found against houseflies, German cockroaches and aphids for trioxabicyclooctanes and dithianes with the trans ethynylcyclohexyl configuration.