Inhibition of antennal esterases of the egyptian armyworm Spodoptera littoralis by trifluoromethyl ketones

Durán, I.; Parrilla, A.; Feixas, Joan; Guerrero, Ángel

doi:10.1016/s0960-894x(01)80722-8

Cited by 49 publications

(38 citation statements)

References 14 publications

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“…These results clearly differentiate the effects of both chemicals, and suggest that the methyl ketone, based on its structural similarity to the pheromone, may compete with the natural attractant for the pheromone receptors and elicit an antagonist response by the CNS (Glover et al 1989). Our results also confirm the important role played by fluorine in the esterase inhibition of fluorinated ketones (Linderman et al 1988;Durµn et al 1993;Rosell et al 1996), as well as in their activity as competitors for pheromone receptor and PBP binding (Plettner 2002;.…”

Section: Discussionsupporting

confidence: 71%

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Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

et al. 2008

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The differing antagonist activity of (Z)-13-hexadecen-2-one (Z11 -14 : MK, 1) and its 1,1,1-trifluoro derivative (Z11 -14 : TFMK, 2), two closely related analogues of the European corn borer pheromone Ostrinia nubilalis (Z strain), and their rationale is reported. Both chemicals exhibited some electrophysiological activity, and topical application of 10 pg of pheromone analogue on male antennae was sufficient to induce significantly lower depolarization responses to the pheromone versus untreated insects. In a wind tunnel, the number of European corn borer males attracted to sources containing mixtures of 1 + pheromone in ratios ! 1 : 1 was significantly lower than the number attracted to a source containing pheromone alone. Source contact behaviour was dramatically impaired when the 1 + pheromone blend reached a ratio of 10 : 1, in which only 2 % of males displayed source contact in the presence of antagonist. When compound 1 was present at the source, males usually flew upwind with occasional downwind reversals; when compound 2 was present at the lure, males performed wider crosswind reversals, with little progress toward the source. In the field, traps baited with mixtures of both compounds with the pheromone in ratios of 5 : 1 and 10 : 1 elicited a significantly decreased number of male catches. In esterase inhibition assays, compound 2 was a potent inhibitor (IC 50 = 70 nM), whereas the nonfluorinated compound 1 was not. The different activity of both compounds is presumed to be due to different mechanisms of action; considerations for using methyl ketone analogues as new behavioural antagonists of the pheromone are outlined.

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Section: Discussionsupporting

confidence: 71%

“…Of particular interest is their effect on antennal esterases present in insect olfactory tissues (Gelb et al 1985;Durµn et al 1993;Prestwich 1993;. Antennal esterases are decisive in rapid degradation of pheromone esters, a necessary step for maintaining a low stimulus noise level in sensory hairs (Vogt et al 1985;Prestwich et al 1986).…”

Section: Introductionmentioning

confidence: 99%

Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

et al. 2008

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“…Vertical scale barϭ0.5 mV, horizontal scale barϭ1 sec. 27) In this context, OTFP displayed remarkable antiesterase activity on antennal extracts of S. littoralis (IC 50 ϭ5.9 mM) 17,19) and Sesamia nonagrioides (IC 50 ϭ16.3 mM), 28) but not OTP which displayed poor antiesterase activity (IC 50 ϭ73 mM, unpublished data). The effect of OTFP and other TFMKs on the EAG repolarization time suggests that a decrease of pheromone deactivation because of esterase inhibition.…”

Section: Figmentioning

confidence: 89%

“…In insects, these chemicals reversibly inhibit the pheromonedegrading esterases present in male olfactory tissues. 13,17) The activity of these compounds results from the unique features induced by fluorine, which closely mimics the steric volume of hydrogen at the enzyme receptor sites. In addition, the strong electronegativity of the halogen induces fluorinated ketones to form stable hydrates in aqueous solutions, forming a tetrahedral hemiacetal-type adduct with the active site of the enzyme.…”

mentioning

confidence: 99%

Inhibition of electrophysiological response to the pheromone of the fall armyworm, Spodoptera frugiperda

2010

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In the search for new control methods for the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), we present the inhibition of the electroantennographic (EAG) response to the pheromone by 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP). As a member of the trifluoromethyl ketones, OTFP is a potent inhibitor of serine esterases, particularly those of insect antennae. Exposure of antennal receptors to OTFP vapors resulted in a decreased amplitude and 2/3 repolarization time (2/3 RT) of the EAG response to the pheromone. The effect was reversible, with the amplitude and repolarization time being recovered upon suppression of the treatment. The non-fluorinated analogue 3-octhylthiopropan-2-one (OTP) did not affect either the amplitude or the 2/3 RT of the EAG response to the pheromone, confirming the key role played by fluorine atoms in this type of chemical. These results may be the basis for new behavioral studies with the aim of considering OTFP in future management strategies of the FAW.

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“…TFKs were first reported as inhibitors of acetylcholine esterase (19), and shortly thereafter as inhibitors of both general esterase activity and JHE activity (19)(20)(21)(22). Subsequently, they have been investigated as inhibitors of other esterases including mammalian esterases (23) and insect pheromone degrading esterases (24)(25)(26). They have proven to be very useful compounds for studying insect development (7).…”

Section: Introductionmentioning

confidence: 99%

Structural Studies of a Potent Insect Maturation Inhibitor Bound to the Juvenile Hormone Esterase ofManduca sexta^,

et al. 2006

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Juvenile hormone (JH) is an insect hormone containing an α,β unsaturated ester consisting of a small alcohol and long, hydrophobic acid. JH degradation is required for proper insect development. One pathway of this degradation is through juvenile hormone esterase (JHE), which cleaves the JH ester bond to produce methanol and JH acid. JHE is a member of the functionally divergent α/β-hydrolase family of enzymes, and is a highly efficient enzyme that cleaves JH at very low in vivo concentrations. We present here a 2.7 Å crystal structure of JHE from the tobacco hornworm Manduca sexta (MsJHE) in complex with the transition state analog inhibitor 3-octylthio-1,1,1-trifluoropropan-2-one (OTFP) covalently bound to the active site. This crystal structure, the first JHE structure reported, contains a long, hydrophobic binding pocket with the solvent inaccessible catalytic triad located at the end. The structure explains many of the interactions observed between JHE and its substrates and inhibitors, such as the preference for small alcohol groups and long hydrophobic backbones. The most potent JHE inhibitors identified to date contain a trifluoromethyl ketone (TFK) moiety and have a sulfur atom beta to the ketone. In this study, sulfur-aromatic interactions were observed between the sulfur atom of OTFP and a conserved aromatic residue in the crystal structure. Mutational analysis supported the hypothesis that these interactions contribute to the potency of sulfur-containing TFK inhibitors. Together these results clarify the binding mechanism of JHE inhibitors and provide useful observations for the development of additional enzyme inhibitors for a variety of enzymes. NIH Public Access Author ManuscriptBiochemistry. Author manuscript; available in PMC 2014 December 23. Figure 1A) is a sesquiterpenoid insect hormone that controls a wide range of biological processes. JH and/or its metabolites are known to have effects on insect life cycle processes such as development, metamorphosis, reproduction, diapause, migration, polyphenism and metabolism (1, 2). Perturbation of this system can have deleterious consequences for the insect, a fact which has been exploited for pest control. For example, the JH analog methoprene is a significant chemical line of defense against the larvae of mosquitoes that carry West Nile Virus (3). JH can be metabolized through cleavage of either its epoxide or ester moiety. The relative importance of these two pathways, both catalyzed by α/β-hydrolase enzymes (4-6), varies with insect species, development stage and tissue. Normal lepidopteran metamorphosis, for example, requires the degradation of JH via ester hydrolysis. Inhibition of ester hydrolysis leads to abnormally large larvae and delayed pupation (7). The enzyme responsible for this ester hydrolysis is juvenile hormone esterase (JHE), which is found in the hemolymph and other tissues of insects at key times in development.Insects have significant effects on human health, as vectors for diseases such as malaria and virus induced en...

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Inhibition of antennal esterases of the egyptian armyworm Spodoptera littoralis by trifluoromethyl ketones

Cited by 49 publications

References 14 publications

Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

Inhibition of electrophysiological response to the pheromone of the fall armyworm, Spodoptera frugiperda

Structural Studies of a Potent Insect Maturation Inhibitor Bound to the Juvenile Hormone Esterase ofManduca sexta^,

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Inhibition of antennal esterases of the egyptian armyworm Spodoptera littoralis by trifluoromethyl ketones

Cited by 49 publications

References 14 publications

Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

Differential activity of non-fluorinated and fluorinated analogues of the European corn borer pheromone

Inhibition of electrophysiological response to the pheromone of the fall armyworm, Spodoptera frugiperda

Structural Studies of a Potent Insect Maturation Inhibitor Bound to the Juvenile Hormone Esterase ofManduca sexta,

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Product

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Structural Studies of a Potent Insect Maturation Inhibitor Bound to the Juvenile Hormone Esterase ofManduca sexta^,