title: New fluorinated derivatives as esterase inhibitors. Synthesis, hydration and crossed specificity studies.
abstract: A variety of new fluorinated chemicals have been prepared for the first time and tested as inhibitors of esterases, one of the main enzymes involved in pheromone catabolism, in two economically important pests, the Egyptian armyworm Spodoptera littoralis (SL) and the Mediterranean corn borer Sesamia nonagrioides (SN). Using the respective major component of the pheromone as substrate, the K(m) and V(max) of the antennal esterase of both insects resulted to be 5.66 x 10(-4) M and 8.47 x 10(-6) Mmin(-1) for SL and 1.61 x 10(-7) M and 1.25 x 10(-7) Mmin(-1) for SN, pointing out that SN esterase has a higher affinity for its corresponding substrate than SL. In general, the trifluoromethyl ketones (TFMKs) exhibited higher inhibitory potency than the corresponding difluoromethyl ketones (DFMKs) or difluoroaldehydes (DFAs). The compounds appeared to hydrate differently in aqueous solution, the extent of hydration following the order: alpha,alpha-DFMKs<alpha,alpha-difluoro-beta-thioalkylmethyl ketones<TFMKs<beta-thiotrifluoromethyl ketones<alpha,alpha-DFAs. No clear correlation has been found between the K(hyd) and the inhibitory potency and no specificity has been found when the chemicals were assayed on extracts of both insects.
authors.affiliation: Department of Biological Organic Chemistry, Institute of Chemistry and Environmental Research (CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Quero
authors.forename: Gloria
authors.initials: G
authors.lastname: Rosell
authors.forename: Oscar
authors.initials: O
authors.lastname: Jiménez
authors.forename: Sergio
authors.initials: S
authors.lastname: Rodriguez
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Bosch
authors.forename: Angel
authors.initials: A
authors.lastname: Guerrero
mesh_terms: D000465:Algorithms; D000818:Animals; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000494:pharmacology*; D004950:Esterases / Q000037:antagonists & inhibitors*; D005461:Fluorine / Q000737:chemistry*; D017611:Fluorine Compounds / Q000138:chemical synthesis* / Q000494:pharmacology*; D007202:Indicators and Reagents; D007313:Insecta / Q000378:metabolism*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D012679:Sense Organs / Q000201:enzymology; D012724:Sex Attractants / Q000378:metabolism; D018411:Spodoptera / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D004791:Enzyme Inhibitors; D017611:Fluorine Compounds; D007202:Indicators and Reagents; D012724:Sex Attractants; D005461:Fluorine; D004950:Esterases