7-Coumaryl permethrate and its cis- and trans- isomers as new fluorescent substrates for examining pyrethroid-cleaving enzymes.

SANTO ORIHUELA P., M. I. PICOLLO, P. GONZÁLEZ AUDINO, S. BARRIOS, E. N. ZERBA AND H. MASUH

PEST MANAGEMENT SCIENCE

Society of Chemical Industry

Lugar: London; Año: 2006 vol. 62 p. 1039 - 1044

1526-498X

7-Coumaryl permethrate and its cis- and trans-isomers as new fluorescent substrates for examining pyrethroidcleaving enzymes Abstract: New esterase substrates were synthesized using cis-, trans- and cis-trans-permethrinic acid chloride and then used to measure pyrethroid-cleaving enzymes in insects. The new substrates, namely cis-, trans- and cis-trans-7-coumaryl permethrates (7-CP), show a structure very similar to permethrin insecticide and yield fluorescent products on hydrolysis. These substrates were hydrolyzed by a commercial porcine preparation that provided esterase-specific activity, and were stable at different pH values (5.2–7.8). Studies made with house fly, Musca domestica (L.), homogenates showed that these compounds are appropriate for determining pyrethroid hydrolysis activity on individual insects. The measured activity of house fly esterase was 870 relative fluorescente units (RFU) min−1 with cis-7-CP as substrate, 1117 RFU min−1 with trans-7-CP as substrate and 1423 RFU min−1 with cis-trans-7-CP as substrate. The fluorescent substrates for pyrethroid-cleaving esterases described in this paper have advantages over methods already given in the literature. They are substrates with structures very similar to pyrethroids, the cleavage of which can be followed by an increase in fluorescence emission at 440nm; it takes only about 5min to measure the reaction, and moreover the high sensitivity of the fluorescence technique allows the quantification of esterase activity on individual insects.