NOVEL SUBSTRATES FOR THE KINETIC ASSAY OF ESTERASES ASSOCIATED WITH INSECTICIDE RESISTANCE

Naphthalene thioesters were synthesized as substrates for a continuous , non-disruptive kinetic assay of general carboxylesterase activity. T he continuous nature of the assay is based on the production of a solu ble dianion chromophore from the reaction of naphthalene thio with 5,5 '-dithiobis (2-nitrobenzoic acid). Applications with 1- and 2-naphthal ene thioacetates demonstrated their use in a fast, accurate kinetic mi croassay of esterase activity, using porcine carboxylesterase as a mod el. These novel esters proved to be useful as substrates for the spect rophotometric assay of insecticide-resistance in two aphid species and may be applicable to other esterase-based diagnostic procedures.