Biotransformation of thianicotinyl neonicotinoid insecticides: Diverse molecular substituents response to metabolism by bacterium Stenotrophomonas maltophilia CGMCC 1.1788

Soil microbial degradation of neonicotinoid insecticides imidacloprid, acetamiprid, thiacloprid and imidaclothiz and its effect on the persistence of bioefficacy against horsebean aphid Aphis craccivora Koch after soil application

“…LC/MS results showed that the molecular masses of metabolites I, II and III were at m / z 246, 260 and 236 respectively. Metabolites I had the same retention time and mass as olefin IMT in a previous report 15. Metabolites II and III have the same mass as the data for nitroso IMT and seco IMT reported by Uneme 26.…”

“…The reagent acetonitrile was HPLC grade, and other chemicals were analytical grade. Guanidine IMI was synthesised as described by Kanne et al ;19 the synthesis of 5‐hydroxy IMI, olefin IMI, 5‐hydroxy IMT, olefin IMT and THI amide were described in previous studies by the present authors 12, 15…”

“…The bacterium Stenotrophomonas maltophilia transformed IMI, IMT and THI to their corresponding hydroxy metabolites and transformed AAP to N ‐demethylated metabolite, whereas S. maltophilia did not transform the pharmacophore cyanoguanidine in AAP and THI or the nitroguanidine in IMT and IMT. Most of these metabolites showed insecticidal activity at the ppm level, but a lower activity than the parent compounds against horsebean aphid, except for the olefin IMI, formed by eliminating water from 5‐hydroxy IMI, which showed 19 times higher bioefficacy than IMI 12–15. The yeast Rhodotorula mucilaginosa strain IM‐2 particularly degraded AAP and THI in the position of the cyanoguanidine pharmacophore to form metabolites IM‐1‐3 and THI amide respectively, while it did not degrade IMI and IMT in the position of the nitroguanidine pharmacophore 16.…”

Nanostructural and mechanical property changes to spider silk as a consequence of insecticide exposure

“…Accordingly they adversely affect insect cognition, learning, orientation, decision making and feeding (Tomizawa et al, 1995). Due to their broad spectrum of efficacy and distinct mode of action, neonicotinoid and pyrethroid use by agriculturalists is expanding worldwide (Honda et al, 2006;Dai et al, 2010). In Uruguay use of these insecticides has increased exponentially of late due to the recent arrival of new crops, such as soybean (Ministry of Agriculture and Fisheries of Uruguay, 2013; Benamú et al, 2013;Lacava, 2014).…”

Co-metabolic transformation of the neonicotinoid insecticide imidacloprid by the new soil isolatePseudoxanthomonas indicaCGMCC 6648

“…This is because P. indica CGMCC 6648 specifically transforms IMI via hydroxylation at the CÀ ÀC bond of the imidazolidine ring but cannot transform the CÀ ÀO bond at the oxadiazinane ring in the TMX molecule. [18] Effects of carbohydrates on the IMI degradation and metabolite formation of P. indica CGMCC 6648…”