Spiromesifen-d9

Spiromesifen-d₉ is intended for use as an internal standard for the quantification of spiromesifen by GC- or LC-MS. Spiromesifen is an insecticide and acaricide that reduces lipid biosynthesis via inhibition of acetyl-CoA carboxylase.^1,2 It inhibits chitinase from Egyptian cotton leafworm (S. littoralis) larvae (IC₅₀s = 0.60 and 0.72 μM for enzyme isolated from lab and field strains, respectively).³ It induces toxicity in whitefly (T. vaporariorum) nymphs (LC₅₀ = 0.61 mg/L), spider mite (T. cinnabarinus) eggs (LC₅₀ = 0.16 mg/kg), and second instar larvae of S. littoralis lab and field strains (LC₅₀s = 0.44 and 0.68 ppm, respectively, at 72 hours post-application).^1,2,3 Spiromesifen (600 mg/kg) also induces 50, 60, and 70% mortality in the Lepidoptera pests H. armigera, O. nubialis, and P. xylostella, respectively, and induces 100% mortality in M. separata when used at a dose of 100 mg/kg.² It induces toxicity in D. magna (EC₅₀ = >0.092 mg a.s./L) and the fish species O. mykiss and L. macrochirus (LC₅₀s = 0.016 and >0.034 mg a.s./L, respectively) but not rats (LD₅₀ = >2,000 mg/kg).⁴ Spiromesifen also inhibits the human GST isozyme GSTA1-1 (IC₅₀ = 12.1 μM).⁵ Formulations containing spiromesifen have been used as insecticides and miticides in agriculture, as well as commercial, industrial, and residential areas.