Absorption, tissue distribution, excretion, and metabolism of clothianidin in rats.

Abstract

Absorption, distribution, excretion, and metabolism of clothianidin [(E)-1-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2-nitroguanidine] were investigated after a single oral administration of [nitroimino-(14)C]- or [thiazolyl-2-(14)C]clothianidin to male and female rats at a dose of 5 mg/kg of body weight (bw) (low dose) or 250 mg/kg of bw (high dose). The maximum concentration of carbon-14 in blood occurred 2 h after administration of the low oral dose for both labeled clothianidins, and then the concentration of carbon-14 in blood decreased with a half-life of 2.9-4.0 h. The orally administered carbon-14 was rapidly and extensively distributed to all tissues and organs within 2 h after administration, especially to the kidney and liver, but was rapidly and almost completely eliminated from all tissues and organs with no evidence of accumulation. The orally administered carbon-14 was almost completely excreted into urine and feces within 2 days after administration, and approximately 90% of the administered dose was excreted via urine. The major compound in excreta was clothianidin, accounting for >60% of the administered dose. The major metabolic reactions of clothianidin in rats were oxidative demethylation to form N-(2-chlorothiazol-5-ylmethyl)-N'-nitroguanidine and the cleavage of the carbon-nitrogen bond between the thiazolylmethyl moiety and the nitroguanidine moiety. The part of the molecule containing the nitroguanidine moiety was transformed mainly to N-methyl-N'-nitroguanidine, whereas the thiazol moiety was further metabolized to 2-(methylthio)thiazole-5-carboxylic acid. With the exception of the transiently delayed excretion of carbon-14 at the high-dose level, the rates of biokinetics, excretion, distribution, and metabolism of clothianidin were not markedly influenced by dose level and sex.

• Authors: Tokunori Yokota, Kazuki Mikata, Hiromi Nagasaki, Kazunari Ohta
• Journal: Journal of agricultural and food chemistry (J Agric Food Chem) Vol. 51 Issue 24 Pg. 7066-72 (Nov 19 2003) ISSN: 0021-8561 [Print] United States
• PMID: 14611173 (Publication Type: Journal Article)

Chemical References

• Carbon Radioisotopes
• Guanidines
• Insecticides
• Neonicotinoids
• Thiazoles
• clothianidin

Topics

• Animals
• Carbon Radioisotopes (analysis, blood, urine)
• Chromatography, High Pressure Liquid
• Chromatography, Thin Layer
• Feces (chemistry)
• Female
• Guanidines (analysis, blood, pharmacokinetics)
• Insecticides (pharmacokinetics)
• Male
• Neonicotinoids
• Rats
• Rats, Wistar
• Thiazoles
• Tissue Distribution