Ethylenethiourea: Metabolism, analysis and aspects of toxicity

Karin Autio

Research output: Book/ReportReport

Abstract

The publication is a summary of five separate research reports dealing with the metabolism and detection of ethylenethiourea (ETU) and a review of the most pertinent literature. Studies on the toxicological aspects of ethylenebis (dithiocarbamate) fungicides and ETU have been included in the review. About 32 % of the radioactivity of 14C-Maneb, manganous ethylenebis (dithiocarbamate) was excreted in urine and about 20 % in the faeces of mice within 22 hours. Of the total radioactivity in urine about 10 % was present as ETU Ethylenebisisothiocyanate sulfide (EBIS), ethyleneurea (EU), 2-imidazolin-2yl sulfenate (ETU-S-monoxide), 4,5-dihydro-1,3,6-diazepine-2-thione (DOT) and elemental sulfur were detected in addition to ETU. ETU-S-monoxide, DOT and elemental sulfur represent previously unknown metabolites of Maneb. Most of the radioactivity in urine was present as unidentified polar compounds. In mice, the main part of ETU was excreted unchanged in the urine. The degradation of ETU in mice involved oxidation at the sulfur atom giving 2-imidazolin2-yl sulfenate as a major degradation product. EU was detected as a minor component. The ETU-S-oxidation was shown to occur in the microsomal fraction of liver. All the above metabolites were synthesized using y-irradiation technique. Dilute aqueous solutions of Maneb and ETU were irradiated with Co-60 y-rays and the Tadiolysis products were purified by high-performance liquidcromatography or preparative thin-layer chromatography. The syntheses of the metabolite candidates were verified by IR, NMR and mass spectrometry. Two methods of analysis are presented for the detection of ETU. One is a simple gas-chromatographic method in which ETU is detected without derivatization. The detection limit is 0.01 mg/kg and the method is suitable for a variety of analytical research problems. The other method has been adapted for the determination of low ETU-concentrations in foodstuffs and cigarette smoke condensate. ETU is derivatized with trimethylanilinium hydroxide, at room temperature, to N,N'-dimethyl-ETU. The limit of sensitivity of the method is 0.001 mg/kg when selective ion monitoring detection is used.
Original languageEnglish
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Number of pages120
ISBN (Print)951-38-1511-0
Publication statusPublished - 1982
MoE publication typeD4 Published development or research report or study

Publication series

SeriesValtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports
Number91
ISSN0358-5077

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    Autio, K. (1982). Ethylenethiourea: Metabolism, analysis and aspects of toxicity. VTT Technical Research Centre of Finland. Valtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports, No. 91