J. P. James, G. B. Quistad, J. Casida
Sep 1, 1995
Citations
2
Influential Citations
14
Citations
Journal
Journal of Agricultural and Food Chemistry
Abstract
Ethylenethiourea (ETU) is a carcinogenic degradation product of major ethylene bis(dithiocarbamate) fungicides with biological activity attributed to poorly characterized oxidation products. The reaction of ETU with H 2 O 2 was examined in aqueous medium at pH 5, 7, and 9 by 1 H NMR spectroscopy giving five principal products : sequential formation of sulfenic, sulfinic, and sulfonic acids as well as imidazoline and ethyleneurea. Maximum yields with 2 equiv of H 2 O 2 at optimal pH were 10, 71, 5, 53, and 100%, respectively. Oxidation proceeds mainly through the sulfinic acid to imidazoline in acidic medium and the S-oxide to ethyleneurea in basic medium. 1 H NMR of urine from mice treated with ETU revealed ETU and imidazoline (no ethyleneurea or S-oxidation products). Albumin was radiolabeled in ∼17% yield by a 10-fold excess of [ 14 C]ETU/H 2 O 2 oxidation products (primarily the sulfenic and sulfinic acids), and such protein modification could be prevented by glutathione.