Metabolism of EPTC in Corn (Zea mays)

Abstract

EPTC (S-ethyl dipropylthiocarbamate) metabolism in corn (Zea mays L. ‘inbred B37’) was studied utilizing carbonyl-14C-EPTC and propyl-1-14C-EPTC. Two radioactive compounds were found in the organic-soluble fraction, namely, EPTC and EPTC-sulfoxide. Five metabolites were found in the water-soluble fraction. Amino acid analysis indicated that one water-soluble metabolite was a glutathione conjugate [S-(N,N-dipropylcarbamyl)glutathione] and that three other metabolites were probably degradation products of the glutathione conjugate. It was determined that EPTC-sulfoxide reacts chemically with reduced glutathione, yielding the conjugate. There was no detectable glutathione S-transferase enzyme activity associated with the sulfoxide cleavage.