Metabolism of Simazine and Atrazine by Wild Cane

Wild cane (Sorghum bicolor (L.) Moench) absorbed equal amounts of 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) and 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine). The plants metabolized 70% of the atrazine and 30% of the simazine absorbed and translocated to the shoot during 24 hr. The major metabolites formed were hydroxyderivatives and very hydrophilic metabolites which were chromatographically identical to peptide conjugates of atrazine, e.g., S-(4-ethylamino-6-isopropylamino-s-triazinyl-2)-glutathione and S-γ-L-glutamyl-(4-ethylamino-6-isopropylamino-s-triazinyl-2)-L-cysteine. Wild cane formed peptide conjugates of atrazine more rapidly than of simazine, but hydroxylation of these s-triazines occurred at approximately the same rate.