| Abstract: | Barley was sown and grown normally in an experimental field. At the growth stage J, 1 Growth stage J: during the stem extension stage; second node of stem formed and next-to-last leaf just visible. the aerial part of the plants was sprayed with an aqueous emulsion of a mixture of triforine and [3H]triforine (uniformly labelled in the piperazine ring) using the recommended dose rate of about 240g triforine ha?1. The barley was harvested when ripe and the straw and grain were analysed separately. The total radioactivity concentration was 20 times higher in straw than in grain. In straw and grain, 12 and 25% respectively of the total incorporated radioactivity in each of these tissues was methanol soluble. The composition of the methanol-soluble radioactive residue was investigated and was shown to contain triforine and its metabolites which were free and unbound in barley straw and grain. No radioactive piperazine was observed, in spite of the high detection sensitivity for radioactivity. The concentrations of triforine and its identified metabolites in straw and grain respectively (mg kg?1, relative to the fresh weight of tissue) were: triforine, 0.034 and 0.0018; N-[(2,2,2-trichloro-1-(piperazin-1-yl)ethyl]formamide), 0.009 and 0.0006; iminodiacetic acid, 0.021 and 0.001; glycine, 0.043 and 0.0033. Other radioactive water-soluble and very polar, unidentified compounds were observed, corresponding to advanced metabolic products of triforine. |
