Translocation, distribution and metabolism of triforine in plants

After short-ter root-treatment of plants with 3H-triforine (labelled in the piperazine ring) or 14C-triforine (labelled in the side chain), the label was translocated primarily to the leaves present at the time of treatment, without any redistribution of the label taking place after termination of the treatment. Autoradiography showed the radioactivity to be very evenly distributed over the leaf blades, without any appreciable accumulation in leaf margins. In infected leaves, however, there was a tendency for increased accumulation at the infection sites. In dilute aqueous solution triforine was decomposed rather rapidly, the chemical half-life being three days only. From these solutions several non-fungitoxic degradtion products have been isolated and their chemical structures determined. In plants, decomposition of triforine was considerably slower than in aqueous solutions, the half-life of the compound varying depending on plant species. In plants, at least four conversion products could be demonstrated, one of which is piperazine. Whether the other three compounds are identical with or structurally related to the breakdown products found in aqueous solution is not yet known. Its low persistence and low animal toxicity suggest that triforine does not offer serious hazards to the environment.