The alkaloids of hemlock ( Conium maculatum L.)—IV : Isotopic studies of the bound forms of alkaloids in the plant

Abstract

When radioactive γ-coniceine is fed to stalks subtending actively growing umbels almost all the radioactivity passes into the umbels. Here it is rapidly converted into the bound forms previously described p1 and into coniine. Conversely, when radioactive coniine is fed, radioactive bound forms and γ-coniceine are produced. The specific activities of all these compounds fluctuated fairly rapidly indicating that they are involved in important metabolic processes. The specific activities of the free alkaloids did not fall markedly even after a period of 19 days and this indicates a re-cycling system. The similarity of this situation to that obtaining with the pyridine nucleotides is discussed and it is suggested that the alkaloids may represent moieties of nucleotide-like compounds concerned with oxidation-reduction processes in this plant.