THE BIOGENESIS OF ALKALOIDS: XVII. FURTHER STUDY OF THE ROLE OF ORNITHINE IN THE BIOGENESIS OF STACHYDRINE

Abstract

Earlier attempts to feed ornithine-2-C¹⁴to Medicago sativa L. Grimm had failed to produce any labelled stachydrine. Repetition of the work has confirmed this result, and a study of the amino acids present in the plant has shown that the proline also was inactive. Feeding pyridoxine with ornithine-2-C¹⁴to the plant did not produce active stachydrine, but gave rise to radioactive proline. Of the other amino acids present, glycine, aspartic acid, and glutamic acid were also active. A similar feeding experiment with radioactive ornithine and pyridoxine, using older plants, also failed to produce active stachydrine although, as before, the proline was active and so was the keto acids fraction.The results seem to indicate that ornithine may be the precursor of stachydrine, but that the transformation to proline and the methylation to the alkaloid occur at a later stage of growth, possibly at seed formation.