THE BIOGENESIS OF ALKALOIDS: XXI. THE BIOGENESIS OF (−)-HOMOSTACHYDRINE AND THE OCCURRENCE OF TRIGONELLINE IN ALFALFA

Abstract

In an attempt to find the precursor of the piperidine ring in homostachydrine, young alfalfa shoots were fed (a) lysine-2-¹⁴C, (b) lysine-2-¹⁴C with pyridoxine, (c) lysine-2-¹⁴C with pyridoxine and folic acid, and finally (d) lysine-2-¹⁴C with pyridoxine, folic acid, and miethionine. In all cases the homostachydrine isolated from the harvested plants showed no radioactivity. It is shown that homostachydrine is not synthesized at the stage of growth at which the experiments were carried out. Alfalfa has been found to contain a hitherto unreported alkaloid shown to be trigonelline by comparison with an authentic sample. Both homostachydrine and trigonelline are found in the seeds, and are not actively synthesized in the plant until seed formation. Asparagine has also been isolated in relatively high yield.