Studies on Reaction of Mimosine with Various Amines and Effects of Mimosine on Tyrosine Decarboxylation

As early as 1897 the toxic effects of mimosine were observed and animals ingesting mimosine showed symptoms of hair loss, infertility, and retardation of growth. Mimosine occurs naturally in leguminous plants indigenous throughout the tropics of the world. Since the forage of these plants has a protein content as high as alfalfa and is relished by all kinds of livestock, the mechanism of the toxicity of mimosine should be explained. Although the effects of mimosine have been known for a long time, the reason or mechanism for these effects has not been explained. Much work has been done on the possible interference of mimosine with the incorporation of certain amino acids into proteins. How mimosine may cause its toxic effects by the inhibition of metal-containing enzymes or by complexing with pyridoxal-5-phosphate has also been studied. However, this work has not yielded any conclusive mechanism for mimosine\u27s toxicity. Because of varied results, the observation that mimosine-induced growth inhibition could be reduced or completely eliminated by supplying animals with additional amino acids has not clarified the mechanism for the toxic. effects of mimosine. Therefore, this research was undertaken to help clarify the mechanism for the adverse effects of mimosine. It was noted that mimosine structurally has many of the same functional groups as pyridoxal, including an ortho hydroxyl group and an oxygen of a carbonyl group being in conjugation with the ring nitrogen. Because of this similarity to pyridoxal, experiments were done to attempt to show that this resemblance is functionally important and may be the main cause for the toxic effects of mimosine