The alkaloidal content of blue lupine (Lupinus angustifolius L.) and its toxicity on small laboratory animals

Abstract

1. A method of extraction and isolation of the alkaloid of blue lupine was adopted for small samples of the various plant parts: seeds, leaves and pods.2. From the evidence presented, it is shown that the seeds of blue lupine contain a higher percentage of crude alkaloid, than do the pods and leaves. On the basis of the extractions and isolation, seeds contained as much as 2·25%, leaves were found to contain 0·69%, and pods contained 1·46%.3. The alkaloid isolated was identified as D-lupanine by its characteristic physical and chemical properties. The anhydrous monohydrochloride salt was prepared in pure form and from it were obtained samples of the pure free base, d-lupanine.4. Toxicity determinations, involving the injection of water solutions of the crude free base, hydrochloride salt and the pure free base, administered intraperitoneally in guinea-pigs, rats and mice were carried out. Mice were found to be most susceptible, rats less susceptible, and guineapigs least susceptible to the effect of the various solutions injected. The minimal lethal dose (m.l.d.) is given for all three species of animals, and in addition the 50% lethal doses l.d. 50 are given for mice. The purest samples were the most toxic.5. The symptoms shown by guinea-pigs, rats and mice poisoned by the alkaloid are similar. Gross pathology of the animals killed indicated death by asphyxiation.