Seeds of the castor bean plant Ricinuscommunis L (CB) contain ricin toxin (RT), one of the most poisonous naturally-occurring substances known. Ricin toxin, a water-soluble glycoprotein that does not partition into the oil extract, is a ribosome-inactivating toxin composed of two chains, labeled A and B. Severity of the toxicity varies depending on the route of exposure to the toxin. Inhalation...

53. WEBB, K. L. & J. W. A. BURLEY. 1962. Sorbitol translocation in apple. Science 137: 766. 54. WVEATHERLEY, P. E., A. J. PEEL, & G. P. HILL. 1959. The physiology of the sieve tube. Preliminary experiments using aphid mouth parts. J. Exptl. Botany 10: 1-16. 55. AXANG, T. T. 1961. A study of tranislocation of of photosynthate in sugar cane plants with C14 anid P;. Rept. Taiwan Sugar Exp. Sta. 23...

Abrin is a toxic protein found in the jequirity seed. L-Abrine (N-methyl-tryptophan) is also found in the jequirity seed and can be used as a biomarker for abrin exposure. Analysis of L-abrine was added to an existing method for quantifying ricinine as a marker for ricin exposure in human urine and analytically validated. Accuracy and reproducibility were enhanced by including a newly synthesiz...

Accidental and intended Ricinus communis intoxications in humans and animals have been known for centuries but the causative agent remained elusive until 1888 when Stillmark attributed the toxicity to the lectin ricin. Ricinus communis is grown worldwide on an industrial scale for the production of castor oil. As by-product in castor oil production ricin is mass produced above 1 million tons pe...

Previous studies in our laboratory have been concerned with the pathway of carbon in the formation of methyl groups in photosynthesizing plants. In the biosynthesis of the N-methyl group of nicotine in tobacco plants, it was shown that, of several possible precursors, formaldehyde was incorporated to the greatest extent (1). This finding led to the suggestion that a “l-carbon” unit at the oxida...

Seeds of the castor bean plant Ricinuscommunis L (CB) contain ricin toxin (RT), one of the most poisonous naturally-occurring substances known. Ricin toxin, a water-soluble glycoprotein that does not partition into the oil extract, is a ribosome-inactivating toxin composed of two chains, labeled A and B. Severity of the toxicity varies depending on the route of exposure to the toxin. Inhalation...