1) A number of methyl linoleate derivatives, all highly purified, were examined on their toxicities for the mice and the chick embryos. Each substance was administered to the mice with a gastric tube or to the yolk sacs of the chick embryos through the egg shells with an injector. The results obtained from both animals were quite similar.
2) The compounds used in this experiment were as follows; methyl hydroperoxyoctadecadienoate (HPO), methyl hydroxyoctadecadienoate (HO), methyl ketooctadecadienoate (K), methyl hydroperoxyepoxyoctadecenoate (HE), methyl trihydroxyoctadecenoate (T), methyl octadecadienoate (trans, trans-conjugated) (t-C), methyl epoxyoctadecenoate (α-unsaturated) (E α), methyl epoxyoctadecenoate (β-unsaturated) (E β), methyl linoleate (ML), and methyl ricinolate (MR). Five compounds from the top of the aboves, especially HE, proved to have strong toxicities as compared with methyl linoleate. When the relation between the radicals in these compounds and their toxicities was investigated, the toxic strength came in the order of -OOH>-CO>-OH.
3) The characteristic disorders were found in all the mice administered with toxic substances, in more or less degree. Those were atrophy of the spleen, marked dilatation of the intestine, several histological changes in the lymphatic system, and decrease in the leucocyte count in the blood.
4) It was shown that the toxic lesions in the mice induced by these compounds were quite the same as those by the rancid edible oils seen previously. These results indicate that the toxicity of rancid edible oils is the sum of the toxicities of numerous oxidation products.