Abstract
Umezawa, Maeda, Kosaka and others have isolated a new antibiotic substance as yellowish needle crystals from the culture fluid as well as from the bacterial bodies of a strain of streptomyces, Sire ptomyces thioluteus Umezawa et Okami, which was isolated in 1947 from a sample of soil collected in Mitaka, Tokyo-to. They named it‘aureothricin’. Following the above, Maeda reported that its molecular formula is C13H13N3S3O3 in view of the extraction method, the chemical properties, and its molecular weight or the results of the elementary analysis. However, no literatures were ever cited relative to the pharamacological studies on aureothricin as yet.
For tl.e investigation in the toxicity of aureothricin, the authors compared the stimulation symptoms in the skin of the inner side of the ear of normal white rabbits with that induced by undecylic acid, which had been hitherto used for the same purpose. Following the above, the toxicity to mice and chick embryos were investigated. Further, the liver of mouse was pathologically and histologically examined to draw the following conclusions.
1) The stimulation symptoms to the skin of aureothricin is almost similar to that induced by undecylic acid, which had hitherto been used for the same purpose.
2) The toxicity to mice is fairly high. The LD50 by subcutaneous injection is approximately 1.6 mg per 10 g.
3) It has fairly high toxicity to chick embryos. When 0.01 mg of aureothricin was injected into developing hens' eggs, only approximately 17% of the total can barely continue to develop, but when 0.05 mg or more was injected, all of the embryos became fatal during the course of the development.
4) In the pathological histological examinations, the findings were roughly the same as those of the controls without any clear findings of the hepatic disturbances owing to the shortnees of the period between the administration of aureothricin and the death of mice.
