Biological Studies on Formycin and Formycin B

The antitumor effect, distribution among various organs and toxicity of formycin and formycin B are studied.Formycin inhibits of Ehrlich carcinoma and L-1210, with stronger activity on the solid form than on the ascites form.Formycin B shows no inhibition of Ehrlich carcinoma or L-1210.The distribution among various organs of mice was examined after subcutaneous injection with 3H-formycin or 3H-formycin B. On the basis of radioactivity, formycin shows high concentrations in spleen and kidney, and formycin B is found in peritoneum, urinary bladder, kidney and spleen.By testing the effect on X. oryzae, low antibacterial activity was shown in various organs.When the lethal dose of formycin was injected in dogs, liver damage was found.Formycin B gives a marked reduction in white blood cells, though this reduction is recovered.Formycin inhibits Ehrlich carcinoma in mice and mouse leukemia L-1210, but formycin B does not show any inhibition of these animal tumors.The toxicity of formycin to mice is relatively slight and that of formycin B is extremely small.Both formycin and formycin B inhibit multiplication of influenza At virus in cells of chick chorioallantoic membrane1*2).Thus, formycin has shown interesting antitumor activity, and formycin B antiviral effects.As shown in a paper reporting the antitumor effect of bleomycin A3>4), informa tion of distribution of an antitumor substance in various organs is helpful in finding -sensitive tumors.Therefore, the distribution of formycin and formycin B in various à"organs was examined.In this paper, the antitumor effect, distribution in various organs and toxicities of formycin and formycin B are reported. MaterialsFormycin and 3H-formycin: Formycin was prepared by Meiji Seika Co. and recrystallized three times from water.It was tritiated by Dr. Komai, Isotope Division in National Institute of Health, Tokyo.3H-Formycin was diluted two times with cold formycin before use.The radioactivity of 3H-formycin employed was 8.31x106 cpm/mg.Formycin B was obtained by chemical deamination of formycin and was tritiated by Dr. Komai.3H-Formycin B thus obtained was diluted two times with cold formycin B and used at 9.30x106 cmp/mg.