THE TOXICITY OF SOME ORGANIC SELENIUM COMPOUNDS

¹ Experiment Station Chemistry Department, South Dakota State College, Brookings, South Dakota

The toxicity of several organic selenium compounds has been studied by oral feeding, injection, and inhibition of fermentation by yeast. By each method all were found to be much less toxic than selenite.

A brief summary of the effects of feeding each of the organic compounds, taken in probable order of increasing toxicity is given below.

selenodipropionic acid. Results of growth curves (chart 1), photographs of livers (fig. 1), retention of selenium (table 2), and post mortem observations show that selenodipropionic acid had very slight toxic effects upon rats at the concentrations fed.

n-Propylseleninic acid. Growth curves show little toxic effect. Photographs of livers show no atrophy of the central lobe which has been described as one of the first evidences of selenium poisoning (Franke (1)). Results of analysis indicate retention in liver, spleen, and kidneys in appreciable amounts. Autopsy records indicate no gross lesions.

seleninopropionic acid. Here the growth curves indicate considerably higher toxicity than the preceding compounds. Autopsies indicated some hemachromatosis as well as small necrotic areas in the liver. Selenium analysis indicates retention in the heart, liver, spleen, and brain, this group showing the most retention of selenium by the brain.

' diselenodipropionic acid. The toxicity of this compound is about the same as that of seleninopropionic acid as indicated by growth curves and analysis of organs. This compound, because of the extreme necrosis of the liver, was considered by the authors to be more toxic than seleninopropionic acid.

Dibenzyldiselenide. This compound causes a distinct depression of growth. Livers show general necrosis as well as atrophy of the central lobe. Analysis of the organs shows a higher retention of selenium by the liver and spleen than from any of the other organic selenium compounds.

Intraperitoneal injections of the organic compounds showed n-propylseleninic acid to be most toxic, seleninopropionic and ' diselenodipropionic acid about equally toxic and less toxic than n-propylseleninic acid. Injections of the sodium salt of selenodipropionic acid in concentrations as high as 40 mgm. Se per kilogram body weight failed to produce fatal results.

None of the organic selenium compounds inhibited the rate of yeast fermentation in concentrations of 1 mgm. of selenium per gram of yeast.