The Synthesis and Biological Activity of 3,3'-Dimethyl-L-Selenocystine, a New Selenocystine Derivative

Using the known synthesis of L-selenocystine,3,3'-diseleno-bis (2-aminopropionic acid), from β‑chloroalanine, a structural analog of natural sulfur-containing amino acids capable of accumulating selenium in the body, we synthesized a new selenium-containing amino acid 3,3'-dimethyl-L-selenocystine ( ) from α-amino-β-chlorobutyric acid. It was shown that, similarly to the selenium released from natural L-selenocystine, the selenium from 3,3'-dimethyl-L-selenocystine accumulated in rat liver, muscles, and serum, where its concentration exceeded that of the control by 40.63, 14.07 and 22.98%, respectively. A close degree of selenium accumulation in the tissues implied a similar metabolic pathway of the amino acids and biological availability of the trace element from the synthesized amino acid. L-Selenocystine and 3,3'‑dimethyl-L-selenocystine decreased concentrations of free amino acids in rat serum by 12.17 and 11.78%, respectively. The most significant reduction, by 74.6 and 66.4% respectively, was observed for proline, a marker of organism stress. Accumulation of selenium in liver and serum indicated close metabolism of L‑selenocystine and its derivative 3,3'-dimethyl-L-selenocystine.