The preparation

purification of

3

H (

2

H) -selagine and distribution of tritium in the molecule are described. It was shown that the isotope exchange reaction between tritium and hydrogen in molecules could be performed at stated conditions.

3

H-selagine was separated from dihydroselagine and tetrahydroselagine by silica-gel loaded paper chromatography. The radiochemical purity of

3

H-selagine is over 99%. The specific activity is 3.37 Ci/mmol. Distribution of

3

H in selagine is shown as following: 3

4-T—10.09%

6

12-Т—36.70%

8

10-Т—16.51%

methyl-T—36.70%.