Three (8

14-

2

H

2

) -tetrahydroprotoberberines (tetrahydroberberine

tetrahydropalmatine and stepholidine) were prepared conveniently by NaBD

4

reduction of the corresponding protoberberines. The configuration of deuterated compounds was confirmed by MS

1

H-NMR and IR spectra.

3

H labelled stepholidine and tetrahydroberberine were prepared similarly. The specific activity and radiochemical purity of

3

H labelled stepholidine are 6.65GBq/mmol and 95% respectively. The specific activity and radiochemical purity of

3

H labelled tetrahydroberberine are 8.53GBq/mmol and 98% respectively.