The Collaborative International Dictionary of English v.0.48:

Depure \De*pure"\, v. t. [F. d['e]purer. See Depurate.]
   To depurate; to purify. [Obs.]
   [1913 Webster]

         He shall first be depured and cleansed before that he
         shall be laid up for pure gold in the treasures of God.
                                                  --Sir T. More.
   [1913 Webster]