The Collaborative International Dictionary of English v.0.48:

Sinapoline \Si*nap"o*line\, n. [Sinapis + L. oleum oil.] (Chem.)
   A nitrogenous base, CO.(NH.C3H5)2, related to urea,
   extracted from mustard oil, and also produced artifically, as
   a white crystalline substance; -- called also diallyl urea.
   [1913 Webster]