The Collaborative International Dictionary of English v.0.48:

Brucine \Bru"cine\, n. [Cf. F. brucine, fr. James Bruce, a
   Scottish traveler.] (Chem.)
   A powerful vegetable alkaloid, found, associated with
   strychnine, in the seeds of different species of Strychnos,
   especially in the Nux vomica. It is less powerful than
   strychnine. Called also brucia and brucina.
   [1913 Webster]

WordNet (r) 3.0 (2006):

brucine
    n 1: a bitter alkaloid poison resembling strychnine and
         extracted from nux vomica