The Collaborative International Dictionary of English v.0.48:

Wrightine \Wright"ine\, n. (Chem.)
   A rare alkaloid found in the bark of an East Indian
   apocynaceous tree (Wrightia antidysenterica), and extracted
   as a bitter white crystalline substance. It was formerly used
   as a remedy for diarrh[oe]a. Called also conessine, and
   neriine.
   [1913 Webster]