The Collaborative International Dictionary of English v.0.48:

Hematein \Hem`a*te"in\, n. [Gr. ?, ?, blood.] (Chem.)
   A reddish brown or violet crystalline substance, C16H12O6,
   got from hematoxylin by partial oxidation, and regarded as
   analogous to the phthaleins.
   [1913 Webster]