The Collaborative International Dictionary of English v.0.48:

Asparagine \As*par"a*gine\, n. [Cf. F. asparagine.] (Chem.)
   A white, nitrogenous, crystallizable substance,
   C4H8N2O3+H2O, found in many plants, and first obtained from
   asparagus. It is believed to aid in the disposition of
   nitrogenous matter throughout the plant; -- called also
   altheine.
   [1913 Webster]

WordNet (r) 3.0 (2006):

asparagine
    n 1: a crystalline amino acid found in proteins and in many
         plants (e.g., asparagus)