Source : Webster's Revised Unabridged Dictionary (1913)

Alanine \Al"a*nine\, n. [Aldehyde + the ending -ine. The -n- is
   a euphonic insertion.] (Chem.)
   A white crystalline base, {C3H7NO2}, derived from aldehyde
   ammonia.

Source : WordNet®

alanine
     n : a crystalline amino acid that occurs in many proteins