diketopiperazine

[dī-kē′tō-pī-pĕrə-zēn′]
n.
  1. A cyclic dipeptide formed by the dehydration of two molecules of glycine.
  2. Any of various cyclic organic compounds formed by the dehydration of alpha-amino acids other than glycine.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.