norleucine

[nôr-lōōsēn′]
n.
  1. A crystalline alpha-amino acid that is isomeric to leucine and isoleucine but not found in proteins and formed in the deamination of lysine.caprine
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.