xanthurenic acid

[zăn′thə-rĕnĭk, zănth′yə-]
n.
  1. A yellow crystalline phenolic acid excreted in the urine of pyridoxine-deficient test animals that have been fed a diet containing additional tryptophan.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.