A simple colorimetric method for the simultaneous determination of N-acetylcysteine and cysteine.
The widespread use of N-acetylcysteine as an antioxidant and a precursor for tissue cysteine creates a need for a simple method that measures both and distinguishes them from one another. We describe a procedure based on the use of the enzyme acylase, which hydrolyzes N-acetylcysteine to cysteine. Cysteine is subsequently measured with a specific colorimetric procedure. Unhydrolyzed N-acetylcysteine gives only a weak colorimetric response (11.5% that for cysteine); after hydrolysis, however, the two are equivalent. Hence, N-acetylcysteine can be distinguished by the enhanced response after hydrolysis.
Ogwu
V
V
Department of Neurology and Neurobiology Research Center, Mount Sinai School of Medicine of the City University of New York, New York 10029, USA.
Cohen
G
G
D000111:Acetylcysteine / Q000032:analysis*; D000581:Amidohydrolases; D000818:Animals; D000975:Antioxidants; D003124:Colorimetry / Q000379:methods*; D003545:Cysteine / Q000032:analysis*; D013552:Swine
D000975:Antioxidants; D000581:Amidohydrolases; C019665:amidase; D003545:Cysteine; D000111:Acetylcysteine