title: Determination of oxalyl thiolesters, N-oxalylcysteine and N-oxalylcysteamine in biological materials.
abstract: A convenient method is described for the quantitative analysis of oxalyl thiolesters (OTEs), a newly discovered class of mammalian metabolites, in biological samples. By this particular technique the total concentration of all OTEs in the sample is determined. The method involves first reacting the biological material with cysteamine (2-aminoethanethiol) or cysteine under conditions that convert OTEs quantitatively to N-oxalylcysteamine (or N-oxalylcysteine), followed by reaction with monobromobimane to give a highly fluorescent derivative that is analyzed by reversed-phase ion-pair chromatography, with tetrabutylammonium ion as the counterion and N-(2-mercaptopropionyl)glycine as an internal standard. The method is capable of detecting as little as 0.6 pmol of the bimane derivative of the N-oxalyl compound in a single HPLC injection. The application of this method has led to the discovery that not only OTEs but also N-oxalylcysteine and N-oxalylcysteamine are normal mammalian metabolites. In various rat tissues the OTE concentration ranges up to 65 nmol/g (wet wt), the N-oxalylcysteine concentration is approximately 10 nmol/g, and the N-oxalylcysteamine concentration is 0-3 nmol/g.
authors.affiliation: Department of Chemistry, Pennsylvania State University, University Park 16802.
authors.forename: S S
authors.initials: SS
authors.lastname: Skorczynski
authors.forename: C S
authors.initials: CS
authors.lastname: Yang
authors.forename: G A
authors.initials: GA
authors.lastname: Hamilton
mesh_terms: D000818:Animals; D001643:Bridged Bicyclo Compounds; D002851:Chromatography, High Pressure Liquid; D003543:Cysteamine / Q000032:analysis* / Q000031:analogs & derivatives; D003545:Cysteine / Q000031:analogs & derivatives* / Q000032:analysis; D004228:Dithionitrobenzoic Acid; D004952:Esters / Q000032:analysis; D005453:Fluorescence; D008099:Liver / Q000737:chemistry; D008297:Male; D010070:Oxalates / Q000032:analysis*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001643:Bridged Bicyclo Compounds; D004952:Esters; D010070:Oxalates; C051227:N-oxalylcysteine; D003543:Cysteamine; C068905:N-oxalylcysteamine; D004228:Dithionitrobenzoic Acid; D003545:Cysteine; C028381:monobromobimane