Analysis of biological thiols: Derivatization with monobromobimane and separation by reverse-phase high-performance liquid chromatography
Abstract
A method is described for determination of biological thiols at the picomole level based upon conversion of thiols to fluorescent derivatives by reaction with monobromobimane and separation of the derivatives by reverse-phase high-performance liquid chromatography. Thiols separated by the procedure include N-acetylcysteine, coenzyme A, coenzyme M, cysteamine, cysteine, cysteinylglycine, ergothioneine, ethanethiol, glutathione, γ-glutamylcysteine, homocysteine, hydrogen sulfide, 2-mercaptoethanol, mercaptopyrimidine, methanethiol, pantetheine, 4′-phosphopantetheine, thiosulfate, and 2-thiouracil. Since monobromobimane has little fluorescence and reacts very selectively with thiols to produce fluorescent derivatives, crude extracts can be derivatized and analyzed without prepurification of the thiols, the entire process requiring only 1 to 2 h. The technique is illustrated by determination of the thiol levels in red blood cells.
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