A new chromatographic method for the determination of cysteine, glutathione, homocysteine and Nɛ-homocysteinyllysine isopeptide in human plasma.

Cysteine and glutathione can be applied as therapeutic targets in civilization diseases such as diabetes mellitus and cancers. On the other hand, an elevated concentration of homocysteine, and its metabolites such as homocysteine thiolactone and Nɛ-homocysteinyllysine result in health problems and has been indicated as an independent risk factor for cardiovascular disease and accelerated atherosclerosis. This work describes the first simplified HPLC-UV method that allows simultaneous determination of Nɛ-homocysteinyllysine isopeptide, cysteine, glutathione and homocysteine in human plasma.