Microdetermination of 1-Methylheptyl gamma-bromoacetoacetate in human blood

One of the authors reported previously on the presence of 1-methylheptyl gamma-bromoacetoacetate (MHBAA) in human cerebrospinal fluid. In this work, a microdetermination of MHBAA in human blood plasma was developed. The sulfhydryl group of 5-(dimethylamino)-1-naphthalene-sulfonyl L-cysteine (DANSYL L-cysteine) reacted with Br at the gamma-position of MHBAA to form a thioether bond, and a fluorescent derivative was obtained. The fluorescent derivative was separated by TLC. Quantitative determination of MHBAA was done by the radiodilution method combined with fluorometry. It was shown that MHBAA exists in human blood plasma at a concentration of several hundred pmol per ml.