Determination of D,L-threo-3,4-dihydroxyphenylserine and of the D- and L-enantiomers in human plasma and urine.

Abstract

DL-threo-3,4-Dihydroxyphenylserine (DOPS) is increasingly being investigated for treatment of disorders involving defects of the sympathetic nervous system, such as Parkinson's disease, Shy-Drager syndrome and congenital dopamine-beta-hydroxylase deficiency. Whilst L-DOPS is converted by aromatic L-amino acid decarboxylase into natural norepinephrine in vitro, D-DOPS inhibits this process. There are no data on the interaction between D- and L-DOPS in vivo because a reliable method for the measurement of the D- and L-enantiomers in plasma and urine is lacking. We describe here such a method based on reversed-phase chromatography after derivatization with o-phthaldialdehyde and N-acetyl-L-cysteine. Good separation was achieved with this procedure (resolution factor 2.33). Two simple and sensitive methods are also presented for total D,L-DOPS estimation, based on reversed-phase chromatography with electrochemical detection after either deproteinization (DP) or liquid-liquid extraction (LE) as sample preparation steps. The two methods gave identical results (regression line DOPS (DP) = 1.026 DOPS (LE) + 33.28; r = 0.997; n = 52). Excellent agreement was found between the sum of the D- and L-DOPS concentrations and the measured total D,L-DOPS concentration (regression line DOPS (D + L) = 0.955 DOPS (total, LE) + 116.65; r = 0.992; n = 100).

• Authors: F Boomsma, F A van der Hoorn, A J Man in 't Veld, M A Schalekamp
• Journal: Journal of chromatography (J Chromatogr) Vol. 427 Issue 2 Pg. 219-27 (Jun 03 1988) Netherlands
• PMID: 3137237 (Publication Type: Journal Article)

Chemical References

• Serine
• o-Phthalaldehyde
• Droxidopa
• Acetylcysteine

Topics

• Acetylcysteine
• Droxidopa (analysis, blood, urine)
• Humans
• Serine (analogs & derivatives)
• Spectrometry, Fluorescence
• Stereoisomerism
• o-Phthalaldehyde