title: Simultaneous determination of serum concentrations of levodopa, dopamine, 3-O-methyldopa and alpha-methyldopa by HPLC.
abstract: Levodopa is the medication of choice for Parkinson's disease. The biological complexity of levodopa and of its main derivatives makes their determination important in the clinical field. The aim of this study was to develop an HPLC method for the simultaneous determination of serum concentrations of levodopa, dopamine, 3-O-methyldopa and alpha-methyldopa. We compared UV and fluorimetric detection of native and derivatised compounds. Though less sensitive than other methods, UV detection is important to exclude naturally fluorescent, interfering substances. Fluorimetric detection of derivatised compounds is more sensitive than UV detection. Since 3-O-methyldopa does not react with the derivatising agent 1,2-diphenylethylenediamine, it cannot be detected. For simultaneous determination of the four compounds after pharmacological treatment of patients we therefore advise fluorimetric detection of the native compound.
authors.affiliation: Department of Internal Medicine, Endocrine-Metabolic Sciences and Biochemistry, Siena University, Siena, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Muzzi
authors.forename: Erica
authors.initials: E
authors.lastname: Bertocci
authors.forename: Lucia
authors.initials: L
authors.lastname: Terzuoli
authors.forename: Brunetta
authors.initials: B
authors.lastname: Porcelli
authors.forename: Ilaria
authors.initials: I
authors.lastname: Ciari
authors.forename: Roberto
authors.initials: R
authors.lastname: Pagani
authors.forename: Roberto
authors.initials: R
authors.lastname: Guerranti
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004298:Dopamine / Q000097:blood*; D005470:Fluorometry; D006801:Humans; D007980:Levodopa / Q000097:blood*; D008750:Methyldopa / Q000097:blood*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D014443:Tyrosine; D007980:Levodopa; D008750:Methyldopa; C008404:3-methoxytyrosine; D004298:Dopamine