title: Development of a 6-hydroxychroman-based derivatization reagent: application to the analysis of 5-hydroxytryptamine and catecholamines by using high-performance liquid chromatography with electrochemical detection.
abstract: We developed a novel derivatization reagent, (2R)-2,5-dioxopyrrolidin-1-yl-2,5,7,8-tetramethyl-6-(tetrahydro-2H-pyran-2-yloxy)chroman-2-carboxylate (NPCA), for electrochemical (EC) detection in HPLC. NPCA was synthesized from (R)-(+)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (alpha-CA), which exhibits intense EC response. NPCA successfully yielded alpha-CA derivatives of primary amines by a two-step derivatization procedure. Following pre-column derivatization with NPCA, a simultaneous determination of alpha-CA derivatives of neuroactive monoamines [dopamine (DA), epinephrine, and 5-hydroxytryptamine (5-HT)], their monoamine oxidase metabolites (3,4-dihydroxyphenylacetic acid, homovanillic acid, and 5-hydroxyindole-3-acetic acid) and their catechol-O-methyltransferase metabolites [3-methoxytyramine (3-MT) and normetanephrine (NMN)] was completely achieved using our HPLC-EC method. Using an HPLC equipped with coulometric electrode-array detection system, the resultant alpha-CA derivatives of NMN, 5-HT, DA and 3-MT showed intense EC responses, that were approximately 1.3, 1.4, 1.1 and 1.4-fold higher than the corresponding native forms, respectively. The detection limits were in the range of approximately 16-60 fmol on column (signal-to-noise ratio 3). The proposed HPLC method was applied to determine 5-HIAA, HVA, alpha-CA-5-HT and alpha-CA-DA in rat urine. As a consequence, these analytes were successfully determined with satisfactory precisions.
authors.affiliation: Division of Bio-Analytical Chemistry, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, Japan.
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Sasaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukushima
authors.forename: Madoka
authors.initials: M
authors.lastname: Ohishi
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Toyo'oka
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000652:urine*; D002839:Chromans / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry / Q000379:methods*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012701:Serotonin / Q000652:urine*
chemical_list: D002395:Catecholamines; D002839:Chromans; D012701:Serotonin