title: Enantioseparation of the constituents involved in the phenylalanine-tyrosine metabolic pathway by capillary electrophoresis tandem mass spectrometry.
abstract: Catecholamines dopamine, norepinephrine, and epinephrine are well-known neurotransmitters playing different roles in the nervous and endocrine system. These compounds are biologically synthesized in the phenylalanine-tyrosine pathway which consists on the successive conversion of l-phenylalanine into l-tyrosine, l-3,4-dihydroxyphenylalanine (L-DOPA), dopamine, norepinephrine, and epinephrine. This work describes the development of an enantioselective CE-ESI-MS2methodology enabling, for the first time, the simultaneous enantioseparation of all the constituents involved in the Phe-Tyr metabolic pathway, since all these compounds except dopamine are chiral. The developed method was based on the use of a dual CDs system formed by 180mM of methyl-β-CD and 40mM of 2-hydroxypropyl-β-CD dissolved in 2M formic acid (pH 1.2) and presented the advantage of avoiding the use of any time-consuming labelling procedure. LODs ranged from 40 to 150nM and the unequivocal identification of the compounds investigated was achieved through their MS2spectra. The applicability of this methodology to the analysis of biological samples (rat plasma) was also demonstrated.
authors.affiliation: Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Sánchez-López
authors.affiliation: Departamento de Psicobiología, UNED, Juan del Rosal 10, Ciudad Universitaria, 28040 Madrid, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Marcos
authors.affiliation: Departamento de Psicobiología, UNED, Juan del Rosal 10, Ciudad Universitaria, 28040 Madrid, Spain.
authors.forename: Emilio
authors.initials: E
authors.lastname: Ambrosio
authors.affiliation: Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain.
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Marina
authors.affiliation: Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain. Electronic address: antonio.crego@uah.es.
authors.forename: Antonio L
authors.initials: AL
authors.lastname: Crego
mesh_terms: D000818:Animals; D003505:Cyclodextrins / Q000737:chemistry; D019075:Electrophoresis, Capillary; D005561:Formates / Q000737:chemistry; D057230:Limit of Detection; D008297:Male; D053858:Metabolic Networks and Pathways; D010649:Phenylalanine / Q000097:blood / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D053719:Tandem Mass Spectrometry; D014443:Tyrosine / Q000097:blood / Q000378:metabolism*
chemical_list: D003505:Cyclodextrins; D005561:Formates; C030544:formic acid; D014443:Tyrosine; D010649:Phenylalanine
keywords: Capillary electrophoresis; Enantiomeric multicomponent separation; Phenylalanine-tyrosine metabolic pathway; Plasma sample; Tandem mass spectrometry