title: 2-picolylamine derivatization for high sensitivity detection of abscisic acid in apicomplexan blood-infecting parasites.
abstract: We have developed a new liquid chromatography-electrospray ionization tandem mass spectrometry methodology based on 2-picolylamine derivatization and positive ion mode detection for abscisic acid (ABA) identification. The selected reaction leads to the formation of an amide derivative which contains a highly active pyridyl group. The enhanced ionization allows for a 700-fold increase over commonly monitored unmodified ABA, which in turn leads to excellent limits of detection and quantification values of 0.03 and 0.15ngmL-1, respectively. This method has been validated in the highly complex matrix of a red blood cell extract. In spite of the high sensitivity achieved, ABA could not be detected in Plasmodium falciparum-infected red blood cells, suggesting that, if present, it will be found either in ultratrace amounts or as brief bursts at defined time points within the intraerythrocytic cycle and/or in the form of a biosynthetic analogue.
authors.affiliation: Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 10-12, ES-08028 Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Rosselló 149-153, ES-08036 Barcelona, Spain; Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, ES-08028 Barcelona, Spain. Electronic address: ernest.moles@isglobal.org.
authors.forename: Ernest
authors.initials: E
authors.lastname: Moles
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar, Doctor Aiguader 88, ES-08003 Barcelona, Spain; Department of Experimental and Health Sciences, Universitat Pompeu Fabra, Doctor Aiguader 88, ES-08003 Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Marcos
authors.affiliation: Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, ES-08028 Barcelona, Spain; Department of Biochemistry and Molecular Biomedicine, University of Barcelona, Avda. Diagonal 643, ES-08028 Barcelona, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Imperial
authors.affiliation: Bioanalysis Research Group, IMIM, Hospital del Mar, Doctor Aiguader 88, ES-08003 Barcelona, Spain.
authors.forename: Oscar J
authors.initials: OJ
authors.lastname: Pozo
authors.affiliation: Nanomalaria Group, Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 10-12, ES-08028 Barcelona, Spain; Barcelona Institute for Global Health (ISGlobal), Barcelona Center for International Health Research (CRESIB, Hospital Clínic-Universitat de Barcelona), Rosselló 149-153, ES-08036 Barcelona, Spain; Nanoscience and Nanotechnology Institute (IN2UB), University of Barcelona, Martí i Franquès 1, ES-08028 Barcelona, Spain. Electronic address: xfernandez_busquets@ub.edu.
authors.forename: Xavier
authors.initials: X
authors.lastname: Fernàndez-Busquets
mesh_terms: D000040:Abscisic Acid / Q000032:analysis*; D004912:Erythrocytes / Q000378:metabolism* / Q000469:parasitology; D006801:Humans; D016778:Malaria, Falciparum / Q000378:metabolism* / Q000469:parasitology; D010848:Picolinic Acids / Q000737:chemistry*; D010937:Plant Growth Regulators / Q000032:analysis; D010963:Plasmodium falciparum / Q000378:metabolism*
chemical_list: D010848:Picolinic Acids; D010937:Plant Growth Regulators; D000040:Abscisic Acid
keywords: Abscisic acid; Apicomplexa; Liquid chromatography-electrospray ionization tandem mass spectrometry; Malaria; Picolylamine; Plasmodium falciparum