title: Development of an accurate and high-throughput methodology for structural comprehension of chlorophylls derivatives. (I) Phytylated derivatives.
abstract: Phytylated chlorophyll derivatives undergo specific oxidative reactions through the natural metabolism or during food processing or storage, and consequently pyro-, 13(2)-hydroxy-, 15(1)-hydroxy-lactone chlorophylls, and pheophytins (a and b) are originated. New analytical procedures have been developed here to reproduce controlled oxidation reactions that specifically, and in reasonable amounts, produce those natural target standards. At the same time and under the same conditions, 16 natural chlorophyll derivatives have been analyzed by APCI-HPLC-hrMS(2) and most of them by the first time. The combination of the high-resolution MS mode with powerful post-processing software has allowed the identification of new fragmentation patterns, characterizing specific product ions for some particular standards. In addition, new hypotheses and reaction mechanisms for the established MS(2)-based reactions have been proposed. As a general rule, the main product ions involve the phytyl and the propionic chains but the introduction of oxygenated functional groups at the isocyclic ring produces new and specific productions and at the same time inhibits some particular fragmentations. It is noteworthy that all b derivatives, except 15(1)-hydroxy-lactone compounds, undergo specific CO losses. We propose a new reaction mechanism based in the structural configuration of a and b chlorophyll derivatives that explain the exclusive CO fragmentation in all b series except for 15(1)-hydroxy-lactone b and all a series compounds.
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), University Campus Pablo de Olavide, Building 46, Carretera de Utrera km. 1, Sevilla 41013, Spain. Electronic address: covichen@hotmail.com.
authors.forename: Kewei
authors.initials: K
authors.lastname: Chen
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), University Campus Pablo de Olavide, Building 46, Carretera de Utrera km. 1, Sevilla 41013, Spain. Electronic address: jrios@ig.csic.es.
authors.forename: José Julián
authors.initials: JJ
authors.lastname: Ríos
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), University Campus Pablo de Olavide, Building 46, Carretera de Utrera km. 1, Sevilla 41013, Spain. Electronic address: aperez@cica.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pérez-Gálvez
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Consejo Superior de Investigaciones Científicas (CSIC), University Campus Pablo de Olavide, Building 46, Carretera de Utrera km. 1, Sevilla 41013, Spain. Electronic address: mroca@ig.csic.es.
authors.forename: María
authors.initials: M
authors.lastname: Roca
mesh_terms: D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D007477:Ions / Q000737:chemistry; D015394:Molecular Structure
chemical_list: D007477:Ions; D002734:Chlorophyll
keywords: Chlorophylls; Fragmentation; HPLC; Mass spectrometry; Pheophytins; Standarized protocol