title: Betaines in fruits of Citrus genus plants.
abstract: Numerous compounds, many of them osmolytes, were quantified in natural juices and in frozen concentrate juices from fruits of plants of the Citrus genus. L-proline, N-methyl-L-proline (hygric acid), N,N-dimethyl-L-proline (stachydrine), 4-hydroxy-L-prolinebetaine (betonicine), 4-hydroxy-L-proline, γ-aminobutyric acid (Gaba), 3-carboxypropyltrimethylammonium (GabaBet), N-methylnicotinic acid (trigonelline), and choline in the fruit juices of yellow orange, blood orange, lemon, mandarin, bitter orange (Citrus aurantium), chinotto (Citrus myrtifolia), and grapefruit were analyzed by sensitive HPLC-ESI-tandem mass spectrometry procedure. It was found that the most represented osmolytes in the juices, that is, L-proline, stachydrine, and betonicine, can be quantified with minimal sample preparation and short analysis time (about 1 min) also by flow injection analysis (FIA) ESI-MS/MS with the same results as obtained by HPLC ESI-MS/MS. In all of the juices, discrete amounts of choline and trigonelline were present. Conversely, GabaBet was always below detection limits. Notably, N-methyl-L-proline and 4-hydroxy-L-prolinebetaine, which were discovered for the first time in the juice of bergamot (Citrus bergamia Risso et Poit), are also present in all of the citrus juices examined.
authors.affiliation: Dipartimento di Biochimica e Biofisica, II Università degli Studi di Napoli, via L. De Crecchio 7, 80138 Naples, Italy. luigi.servillo@unina2.it
authors.forename: Luigi
authors.initials: L
authors.lastname: Servillo
authors.forename: Alfonso
authors.initials: A
authors.lastname: Giovane
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Balestrieri
authors.forename: Andrea
authors.initials: A
authors.lastname: Bata-Csere
authors.forename: Domenico
authors.initials: D
authors.lastname: Cautela
authors.forename: Domenico
authors.initials: D
authors.lastname: Castaldo
mesh_terms: D001622:Betaine / Q000031:analogs & derivatives / Q000032:analysis*; D001628:Beverages / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D002957:Citrus; D005638:Fruit / Q000737:chemistry*; D011392:Proline / Q000031:analogs & derivatives / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry
chemical_list: D001622:Betaine; D011392:Proline; C003342:stachydrine