title: Serotonin 5-O-β-Glucoside and Its N-Methylated Forms in Citrus Genus Plants.
abstract: Citrus genus is characterized by a specific presence of indole metabolites deriving from the N-methylation of tryptamine and its hydroxylated form, 5-hydroxytryptamine (serotonin), which are likely involved in plant defense mechanisms. In this study, we identified for the first time the occurrence in Citrus plants of serotonin 5-O-β-glucoside and all its N-methylated derivatives, that is, N-methylserotonin 5-O-β-glucoside, N,N-dimethylserotonin (bufotenine) 5-O-β-glucoside, and N,N,N-trimethylserotonin (bufotenidine) 5-O-β-glucoside. The identification of the glucosylated compounds was based on mass spectrometric studies, hydrolysis by glucosidase, and in some cases, comparison to authentic compounds. Beside leaves, the distribution of the glucosylated forms and their aglycones in some Citrus species was evaluated in flavedo, albedo, juice, and seeds. The simultaneous presence of serotonin and its N-methylated derivatives, together with the corresponding glucosylated forms, is consistent with the occurrence of a metabolic pathway, specific for Citrus, aimed at potentiating the defensive response to biotic stress through the optimization of the production and use of the most toxic of such metabolites.
authors.affiliation: †Dipartimento di Biochimica, Biofisica e Patologia Generale, Seconda Università degli Studi di Napoli, Via Luigi de Crecchio 7, 80138 Napoli, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Servillo
authors.affiliation: †Dipartimento di Biochimica, Biofisica e Patologia Generale, Seconda Università degli Studi di Napoli, Via Luigi de Crecchio 7, 80138 Napoli, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Giovane
authors.affiliation: †Dipartimento di Biochimica, Biofisica e Patologia Generale, Seconda Università degli Studi di Napoli, Via Luigi de Crecchio 7, 80138 Napoli, Italy.
authors.forename: Rosario
authors.initials: R
authors.lastname: Casale
authors.affiliation: †Dipartimento di Biochimica, Biofisica e Patologia Generale, Seconda Università degli Studi di Napoli, Via Luigi de Crecchio 7, 80138 Napoli, Italy.
authors.forename: Nunzia
authors.initials: N
authors.lastname: D'Onofrio
authors.affiliation: ‡Dipartimento di Ingegneria Industriale e ProdAL scarl, Università degli Studi di Salerno, Via Ponte don Melillo, 84084 Fisciano, Salerno, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Ferrari
authors.affiliation: §Stazione Sperimentale per le Industrie delle Essenze e dei derivati dagli Agrumi (SSEA), Azienda Speciale della Camera di Commercio di Reggio Calabria, Via Tommaso Campanella 12, 89127 Reggio Calabria, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Cautela
authors.affiliation: †Dipartimento di Biochimica, Biofisica e Patologia Generale, Seconda Università degli Studi di Napoli, Via Luigi de Crecchio 7, 80138 Napoli, Italy.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Balestrieri
authors.affiliation: §Stazione Sperimentale per le Industrie delle Essenze e dei derivati dagli Agrumi (SSEA), Azienda Speciale della Camera di Commercio di Reggio Calabria, Via Tommaso Campanella 12, 89127 Reggio Calabria, Italy.|#Ministero dello Sviluppo Economico (MiSE), Via Molise 2, 00187 Roma, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Castaldo
mesh_terms: D002957:Citrus / Q000737:chemistry* / Q000378:metabolism; D005960:Glucosides / Q000737:chemistry* / Q000378:metabolism; D008745:Methylation; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry* / Q000378:metabolism; D012701:Serotonin / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005960:Glucosides; D010936:Plant Extracts; D012701:Serotonin
keywords: Citrus plants; N-methylserotonin 5-O-β-glucoside; biotic stress; bufotenidine 5-O-β-glucoside; bufotenine 5-O-β-glucoside; serotonin 5-O-β-glucoside; serotonin derivatives; tryptamine derivatives