title: Liquid Chromatography-Electrospray Ionization Mass Spectrometry Analysis of Limonoids and Flavonoids in Seeds of Grapefruits, Other Citrus Species, and Dietary Supplements.
abstract: A selective UHPLC-DAD-QToF-MS method was developed to screen grapefruit seeds, and the seeds of other Citrus species for limonoid aglycones, acids, glucosides, and flavonoids. These classes of compounds were identified in positive and negative ion modes over a mass-to-charge range from 100-1500. Accurate mass values, elution times, and fragmentation patterns obtained by QToF-mass spectrometry were used to identify or tentatively characterize the compounds detected in the sample of this study. Limonin was the major limonoid in most of the seeds of Citrus species, followed by nomilin. This analytical method was successfully applied for the analysis of commercial extracts and dietary supplements claiming to contain grapefruit seed extract, or extracts made from the seed and other fruit parts such as the peel or pulp. Many commercial products contained large numbers of flavonoids, indicating the use of peel, pulp, or seed coat. This method also permitted detection of synthetic preservatives such as benzethonium chloride, methylparaben, and triclosan in commercial grapefruit seed extract products. Out of the 17 commercial products analyzed, two contained the synthetic antimicrobial agent benzethonium chloride.
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS, USA.
authors.forename: Bharathi
authors.initials: B
authors.lastname: Avula
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS, USA.
authors.forename: Satyanarayanaraju
authors.initials: S
authors.lastname: Sagi
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS, USA.
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Wang
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS, USA.
authors.forename: Mei
authors.initials: M
authors.lastname: Wang
authors.affiliation: American Botanical Council, Austin, TX, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Gafner
authors.affiliation: U. S. Horticultural Research Laboratory, Agricultural Research Service, U. S. D. A., Ft. Pierce, FL, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Manthey
authors.affiliation: National Center for Natural Products Research, Research Institute of Pharmaceutical Sciences, The University of Mississippi, University, MS, USA.
authors.forename: Ikhlas A
authors.initials: IA
authors.lastname: Khan
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002957:Citrus / Q000737:chemistry*; D032083:Citrus paradisi / Q000737:chemistry*; D019587:Dietary Supplements; D005419:Flavonoids / Q000032:analysis*; D036701:Limonins / Q000032:analysis*; D012639:Seeds / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D005419:Flavonoids; D036701:Limonins; C001546:limonin