title: Electron ionization mass spectrometry of citrus limonoids.
abstract: Electron ionization (EI) mass spectrometry was used to differentiate four structurally closely related citrus limonoid aglycones, including limonin, nomilin, obacunone, and deacetylnomilin. The limonoids were isolated and purified from citrus seeds. Structures of major fragment ions were elucidated by high-resolution mass spectrometry (HRMS) and fragmentation pathways were proposed. The fragmentation patterns observed in the EI spectra can be used as important references for the positive characterization of limonoid aglycones.
authors: Texas A&M University-Kingsville Citrus Center, 312 N International Blvd, Weslaco, TX 78596, USA.
authors: Qingguo
authors: Q
authors: Tian
authors: Dan
authors: D
authors: Li
authors: Damon
authors: D
authors: Barbacci
authors: Steven J
authors: SJ
authors: Schwartz
authors: Bhimanagouda S
authors: BS
authors: Patil
mesh_terms: D001584:Benzoxepins / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D002957:Citrus / Q000737:chemistry*; D036701:Limonins / Q000737:chemistry; D012639:Seeds / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization; D014315:Triterpenes / Q000737:chemistry*
chemical_list: D001584:Benzoxepins; D036701:Limonins; D014315:Triterpenes; C067207:obacunone; C059405:nomilin