title: Characterization of limonin glucoside metabolites from human prostate cell culture medium using high-performance liquid chromatography/electrospray ionization mass spectrometry and tandem mass spectrometry.
abstract: The metabolism of limonin 17-beta-D-glucopyranoside (LG) by non-cancerous (RWPE-1) and cancerous (PC-3) human prostate epithelial cells was investigated using high-performance liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) with in-source fragmentation and tandem mass spectrometry (MS/MS). During positive ion LC/ESI-MS, LG formed an abundant sodiated species ([M+Na]+) while the protonated molecule was barely observable. [M+Na]+ further fragmented into the less abundant [LARL+H]+ and a predominantly protonated aglycone molecule (limonin) due to in-source fragmentation. The major metabolite, limonin A-ring lactone (LARL), formed an abundant protonated molecule that was fragmented into a protonated molecule of limonin by loss of one molecule of water. In MS/MS by collisionally activated dissociation (CAD), LG produced the sodiated aglycone, [aglycone+Na]+, while LARL fragmented into [M+H]+ of limonin and fragment ions resulted by further loss of water, carbon monoxide and carbon dioxide, indicating the presence of oxygenated-ring structures. The limits of detection of LG were 0.4 and 20 fmol in selected-ion monitoring (SIM) and selected-reaction monitoring (SRM) detection, respectively.
authors.affiliation: Department of Food Science and Technology, The Ohio State University, Columbus, OH 43210-1007, USA.
authors.forename: Qingguo
authors.initials: Q
authors.lastname: Tian
authors.forename: Kyle D
authors.initials: KD
authors.lastname: Kent
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Bomser
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Schwartz
mesh_terms: D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D002957:Citrus; D017077:Culture Media, Conditioned / Q000737:chemistry*; D005960:Glucosides / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D036701:Limonins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D008297:Male; D015394:Molecular Structure; D011467:Prostate / Q000166:cytology / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D017077:Culture Media, Conditioned; D005960:Glucosides; D036701:Limonins; C001546:limonin