title: Screening for in vivo metabolites of isovalertatin family oligosaccharides in rats by liquid chromatography coupled to electrospray ionization tandem mass spectrometry.
abstract: Liquid chromatography/electrospray ionization tandem mass spectrometry (LC/MS(n)) was used to identify trace levels of in vivo metabolites after the administration of isovalertatin M23 or isovalertatin D23 to rats. The biosamples of urine, feces, and ileum incubation were pre-treated by solid-phase extraction (SPE), and then chromatographed with a reversed-phase C8 column with acetonitrile/1.5 mM aqueous ammonia (18:82, v/v) as the mobile solvent. The parent drug and the possible metabolites were identified by two independent qualitative parameters, retention time and collision-induced dissociation product ions. Nine and seven metabolites were successfully characterized from biosamples after administration of isovalertatins M23 and D23, respectively, to rats. The metabolism seemed to take place in the rat intestinal tract, and metabolic pathways were identified including isovaleryl de-esterification and hydrolysis of alpha-glucose units located either at the reducing or the non-reducing terminus.
authors.affiliation: Tianjin State Key Laboratory of Pharmacokinetics and Pharmacodynamics, Tianjin Institute of Pharmaceutical Research, Tianjin 300193, China. ddysi@sohu.com
authors.forename: Duanyun
authors.initials: D
authors.lastname: Si
authors.forename: Dafang
authors.initials: D
authors.lastname: Zhong
authors.forename: Changxiao
authors.initials: C
authors.lastname: Liu
mesh_terms: D000588:Amines / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013302:Streptomyces / Q000737:chemistry / Q000378:metabolism
chemical_list: D000588:Amines; D004791:Enzyme Inhibitors; D009844:Oligosaccharides; C516182:isovalertatin D23; C516181:isovalertatin M23