title: Identification of urinary metabolites of imperatorin with a single run on an LC/Triple TOF system based on multiple mass defect filter data acquisition and multiple data mining techniques.
abstract: The detection of drug metabolites, especially for minor metabolites, continues to be a challenge because of the complexity of biological samples. Imperatorin (IMP) is an active natural furocoumarin component originating from many traditional Chinese herbal medicines and is expected to be pursued as a new vasorelaxant agent. In the present study, a generic and efficient approach was developed for the in vivo screening and identification of IMP metabolites using liquid chromatography-Triple TOF mass spectrometry. In this approach, a novel on-line data acquisition method mutiple mass defect filter (MMDF) combined with dynamic background subtraction was developed to trace all probable urinary metabolites of IMP. Comparing with the traditionally intensity-dependent data acquisition method, MMDF method could give the information of low-level metabolites masked by background noise and endogenous components. Thus, the minor metabolites in complex biological matrices could be detected. Then, the sensitive and specific multiple data-mining techniques extracted ion chromatography, mass defect filter, product ion filter, and neutral loss filter were used for the discovery of IMP metabolites. Based on the proposed strategy, 44 phase I and 7 phase II metabolites were identified in rat urine after oral administration of IMP. The results indicated that oxidization was the main metabolic pathway and that different oxidized substituent positions had a significant influence on the fragmentation of the metabolites. Two types of characteristic ions at m/z 203 and 219 can be observed in the MS/MS spectra. This is the first study of IMP metabolism in vivo. The interpretation of the MS/MS spectra of these metabolites and the proposed metabolite pathway provide essential data for further pharmacological studies of other linear-type furocoumarins.
authors.affiliation: School of Pharmacy, Hebei Medical University, 361 East Zhongshan Road, Shijiazhuang, 050017, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Qiao
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Shi
authors.forename: Rui
authors.initials: R
authors.lastname: Shi
authors.forename: Man
authors.initials: M
authors.lastname: Liu
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.forename: Kerong
authors.initials: K
authors.lastname: Zhang
authors.forename: Qiao
authors.initials: Q
authors.lastname: Wang
authors.forename: Meicun
authors.initials: M
authors.lastname: Yao
authors.forename: Lantong
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D057225:Data Mining / Q000379:methods*; D011564:Furocoumarins / Q000008:administration & dosage* / Q000652:urine*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D011564:Furocoumarins; C031534:imperatorin