title: Simultaneous characterization of quaternary alkaloids, 8-oxoprotoberberine alkaloids, and a steroid compound in Coscinium fenestratum by liquid chromatography hybrid ion trap time-of-flight mass spectrometry.
abstract: Simultaneous characterization of quaternary alkaloids, 8-oxoprotoberberine alkaloids, and a steroid compound in Coscinium fenestratum was successfully performed by liquid chromatography hybrid ion trap time-of-flight mass spectrometry (LC/IT-TOF MS). A total of 32 compounds, including 2 benzylisoquinoline alkaloids, 3 aporphine alkaloids, 12 quaternary protoberberine alkaloids, 10 8-oxoprotoberberine alkaloids, 3 tetrahydroprotoberberine alkaloids, and a steroid compound were simultaneously separated and characterized by matching the empirical molecular formulae with those published in literature and the multi-stage mass spectrometry (MS(n)) data obtained using structural information from IT, accurate mass measurement obtained from TOF MS, and HPLC separation. A total of 20 compounds, including 4 novel natural products were identified or tentatively identified for the first time from Coscinium fenestratum. In the positive-ion mode, 8-oxoprotoberberines produced [M+H](+) and [M+Na](+); the fragmentation of 8-oxodihydroprotoberberines produced [M+H-*CH(3)](+*), [M+H-*CH(3)-*CH(3)](+), and [M+H-*CH(3)-*CH(3)-CO](+), while 8-oxotetrahydroprotoberberines generated [M+H-*CH(3)](+*), [M+H-*CH(3)-*CH(3)](+), [M+H-*CH(3)-*H](+), and iminium ions from the cleavage of the protoberberine skeleton. The method can be applied for the analysis of 8-oxoberberine and other alkaloids in Coptis japonica, Phellodendron amurense, and other herbal medicines.
authors.affiliation: Department of International Development Engineering, Graduate School of Science and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan. deevanhxay.p.aa@m.titech.ac.jp
authors.forename: Phengxay
authors.initials: P
authors.lastname: Deevanhxay
authors.forename: Makoto
authors.initials: M
authors.lastname: Suzuki
authors.forename: Nariaki
authors.initials: N
authors.lastname: Maeshibu
authors.forename: He
authors.initials: H
authors.lastname: Li
authors.forename: Ken
authors.initials: K
authors.lastname: Tanaka
authors.forename: Sachio
authors.initials: S
authors.lastname: Hirose
mesh_terms: D000470:Alkaloids / Q000032:analysis* / Q000302:isolation & purification; D002853:Chromatography, Liquid / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods; D008519:Medicine, Traditional; D029583:Menispermaceae / Q000737:chemistry*; D013256:Steroids / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D000470:Alkaloids; D013256:Steroids