title: LC/MS/MS of steroids having vicinal diol as electrospray-active boronates.
abstract: A derivatization procedure with (3-dimethylaminophenyl)dihydroxyborane (DAPB) was introduced to enhance the detectability of steroids having a vicinal diol in LC/electrospray ionization (ESI)-MS/MS. DAPB reacted with the vicinal diol on the steroids [4β-hydroxycholesterol (4-HCh), pregnanetriol (PT) and 20R,22R-dihydroxycholesterol] in pyridine at 50°C within 1 h. The resulting DAPB-derivatives were highly responsive in ESI-MS operating in the positive-ion mode and gave characteristic product ions during MS/MS, which enabled sensitive detection using a selected reaction monitoring mode; the detection responses of the DAPB-derivatives were increased by 20-160-fold over those of the intact steroids and the limits of detection were in the low femtomole or attomole range. The derivatization procedure was successfully applied to biological sample analysis; the derivatization followed by LC/ESI-MS/MS enabled the specific detection of trace amounts of 4-HCh in human plasma and PT in human urine with a small sample volume, simple pretreatment and short chromatographic run time.
authors: Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Chiba, Japan. higashi@rs.tus.ac.jp
authors: Tatsuya
authors: T
authors: Higashi
authors: Katsumi
authors: K
authors: Kawasaki
authors: Nagisa
authors: N
authors: Matsumoto
authors: Shoujiro
authors: S
authors: Ogawa
authors: Kuniko
authors: K
authors: Mitamura
authors: Shigeo
authors: S
authors: Ikegawa
mesh_terms: D000873:Anthracenes / Q000737:chemistry; D001897:Boronic Acids / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods; D006801:Humans; D006888:Hydroxycholesterols / Q000097:blood / Q000737:chemistry* / Q000652:urine; D011279:Pregnanetriol / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013256:Steroids / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D000873:Anthracenes; D001897:Boronic Acids; D006888:Hydroxycholesterols; D011725:Pyridines; D013256:Steroids; C099828:cholest-5-ene-3,4-diol; D011279:Pregnanetriol; C013946:dihydroxydianthrone; C023666:pyridine