Desorption Chemical Ionization Mass Spectra of Underivatized Abscisic Acid-conjugated Metabolites,a Useful Aid for Structural Characterization |
| |
| Authors: | Naohito Takeda Ken-ichi Harada Makoto Suzuki Akira Tatematsu Nobuhiro Hirai Koichi Koshimizu |
| |
| Institution: | 1. Faculty of Pharmacy, Meijo University, Tempaku, Nagoya 468, Japan;2. Faculty of Agriculture, Kyoto University, Kyoto 606, Japan |
| |
| Abstract: | The use of desorption chemical ionization (D/CI) mass spectrometry for the structural characterization of the abscisic acid (ABA)-conjugated metabolites, abscisic acid-γ-d-glucosyl ester (ABAGE), 4′-O-dihydrophaseic acid-γ-d-glucoside (DPAGS) and γ-hydroxy-γ-methylglutaryl-hydroxyabscisic acid (HMG-HOABA), was studied. The effects of the D/CI source temperature on the spectral features are described. Enhanced quasi-molecular ion intensities (e.g., M·NH4]+) were observed in the D/CI(NH3) spectrum at a low source temperature (170°C). When a higher source temperature (250°C) was used, more extensive fragmentation occurred, and structurally diagnostic fragment ions appeared in the spectra. The spectra obtained at two degrees of source temperature were complementary to each other for the structural characterization. |
| |
| Keywords: | |
|
|
