CHROMATOGRAPHY, Vol. 25 (2004), No. 2, pp. 55-59
Original
LC/PAD/APCI-MS for the characterization and analysis of porritoxin and
its related compounds from Alternaria porri.
Masayuki Horiuchi1*, Keiichiro Ohnishi2, Masakazu Yamashita2 and Takashi Maoka1
1Research Institute for Production Development, 15 Shimogamo-Morimoto-cho, Sakyo-ku, Kyoto 606-0805, Japan
2Department of Molecular Science and Technology, Faculty of Engineering, Doshisha University, 1-3, Tatara miyakotani, Kyotanabe-shi, Kyoto 610-0312, Japan
Abstract:
LC/PAD/APCI-MS was utilized in the analysis of porritoxin and its structurally related compounds produced by Alternaria porri. APCI-MS
of the porritoxins produced protonated molecules [M + H]+ and fragment ions attributed to the elimination of side chains. UV spectra provided
chromophore information, by which three structural types of porritoxin and its related compounds can be characterized. A combination
of APCI-MS and UV spectral data afforded accurate information for the identification of porritoxins by HPLC. This method was utilized in
the analysis of porritoxins produced by A. porri in five kinds of culture media. Furthermore, this method gave quantitative information about
porritoxin, which showed the strongest inhibitory effect on the growth of seedlings of stone leek and lettuce among porritoxins, and displayed
excellent linearity from 10 ng/injection to 100 μg/injection. Porritoxin in five kinds of culture media was determined using this method.
Keywords:
Porritoxin; isoindoline; phthalide; zinniol; Alternaria porri; LC/PAD/APCI-MS
