Miyazaki Sho, Kimura Honoka, Natsume Masahiro, Asami Tadao, Hayashi Ken-Ichiro, Kawaide Hiroshi, Nakajima Masatoshi
Department of Applied Biological Chemistry, The University of Tokyo, Tokyo 113-8657, Japan.
Institute of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.
Biochem Biophys Rep. 2015 May 30;2:103-107. doi: 10.1016/j.bbrep.2015.05.010. eCollection 2015 Jul.
-Kaurenoic acid (KA) is a key intermediate connected to a phytohormone gibberellin. To date, the general procedure for quantifying KA is by using traditional gas chromatography-mass spectrometry (GC-MS). In contrast, gibberellins, which are more hydrophilic than KA, can be easily quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this study, we have established a new method to quantify KA by LC-MS/MS by taking advantage of a key feature of KA, namely the lack of fragmentation that occurs in MS/MS when electrospray ionization (ESI) is in the negative mode. Q1 and Q3 were adopted as identical channels for the multiple reaction monitoring of KA. The method was validated by comparing with the results obtained by selected ion monitoring in GC-MS. This new method could be applicable for the quantification of other hydrophobic compounds.
