Characterization of a New Abscisic Acid-conjugated Metabolite in Crude Plant Extract by Desorption Chemical Ionization and Secondary Ion Mass Spectrometry

Abstract

A new conjugate of hydroxyabscisic acid, tentatively named MeHMG-HOABA, along with a known conjugate, p-hydroxy-p-methylglutarylhydroxyabscisic acid (HMG-HOABA), were isolated from immature seeds of Robinia pseudacacia and determined. Evidence for the occurrence of MeHMG-HOABA as a natural metabolite, and not as an artifact, was provided by desorption chemical ionization (Del) and secondary ion mass spectrometry (SIMS) in conjunction with the technique of linked scanning at constant BIE. The mass spectrometric technique allows the detection and characterization of the conjugates to be analysed even in a crude plant extract.