Rapid screening and characterization of metabolites from a marine-derived actinomycete by high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry

A rapid and reliable method has been optimized and established for the analysis of the metabolites from a marine actinomycete by high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC/QTOF MS/MS). From MS/MS spectra, the product ions of [M+H](+) were recorded to provide abundant structural information of the mother nucleus and peptide moieties. Using the QTOF MS/MS and in-source collision-induced dissociation (in-source CID) techniques, three main metabolites including actinomycin D, actinomycin V and actinomycin I were determined and characterized by elemental compositions of precursor and product ions (<7 ppm). Additionally, this method provided information about the compositions of the peptide residues and the sequences of the amino acid from a series of fragment ions. It proved useful for the identification of the metabolites in marine samples which have similar structures especially when there were no reference compounds available. Copyright (C) 2010 John Wiley & Sons, Ltd.