Indole alkaloids have attracted great interest from biogenetic and biological points of view such as anticancer, antibacterial, anti-inflammatory, antitussive, and antimalarial properties. Therefore, reliable, fast, and low-cost analytical methods for this class of compounds are highly desirable.

Mass spectrometry (MS), especially tandem mass spectrometry (MS/MS), is an important physicochemical method for the identification of these natural products In the laboratory, two indole alkaloids with a rare uleine skeleton, that is alstilobanine and undulifoline were isolated from the trunk bark of Winchia calophylla.

To the knowledge, uleine alkaloids have not been studied in detail by electrospray ionization (ESI)-MS/MS. The aim of the study was to obtain sufficient information on the structural elucidation of this class of compounds, such as their degradation products, metabolites, and biosynthetic intermediates.