Letter: Characterisation and Identification of Spermine and Spermidine Derivatives in Microdesmis Keayana and Microdesmis Puberula Roots by Electrospray Ionisation Tandem Mass Spectrometry and High-Performance Liquid Chromatography/Electrospray Ionisation Tandem Mass Spectrometry

Three new N¹,N⁵,N¹⁴-tris(4-hydroxycinnamoyl)spermines were identified in hydromethanolic root extracts of Microdesmis keayana J. Léonard and Microdesmis puberula Hook f. The electrospray ionisation tandem mass spectrometry (ESI-MS/MS) technique with specific nuclear magnetic resonance analysis of hydrolysed products made it possible to identify N¹,N⁵,N¹⁴-tris(p-coumaroyl)spermine, N¹-feruloyl,N⁵,N¹⁴-di(p-coumaroyl)spermine and N¹,N⁵,N¹⁴-tris(feruloyl)spermine, named keayanines B, C and D, respectively. ESI-MS/MS analysis most effectively provided structural data although high-performance liquid chromatography/electrospray ionisation tandem mass spectrometry was also used to characterise four other compounds from Microdesmis puberula—keayanidines A, B, C and keayanine A—which had already been identified in M. keayana. This chemical data is the first to be published for M. puberula which is a commonly used plant in Central African traditional medicine.