Application of high performance liquid chromatography coupled with ultraviolet spectroscopy and electrospray mass spectrometry to the characterisation of ellagitannins from Terminalia macroptera roots

Purpose. Terminalia macroptera roots are used in Guinea-Bissau and other We st African countries to treat infectious diseases like gonorrhoea. Previous work showed an ethanol extract of T. macroptera roots (T) to have an in vi tro antimicrobial profile against Neisseria gonarrhoae (including resistant strains) and enteropathogenic agents. The most active fractions of this ex tract were identified as the diethyl ether (T2) and water (T5) fractions. T he aim of the present study was the identification of major compounds prese nt in T and simultaneously in T2 or T5. Methods. The T extract and T2 and T5 fractions were analysed by high perfor mance liquid chromatography coupled with ultraviolet photodiode array (LC-U V) spectroscopy and electrospray ionization mass spectrometry (E-MS). These analyses indicated the presence of ellagitannin derivatives. In order to c onfirm the identities of the detected compounds, they were isolated from T2 and T5 by preparative chromatographic techniques and identified by spectro scopic methods including tandem mass spectrometry. Results. By using LC-UV-ES-MS, four major compounds (ellagic acid, gallic a cid, punicalagin, terchebulin) could be identified in the T extract. Three other compounds (3,3'di-O-methylellagic acid, 3,4,3',4'-tetra-O-methylellag ic acid, terflavin A) were also isolated and identified. Conclusions. LC-UV-ES-MS is a useful technique for the analysis of mixtures containing ellagitannins.