RESUMO
<p><b>OBJECTIVE</b>To study antifungal activity of a new ellagitannin isolated from the plant residues of Euphorbia antisyphilitica (E. antisyphilitica) Zucc in the wax extraction process.</p><p><b>METHODS</b>An extract was prepared from dehydrated and pulverized residues and fractionated by liquid chromatography on Amberilte XAD-16, until obtained an ellagitannin-rich ethanolic fraction which was treated by rotaevaporation to recover the ellagitannin as fine powder. An aqueous solution was prepared and treated through ionic exchange liquid chromatography (Q XL) and gel permeation chromatography (G 25). The ellagitannin-rich fraction was thermogravimetrically evaluated (TGA and DTA) to test the thermo-stability of ellagic acid (monomeric unit). Then ellagitannin powder was analyzed by infrared spectrospcopy to determinate the functional groups and, also mass spectroscopy was used to determine the molecular ion.</p><p><b>RESULTS</b>The principal functional groups of ellagitannin were determined, the molecular weight was 860.7 g/mol; and an effective antifungal activity against phytopathogenic fungi was demonstrated.</p><p><b>CONCLUSIONS</b>It can be concluded that the new ellagitannin (860.7 g/mol) isolated from E. antisyphilitica Zucc is an effective antifungal agent against Alternaria alternata, Fusarium oxyzporum, Colletotrichum gloeosporoides and Rhizoctnia solani.</p>