Isolation of antibacterial fatty acids from Schotia brachypetala.

In southern Africa, the roots of Schotia brachypetala are used by traditional healers to treat dysentery and diarrhoea. Activity-directed fractionation of the ethanol extract of the dried leaves yielded 9,12,15-octadecatrienoic (linolenic) acid and methyl-5,11,14,17-eicosatetraenoate. These fatty acids displayed antibacterial activity against the Gram-positive bacteria Bacillus subtilis and Staphylococcus aureus and to a lesser extent, against the Gram-negative Escherichia coli and Klebsiella pneumoniae.