This study describes the isolation and structural elucidation of compounds from Euphorbia
hirta L. and evaluates the antibacteriai activity of the isolated compounds against bacteria strains
causing diseases on aquaculture species. Column chromatography was used to fractionate and
purif,rlhe extract of Euphorbia hirta L. and the chemical structures of the compounds were
ietermined using spectroscopic techniques 1D- and 2D-NMR as well as their physical proper-ties
and comparison with literature data. The antibacterial activity was assessed using the agar well
diffusion method. The phytochemical investigation isolated four compounds: (+)-catechin (1),
2$,16a,19-tnhydroxy-ent-kaurane (2), 1'-O-benzyl-rutinoside (3) and taraxerone (4). Taraxerone
was the major compound and also the most active constituent with the lowest of MIC value,
which suggest potential antibacterial activity of this plant species.