OBJECTIVETo investigate the chemical constituents of the brown alga D. divaricata, and to test cytotoxicities of the purified compounds.

METHODCompounds were isolated by normal phase silica gel, Sephadex LH-20 chromatography and reverse phase HPLC techniques. Their structures were elucidated by spectroscopic methods including IR, MS and NMR. Cytotoxicities were tested by MTT method.

RESULTEight compounds were isolated from ethanolic extract of the brown alga D. divaricata and their structures were identified as (-)-torreyol (I), 4beta, 5alpha-dihydroxycubenol (II), 3-farnesyl-p-hydroxybenzioc acid (III), chromazonarol (IV), fucosterol (V), phenyl acetylamine (VI), 4-hydroxybenzoic acid (VII) and n-hexadecanoic acid (VIII).

CONCLUSIONCompound II and IV were obtained from this alga for the first time. The others were isolated from the Dictyotaceae algae for the first time. All compounds were inactive (IC50 > 10 microg x mL(-1)) against human tumor cell lines KB, Bel-7402, PC-3M, Ketr 3 and MCF-7.