[Studies on chemical constituents of the brown alga Dictyopteris divaricata].

ABSTRACT

OBJECTIVE: To investigate the chemical constituents of the brown alga D. divaricata, and to test cytotoxicities of the purified compounds. METHOD: Compounds 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. RESULT: Eight 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). CONCLUSION: Compound 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.