Sargassum fusiforme,common off the coasts of Japan,Korea and China is also found off the North American Atlantic coast.S.fusiforme has long been used in traditional medicines.Careful fractionation of this plant has revealed that at least three of its components are effective in combating HIV infection.Palmitic acid has been shown to block HIV entry by interfering with viral CD4binding while linoleic and oleic acids block reverse transcriptase action.