Four polyphenols were isolated and purified from a brown alga Eisenia arborea. These phlorotannin compounds showed strong radical scavenging some enzyme inhibitory activities. All of the antioxidative, acetylcholinesterase butyrylcholinesterase inhibitory, tyrosinase inhbibitory activities at 100 μg/mL. Dieckol PFF inhibited butyrylcholinesterase, new target for treatment Alzheimer’s disease, v...

The dissipation of energy as heat is essential for photosynthetic organisms to protect themselves against excess light. We compared Photosystem II florescence changes (non-photochemical quenching, NPQ) in the brown alga Macrocystis pyrifera with that of Ficus sp., a higher plant to examine if the mechanism of heat dissipation (energy-dependent quenching, qE) differs between these evolutionary d...

Three experiments were carried out in 300 l mesocosms using natural seawater from the Peconic Bays ecosystem, Long Island, New York, to examine the ability of the northern quahog Mercenaria mercenaria to prevent blooms of the brown tide alga Aureococcus anophagefferens. Nutrient enrichment and mixing of the mesocosms was conducted according to previous methods that we have employed to induce br...

Freshly released eggs of the marine brown alga Dictyota dichotoma secrete a substance that attracts spermatozoids. This compound has been identified as n-butyl-cyclohepta-2,5-diene. It is closely related to attractants in several other brown algae and confirms that a relation exists between phylogeny and attractant compounds.

A novel fucan sulfate (Hor-1) was isolated from the hot water extract of an edible brown alga, Sargassum horneri (Turner) C. Agardh. The fucan sulfate was revealed to have sugar linkage types, sulfate content and uronic acid content different from those of sodium hornan (Na-HOR), another fucan sulfate isolated from this alga. However, it exhibited inhibitory activity against replication of herp...