11-hydroxyamentadione

11-hydroxyamentadione is a natural meroditerpenoid isolated from the brown macroalga *Cystoseira usneoides*. It exhibits significant antioxidant, anti-inflammatory, and antiplatelet properties. In preclinical and ex vivo studies, 11-hydroxyamentadione has been shown to inhibit arachidonic acid-induced platelet aggregation at low micromolar concentrations, prevent thromboxane B2 (TXB2) formation, and mildly inhibit intracellular calcium transport. Additionally, it suppresses the production of the pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) in lipopolysaccharide (LPS)-stimulated human macrophages, indicating potential therapeutic utility in cardiovascular and inflammatory disorders.