A xylogalactofucan from the brown seaweed Spatoglossum schröederi stimulates the synthesis of an antithrombotic heparan sulfate from endothelial cells.

The brown seaweed Spatoglossum schröederi (Dictyotaceae) contains three main fucans (fucans A, B and C) with different mobility in electrophoresis. The fucan with highest mobility (fucan C) was precipitated with 2.0 volumes of acetone, purified using a combination of ion exchange chromatography and electrophoresis.