<jats:title>Abstract</jats:title><jats:p>The sea star <jats:italic>Oreaster reticulatus</jats:italic> contains, along with the known ophidiacerebrosides C–E, nine new glycosphingolipids named oreacerebrosides A–I. Their structures were elucidated by a combination of spectroscopic methods and chemical degradation. All compounds contain a 4,8,10‐triunsaturated sphingoid base. Oreacerebrosides A–C have a β‐glucopyranoside as the sugar residue, as found in ophidiacerebrosides C–E and in all known compounds of this type; in contrast, oreacerebrosides D–I are the first examples of β‐galactosylceramides containing this unusual sphingoid base. Four representative glycosphingolipids were tested for cytotoxic activity on rat glioma C6 cells and were shown to be mildly cytotoxic; the glucosylceramides were more active than the galactosylceramides. In addition, oreacerebroside I, but not ophidiacerebroside E, was shown to exert proangiogenic activity and was able to increase VEGF‐induced human endothelial cell proliferation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)