Gracilarioside and Gracilamides from the Red Alga <i>Gracilaria </i><i>asiatica</i>

Abstract

One gracilarioside and two gracilamides with unusual cyclopropane-containing alkyl chains were isolated from the red alga Gracilaria asiatica. Their structures were determined by spectroscopic methods and microscale chemical degradation. To our knowledge, no ceramides with a cyclopropane ring have been reported from marine organisms. These three compounds were mildly cytotoxic to the human A375-S2 melanoma cell line.