Isolation of Ciliatamide D from a Marine Sponge <i>Stelletta</i> sp. and a Reinvestigation of the Configuration of Ciliatamide A

Abstract

A new lipopeptide, ciliatamide D (<b>1</b>), was isolated from a marine sponge <i>Stelletta</i> sp., collected at Oshimashinsone, together with the known compound ciliatamide A (<b>2</b>). Ciliatamide D (<b>1</b>) is a congener of <b>2</b>, in which <i>N</i>-Me-Phe is replaced by <i>N</i>-Me-Met­(O). Marfey’s analysis of the acid hydrolysate of <b>1</b> demonstrated that the two constituent amino acids were both in the l-form. This result prompted us to carefully investigate the configuration of <b>2</b>, resulting in the assignment of the l-form for both residues