Three new isomeric ceramides, 2-hydroxy-N-(1,3,4-trihydroxy-17-methyloctadecan-2-yl)-18- methylarachidamide (1), 2-hydroxy-N-(1,3,4-trihydroxy-17-methyloctadecan-2-yl)-19-methylhenei-cosanamide (2) and 2-hydroxy-N-(1,3,4-trihydroxy-17-methyloctadecan-2-yl)-20-methylbehenamide (3), were isolated from Spongia suriganensis collected from the China South Sea. Their structures were confirmed by spectroscopic analysis and hydrolysis.

Key words: spongia suriganensis, ceramide, sponge