TWO CYCLIC HEXAPEPTIDES FROM THE MARINE SPONGE THEONELLA CUPOLA

Ilkay ERDOGAN*°, Jun’ichi TANAKA**, Tatsuo HIGA**

*Gazi University, Faculty of Pharmacy, Department of Pharmacognosy, 06330 Etiler, Ankara, TURKEY.
** Department of Biology, Chemistry and Marine Sciences, College of Science, University of the Ryukyus, Okinawa, JAPAN.
°Corresponding Author

Summary:
Two cyclic hexapeptides, dehydromicrosclerodermins C and D (I and II) were isolated from the marine sponge Theonella cupola of Okinawan origin as the major components. Six amino acid residues were detected in both compounds. The amino acid residues were shown to be 3-amino-8-phenyl-2,4,5-trihydroxyoct-7-enoic acid, 4-amino-3-hydroxybutyric acid, glycine, 1,3,6-trisubstituted-tryptophan, N-methyl-glycine and a pyrrolidone derivative by using spectral methods and by comparison with the literature.

Key words:
Theonella cupola, Hexapeptide, Dehydromicrosclerodermins C and D, Sponge.