Gymnastatins and dankastatins, growth inhibitory metabolites of a gymnascella species from a Halichondria sponge.

Four new metabolites, gymnastatins Q ( 3) and R ( 4) and dankastatins A ( 5) and B ( 6), have been isolated from the mycelial MeOH extract of a fungal strain of Gymnascella dankaliensis separated from a Halichondria sponge. Their stereostructures have been established on the basis of spectroscopic analysis using 1D and 2D NMR techniques. All of the isolated metabolites ( 3- 6) exhibited growth inhibition against the P388 cancer cell line. Furthermore, gymnastatin Q ( 3) showed appreciable growth inhibition against BSY-1 (breast) and MKN7 (stomach) human cancer cell lines.