Metachromins L–Q, new sesquiterpenoid quinones with an amino acid residue from sponge Spongia sp.

Six new sesquiterpenoid quinones with an amino acid residue, metachromins L–Q (1–6), have been isolated from an Okinawan marine sponge Spongia sp. The structures and stereochemistry of 1–6 were elucidated on the basis of the spectroscopic data and chemical correlations. Metachromins L (1) and M (2) showed modest cytotoxicity.