Metachromin C, a New Cytotoxic Sesquiterpenoid from the Okinawan Maring Sponge Hippospongia metachromia

Abstract
A new sesquiterpenoid quinone, metachromin C [1], with potent cytotoxic activity has been isolated together with a known terpenoid metachromin A [2] from the Okinawan marine sponge Hippospongia metachromia and the structure determined by spectroscopic data, especially several types of 2D nmr spectra including 1H-detected heteronuclear multiple-bond correlation (HMBC).