SEARCH

SEARCH BY CITATION

Summary.

Pigment with the characteristics of a naphthaquinone is widely distributed throughout the body of the echinoid Diadema antillarum. Chromatography indicates that there is a main reddish orange pigment sometimes accompanied by small amounts of a purple pigment.

The purified main pigment crystallises in red needles which melt at 223°C, sublime about 200°C, and in acidified ether show absorption maxima at 263/64: 337/39: 462/63 mμ. It appears to be a hydroxynaphthaquinone resembling echinochrome A.