Pigments of marine animals. V. Rubrocomatulin monomethyl ether, an anthraquinoid pigment of the Comatula genus of crinoids

Abstract
The chemistry of rubrocomatulin monomethyl ether, the third major quinone pigment of the crinoids Comatula pectinata Linnaeus and C. cratera A. H. Clark, and supporting spectral data determine the structure as 8-butyryl-1,4,5,7-tetra-hydroxy-2-methoxyanthraquinone. The paper chromatography of hydroxyanthraquinones and the utility of various adsorbents in their column chromatography are discussed.