Hypalocrinins, Taurine-Conjugated Anthraquinone and Biaryl Pigments from the Deep Sea Crinoid Hypalocrinus naresianus.

Five new water-soluble amido- and aminoanthraquinone pigments, hypalocrinins A-E (1-5), the new amidoanthraquinone biaryls hypalocrinin F (6) and hypalocrinin G (7), and the known compounds 6-bromoemodic acid (8), crinemodin (9), and crinemodin sulfate (10) were isolated from the deep sea crinoid Hypalocrinus naresianus collected off Japan. The structures of the compounds were elucidated by NMR spectroscopy and mass spectrometry. Amido- and aminoquinones are quite unusual among natural products. The hypalocrinins are the first naturally occurring anthraquinones and anthraquinone biaryls conjugated with taurine.