Pigments of marine animals. X. Substituted naphthopyrones from the crinoid Comantheria perplexa

Abstract

Acetone extraction of the flesh of the comatulid crinoid Comantheria perplexa (H. L. Clark) yields a mixture of substances from which the sodium salt of the sulphuric ester (12) of 8-hydroxy-5,6-dimethoxy-2-methyl-4H-naphtho[2,3-b]pyran-4-one (8) has been isolated. Acid hydrolysis of (12) yields the phenol (8) which on methylation is converted into rubrofusarin dimethyl ether and on partial demethylation yields a product identical with a dehydration product (10) of fonsecin. Hydrolysis of the crude extract from C. perplexa yields (8), (10), and 8-hydroxy-5,6-dimethoxy-2-n-propyl-4H-naphtho[2,3-b]pyran-4-one (13). The structures of the isolated substances suggest a polyketide-type synthetic activity by this species. The stalked crinoids Endoxocrinus parrae (Gervais) and Neocrinus decorus (Wyville Thomson) yield negligible quantities of aromatic polyketides.