Echinamines A and B, first aminated hydroxynaphthazarins from the sea urchin Scaphechinus mirabilis

Two new spinochromes, echinamines A (1) and B (2), were isolated from the sea urchin Scaphechinus mirabilis. Compounds 1 and 2 represent the first examples of natural polyhydroxynaphthazarins with a primary amine group. The structures of 1 and 2 were established by analysis of spectroscopic data and synthesis of their dimethyl ethers.