Note
A number of bis(indole) alkaloids have been reported from the marine environment over the past few years. Some examples reported from sponges include: the topsentins reported from Topsentia genitrix,1 Spongosorites spp., 2 and Hexadella sp.3 which have a ketone and imidazole spacer between the two indole rings; the dragmacidins reported from both Dragmacidon sp.4 and Hexadella sp.5 which have a piperazine spacer; the nortopsentins reported from a Spongosorites sp. which lack the ketone observed in the topsentins;6 and fascaplysin, a fully aromatized compound reported from Fascaplysinopsis sp.7 Bidindole) alkaloids have also been reported from the ascidians Dendroda grossularia and Didemnum candidum.9