5-Hydroxytryptamine-derived alkaloids from two marine sponges of the genus Hyrtios

Indonesian specimens of the marine sponges Hyrtios erectus and H reticulatus were found to contain 5 hydroxytryptamine-derived alkaloids Their structures were determined on the basis of their spectral properties H erectus contained hyrtiosulawesine (4), a new beta carboline alkaloid, together with the already known alkaloids 5 hydroxyindole 3 carbaldehyde (1), hyrtiosin B (2), and 5 hydroxy 3 (2 hydroxyethyl) indole (3) H reticulatus contained the novel derivative 1,6 dihydroxy 1,2,3,4 tetrahydro P carboline (11) together with serotonin (5), 6 hydroxy 1 methyl-1,2,3,4-tetrahydro beta carboline (7), and 6 hydroxy 3,4-dihydro 1 oxo beta carboline (9).