Indole-type Alkaloids from the Marine Sponges

Abstract

Much attention has been focused on indole alkaloids owing to their potential utilities and significant biological activities, such as cytotoxic, antiviral, antimicrobial, antiparasitic, and anti-inflammatory activities. A variety of marine sources such as sponges, tunicates, red algae, and symbiotic bacteria have been shown to generate indole alkaloids which represent the largest number and the most complicated structures of the marine alkaloids [1].In the course of our study on the chemical investigation of marine organisms [2], we found indole alkaloids from the sponge Hyrtios sp. collected in Chuuk State, Federated States of Micronesia and the sponge Psammocinia sp. collected at Dokdo Island, Korea. Bioassay-guided separations of the crude extracts using various chromatographic techniques yielded a new ？-carboline alkaloid together with known hydroxyindole alkaloids. From the extracts of Hyrtios sp., 1-carboxy-6-hydroxy-3,4-dihydro-？-carboline, 6-hydroxy-3,4-dihydro-1-oxo-？-carboline, 5-hydroxy-1H-indole-3-carboxylic acid methyl ester, serotonin, hyrtiosin A, 5-hydroxyindole-3-carbaldehyde, and hyrtiosin B were isolated. And bis-indole alkaloid, hyrtinadine A together with other known metabolites were isolated from the extracts of Psammocinia sp. A structure of the new compound was elucidated by spectroscopy method including mass spectroscopy and 2D NMR spectroscopy.