Two new imidazole alkaloids from Leucetta chagosensis sponge.

Chemical investigation of the sponge Leucetta chagosensis, has led to the isolation of two new imidazole alkaloids, methyldorimidazole (1), preclathridine B (2) along with the known compounds naamine E (3) and leucettamine C (4). The structures of the newly compounds (1 and 2) were elucidated by employing spectroscopic techniques ((1)H NMR, MS and UV). The structures of the known compounds 3 and 4 were determined by comparison of their (1)H NMR and Mass spectroscopic data with published values.