Novel Discorhabdin Derivatives from Antarctic Sponges of the Genus Latrunculia: Expanding the Chemical Diversity of Polar Marine Natural Products

In this study, three Antarctic sponges of the genus Latrunculia were investigated, leading to the isolation of five unreported pyrroloiminoquinone alkaloids along with the known metabolite (+)-debromodiscorhabdin A (3). Three of the new metabolites were brominated, while the other two were found to have a C-5/C-8 sulfur bridge and a C-2/N-18 bridge. Three of the metabolites were shown to have a phenyl ketone substituent on C-14, not previously reported for discorhabdin derivatives. The cytotoxicity against the A549 cell lines was studied and compounds 1–4 showed activity of 4.3, 1.8, 1.0, and 23.9 µM, respectively, while no inhibition was found for 5 and 6. Read full article