Pseudoceratonic Acid and Moloka'iamine Derivatives from the Red Sea Verongiid Sponge .

During an investigation of the chemistry of the Red Sea Verongiid sponge we discovered a small molecule, pseudoceratonic acid (), along with the new moloka'iamine derivatives, ceratinines N (), O (), and the previously reported compounds moloka'iamine (), hydroxymoloka'iamine () and ceratinamine (). The structural assignments of - were accomplished by interpretation of their NMR and HRESIMS spectral data. Pseudoceratonic acid possesses a dibrominated hydrazine-derived functional group not found in any reported chemical compound. Pseudoceratonic acid selectively inhibited the growth of and , while ceratinine N selectively inhibited . Further, ceratinine N showed potent cytotoxic effects against the triple-negative breast cancer, colorectal carcinoma, and human cervical carcinoma cell lines down to 2.1 µM.