Hydrophobically modified homo and copolymers of the poly(alkylmethyldiallylammonium bromide) type form hydrophobic microdomains in aqueous solution depending on the length(s) of the alkyl chain(s) and, most likely, the flexibility of the polymer main chain. The polysoaps allow interesting comparisons between intra- and intermolecular micellization processes. Three novel cytotoxic and antifungal alkaloids, nortopsentins A (1), B (2), and C (3), along with two known compounds, topsentin (4) and bromotopsentin (5), were isolated from the Caribbean deepsea sponge Spongosorites ruetzleri. The structures of the nortopsentins were established mainly on the basis of NMR spectroscopic data. The unique imidazolediylbis[indole] skeleton of the nortopsentins demonstrates a new condensation process in tryptophan metabolism. The nortopsentins exhibited in vitro cytotoxicity against P388 cells and antifungal activity against Candida albicans. A wide variety of bioactive imidazole alkaloids derived from aromatic amino acids were reported from marine invertebrates. Representative structures included aplysinopsins, topsentins, polyandrocarpamide D, and na-amidines. During the course of our search for antitumor compounds from marine organisms, we isolated a novel brominated (aminoimidazolinyl)indole, designated as discodermindole (1), from the sponge Discodermia polydiscus DuBocage 1879 (family Theonellidae, order Lithistida). In in vitro assays, 1 yielded IC50 values of 1.8 µg/mL against P388 (murine leukemia), 4.6 µg/mL against A-549 (human lung), and 12 µg/mL against HT-29 (human colon) cell lines. Its isolation and structure elucidation are reported herein.