Abstract
Sponges are at the forefront of marine natural product research. In the deep sea, extreme conditions have driven secondary metabolite pathway evolution such that we might expect deep-sea sponges to yield a broad range of unique natural products. Here, we investigate the chemodiversity of a deep-sea tetractinellid sponge, Characella pachastrelloides, collected from ~800 m depth in Irish waters. First, we analyzed the MS/MS data obtained from fractions of this sponge on the GNPS public online platform to guide our exploration of its chemodiversity. Novel glycolipopeptides named characellides were previously isolated from the sponge and herein cyanocobalamin, a manufactured form of vitamin B12, not previously found in nature, was isolated in a large amount. We also identified several poecillastrins from the molecular network, a class of polyketide known to exhibit cytotoxicity. Light sensitivity prevented the isolation and characterization of these polyketides, but their presence was confirmed by characteristic NMR and MS signals. Finally, we isolated the new betaine 6-methylhercynine, which contains a unique methylation at C-2 of the imidazole ring. This compound showed potent cytotoxicity towards against HeLa (cervical cancer) cells.
Highlights
Deep-sea habitats at 200 m–2000 m on the continental margin may be highly diverse, especially in submarine canyon systems, where hydrography concentrates food resources [1]
In our quest for bioactive compounds from Irish deep-sea sponges, we focused on a tetractinellid sponge Characella pachastrelloides, collected in Whittard Canyon, one of the largest submarine canyon systems in the NE Atlantic
The extract prepared from C. pachastrelloides using a mixture of solvents CH2Cl2/MeOH (1:1) was fractionated using C18 Solid Phase Extractions (SPE) into five fractions of decreasing polarity from H2O to MeOH and CH2Cl2
Summary
Deep-sea habitats at 200 m–2000 m on the continental margin may be highly diverse, especially in submarine canyon systems, where hydrography concentrates food resources [1]. Such habitats are rich in sponges and corals [2], taxa whose holobionts represent the most promising sources of bioactivity [3]. There are known difficulties in collecting deep-sea samples, and of the ~9620 compounds isolated from sponges, only ~290 were isolated from specimens collected from below 200 m [8]. In our quest for bioactive compounds from Irish deep-sea sponges, we focused on a tetractinellid sponge Characella pachastrelloides, collected in Whittard Canyon, one of the largest submarine canyon systems in the NE Atlantic. The natural product chemistry of few deep-water tetractinellids has been investigated, but those few have yielded a variety of natural products including bisindole alkaloids [11], cytotoxic peptide lactones [12], macrolides [13,14] and other polyketides [15], steroidal saponins [16], and cytotoxic linear acetylenes [17], suggesting this group has potential for yielding new bioactive metabolites
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
