35 Years of Marine Natural Product Research in Sweden: Cool Molecules and Models from Cold Waters

Barrettides: A Peptide Family Specifically Produced by the Deep-Sea Sponge Geodia barretti

Natural product discovery by isolation and structure elucidation is a laborious task often requiring ample quantities of biological starting material and frequently resulting in the rediscovery of previously known compounds. However, peptides are a compound class amenable to an alternative genomic, transcriptomic, and in silico discovery route by similarity searches of known peptide sequences against sequencing data. Based on the sequences of barrettides A and B, we identified five new barrettide sequences (barrettides C-G) predicted from the North Atlantic deep-sea demosponge Geodia barretti (Geodiidae). We synthesized, folded, and investigated one of the newly described barrettides, barrettide C (NVVPCFCVEDETSGAKTCIPDNCDASRGTNP, disulfide connectivity I-IV, II-III). Co-elution experiments of synthetic and sponge-derived barrettide C confirmed its native conformation. NMR spectroscopy and the anti-biofouling activity on larval settlement of the bay barnacle Amphibalanus improvisus (IC50 0.64 μM) show that barrettide C is highly similar to barrettides A and B in both structure and function. Several lines of evidence suggest that barrettides are produced by the sponge itself and not one of its microbial symbionts.

Pharmacognosy and Its Role in the System of Profile Disciplines in Pharmacy

The primal discipline from which pharmacy has developed can be considered as pharmacognosy. This review defines pharmacognosy while reflecting on the latest development and discourse about its justifiability in the educational system in pharmaceutical faculties and the history of development of new drugs under the influence of pharmacognosy. The article defines the status quo of the pharmacognosy area, or more precisely its parts (biology, chemistry, production, and technology) and discusses their connections. It underlines the legitimacy of application of natural drugs in therapy, which is undeniable, and proves that whether a new drug was prepared either synthetically or isolated from a natural source is not important. The overview follows the basic requirements of pharmacognosy, especially its methodology (usage of faster and more effective phyto-analytical methods, reverse pharmacology, and reverse pharmacognosy, in silico methods). Pharmacognosy is confronted by three major challenges in the 21st century that can push it significantly forward: ethnopharmacological sources evaluation, evaluation of nutraceuticals, and pharmacognosy of marine organisms. The educational system of universities should correspond to these new demands. However, in some areas the educational system is not prepared to face the challenges of the time. The basic requirement is to adopt a complex attitude to biogenic material and utilize the connections of this complexity in the teaching of modern pharmacy.

K092A and K092B, Two Peptides Isolated from the Dogfish (Scyliorhinus canicula L.), with Potential Antineoplastic Activity Against Human Prostate and Breast Cancer Cells

Cancer therapy is currently a major challenge within the research community, especially in reducing the side effects of treatments and to develop new specific strategies against cancers that still have a poor prognosis. In this context, alternative strategies using biotechnologies, such as marine peptides, have been developed based on their promise of effectivity associated with a low toxicity for healthy cells. The purpose of the present paper is to investigate the active mechanism of two peptides that were isolated from the epigonal tissue of the lesser spotted dogfish Scyliorhinus canicula L., identified NFDTDEQALEDVFSKYG (K092A) and EAPPEAAEEDEW (K092B) on the in vitro growth inhibition of ZR-75-1 mammary carcinoma cells and MDA-Pca-2b prostate cancer cells. The effects of the peptides on cell proliferation and cell death mechanisms were studied by the flow cytometry and immunofluorescence microscopy approaches. The results have shown the onset of both K092A- and K092B-induced early cytoskeleton changes, and then cell cycle perturbations followed by non-apoptotic cell death. Moreover, impedance perturbation and plasma membrane perforation in ZR-75-1 K092A-treated cell cultures and autophagy inhibition in MDA-Pca-2b K092B-treated cells have been observed. In conclusion, these two bioactive peptides from dogfish exhibit antineoplastic activity on the human prostate and breast cancer cells in vitro.