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Marine sponges (phylum Porifera) are the leading source of novel drug leads from the marine world. The sessile, unmoving nature of sponges have necessitated the development of protective chemicals to fight for space and ward of infections. As a result, sponges are particularly interesting as sources of novel antimicrobial and cytotoxic drug leads. Levels of antimicrobial resistance and incidences of cancer continue to increase worldwide and are some of the greatest clinical threats facing humanity. 

The Pharmacognosy research group at Uppsala university is conducting research on the understudied marine sponge species Weberella bursa, native to the north Atlantic. Previously two peptides, the Weberellanins, have been isolated from Weberella bursa and sequenced. The current study was aimed at the synthesise these peptides in enough quantity to allow for bioactivity testing. Both peptides were successfully synthesised through solid phase peptide synthesis. Bioactivities of the Weberellanins were studied through an Artemia cytotoxicity bioassay and a peptide-adapted minimum inhibitory concentration (MIC) antibacterial and antifungal bioassay on Staphylococcus aureus, Escherichia coli and Candida albicans. No bioactivity was observed in either assay. 

 The successful synthesis of the novel Weberellanins opens the door for further research on these peptides. Peptides often have highly specific mechanisms of actions, and it takes some luck to identify their capabilities. Now that the amount of available peptide is not a hindering factor, the hunt for the Weberellanins activity will continue.