In the current study we investigate the antifouling potential of three polyphenolic resveratrol multimers (–)-hopeaphenol, vaticanol B and vatalbinoside A, isolated from two species of Anisoptera found in the Papua New Guinean rainforest. The compounds were evaluated against the growth and settlement of eight marine microfoulers and against the settlement and metamorphosis of Amphibalanus improvisus barnacle cyprids. The two isomeric compounds (–)-hopeaphenol and vaticanol B displayed a high inhibitory potential against the cyprid larvae metamorphosis at 2.8 and 1.1 μM. (–)-Hopeaphenol was also shown to be a strong inhibitor of both microalgal and bacterial adhesion at submicromolar concentrations with low toxicity. Resveratrol displayed a lower antifouling activity compared to the multimers and had higher off target toxicity against MCR-5 fibroblasts. This study illustrates the potential of natural products as a valuable source for the discovery of novel antifouling leads with low toxicity.
The authors acknowledge the National Health and Medical Research Council (APP1024314 to RAD), the Australian Research Council for support toward nuclear magnetic resonance (NMR) and mass spectrometry (MS) equipment (LE0668477, LE140100119, and LE0237908), and a linkage research grant (LP120200339 to RAD). HP and GC were supported by the Centre for Marine Chemical Ecology (http://www.cemace.science.gu.se) at the University of Gothenburg.