Fucoidanase inhibitory activity of phlorotannins from brown algae

The inhibitors of recombinant fucoidanase FFA2 from the marine bacterium Formosa algae KMM 3553T were found among the metabolites of brown algae Fucus evanescens and Costaria costata. NMR spectroscopy and mass spectrometry analysis showed that high molecular weight phlorethols (degree of polymerization (DP) of 12-25 monomers) from C. costata (ICc) and fucophloretol (DP = 3) from F. evanescens (IFe) were inhibitors of fucoidanase. To inhibit one mole of FFA2 fucoidanase about two molecules of the ICc inhibitor or 7 molecules of the IFe inhibitor are needed. It has been suggested that the effectiveness of inhibition increases with the increasing molecular weight of phlorotannins. An irreversible type of inhibition was established.