Deodorizing Effects of Phlorotannins from Edible Brown Alga Eisenia bicyclis on Methyl Mercaptan

Abstract

In search for new deodorizing compounds, we were identified three phlorotannins; eckol (1), dioxinodehydroeckol (2) and dieckol (3) from edible brown seaweed Eisenia bicyclis and characterized by Fast-atom bombardment mass spectrometry (FAB-MS) and nuclear magnetic resonance (NMR). The deodorizing activity of those compounds was evaluated against methyl mercaptan, which is well known as a major causative material of halitosis and off-flavor. Among them, compound 3 exhibited the highest deodorizing activity against methyl mercaptan at the IC 50 values of 26.71 ± 4.16 µg mL -1 , followed by compound 2 (40.57 ± 0.63 µg mL -1) and compound 1 (43.62 ± 1.52 µg mL -1). Thus, these results suggest that the phlorotannins derived from E. bicyclis can be an effective deodorizing constituent in the food industry and pharmaceutical industries.