Purification and Characterization of Neoagarotetraose from Hydrolyzed Agar

The whitening effect, tyrosinase inhibition, and cytotoxicity of neoagarotetraose were measured after its purification from hydrolyzed agar by gel filtration chromatography. In melanoma B16F10 cells, the melanin content of neoagarotetraose-treated cells was the same as that treated by kojic acid or arbutin. In addition, tyrosinase of melanoma cells was strongly inhibited by neoagarotetraose at a concentration of $1{\mu}g/ml$ and similarly inhibited at 10 and $100{\mu}g/ml$ compared with those by arbutin or kojic acid. The activity of mushroom tyrosinase showed a 38% inhibition by neoagarotetraose at $1{\mu}g/ml$, and this inhibitory effect was more efficient than that by kojic acid. Neoagarotetraose revealed a similar $IC_{50}$ (50% inhibition concentration) value for mushroom tyrosinase as that by kojic acid. These data suggest that the neoagarotetraose generated from agar by recombinant $\beta$-agarase might be a good candidate as a cosmetic additive for the whitening effect.