Purification and characterization of neoagarotetraose from hydrolyzed agar.

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