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Melanin synthesis is catalyzed by tyrosinase. To investigate the whitening effect of Hizikia fusiformis, fractions from ethanol extract of H. fusiformis were prepared by a systematic fractionation procedure with solvents such as methanol, hexane, butanol, and H2O. The ethanol extract and its fractions were then subjected to evaluate the inhibitory effects on the tyrosinase activity and melanin synthesis in murine B16F10 melanoma cells. The ethanol extract and aqueous fraction exhibited a whitening effect with no cytotoxicity. The ethanol extract showed the highest whitening effect among the samples. The inhibitory effect of 100 μg/ml of ethanol extract was higher than that of 10 μg/ml of arbutin, but it was lower than that of 10 μg/ml of kojic acid. Furthermore, the inhibitory effects of 100 μg/ml of methanol, hexane, butanol, and aqueous fractions were similar to those of 10 μg/ml of arbutin. The antioxidant activities were examined by comparing the results with that of ascorbic acid as a positive control. The ethanol extract and aqueous fraction showed relatively higher DPPH radical-scavenging activities compared with the other samples. Furthermore, 500 μg/ml of ethanol extract and aqueous fraction diminished LPS-induced iNOS expression to 82 and 80%, respectively. These results suggest that ethanol extract and aqueous fraction of H. fusiformis could be used as cosmetic ingredients for whitening and skin protection effects.

Authors report the glycoside hydrolase (GH) family 16 β-agarase from the strain of Agarivorans sp.JA-1, which authors previously stated as recombinant expression and characterization of GH-50 and GH-118 β-agarase. It comprised an open reading frame of 1,362 base pairs, which encodes a protein of 49,830 daltons consisting of 453 amino acid residues. Valuation of the total sequence showed that the enzyme has 98% nucleotide and 99% amino acid sequence similarities to those of GH-16 β-agarase from Pseudoalteromonas sp. CY24. The gene corresponding to a mature protein of 429 amino acids was recombinantly expressed in Escherichia coli, and the enzyme was purified to homogeneity by affinity chromatography. It showed maximal activity at 40°C and pH 5.0, representing 67.6 units/mg. Thin layer chromatography revealed that mainly neoagarohexaose and neoagarotetraose were produced from agarose. The enzyme would be valuable for the industrial production of functional neoagarooligosaccharides.