Phenolic Substances

Higa, Tatsuo

doi:10.1016/b978-0-12-624004-7.50010-x

Cited by 14 publications

(2 citation statements)

References 143 publications

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“…Therefore, 7-phloroeckol ( 3 ) was identified as a noncompetitive inhibitor of mushroom tyrosinase. In this mode of inhibition, the inhibitor caused a change in the structure and shape of the enzyme, and the modified enzyme was no longer capable of binding correctly with the substrate .…”

Section: Resultsmentioning

confidence: 99%

Inhibitory Effect of Phlorotannins Isolated from Ecklonia cava on Mushroom Tyrosinase Activity and Melanin Formation in Mouse B16F10 Melanoma Cells

Yoon

Eom²,

Kim

et al. 2009

J. Agric. Food Chem.

156

100

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In this study, to assess the feasibility of phlorotannins isolated from Ecklonia cava as an inhibitor of melanin formation, we evaluated its inhibitory effects on mushroom tyrosinase and 3-isobutyl-1-methylxanthine (IBMX)-induced melanin formation inhibitory effects in B16F10 melanoma cell. The ethanolic (EtOH) extract and ethyl acetate (EtOAc) soluble fraction obtained from E. cava evidenced a marked inhibitory effect on mushroom tyrosinase at a concentration of 50 μg/mL. Repeated column chromatography of the active EtOAc fraction resulted in the isolation of three phlorotannins. Their structures were elucidated on the basis of spectroscopic techniques [1D and 2D nuclear magnetic resonance (NMR)] and characterized as phloroglucinol (1), dioxinodehydroeckol (2), and 7-phloroeckol (3), respectively. Among the compounds, 7-phloroeckol (3) evidenced more potent tyrosinase inhibitory effect with an IC(50) value of 0.85 μM than arbutin (IC(50) = 243.16 μM) and kojic acid (IC(50) = 40.28 μM), which were used as positive controls. Lineweaver-Burk plots suggest that 7-phloroeckol plays as a noncompetitive inhibitor against tyrosinase. Furthermore, these compounds were evaluated for their inhibitory effects on IBMX-induced melanin formation in B16F10 melanoma cells. Treatment with 7-phloroeckol (6.25-100 μM) resulted in a significant inhibition of melanin production in the melanoma cells. In this study, we suggest that 7-phloroeckol might prove useful as a novel inhibitor of melanin formation in cosmetic applications.

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Section: Resultsmentioning

confidence: 99%

Inhibitory Effect of Phlorotannins Isolated from Ecklonia cava on Mushroom Tyrosinase Activity and Melanin Formation in Mouse B16F10 Melanoma Cells

Yoon

Eom²,

Kim

et al. 2009

J. Agric. Food Chem.

156

100

View full text Add to dashboard Cite

show abstract

“…They have a wide range of molecular sizes (126 Da-650 kDa) (Ragan andGlombitza 1986, Hay andFenical 1988) and are analogous to the terrestrial condensed tannins since they do not contain a carbohydrate core (Ragan and Glombitza 1986). Based on the type of structural linkages that result from the polymerization process and on the number of hydroxyl groups, they are divided into six categories: fucols, phlorethols, fucophlorethols, fuhalols, isofuhalols, and eckols (Higa 1981, Ragan and Glombitza 1986, Fukuyama et al 1990). Vesicles within brown algal cells, the physodes, contain most, if not all, of the phenolics found in brown algae (Ragan 1976, Ragan and Glombitza 1986, Kaur and Vijayaraghavan 1992.…”

Section: Characteristicsmentioning

confidence: 99%