• YAKHAK HOEJI
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• v.43 no.1
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• pp.28-32
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• 1999

Four derivatives of kojic acid were synthesized and their inhibitory activities against tyrosinase were evaluated. The C-2 hydroxymethyl and C-7 hydroxyl of kojic acid were replaced by carboxylate and amine, respectively. These derivatives were coupled to L-phenylalanine, producing two amide compounds. The carboxylate derivative (3), its amide compound (5), and the amine derivative (7) were weak inhibitors. The amide compound (9) where amine derivative (7) coupled to L-phenylalanine showed strong inhibitory activity ($IC_{50}=24.6{\;}{\mu}M$) comparable to kojic acid.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.141-146
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• 2014

In this study, we investigated on antioxidative activities and tyrosinase inhibitory activities of methanol extract and its fractions from roots of Arctium lappa. The total phenolic compound and flavonoid content of the ethylacetate fraction was found to be 818.29 mg/g and 360.59 mg/g as the highest content. In the measurement of DPPH radical scavenging ability and tyrosinase inhibitory activity, the ethylacetate fraction was higher than the other fractions and the extract. In addition, comparative analysis of phenolic compounds by liquid chromatography-mass spectrometry (MS)/MS system under the multiple-reaction monitoring (MRM) with negative-ion electrospray ionization mode. The main phenolic compounds in the extract and fractions of roots from Arctium lappa were cynarin and chlorogenic acid. The main phenolic compound of the ethylacetate fraction was cynarin. n-Butanol fraction had a significantly higher chlorogenic acid content than other samples. In conclusion, DPPH radical scavenging ability and tyrosinase inhibitory activity of the cynarin-riched ethylacetate fraction showed the highest activity.

• Fisheries and Aquatic Sciences
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• v.21 no.11
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• pp.35.1-35.7
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• 2018

Background: The aim of this study was to investigate the in vitro inhibitory effects of Fucofuroeckol-A isolated from Eisenia bicyclis against tyrosinase activity and 3-isobutyl-1-methylxanthine (IBMX)-induced melanin biosynthesis in B16F10 melanoma cells. Result: Among the ethanolic (EtOH) extract of E. bicyclis and its organic solvent fractions, the ethyl acetate (EtOAc) soluble fraction showed a noticeable inhibitory effect on mushroom tyrosinase with an $IC_{50}$ value of $37.6{\pm}0.1{\mu}g/mL$. Repeated column chromatography of the active EtOAc fraction resulted in the isolation of Fucofuroeckol-A. It evidenced more potent tyrosinase inhibitory effect with an $IC_{50}$ value of $11.4{\pm}1.4{\mu}M$ than arbutin ($IC_{50}=1076.6{\pm}44.3{\mu}M$), which was used as a positive control. Lineweaver-Burk plots suggest that Fucofuroeckol-A plays as a noncompetitive inhibitor against tyrosinase. Furthermore, we have evaluated the inhibitory effects of Fucofuroeckol-A on IBMX-induced melanin formation in B16F10 melanoma cells. Fucofuroeckol-A ($12.5-100{\mu}M$) exhibited a significant inhibition of melanin production in the melanoma cells. Conclusion: In the present study, we suggested that Fucofuroeckol-A might prove possibility as a novel inhibitor of melanin biosynthesis in cosmetic applications.

• Journal of Applied Biological Chemistry
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• v.54 no.2
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• pp.108-113
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• 2011

The tyrosinase inhibitory activity of extracts from Phellodendron amurense was examined. Tyrosinase inhibitory activity of 60% ethanol extracts was determined as 25% and the inhibitory activity of 60% ethanol extracts against melanin biosynthesis in melanoma cell (B16F10) was 31.2%. The purified inhibitory compounds against tyrosinase by Sephadex LH-20, MCI-gel CHP-20 column chromatography from P. amurense was confirmed as obacunone by $^1H$-NMR, $^{13}C$-NMR and Fast atom bombardment (FAB)-Mass spectrum. The tyrosinase inhibitory activities of purified obacunone was respectively as 35.1%. The safety of essence with tyrosinase inhibitory compounds from P. amurense was also assayed by various safety profiles. First, pH and viscosity change of essence for 60 days were not detected. The essence also showed the stability against temperature and light for 60 days. All these findings suggest that extracts from P. amurense has a great potential as a cosmeceutical ingredient, which has a potent whitening effect.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.368-376
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• 2021

This study was to investigate the Taraxinic acid from Taraxacum coreanum on tyrosinase activity and melanogenesis. In B16BL6 cell, Taraxinic acid did not show cytotoxicity even at concentrations of up to 100 ㎍/mL. In addition, tyrosinase inhibitory activity and melanogenesis inhibitory activity were confirmed by stimulation with α-melanocyte stimulating hormone (α-MSH) in the presence of taraxinic acid. Taraxinic acid was added to cells at concentrations of 10, 50 and 100 ㎍/mL and treated for 48 hours to confirm tyrosinase inhibitory activity and melanin production. The tyrosinase inhibitory activity increased in proportion to the amount of the sample, and showed an inhibitory activity of about 54.5% at a concentration of 50 ㎍/mL. Melanin production decreased in proportion to the sample amount, and it was about 62.2% at the concentration of 10 ㎍/mL. From the above results, it was found that Taraxinic acid had higher tyrosinase activity and melanin synthesis inhibitory activity in melanocyte than arbutin. The results suggest that Taraxinic acid can be utilized in natural whitening cosmetics.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.28 no.1
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• pp.11-22
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• 2015

Objective : Siegesbeckia Herba can treat various skin disease by expelling wind and removing dampness and clearing away heat and toxic material effects. This study was designed to investigate effects of Siegesbeckia Herba Extracts(SHE) on skin elasticity and whitening using B16F10 cell lines. Method : In this experiment, We observed effect of SHE on cell viability, inhibition of melanin synthesis and inhibitory effect on tyrosinase and elastase. Results : 1. SHE treated group showed decreased cell viability rates significantly compared with non-treated group. More than SHE $250{\mu}g/ml$, $500{\mu}g/ml$ and $1,000{\mu}g/ml$ of treated groups were lower levels of melanin synthesis respectively. 2. SHE significantly showed tyrosinase inhibitory activity in vitro, SHE increased tyrosinase inhibitory activity and elastase inhibitory activity in B16F10 cells, and tyrosinase inhibitory activity in vitro. 3. Tyrosinase inhibitory activity and elastase inhibitory activity in B16F10 cells, tyrosinase inhibitory activity in vitro were not accepted statistical significance compared with non-treated group. 4. SHE treated group showed increased SOD-like activity rates significantly compared with non-treated group. More than SHE $250{\mu}g/ml$, $500{\mu}g/ml$ and $1,000{\mu}g/ml$ of treated groups were lower levels of melanin synthesis respectively. Conclusion : These results suggest that SHE can inhibit melanin synthesis and tyrosinase inhibtory activity. So, We suggest that SHE can be maintained skin whitening.

• Advances in Traditional Medicine
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• v.1 no.2
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• pp.6-13
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• 2000

Melanin is specifically produced in melanocytes. The pathway for melanin biosynthesis is mainly controlled by tyrosinase. To estimate the inhibitory effect of melanin biosynthesis from 31 medicinal plants extracts, we tested the inhibitory effects of the tyrosinase promoter on B16 mouse melanoma cells. The result of this study demonstrated that Mori Radicis Cortex and Castena Fractus extracts only in tested medicinal plant extracts have high inhibitory effects on tyrosinase promoters with very low cytotoxicity on B16 mouse melanoma cells. Therefore, extracts of Mori Radicis Cortex and Castena Fractus were evaluated as very effective negative regulators of tyrosinase gene expression.

• Natural Product Sciences
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• v.17 no.3
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• pp.198-201
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• 2011

Tyrosinase is one of the important enzymes in the mammalian melanin synthesis. In the process of melanin synthesis, tyrosine is oxidized to DOPA (3,4-dihydroxyphenylalanine), and DOPA is further oxidized to dopaquinone. Tyrosinase is an enzyme catalyzing this oxidation of tyrosine, so chemicals that inhibit the activity of tyrosinase can be used as skin whitening agents. In this study, we isolated five constituents from the 80% MeOH extract of Morus bombycis cortex by bioactivity-guided fractionation. We performed mushroom tyrosinase inhibition assay. As a result, 7,2',4'-trihydroxyflavanone (1), 2',4',2,4,-tetrahydroxychalcone (2), and oxyresveratrol (3) showed the more potent inhibitory effect compared to kojic acid, a well-known skin whitening agent with antityrosinase effect. Moracinoside M (4) and moracin M-3'-O-${\beta}$-D-glucopyranoside (5) also showed the moderate tyrosinase inhibitory activities.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.16 no.2
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• pp.96-118
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• 2003

The effect of Glycyrrhizae Radix water extract, known as depigmenting agent, on melanin biosynthesis was investigated in cellular level by using B16 mouse melanoma cells. The inhibitory effect of Glycyrrhizae Radix water extract on melanogenesis was determined by mushroom tyrosinase assay traditionally using in vitro screening test. To determine whether Glycyrrhizae Radix water extract suppress melanin synthesis in cellular level, B16 mouse melanoma cells were cultured in the presence of different concentrations of Glycyrrhizae Radix water extract. Effects on cell proliferation, melanin biosynthesis, tyrosinase activity, DOPAchrome tautomerase activity, and expression level of mRNA for tyrosinase were examined. The maximum concentration of Glycyrrhizae Radix water extract that was not inhibitory to growth of the cells was 2 mgml. At that concentration, melanin synthesis was significantly inhibited without cytotoxicity after 5 days, compared with untreated cells. The treatment with Glycyrrhizae Radix water extract reduced tyrosinase and DOPAchrome tautomerase activity in a dose-dependent manner. However, the treatment with Glycyrrhizae Radix water extract did not affect significantly mRNA levels for tyrosinase. These results suggest that the inhibitory effect of Glycyrrhizae Radix water extract on melanogenesis is correlated with the suppression of tyrosinase and DOPAchrome tautomerase activity more than altering mRNA levels of tyrosinase.

• Korean Journal of Korean Medical Institute of Dermatology and Aesthetics
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• v.1 no.1
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• pp.91-97
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• 2005

(1) Objectives: To discover natural skin-lightening agents, we have evaluated the inhibitory activity of EtOH extracts from 20 medicinal plants against mushroom tyrosinase. (2) Methods: Tyrosinase activity was determined by the dopachrome method using L-tyrosine as the substrates. (3) Results: Of the plant extracts tested, the extracts of 4 plants, Albizzia julibrissin, Curcuma longa, Anethum graveolens and Sophora flavescens, exhibited potent inhibitory activity (> 50%) in mushroom tyrosinase assay. Four plant extract, extracts of Agrimonia pilosa, Paeonia moutan, Magnolia obovata and Eugenia caryophyllata also showed relatively strong inhibitory (> 40%) against mushroom tyrosinase. (4) Conclusion: These active medicinal plants may be useful for the development of skin-whitening agents. Since the active medicinal plants may contain effective tyrosinase inhibitors even more than kojic acid, further study to identify the active constituents from the plants is expected.