• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.4
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• pp.383-390
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• 2014

The following conclusion was made from the 2D-QSAR model for the tyrosinase inhibitory activity according to the variation of the substituents R1 and R2 in analogues of compound 2-[(2,6-dioxocyclohexyl)methyl]cyclohexane- 1,3-dione (1-23). The best optimized 2D-QSAR model was $Obs.pI_{50}=-0.295({\pm}0.031)TDM$ $-0.120({\pm}0.014)DMZ+0.135({\pm}0.050)DMX.R_2+6.382({\pm}0.17)$, and the correlation $r^2=0.905$) of which was greater than its predictability ($q^2=0.843$). The magnitude of the effect of tyrosinase inhibitory activities was in order of TDM > $DMX.R_2{\geq}DMZ$, and it tended to increase as the hydrophobicity of substrate molecule (ClogP > 0) as well as the steric favor of substituent $R_1$ increased. The analysis of the model implies that inhibitory activity of substrate molecule will increase as $DMX.R_2$ (Dipole moment X component of $R_2$-substituent) increases, while TDM (Total Dipole Moment) and DMZ(Dipole Moment of Z-Component) decrease. As such, it is deemed feasible to conclude, that in order to increase the inhibitory effect, it would be rather desirable to replace the polar groups within the molecules with non-polar functional groups.

• Korean Journal of Pharmacognosy
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• v.39 no.3
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• pp.174-178
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• 2008

Melanin is a polymer of phenol which produces hyperpigmentation in the skin. Melanin synthesis is catalyzed by the enzyme tyrosinase. To investigate the whitening activity of the fractions from the ethanol extract of Enteromorpha linza, we studied the inhibitory effect on the tyrosinase activity and melanogenesis in the B16/F1 melanoma cells. The inhibition ratio of tyrosinase activity of ethylacetate fraction from E. linza was as strong as that of kojic acid, a positive control. Also, the melanin production was significantly inhibited by the ethylacetate fraction in a dose dependent manner. The ethylacetate fraction showed the highest activity in the fractions and as strong activity as that of arbutin, a positive control. From these results, we suggest that the E. linza extract might be able to apply to cosmetic and medical fields.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.1
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• pp.94-103
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• 2004

Objective: This study was performed to detennine the depigmenting effects of Kamibongpungtongsung-San. Methods: To determine the depigmenting effects of Kamibangpungtongsung-San. we measured the degree of tyrosinase inhibition, melanin production & cell viability in cultured B16 melanoma cells, UV screen and cytoprotective effects on PC12 cells injured by hydrogen peroxide. Results: Komibangpungtongsung-San did not show inhibitory effects on melanin production in melanoma cells, UV screen and cytoprotective effects on PC12 cells injured by hydrogen peroxide. However it showed mild inhibitory effects on tyrosinase activity. Conclusion : This study shows that Kamibangpungtongsung-San, a generally used prescription for dermatologic diseases, do not have depigmenting effects via tyrosinase inhibition. Therefore, the depigmenting effect and mechanism of depigmentation by Kamibangpungtongsung-San need to be evaluated and investigated in other directions.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.362-367
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• 2011

The study was conducted to investigate functional materials as skin whitening and anti-inflammatory agent from Taraxacum officinale and Taraxacum coreanum. The total polyphenol and flavonoid content in the ethanol extract of Taraxacum officinale were found to be 64.07mg/g and 32.46mg/g, respectively. In tyrosinase inhibitory activity, the hot water extract of Taraxacum coreanum was higher than the other extracts. However, in nitric oxide (NO) scavenging ability, the ethanol extract of Taraxacum coreanum was higher than the other extracts. the ethanol extract of Taraxacum coreanum showed strong NO production inhibitory effect in lipopolysaccharide (LPS)-stimulated Raw 264.7 cell. In the cell viability measurement by MTT assay and the lactate dehydrogenase (LDH) assay against L929 cell, the extracts were exhibited fine cell viabilities and normal LDH release levels as nontoxic result in sample concentration of $250{\sim}1000{\mu}g/m{\ell}$. As a result, the ethanol extract and the hot water extract of Taraxacum coreanum could be applicable to functional materials for anti-inflammatory and skin whitening related fields, respectively.

• Korean Journal of Medicinal Crop Science
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• v.21 no.6
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• pp.439-443
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• 2013

This study was conducted to investigate the antioxidative activity and tyrosinase inhibitory activity of 50% ethanol extract and its fractions from the branch of Rhododendron schlippenbachii. In DPPH radical scavenging ability, butanol and ethyl acetate fractions showed 59.98% and 55.17% of relative activity compared with positive control (ascorbic acid), but the 50% ethanol extract showed relatively low activity. In nitric oxide (NO) scavenging ability, the ethyl acetate and butanol fractions showed 141.80% and 131.55% relative activity compared with ascorbic acid as used for positive control. On the other hand, tyrosinase inhibitory activity of the ethyl acetate and butanol fractions showed about twice higher activity than positive control (arbutin). It means that the ethyl acetate and butanol fractions from the extract of R. schlippenbachii branch has ability for used as effective radical scavenger and tyrosinase inhibitor.

• Journal of Life Science
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• v.21 no.7
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• pp.976-984
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• 2011

Total phenolic content was the highest in 60% ethanol extracts at 21.91 mg/g, and inhibitory activity against tyrosinase of 60% ethanol extracts was higher than ethanol extracts of other concentration. The inhibitory compounds against tyrosinase from Persimmon leaves were purified using Sephadex LH-20, MCI-gel CHP-20 column chromatography with gradient elution. Two purified compounds were isolated as a result. The chemical structures of each compound were determined and identified using $^1H$-NMR and $^{13}C$-NMR, FAB-Mass. The compounds were confirmed as (+)-gallocatechin and prodelphinidin B-3. The tyrosinase inhibitory activities of purified (+)-gallocatechin and prodelphinidin B-3 were 29.5 and 40.2%, respectively. The inhibitory activities of (+)-gallocatechin and prodelphinidin B-3 against melanin biosynthesis in melanoma cell were 32.5 and 46.7%. The safety of essence with tyrosinase inhibitory compounds from persimmon leaves was also assessed by various safety profiles. First, changes in pH (4.90~4.95) and viscosity (23,000~26,000 cP) was not detected for 60 days. Essence also showed stability against temperature and light for 60 days. All these findings suggest that extracts from persimmon leaves have a great potential as a cosmetical ingredient with a potent whitening effect.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.3
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• pp.51-62
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• 2007

Objective : The aim of this study is to assess the effect of Schizandrae Fructus on melanin synthesis inhibition and whitening effect. Methods : We assessed inhibitory effects of Schizandrae Fructus on melanin-release from B16F10, on melanin production in B16F10, on mushroom tyrosinase activity in vitro, on tyrosinase activity in B16F10 and effect of Schizandrae Fructus on the expression tyrosinase, TRP-1, TRP-2, PKA, ERK-1 ERK-2, AKT-1, MITF in B16F10. Results and Conclusion : 1. Schizandrae Fructus inhibited melanin-release, melanin production in B16F10. 2. Schizandrae Fructus inhibited tyrosinase activity in vitro and in B16F10. 3. Schizandrae Fructus suppressed the expression of tyrosinase, TRP-1, TRP-2, PKA, ERK-2 in B16F10.

• KSBB Journal
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• v.19 no.6 s.89
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• pp.437-440
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• 2004

To determine the inhibition of tyrosinase activity and melanogenesis, gardenia fruit was extracted initially with $95\%$ ethanol (w/v), The ethanol extract was fractionated subsequently with hexane, chloroform and ethyl acetate in that order. The inhibitory effect of the ethanol extract on tyrosinase activity was higher than water extract. When 10 mg/mL of ethyl acetate fraction was applied, the inhibition ratio of tyrosinase activity was much higher ($99.7{\pm}0.1\%$) than that of arbutin. The inhibition of melanogenesis using B16F10 melanoma cell, the ethanol extract also showed higher inhibitory effect than water extract. The highest inhibitory activity of melanogenesis was also shown in ethyl acetate fraction ($89.1{\pm}1.4\%$ at the cone. of $100\;{\mu}g/mL$). These results suggests that gardenia extracts might be used to be a potential agents for whitening.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.27 no.1
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• pp.99-109
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• 2001

Novel glucoconjugates phenolic moiety, 3-(methoxycarbonyl)-4-(hydroxyphenyl)-$\beta$-D-glucopyranoside(4), 3-(methoxyacetyl)-4-(hydroxyphenyl)-$\beta$-D-glucopyranoside(7), 4-(hydroxyphenyl)-$\beta$-D-ribofuranoside(11), were synthesized. In order to investigate their depigmentation effect, inhibitory activity against mushroom tyrosinase and inhibitory activity of melanin synthesis in B16 melanoma cell were evaluated in vitro. Compound 11 showed 92.0$\mu\textrm{g}$/㎖ of tyrosinase inhibitory activity whereas compound 4 and 7 showed very low activity not less than 300$\mu\textrm{g}$/㎖. Inhibitory activities of melanin synthesis in B16 melanoma cell of compound 4, 7, and 11 were 8.7, 15.1, and 36.0%, respectively, at the concentration of 100$\mu\textrm{g}$/㎖. Inhibitory activity of compound 11 was much higher than that of arbutin at the same concentration.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.477-482
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• 2009

Inhibitory effect of skin and seed of three species grape cultivated in Korea on melanogenesis was investigated. Melanin generation was examined in $\alpha$-Melanin Stimulating Hormone-stimulated B16 cell, mouse melanoma, in the presence of samples. All skin sample did not show the inhibitory effect. Seed extract of Campbell early and Neo Muscat had negative effect on cell viability. When $50{\mu}g/ml$ seed extract of Muscat Bailey A was treated, amount of generated melanin and cell viability were $51.6{\pm}20.5%$ and $90.4{\pm}11.3%$ compared to control, respectively. Seed extract of Muscat Bailey A reduced the tyrosinase protein induced by $\alpha$-Melanin Stimulating Hormone, which suggests that inhibitory effect of seed extract of Muscat Bailey A on melanin is partly due to suppression of tyrosinase that is responsible for melanin production.