• Korean Journal of Pharmacognosy
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• v.44 no.2
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• pp.182-187
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• 2013

This study was conducted to investigate glutathione S-transferase(GST) activity, tyrosinase inhibitory effect and elastase inhibitory effect in persimmon calyx(calyx of Diospyros kaki Thunberg) for screening of functional materials from natural products. As a result, EtOAc extract of persimmon calyx turned out to be having tyrosinase inhibitory effect and elastase inhibitory effect. The active constituents of tyrosinase and elastase inhibitory effect were isolated from EtOAc extract of persimmon calyx. Their structure of compounds were identified as ursolic acid and (-)-daucosterol by spectroscopic evidence, respectively.

• Korean Journal of Pharmacognosy
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• v.42 no.1
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• pp.89-97
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• 2011

This study was conducted to investigate tyrosinase inhibitory effect, hyaluronidase inhibitory effect and antioxidant activity by DPPH radical scavenging method on the MeOH extract of 50 species medicinal plant for screening of functional properties. As a result, Chaenomeles sinensis Koehne extract among 50 species medicinal plant turned out to be having tyrosinase, hyaluronidase inhibitory effect and antioxidant activity. The major component of tyrosinase and hyaluronidase inhibitory effect was isolated from EtOAc extract of Chaenomeles sinensis Koehne. And the component of antioxidant activity was isolated from n-BuOH extract of Chaenomeles sinensis Koehne. Their structure of compounds were identified as oleanolic acid and (-)-epicatechin by spectroscopic evidence, respectively.

• YAKHAK HOEJI
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• v.45 no.2
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• pp.214-219
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• 2001

Nineteen hydrolysable tannins isolated from the Euphorbia helioscopia (Euphorbiaceae) were tested for the inhibitory effect on mushroom tyrosinase activity in vitro. Inhibitory effect of gallotannin group exhibited more potent than that of phenolcarboxylic acid and ellagitannin groups against the enzyme activity. The inhibitory activity by pentagalloyl glucose on mushroom tyrosinase was more potent ($IC_{50}$/, 4.9 $\mu$M) than that of kojic acid ($IC_{50}$/, 8.7 $\mu$M).

• Korean Journal of Pharmacognosy
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• v.46 no.1
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• pp.84-92
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• 2015

Tyrosinase is a key enzyme to control the biosynthesis of melanin pigments and has two enzyme activities, namely of 1-tyrosine hydroxylase and of 1-dopa oxidase. Thus, tyrosinase is regarded as a target in skin-whitening and therapeutic intervention of local hyperpigmentation diseases. We have tested tyrosinase inhibitory activity on the water extracts of 50 species oriental medicinal plant. Among them, five medicinal plants, Linderae Radix, Clematidis Radix, Cinnamomi Cortex Spissus, Fritillariae Thunbergii Bulbus and Bulbus Fritillariae Cirrhosae were investigated strong inhibition effect. Five medicinal plants were fractionated using organic solvents (methylene chloride, ethyl acetate, n-butanol, water). Cinnamomi Cortex Spissus (ethyl acetate fraction) was investigated strong inhibition effect. Tyrosinase inhibitory activity below $IC_{50}\;40{\mu}g/ml$ is confirmed in five herbal plants that are Linderae Radix, Clematidis Radix, Cinnamomi Cortex Spissus, Fritillariae Thunbergii Bulbus and Bulbus Fritillariae Cirrhosae. Tyrosinase inhibitory levels ($IC_{50}\;{\mu}g/ml$) of each plants were 15.56, 35.02, 25.14, 15.20 and 39.77. We also investigate the effect of effective plant's fraction. in dose of $100{\mu}g/ml$, Cinnamomi Cortex Spissus (P-36) EtOAc fraction significant inhibitory effect over 50%. Clematidis Radix (P-35) and Cinnamomi Cortex Spissus (P-36) MC fraction inhibit tyrosinase each 36.60% and 43.21%. inhibitory rates of Fritillariae Thunbergii Bulbus (P-40) EtOAc and $H_2O$ fraction are 31.40% and 31.51%. Bulbus Fritillariae Cirrhosae (P-45) BuOH fraction regulate tyrosinase activity to 37.71%. We examined tyrosinase inhibitory activity of natural products and these results suggest that several herbs have potential as a new whitening material.

• Journal of environmental and Sanitary engineering
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• v.21 no.3 s.61
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• pp.44-51
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• 2006

To estimate the inhibitory effect of Rubus coreanum extract on melanin biosynthesis, we tested its inhibitory effects on tyrosinase promoter in B16 mouse melanoma cells. Rubus coreanum extract by methanol had inhibitory effect approximately 10% on tyrosinase promoter at $100{\mu}g/mL$. In the MTT assay, the same extract exhibited very low cytotoxicity under $100{\mu}g/mL$. The fractions of methylene chloride, butyl alcohol and water did not showed the inhibitory effect on tyrosinase promoter, but the fraction of ethyl acetate exhibited inhibitory effect approximately 11% at $100{\mu}g/mL$.

• Korean Journal of Pharmacognosy
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• v.32 no.1 s.124
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• pp.68-71
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• 2001

For the use of tannins in the whitening-effect cosmetics, inhibitory effect against tyrosinase activity was determined. Three condensed tannins including gallocatechin, gallocatechin 3',4'-di-O-gallate and epicatechin 3-O-gallate and three hydrolyzable tannins, 1,2,6-tri-O-galloyl-${\beta}$-D-glucose, 2,3-(S)-HHDP-D-glucose and pedunculagin showed 15-29% mild inhibitory effects against tyrosinase activity.

• KSBB Journal
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• v.18 no.1
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• pp.45-50
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• 2003

In this study, the optimum conditions for mycelium culture of the mushroom Tricholoma matsutake and the inhibitory effect of the mycelium extracts no tyrosinase activity have been examined. When the extracts of the Tricholoma matsutake mycelia were tested for inhibitory activity on tyrosinase, it was found that the components extracted with ethyl acetate and water showed the highest inhibitory activity. The effect of antioxidants on the growth of mycelium and tyrosinase-inhibiting activity was also investigated. The results showed that tocopherol inhibited the growth in a concentration-dependent manner. In terms of tyrosinase-inhibiting activity, however, tocopherol was found to enhance the inhibitory activity.

• Korean Journal of Pharmacognosy
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• v.30 no.4
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• pp.397-403
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• 1999

Tyrosinase plays an important role in the process of melanin polymer biosynthesis. Therefore, the enzyme inhibitors have been of great concern as cosmetics to have skin-whitening effects on the local hyperpigmentation. During the search for new inhibitory compounds on melanin polymer biosynthesis from natural sources, MeOH extracts of 589 higher plants were tested for the inhibitory effect on tyrosinase activity by the muschroom tyrosinase assay in vitro. Among plants tested, the leaves of Cercis chinensis exhibited potent inhibitory effect on mushroom tyrosinase activity. Subsequently seven active compounds were isolated from the ethyl acetate soluble part of acetone extract of the leaves of C. chinensis by the activity guided fractionation monitoring the inhibitory effect on tyrosinase activity. Their chemical structures were identified as $kaempferol-3-0-{\alpha}-L-rhamnoside$, quercitrin, $myricetin-3-0-{\alpha}-L-rhamnoside$, myricetin-3-0-(2'-O-galloyl)- ${\alpha}$ -L-rhamopyranoside (desmanthin), (-)-epicatechin-3-0-gallate, (-)-epigallocatechin-3-0-gallate, and methyl gallate on the basis of the speculation of spectral data and chemical reaction. Among the flavonol rhamnosides, myricetin-3-0-(2'-O-galloyl)- -L-rhamnoside(desmanthin) showed most potent inhibitory effect on tyrosinase activity and the structure of B-ring in flavonol moiety was related to the activity. (-)-Epigallocatechin-3-O-gallate having pyrogallol group in flavan-3-ol moiety exhibited more potent inhibitory effect than (-)-epicatechin-3-0-gallate having catechol group in flavan-3-ol moiety on mushroom tyrosinase activity.

• Journal of Microbiology and Biotechnology
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• v.19 no.7
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• pp.681-684
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• 2009

This study was carried out to evaluate the inhibitory effect of Flammulina velutipes extracts on tyrosinase activity and to identify its biologically active component. The ethyl acetate and n-butanol extracts showed potent tyrosinase inhibitory activities. Subsequently, fractions of the n-butanol extract showed only a partial tyrosinase inhibitory activity. The most active compound of tyrosinase inhibitory activity was identified from the ethyl acetate extract as 1',3'-dilinolenoyl-2'-linoleoylglycerol (LnLLn) by comparing its mass, $^1H-$, and $^{13}C-NMR$spectral data with those previously reported in the literature. LnLLn showed tyrosinase inhibitory activity with an $IC_{50}$value of 16.1 ${\mu}g/ml$. These results suggest that the ethyl acetate extract of F. velutipes could be applicable for the development of a new whitening agent.

• 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.