• Food Science and Preservation
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• v.8 no.3
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• pp.296-301
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• 2001

Physiological functionalities in various extracts of Heugjinju rice bran were determined and its optimal extraction condition were also investigated Angiotensin-converting enzyme(ACE) inhibitory activity, fibrinolytic activity and tyrosinase inhibitory activity were higher in water extracts than those of 80% ethanol and methanol, hexane. Electron donating abilities were 97.8% in hexane extract and 83% in water extracts. ACE inhibitor was maximally extracted from Heugjinju rice bran when it was treated with 20 times of distilled water for 12 h at 20 $\^{C}$. Fibrinolytic compound was also maximally extracted by treatment of 10 times of distilled water for 18 h at 20 $\^{C}$. Electron donating compound and tyrosinase inhibitor were maximally extracted by treatment of 20 times of hexane and 10 times of distilled water at 20 $\^{C}$ for 18 h, respectively

• Korean Journal of Plant Resources
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• v.29 no.6
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• pp.690-698
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• 2016

Various bioactive substances are found in mistletoe, including viscumneoside III (1) and homoflavoyadorinin B (2), both which inhibit tyrosinase. These two compounds are mainly found in the EtOAc fraction of the mistletoe extract and demonstrate higher rates of tyrosinase inhibition than ascorbic acid, which was used as a control. Our results suggest that mistletoe extracts can be utilized in skin whitening cosmetics.

• Korean Journal of Plant Resources
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• v.30 no.6
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• pp.618-622
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• 2017

Various bioactive substances are found in Loranthus tanakae, including quercetin 3-rhamnoside (1), kaempferol 3-rhamnoside (2), rhamnetin 3-rhamnoside (3), and rhamnocitrin 3-rhamnoside (4), which inhibit tyrosinase. These compounds are mainly found in the EtOAc fraction of L. tanakae extract and demonstrate higher rates of tyrosinase inhibition than ascorbic acid, which was used as a control. Our results suggest that L. tanakae extracts can be utilized in skin whitening cosmetics.

• Food Science and Preservation
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• v.7 no.1
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• pp.103-107
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• 2000

Previously , the methanolic extract of peach sees was found to have a strong tyrosinase inhibitory activity in an in vitro assay. Several phenolic compunds were isolated from the seeds by solvent fractionation , Sephadex LH-20 chromatography, and preparative HPLC , and one of them showing strong tyrosinase inhibition was identified as benzoic acid by UV, IR, $^1$H/$^1$$^3$C-NMR, and EI-MS spectrsopy. Benzoic acid (IC50= 250$\mu\textrm{g}$/ml) and L-ascorbic acid (IC50=28$\mu\textrm{g}$/ml), well-known tyrosinase inhibitors. In particular , benzoic acid inhibited markedly the enzymatic browing (melanosis) of apple juices at low concentration of 0.01% and 0.05, comparable to that of L-ascorbic acid (P<0.05). these results suggest that benzoic acid, one of an effective food preservatives, may be potentially useful as a functional alternative to sulfites for the control of melanosis in fruit juices.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.3
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• pp.211-218
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• 2011

Effects of Kenpaullone, a specific inhibitor of GSK3${\beta}$, on melanin synthesis in B16 melanoma cells and human melanocytes were investigated. Kenpaullone showed a melanogenesis stimulation activity in a concentrationdependent manner in murine B16 melanoma cells and human melanocytes without any significant effects on cell proliferation. Tyrosinase activity was increased 48 h after treatment of B16 cells with Kenpaullone. The protein expression level of tyrosinase was dose-dependently enhanced after the treatment with Kenpaullone. At the same time, the expression level of tyrosinase mRNA was also increased after addition of Kenpaullone. The stimulatory effect of Kenpaullone mainly resulted from increased expression of tyrosinase. These findings suggest that the application of GSK3${\beta}$ inhibitors may be a potential therapeutic agent for the treatment of hypopigmentation disorder.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.760-763
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• 2001

To develop a functional beverage from Korean cherry (Prunus tomentosa Thunberg), inhibition effect of ethanol extract and juice of the korean cherry on melanin systhesis and tyrosinase activity in vitro was investigated. Inhibition ratio of tyrosinase activity increased as the concentration of solid of korean cherry juice increased, and inhibition affect was high in initiation step of enzyme reaction and then gradually decreased. Inhibition ratio of tyrosinase activity was high in the 70% (v/v) ethanol extract of the cherry and the highest in the ethyl acetate fraction of the 70% (v/v) ethanol extract. Ultimatly, the amounts of functional matter (melanin synthesis inhibitor) in the cherry was highest in ethyl acetate fraction of the ethanol extract.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.1
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• pp.179-183
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• 2005

Recent interest in the possible protective effects of dietary antioxidant compounds against human degenerative disease has prompted investigation of foods such as blueberries, which have a high antioxidant capacity. This study was performed to determine the antioxidative activity of methanol extract and solvent fractions from blueberry. Blueberry was extracted with methanol and then fractionated with n-hexane, EtOAc, BuOH and water to get active fractions. And their antioxidant capacities in each fraction were determined by using the DPPH and FRAP assay, and tyrosinase inhibitor. Ethyl acetate fraction of blueberry exhibited antioxidant capacity.

• 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.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2375-2378
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• 2010

• Bulletin of the Korean Chemical Society
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• v.22 no.1
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• pp.97-99
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• 2001