• Bulletin of the Korean Chemical Society
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• 제31권4호
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• pp.971-975
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• 2010

Eight hydroxylated stilbene derivatives including resveratrol, desoxyrhapontigenin and piceatannol as potential radical scavenger and tyrosinase inhibitor are synthesized using optimized Wittig-Horner reaction for excellent trans-selectivity in good yields. Antioxidant activity was tested against ABTS radical and tyrosinase inhibitory activity was performed with L-tyrosine as the substrate based on previous procedure with some modification. In general, catecholic stilbenes showed stronger activity against ABTS radical and resorcinolic moiety showed stronger tyrosinase inhibitory activity. Synthetic piceatannol which containing both catecholic and resorcinolic moieties showed the strongest activity in both as ABTS radical scavenger and tyrosinase inhibitor with $IC_{50}$ values of 4.1 and $8.6\;{\mu}M$, respectively.

• Archives of Pharmacal Research
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• 제27권11호
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• pp.1132-1135
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• 2004

In order to find new tyrosinase inhibitors and the effects of prenyl residue on flavonoid molecules, eight prenylated and three synthetic vinylated flavonoids were examined on their inhibitory effect against tyrosinase activity. From the results, kuwanon C, papyriflavonol A, sanggenon D and sophoflavescenol were found to possess the considerable inhibitory activity. Especially, sanggenon D is revealed as a potent inhibitor ($IC_{50}$ =7.3$\mu$ M), compared to the reference compound, kojic acid ($IC_{50}$ =24.8 $\mu$M). However, the prenylation with isoprenyl group or the vinylation to flavonoid molecules did not enhance tyrosinase inhibitory activity.

• 생약학회지
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• 제42권2호
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• pp.195-200
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• 2011

In this study, we investigated on antioxidative activity, tyrosinase inhibitory activity and nitric oxide(NO) production inhibitory activity in the hot water extract of Taraxacum coreanum and its fractions. The total polyphenol and flavonoid contents of the extract were found to be 65.42 mg/g and 9.83 mg/g, respectively. And the total polyphenol and flavonoid contents of the ethyl acetate fraction were found to be 168.23 mg/g and 31.92 mg/g, respectively. In DPPH radical scavenging ability, $SC_{50}$ values of the ethyl acetate and butanol fraction were exhibited 64.65 ${\mu}g/ml$ and 277.42 ${\mu}g/ml$, respectively. Moreover, ethyl acetate fraction showed higher inhibitory activity than other samples in tyrosinase inhibitory activity. In NO production inhibitory activity, the extract and its fractions showed NO production inhibitory effect. Especially, the ethyl acetate, chloroform and butanol fraction was exhibited higher NO production inhibitory activity than other samples. As a result, the ethyl acetate and butanol fraction from the water extract of T. coreanum could be applicable to functional materials for skin-related fields.

• 약학회지
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• 제52권3호
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• pp.165-171
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• 2008

To develop effective skin whitening agents, we tested natural herbal extracts for their melanogenic inhibitory activities. Sedum samentosum was selected for its inhibitory effect on melanogenesis in B16 melanoma cells. Ethanolic extract of S. samentosum (SSE) was evaluated for antioxidative effect and tyrosinase inhibitory activity of melanogenesis. We investigated the changes in protein level and mRNA level of tyrosinase, tyrosinase related protein (TRP)-1 and TRP-2 by using western blotting and RT-PCR, respectively. SSE showed scavenging activities of free radicals and reactive oxygen species (ROS) with the $IC_{50}$ of 342.7 $\mug/ml$ against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 64.69 $\mug/ml$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. SSE treatment suppressed the biosynthesis of melanin up to 46% and reduced tyrosinase activity up to 51% at 100 $\mug/ml$ in B16 melanoma cells. The tyrosinase activity and tyrosinase expression in B16 melanoma cells were reduced in a dose-dependent manner by SSE. Also, SSE was able to significantly inhibit tyrosinase and TRP-1 expression in mRNA level. These results suggest that SSE inhibited melanin production which may be dependent on tyrosinase activity and expression in B16 melanoma cells, and an effective whitening agent for the skin.

• Journal of Applied Biological Chemistry
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• 제53권4호
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• pp.212-218
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• 2010

연구는 전통발효공정에 따라 오미자를 발효시켜 제조한 오미자 발효액의 여러 가지 생리활성에 대하여 조사하였다. 우선, 오미자 발효액의 일반성분, 무기질 및 비타민 분석을 시행한 결과에서 발효전의 오미자보다 탄수화물과 비타민 C 함량이 높게 나타났다. 또한, 주요 맛 성분인 유리당 함량을 측정한 결과, 오미자 발효액에서 glucose와 fructose 함량이 발효 전의 오미자 보다 높게 나타났다. 이에 반해, 발효 전 오미자에서 검출되는 sucrose가 오미자 발효액에서는 나타나지 않았다. 오미자 발효액의 항산화 효과를 분석하기 위해 DPPH radical 소거능을 측정한 결과, 4배 희석한 오미자 발효액 (25%)에서 79.7%의 DPPH radical 소거능을 나타내었는데, 0.01%의 BHA와 유사한 항산화력이 측정되었다. 또한 오미자 발효액의 94.7%의 C의 경우 농노 0.1%일 때 98.1%로 보고되어 있어 오미자 발효원액(100%)과 유사한 항산화능을 나타내고 있다. 이것으로 볼 때 오미자 발효액의 항산화 활성이 아주 높은 것으로 항산화력에 관한 높은 이용가치를 의미한다. 또한, 오미자 발효액의 항균활성을 관찰한 결과 오미자 발효원액 (100%)에서 E. coli에 대한 항균효과가 나타났다. Tyrosinase의 저해효과는 사료의 농도가 증가함에 따라 유의적으로 증가하는 경향을 나타내었는데 50% 농도의 오미자 발효액에서 82%의 높은 tyrosinase 억제효과를 나타내었다. 오미자 발효액의 피부 주름 예방효과를 측정하기 위하여 elastasc 저해효과 실험을 실시한 결과 전반적으로 농도가 높아짐에 따려 비례적으로 저해활성이 증가하였다. 이상의 결과는 오미자 발효액의 우수한 생리활성을 증명하고 있고, 항산화능, 항균력, 피부미용 효과가 높은 것으로 나타나 기능성 음료의 소재로서 그 활용도가 높을 것으로 판단된다.

• 한국균학회지
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• 제43권2호
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• pp.99-103
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• 2015

제주도, 울릉도, 욕지도 등 우리나라 섬들과 계족산, 오서산, 백암산 등의 산에서 서식하는 야생화들에서 분리한 207 효모 균주들을 YPD 배지에 24시간 배양하여 각각의 무세포추출물과 배양상등액을 제조한 후 이들의 항산화활성과 Xanthine oxidase 저해활성 및 tyrosinase 저해활성을 측정하였다. 섬 지역 야생화들에서 분리한 Kuraishia capsulata UL40-2와 산 지역 야생화에서 분리한 Sporobolomyces ruberrimus 121-Z-3의 무세포추출물이 각각 46.4%와 48.3%의 비교적 높은 항통풍성 xanthine oxidase 저해활성을 보였다. 또한 Starmerella bombicola 80-J-1의 무세포추출물 역시 36.2%의 미백성 tyrosinase 저해활성을 보였다. 그 밖의 항산화활성과 tyrosinase 저해활성은 모든 분리효모들에서 없거나 30% 미만으로 미약하였다. 이들 가운데 xanthine oxidase 저해활성이 우수하였던 Kuraishia capsulate UL40-2와 Sporobolomyces ruberrimus 121-Z-3의 xanthine oxidase 저해제의 최적 생산 조건을 검토한 결과 두 효모 각각을 YPD에 접종하여 $30^{\circ}C$에서 24시간 배양하여 얻은 무세포추출물이 47.2%와 49.5%의 높은 xanthine oxidase 저해활성을 보였다.

• Journal of Applied Biological Chemistry
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• 제54권2호
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• pp.108-113
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• 2011

황백 추출물의 tyrosinase 억제효과를 검토한 결과 60% 에탄올추출물에서 25% 정도의 억제효과를 나타내었으며, melanoma세포(B16F10)에서의 멜라닌 생합성을 측정한 결과 31.2%의 저해활성을 나타내어 멜라닌생성억제효과가 있음을 알 수 있었다. 황백추출물에서 tyrosinase저해 활성물질을 정제하고자 Sephadex LH-20과 MCI-gel CHP-20 open column을 이용하여 용출한 결과 순수하게 정제된 활성물질을 얻을 수 있었으며, 정제물질을 구조 동정한 결과 미백물질은 obacunone으로 동정되었다. 정제된 obacunone은 35.1%의 저해활성을 나타내어 미백 활성이 비교적 우수함을 확인할 수 있었으며, 황백추출물로부터 분리한 미백물질을 이용한 미백 화장품을 제조하여 관능평가를 한 결과 우수한 평가를 받았다. 미백화장품의 안정성 검사를 위해 pH, 점도 및 복소탄성률의 변화를 측정하였으나 저장기간 60일 동안 큰 변화를 나타내지 않았다. 또한 온도변화, 인공 및 자연광에 의한 변화, 온도순환에 의한 변화 및 냉 해동순환(Freeze & Thaw cycling)에 따른 변화들 살펴본 결과 저장 60일 동안 모든 조건에서 상의 분리와 변색, 변취 등의 변화 없이 안정성을 나타내었다.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.885-888
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• 2002

Four diarylheptanoids, (5R)-1,7-bis (3,4-dihydroxyphenyl)-heptane-5-O-$\beta$-D-glucoside (1), (5R)-1,7-bis (3,4-dihydroxyphenyl)-heptane-5-ol (2), oregonin (3), hirsutanonol (4), were isolated from the bark of Alnus hirsuta Turcz and its inhibitory effects on melanogenesis by measuring the melanin level and tyrosinase activity in B16 melanoma cell were examined. Melanin level and tyrosinase activity were reduced to 75 to 85% by addition of diarylheptanoids to incubation medium of the melanoma cell. On the other hand, melanin level and tyrosinase activity were reduced to 13 to 43% by the addition of diarylheptanoids to incubation medium of the melanoma cell treated with melanogenesis stimulator, $\alpha$-MSH and forskolin. These melanogenesis inhibitory effects were significantly different compared with control.

• 약학회지
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• 제53권1호
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• pp.1-5
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• 2009

This study was performed to investigate the effects of acteoside and isoacteoside isolated from Clerodendron trichotomum Thunberg on melanin production in B16 melanoma cells. In DPPH radical scavenging activity, acteoside and isoacteoside had a potent anti-oxidant activity in a dose-dependent manner. Both acteoside and isoacteoside dose-dependently inhibited silica-induced ROS (reactive oxygen species) generation in B16 melanoma cells. They significantly inhibited tyrosinase activity and melanin production in MSH-stimulated B16 melanoma cells. The inhibitory effect of acteoside was more potent than that of isoacteosidee. In Western blot of tyrosinase, acteoside inhibited MSH-induced tyrosinase expression in B16 melanoma cells, which is related to the inhibitory action of acteoside on tyrosinase activity and melanin production. These results show that acteoside and isoacteoside from Clerodendron trichotomum Thunberg has a potent antioxidant activity and whitening activity. The underlying mechanism of acteoside on whitening activity may be due to the inhibition of tyrosinase activity and tyrosinase expression.

• Journal of Microbiology and Biotechnology
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• 제16권12호
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• pp.1977-1983
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• 2006

Kaempferol was isolated and identified from the methanol extract of the flowers of Impatiens balsamina. Kaempferol showed inhibitory activity against mushroom tyrosinase with an $ID_{50}$ of 0.042 mM. Inhibition kinetics, as determined using a Lineweaver-Burk plot, showed kaempferol to be a competitive inhibitor of mushroom tyrosinase with a $K_i$ value of 0.011 mM. The lag phase of tyrosine hydroxylation catalyzed by mushroom tyrosinase clearly increased on increasing the concentration of kaempferol. In addition to its tyrosinase inhibiting activity, kaempferol strongly inhibited melanin production by Streptomyces bikiniensis, in a dose-dependent manner, without inhibiting cell growth. For comparative purposes, the tyrosinase inhibitory activity of kaempferol was also assayed versus quercetin, a positive standard.