• Title/Summary/Keyword: L-DOPA synthesis

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Isolation of a Natural Antioxidant, Dehydrozingerone from Zingiber officinale and Synthesis of lts Analogues for Recognition of Effective Antioxidant and Antityrosinase Agents

  • Kuo, Ping-Chung;Damu, Amooru G.;Cherng, Ching-Yuh;Jeng, Jye-Fu;Teng, Che-Ming;Lee, E-Jian;Wu, Tian-Shung
    • Archives of Pharmacal Research
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    • v.28 no.5
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    • pp.518-528
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    • 2005
  • In the present study, the antioxidative and inhibitory activity of Zingiber officinale Rosc. Rhizomes-derived materials (on mushroom tyrosinase) were evaluated. The bioactive co mponents of Z. officinale rhizomes were characterized by spectroscopic analysis as zingerone and dehydrozingerone, which exhibited potent antioxidant and tyrosinase inhibition activities. A series of substituted dehydrozingerones [(E)-4-phenyl-3-buten-2-ones] were prepared in admirable yields by the reaction of appropriate benzaldehydes with acetone and the products were evaluated in terms of variation in the dehydrozingerone structure. The synthetic analogues were examined for their antioxidant and antityrosinase activities to probe the most potent analogue. Compound 26 inhibited Fe$^{2+}$-induced lipid peroxidation in rat brain homogenate with an IC$_{50}$ = 6.3${\pm}$0.4 ${\mu}$M. In the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) radical quencher assay, compounds 2, 7, 17, 26, 28, and 29 showed radical scavenging activity equal to or higher than those of the standard antioxidants, like ${\alpha}$-tocopherol and ascorbic acid. Compound 27 displayed superior inhibition of tyrosinase activity relative to other examined analogues. Compounds 2, 17, and 26 exhibited non-competitive inhibition against oxidation of 3,4- dihydroxyphenylalanine (L-DOPA). From the present study, it was observed that both number and position of hydroxyl groups on aromatic ring and a double bond between C-3 and C-4 played a critical role in exerting the antioxidant and antityrosinase activity.

Effects of Polygonati Rhizoma Extracts on the Collagenase Activity and Procollagen Synthesis in Hs68 Human Fibroblasts and Tyrosinase Activity

  • Park, Dong-Su;Shin, Seon-Mi;Leem, Kang-Hyun
    • The Korea Journal of Herbology
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    • v.28 no.3
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    • pp.1-5
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    • 2013
  • Objectives : This study was designed to investigate the collagen metabolism and tyrosinase activity of Polygonati Rhizoma extracts (PR). It's effects are to tonify spleen qi and augment the spleen yin. It enrichs the yin and moisten the lung. Methods : The effect of PR on type I procollagen production and collagenase (matrix metalloproteinase-1, henceforth referred as MMP-1) activity in human normal fibroblasts Hs68 after ultraviolet B (UVB, 312 nm) irradiation was measured by ELISA method. The tyrosinase activity after treatment of PR was measured. Results : There were no cytotoxicity at concentrations of 10, 30, $100{\mu}g/ml$. The reduced type I procollagen production was recovered by PR in UVB damaged Hs68 cells at a concentration of $100{\mu}g/ml$ ($16.2{\pm}0.0$ ng/ml) from control group ($13.9{\pm}0.5$ ng/ml). However there was no statistical significance. PR reduced The increased MMP-1 activity after UVB damage at concentrations of $10{\mu}g/ml$, $30{\mu}g/ml$, and $100{\mu}g/ml$ in a dose dependent manner ($42.2{\pm}20.5%$, $44.8{\pm}8.5%$, and $22.0{\pm}5.8%$). PR $100{\mu}g/ml$ treatment showed the statistical significace (p < 0.05). PR significantly reduced the tyrosinase activity at a concentration of 10 mg/ml ($32.0{\pm}12.8%$, p < 0.05). However, the L-DOPA oxidation was not changed. Conclusion : PR showed the anti-wrinkle effects and whitening effects in vitro. Although more researches are needed to validate the efficacy, these results suggest that PR may have potential as an anti-aging ingredient in cosmetic herb markets.

Melanogenesis Inhibitory and Antioxidant Activities of Phellinus baumii Methanol Extract (장수진흙버섯 메탄올 추출물의 멜라닌 생성 저해작용)

  • Lee, J.S.;Shin, D.B.;Lee, S.M.;Kim, S.H.;Lee, T.S.;Jung, D.C.
    • The Korean Journal of Mycology
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    • v.41 no.2
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    • pp.104-111
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    • 2013
  • Phellinus baumii is a medicinal mushroom used in Asian countries for a long period of time. The purpose of this study was to investigate the skin whitening activities of methanol extracts from fruiting bodies of P. baumii. To evaluate the antioxidant activities of the extract, polyphenol and flavonoid contents, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and chelating activity on ferrous ions were studied. For assay of skin whitening activities, tyrosinase and DOPA inhibitory activities, and tyrosinase and melanin synthesis inhibitory activities of B16/F10 melanoma cells treated with the methanol extract were investigated. The total polyphenol content of P. baumii methanol extract was 4.19. DPPH scavenging ability of P. baumii methanol extract was 88.26% in $25{\mu}g/mL$ concentration. We tested tyrosinase inhibitory activity and melanin contents in melanoma cells. The tyrosinase activity was inhibited to 65.17% at the concentration of $125{\mu}g/mL$ and melanin synthesis was inhibited to 57.61% at the concentration of $25{\mu}g/mL$. Overall, the experimental results showed that P. baumii methanol extract had inhibitory activities of tyrosinase and melanin synthesis by dose dependent manner in B16/F10 melanoma cells. Strong ultra-violet absorption spectra in the range of 270~370 nm indicated that ethanol extract of P. baumii could protect the skin from UV. Therefore, P. baumii methanol extract might be used for development of skin whitening, anti-UV and skin care agents.

Anti-Oxidant Property and Inhibition of Melanin Synthesis of Eight Plant Extracts (수종의 식물수출물의 항산화 및 Melanin 합성 억제효과)

  • Kim, Jae-Young;Lee, Jin-Young;Lee, Wi-Young;Yi, Yong-Sub;Lim, Yoong-Ho
    • Microbiology and Biotechnology Letters
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    • v.38 no.4
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    • pp.414-419
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    • 2010
  • Plants extracts are good resources to find functional compounds for human health. The following eight plants were collected and total phenolic contents were determined. Acer psedo-siebolianum showed the highest phenolic contents, 16.4 mg/g, whereas Cercidiphyllum japonica showed the lowest contents, 1.9 mg/g. The DPPH free radical scavenging capacities of the plant extracts showed high activity in following order : Acer ginnala ($21.3\;{\mu}g/mL$) > Cornus walteri ($23.9\;{\mu}g/mL$) > Distylum racemosum ($29.2\;{\mu}g/mL$) > Castanopsis cuspidata var. Thunbergii ($31.7\;{\mu}g/mL$) > Acer psedo-siebolianum ($34.6\;{\mu}g/mL$) > Thuijopsis dolabrata cv. Aurea ($53.1\;{\mu}g/mL$) > Cercidiphyllum Japonica ($115.2\;{\mu}g/mL$). Also the mushroom tyrosinase inhibitory activities of total extracts were determined at different concentration. D. racemosum extract showed highest (49.1% at 1,000 mg) in inhibitory activity than other seven extracts. The ethanol fraction $IC_{50}$ value: $118.1\;{\mu}g/mL$) from D. racemosum showed more inhibitory activity than ethyl acetate fraction ($IC_{50}$ value: $203\;{\mu}g/mL$). The ethanol fraction on showed no significant cytotoxicity in B16/F1 cells line up to $60\;{\mu}g/mL$. Over $80\;{\mu}g/mL$ of ethanol fraction showed cytotoxicity in B16/F1 cells. The melanin contents of cells were significantly attenuated by ethanol fraction in a dose-dependent manner. The $IC_{50}$ value of ethanol fraction was $75.4\;{\mu}g/mL$.