• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.707-711
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• 2008

The principal objective of the current study was to isolate a purpurogallin derivative as an oxidation product from gallic acid, in an effort to assess the anti-inflammatory effects of this compound. Purpurogallin derivative is known to be the one of the oxidation products of gallic acid. This compound has been identified as a minor chemical component in fermented tea products. It has been previously demonstrated that theaflavins, the oxidation products of catechins found in fermented tea products, exert profound antioxidant and anti-inflammatory effects. However, the biological activities of a minor chemical component in fermented teas have yet to be evaluated. Purpurogallin carboxylic acid (PCA) was identified as a major oxidation product of gallic acid from a peroxidase/hydrogen peroxide oxidation model system. The identity of the PCA was verified by $^{1}H$ NMR, $^{13}C$ NMR and MS techniques. PCA treatment significantly suppressed the generation of pro-inflammatory mediators including nitric oxide and IL-6 in lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophages. According to the nitrite assay, PCA 100, 75, and $50{\mu}g/mL$ treatment dose-dependently inhibited NO production by 57.6, 41.5, and 21.8%, respectively, in LPS-stimulated RAW264.7 murine macrophage cells. Moreover, IL-6 production was inhibited to a significant degree with PCA treatment of 100 and $75{\mu}g/mL$ at 43.1 and 23.9%, respectively. PCA treatment also significantly suppressed $PGE_2$ production at levels of 100 and $75{\mu}g/mL$. These results showed that PCA exerts inhibitory effects on the production of inflammatory mediators.

• Journal of Integrative Natural Science
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• v.9 no.2
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• pp.86-93
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• 2016

The peptide sequences, GHK(Gly-His-Lys) and KTTKS(Lys-Thr-Thr-Lys-Ser), using a collagen stimulator recently were manipulated at N-terminal as a multifunctional peptide derivative with PEG(polyethyleneglycol) linker connected to gallic acid which presents anti-inflammatory activity. The multifunctional peptide derivatives were obtained in a normal peptide preparation method through SPPS(solid phase peptide synthesis) using Fmoc chemistry and a carboxyl group insertion reaction of PEG-3,4,5-triacetoxy benzoate by using potassium tert-butoxide and ethyl bromoacetate, which was separated by Sephadex DEAE. It gave a good compromise to a cosmetic application for cell cytotoxicity, anti-wrinkle, and anti-inflammation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5452-5457
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• 2015

Conjugating a phytochemical, a strong antioxidant, with a functional peptide not only compensates for its stability, but also improves its solubility and anti-wrinkle effects, thereby contributing to the possibility of becoming an excellent cosmetic ingredient. Thus, in this study we examined the potential cosmetic use of a phytochemical-peptide derivative using gallic acid, a phytochemical with antioxidant, anti-inflammatory, and anti-cancer effects. To evaluate the antioxidant and wrinkle-improving efficacy of 5 synthesized gallic acids conjugated with LVH, IVH, KTTKS, YGGFM, and YGGFLRKYP respectively, we observed the expression of genes related to wrinkle improvement using DPPH radical scavenging activity and real-time PCR. As a result, all 5 derivatives had excellent free radical scavenging effects. The expression level of genes involved collagen synthesis also increased, and the secreted peptides during collagen production contributed to their antioxidant and wrinkle improving effects. These results mark the potential use of gallic acid peptide derivatives as a cosmetic ingredient for anti-oxidation and wrinkle improvement.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.777-784
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• 2013

The ethyl acetate (EtOAc) layer of Canavalia gladiata (sword bean) methanol extracts showed higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity than other layers. Four phenolic compounds were isolated from the EtOAc layer by silica gel column chromatography and prep-HPLC using a guided DPPH radical-scavenging assay. The isolated compounds were identified as methyl gallate (1), gallic acid (2), 1,6-di-O-galloyl ${\beta}$-$\small{D}$-glucopyranoside (3), and 1,4,6-tri-O-galloyl ${\beta}$-$\small{D}$-glucopyranoside (4) based on MS and NMR analyses. Among the four compounds, no. 4 was isolated from this plant for the first time. Their DPPH radical-scavenging activities based on $SC_{50}$ decreased in the following order: 4 (6.9 ${\mu}M$)>3 (8.3 ${\mu}M$)>2 (10.0 ${\mu}M$)>1 (10.3 ${\mu}M$).

• Korean Journal of Pharmacognosy
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• v.31 no.3
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• pp.351-356
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• 2000

The hepatoprotective effects of bergenin and its derivative, acetylbergenin, were evaluated against D-galactosamine-induced liver damage in rats. Bergenin is a C-glucoside of 4-O-methyl gallic acid that has been isolated from the cortex of Mallotus japonicus (Euphorbiaceae). Acetylbergenin was synthesized from acetylation of bergenin to increase lipophilic and physiological activities. Bergenin (50, 100 and 200 mg/kg) and acetylbergenin (25, 50 and 100 mg/kg) were administered orally once daily for successive 5 days after the injection of galactosamine (400 mg/kg, i.p.), respectively. The substantially elevated serum enzyme activities of alanine/aspartate aminotransferase, sorbitol dehydrogenase and ${\gamma}-glutamyltransferase$ due to galactosamine treatment were dose-dependently restored towards normalization by post-treatment with bergenin and acetylbergenin. Bergenin and acetylbergenin also significantly prevented the elevation of hepatic malondialdehyde formation and depletion of reduced glutathione content induced by galactosamine in a dose-dependent manner. In addition, the decreased activities of glutathione S-transferase and glutathione reductase were restored towards normalization. These results suggest that effects of bergenin and acetylbergenin may be related to complex mechanisms that involve prevention of lipid peroxidation and preservation of hepatic glutathione. The results of this study clearly indicate that bergenin and acetylbergenin have potent hepatotherapeutic action against galactosamine-induced hepatotoxicity in rats, and lipophilic acetylbergenin is more active in the antihepatotoxic effects against galactosamine than much less lipophilic bergenin.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1317-1328
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• 2023

Green tea (GT) polyphenols undergo extensive metabolism within gastrointestinal tract (GIT), where their derivatives compounds potentially modulate the gut microbiome. This biotransformation process involves a cascade of exclusive gut microbial enzymes which chemically modify the GT polyphenols influencing both their bioactivity and bioavailability in host. Herein, we examined the in vitro interactions between 37 different human gut microbiota and the GT polyphenols. UHPLC-LTQ-Orbitrap-MS/MS analysis of the culture broth extracts unravel that genera Adlercreutzia, Eggerthella and Lactiplantibacillus plantarum KACC11451 promoted C-ring opening reaction in GT catechins. In addition, L. plantarum also hydrolyzed catechin galloyl esters to produce gallic acid and pyrogallol, and also converted flavonoid glycosides to their aglycone derivatives. Biotransformation of GT polyphenols into derivative compounds enhanced their antioxidant bioactivities in culture broth extracts. Considering the effects of GT polyphenols on specific growth rates of gut bacteria, we noted that GT polyphenols and their derivate compounds inhibited most species in phylum Actinobacteria, Bacteroides, and Firmicutes except genus Lactobacillus. The present study delineates the likely mechanisms involved in the metabolism and bioavailability of GT polyphenols upon exposure to gut microbiota. Further, widening this workflow to understand the metabolism of various other dietary polyphenols can unravel their biotransformation mechanisms and associated functions in human GIT.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.4
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• pp.287-301
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• 2008

In order to develop a new depigmenting agent, extracts were obtained from 60 native plants and their antimelanogenic activities were screened by evaluating the inhibitory effect on tyrosinase which is a major enzyme responsibles for the melanin synthesis. The extracts of Trichosanthes kirilowii fruits, Phyllostachys bambusoides inner films (BIF), Clerodendrum trichotomum leaves, and Acer okamotoanum leaves showed relatively high inhibitory effect on tyrosinase and their $IC_{50}$ values were $50{\sim}100{\mu}g/mL$. The extract of BIF inhibited melanin synthesis of B16F10 melanoma cells by 52%, which was the highest among those of various extracts. Furthermore, the effect of BIF extract is 10% higher than that of arbutin (42%), a popular depigmenting agent in Korea. Ten compounds having antimelanogenic activity were isolated from the BIF extract by solvent extraction and chromatography. These compounds were identified as phenolic derivatives: SM701, SM702, SM703, and BPR211 were hydroquinone derivatives; SM707 a gallic acid derivative; SM704, SM705, SM706, SM708 and SM709 ferulic acid derivatives. The free radical scavenging activities of these compounds were measured and compared to those of hydroquinone and vitamin C. The $SC_{50}$ values scavenging 50% DPPH of SM702 and SM709 were $60{\sim}70{\mu}M$ similar to that of hydroquinone and those of SM701 and SM708 were $30{\sim}40{\mu}M$ slightly lower than that of vitamin C. These results suggest the presence of components having high antioxidant activity in the BIF extract. The SM709, identified as 1,2-O-diferulylglycerol, inhibited the activities of tyrosine hydroxylase and dopa oxidase by 18 and 60%, respectively. The SM709 also inhibited the melanin synthesis of B16F10 melanoma cells by 62% and this was the highest antimelanogenic activity among those obtained from the various purified compounds. Therefore, antimelanogenic activity of the BIF extract was concluded to be due to both inhibition of DOPA oxidase and antioxidant activity.