• Korean Journal of Pharmacognosy
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• v.41 no.3
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• pp.174-179
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• 2010

Activity guided isolation of 80% acetone extract from the barks of Acer ginnala Maxim. yielded five gallotannins [6-galloyl-1,5-anhydroglucitol (ginnalin B) (1), acertannin (3,6-digalloyl-1,5-anhydroglucitol) (2), methyl gallate (3), acertannin (2,6-digalloyl-1,5-anhydroglucitol) (4) and gallic acid (5)]. All of these isolated compounds from Acer ginnala(1-5) were firstly isolated from Acer ginnala Maxim. And contents of compounds from barks of Acer ginnala (Comp. 1: 0.73$\pm$0.002%, Comp. 2: 0.48$\pm$0.001%, Comp. 3: 0.66$\pm$0.002%, Comp. 4: 1.05$\pm$0.002% and Comp. 5: 0.29$\pm$0.001%) were evaluated by HPLC analysis. And, in order to evaluate anti-oxidative activities on Comp. 1-5 isolated from Acer ginnala, DPPH radical scavenging activity was measured in vitro. All of these isolated compounds from Acer ginnala exhibited potent DPPH radical scavenging activities.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.46-46
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• 2012

• 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).

• Journal of Nutrition and Health
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• v.17 no.1
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• pp.41-49
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• 1984

Tannin from acorn was identified by TLC and gallic acid in the tannin was determined by HPLC. The tannin extracted with methanol-butanol was not dissolved in ethanol, methanol for HPLC and water, while the tannin extracted with acetone-ethylacetate was so pure that it could be used for HPLC-running. The gallic acid showed a Rf -value of 0.39, the digallic acid of 0.21, the trigallic acid of 0.09, and the gallotannin of 0.00 respectively. The content of gallic acid in the tannin from acorn powder was 3.04%, from acorn starch, 0.90%, and from acorn starch gels, 0.64-0.86% respectively. The effect of tannin contents on the viscosity of acorn atarch was also studied. The maximum and cooling viscosity of the starch were decreased as the contents of tannin increased.

• Journal of Forest and Environmental Science
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• v.23 no.1
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• pp.1-4
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• 2007

The bark of Juglans mandshurica Maxim. was collected, extracted with acetone-$H_2O$ (7:3, v/v), fractioned with n-hexane, $CH_2Cl_2$ and EtOAc, then each fraction was freeze-dried to give some powders. A portion of the EtOAc (28.4 g) fraction was chromatographed on a Sephadex LH-20 column eluting with a series of MeOH-$H_2O$ and EtOH-hexane mixture. Four gallotannins, gallic acid (1), ellagic acid (2), 1,2,4,6-tetra-O-galloyl-${\beta}$-D-glucose (3) and 1,2,3,4,6-penta-O-galloyl-${\beta}$-D-glucose (4), have been isolated from the EtOAc fraction Their structures were elucidated on the basis of chemical evidence and spectrometric analysis such as NMR and MS. The antioxidant activities on each fraction and the isolated gallotannins were evaluated by DPPH radical scavenging test.

• The Korean Journal of Food And Nutrition
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• v.29 no.1
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• pp.58-64
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• 2016

This study was conducted to investigate the health effects of the general components of acorns in animals. In Korea, acorns have been used as food material in the form of acorn starch. Acorns contain tannin, gallic acid, digallic acid, and gallotannin. Therefore, the health effects of acorns as functional food are actively being studied. The chemical composition of acorns may vary according to the harvest time, region, and breed. Acorns have excellent antioxidant properties and might be beneficial in controlling hyperlipidemia, obesity, cardiovascular disease, and dementia, as well as strengthening immune competence. Further study is necessary to better understand the benefits of acorns, as it is expected to represent a large part of the food industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.693-700
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• 1992

As an approach to study a new natural antioxidant for edible fats and oils, antioxidative fractions from acorn powder were characterized. The oxidative stabilities of soybean, palm, beef tallow, and lard oil containing the acorn active fraction extracted with various organic solvents were studied by determining the peroxide value during the storage at $60^{\circ}C.$ And this effective antioxidative components were isolated and identified by thin layer chromatography and high performance liquid chromatography. The proximate compositions of acorn powder were water 11.9~12.0%, protein 7.1~7.4%, starch 65.5~69.4%, fat 2.1~2.6%, fiber 2.1~3.6%, ash 2.4~2.6%, and total tannin 4.6~6.8%, respectively. The final yield of fraction extracted by sequential order of acetone : $H_2O$(1 : 1) and ethylacetate was 2.8~3.1%. Gallic acid, digallic acid and gallotannin were contained this final fraction. The main antioxidative activity was speculated due to the presence of gallic acid in acorn powder extract. The antioxidative activity was more effective in fat water emulsion than just fat system. Antioxidative activities measured by peroxide value were quite high in beef tallow and soybean emulsion, but low in lard and palm oil emulsion in the concentration of 200ppm acorn extract. Therefore, the addition of 200ppm acorn extract was suggested to expect effective antioxidation concentration in the reaction system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.409-416
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• 2017

1,2,3,4,6-Penta-O-galloyl-${\beta}$-D-glucose (PGG) is a gallotannin isolated from Galla Rhois. In a previous study, PGG was shown to suppress the allergic response by attenuating immunoglobulin E production both in vitro and in vivo. However, the effect of PGG on bacteria-induced inflammation at physiological concentration remains unclear. Therefore, the aim of this study was to investigate the effect of PGG on lipopolysaccharide (LPS)-stimulated macrophages. PGG inhibited release of nitric oxide (NO) and prostaglandin $E_2$ by alleviating protein expression of inducible NO synthase and cyclooxygenase-2 in LPS-treated RAW264.7 cells. Furthermore, PGG suppressed the release of interleukin-6 and tumor necrosis factor-${\alpha}$ induced by LPS. Further study indicated that PGG blocked translocation of the p65 subunit of nuclear factor-${\kappa}B$ from the cytosol into the nucleus, which is one of the underlying mechanisms of the anti-inflammatory action of PGG. Collectively, these data suggest that PGG might be useful for the treatment of inflammatory disease.

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.72-78
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• 1986

The studies were performed to investigate the optimum conditions for tannic processing of silk by use Chinese Gallotannin and synthesized tannic acid, which are aimed at weighting, dyeing and physical properties of tannin treated silk. 1. It was reasonable that the concentration of tannin solution is 30 grams per liter of Chinese Gallotannin, 15 grams per liter of tannic acid for the efficient weighting of processed silk. The temperature and time for tannin treatment was optimum at 80$^{\circ}C$, 60 minutes and the acidity of tannin solution at pH 2 to 3. 2. In dyeing the tannintreated silk by Acid dye Orange II, the temperature and time was reasonable at 60$^{\circ}C$, 90 minutes to control the desorption of tannin components weighted onto silk. 3. The colour differences ($\Delta$E) of dyed silk fabric by soaping could be remarkably narrowed by tannin treatment, resulting in improving the washing fastness of tannin treated silk by two grades more than that of untreated one. 4. The light fastness of tannin treated silk could be drastically improved by reducing the dye-loss of dyed silk fabric which was coused from the Ultra-violet ray irrdiation. 5. The rubbing fastness and water repellency of tannin treated silk was at the same level with that of untreated one. However, the Drape coefficient of tannin treated silk was decreased more than that of untreated one, which is closely related with fabric softness and dressing appearence.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.715-721
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• 2021

Cognitive impairment and Alzheimer's disease are serious social problems associated with the rising elderly population in Korea. 1,2,3,4,6-Penta-O-galloyl-β-ᴅ-glucopyranose (PGG) is a gallotannin isolated from medicinal plants such as Rhus chinensis. This study was performed to evaluate the effect of PGG on biomarkers related to cognitive function in human neuroblastoma SK-N-SH cells. Inhibition of acetylcholinesterase (AChE) activity is considered to be one of the main therapeutic strategies. PGG inhibited AChE activity in the test tube as well as in SK-N-SH cells. In addition, PGG induced protein and mRNA expression of brain-derived neurotrophic factor (BDNF), which is a mammalian neurotrophin that plays major roles in the development, maintenance, repair, and survival of neuronal populations. As one of the underlying molecular mechanisms that induce BDNF expression, PGG induced the activation of Ca²⁺/calmodulin (CaM)-dependent protein kinase II (CaMKII)-cAMP response element binding protein (CREB) pathway. In conclusion, PGG may be an useful material for improving cognitive function.