• 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).

• YAKHAK HOEJI
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• v.41 no.4
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• pp.524-529
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• 1997

Seventy three hydrolysable tannins and related compounds were isolated from seven Euphorbia plants. Among them, 28 compounds including nine gallotannins, eleven ellagitannins and eight related compounds were selected according to the structural similarity. Cytotoxicity of them on the human tumor cell lines including A-549, SK-OV-3, SK-MEL-2, XF-498 and HCT-15 were evaluated by the SRB method in vitro. 3,4,6-Tri-O-galloyl-D-glucose was shown to exhibit most potent cytotoxic effect($4.4{\mu}g/ml).

• Natural Product Sciences
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• v.8 no.4
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• pp.183-185
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• 2002

To investigate skin whitening natural substances, the effects on melanogenesis by measuring the tyrosinase activity and the melanin contents of three hydrolysable tannins, $1,2,6-tri-O-galloyl-{\beta}-D-glucose$ (1), 2,3-(S)-HHDP-D-glucose (2) and pedunculagin (3) in B16 melanoma cells were examined. $1,2,6-Tri-O-galloyl-{\beta}-D-glucose$ (1), 2,3-(S)-HHDP-D-glucose (2) and pedunculagin (3) inhibited tyrosinase activity in B16 melanoma cells in a dose-dependent manner.

• Korean Journal of Pharmacognosy
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• v.23 no.4
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• pp.211-217
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• 1992

Seven hydrolysable tannins and two related compounds have been isolated from the acetone-water(4 : 1) soluble portion of the aerial parts of Euphorbia ebracteolata(Euphorbiaceae). Seven hydrolysable tannins have been determined as 3-O-galloyl-shikimic acid, 1, 3, 4, 6-tetra-O- and $1,\;2,\;3,\;4,\;6-penta-O-galloyl-{\beta}-D-glucose$, corilagin, tercatain, punicafolin and geraniin and two related compounds determinedasgallicacidandellagicacidonthebasisof spectral data and physico-chemical evidence.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1998.11a
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• pp.89-92
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• 1998

Tannins are complex polyphenolic substances present in plants. They may be classified as either hydrolysable or condensed tannins, and extracts of the latter type have displayed carcinogenic properties in animal studies (Hausen, 1981). The International Agency for Research on Cancer has determined that exposure to airborne wood dust, especially hardwood dust during furniture manufacture, is a cause of sino-nasal cancer, notably nasal adenocarcinoma. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.9
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• pp.1462-1467
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• 2007

This study investigated the effect of chemical treatments on tannins (condensed and hydrolysable) and on the trypsin inhibitor (TI) activity in salseed meal. Triplicate samples of ground salseed meal (1 kg) were mixed with 820 ml of either distilled water (pH 5.3), 0.67 M acetic acid (pH 2.4), 0.67 M sodium bicarbonate (pH 8.2) or 2% polyvinyl-pyrrolidone (PVP) solution. The material was placed in airtight plastic containers and incubated at $37^{\circ}C$ for 0, 3, 6, 12, 24, 48 and 72 h. Samples of untreated salseed meal which had not been subjected to soaking or incubation were run through the analysis to serve as control. Addition of water, acetic acid, sodium bicarbonate and PVP solutions to salseed meal and subsequent anaerobic incubation at $37^{\circ}C$ significantly reduced chemically detectable tannins. At each incubation time, alkali solution was more effective than its counterparts. The effect of acidic solution on hydrolysable tannin was least among the treatments. All the treatments reduced TI activity of salseed meal. The reduction in TI activity by these treatments was similar and ranged between 80-84%. Treatment time effected a decrease in the contents of antinutritional substances. However, the effect of the treatment with the reagents, even for zero incubation time, was quite pronounced. It may be concluded from the present results that the treatment of salseed meal with sodium bicarbonate (0.67 M) is more effective in reducing hydrolysable and condensed tannin contents than PVP, water and acid solutions. Treatment with sodium bicarbonate solution is more economical and easier to handle than acid and PVP treatments. Incubation of the treated material for 12 h is reasonably effective, economical and safe from any mould growth.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.8
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• pp.1134-1138
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• 2006

Forest tree leaves (12 different species) of semi hilly arid region of Punjab State were collected at 30-day interval throughout the year to assess the seasonal variations in tannin profile. Tannins were extracted and fractionated from fat free samples and data were analyzed statistically by $12{\times}12$ factorial design. The leaves of Anogeissus latifolia had the highest (p<0.05) concentration of total phenols (17.4%), net (15.9%) and hydrolysable (16.9%) tannins, followed by leaves of Acacia nilotica. Majority of the tree leaves selected had moderate levels (2-5%) of net tannins. Leaves of Carrisa had the highest (p<0.05) concentration of condensed tannins (CT), whereas the leaves of Anogeissus had the lowest (p<0.05) concentration of condensed tannins. The protein precipitable phenols (PPP) corresponded well with the net tannin content present in different tree leaves. Seasonal variation data revealed that in summer, net tannins and PPP decline in leaves of Bauhinia and Zizyphus whereas the net tannin content of Anogeissus and that of Carrisa increased during summer. The CT and PPP content in the leaves of Pheonix, Leucaena, Zizyphus and Ougenia increased in winter till spring season. Tree leaves generally had higher concentration of HT during summer months. It was concluded that leaves of leaves of A. nilotica, A. latifolia and L. leucocephala could serve as an excellent alternate feed stuffs for ruminants. However, leaves of Phoenix, Carrisa, Bauhinia and Dodonea should be avoided.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.559-570
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• 2016

The EtOAc and $H_2O$ soluble fractions of Katsura tree (Cercidiphyllum japonicum Sieb. Et Zucc) bark extracts were chromatographed on a Sephadex LH-20 column with various aqueous MeOH. Gallic acid (1), methyl galate (2), kurigalin (3), 1,2,3,6-tetra-O-galloyl-${\beta}$-D-glucose (4) and 1,2,3,4,6-penta-O-galloyl-${\beta}$-D-glucose (5) were isolated from EtOAc fraction. Isocorilagin (6) and methyl galate (2) were separated from $H_2O$ fraction. The structure determination was done by $^1H$ and $^{13}C$ NMR. Of these isolated compounds, methyl galate (2), kurigalin (3) and isocorilagin (6) were isolated, for the first time, from the bark extracts of Cercidiphyllum japonicum.

• BMB Reports
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• v.52 no.6
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• pp.409-414
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• 2019

Natural compounds isolated from medicinal herbs and plants have immense significance in maintaining bone health. Hydrolysable tannins have been shown to possess a variety of medicinal properties including antiviral, anticancer, and anti-osteoclastogenic activities. As a part of a study on the discovery of alternative agent against skeletal diseases, we isolated a hydrolysable tannin, 2-O-digalloyl-1,3,4,6-tetra-O-galloyl-${\beta}$-D-glucose (DTOGG), from Galla Rhois and examined the effect on osteoclast formation and function. We found that DTOGG significantly inhibited receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation by downregulating the expression of the key regulator in osteoclastogenesis as well as osteoclast-related genes. Analysis of RANKL/RANK signaling revealed that DTOGG impaired activation of $I{\kappa}B{\alpha}$ and p65 in the nuclear factor kappa-lightchain-enhancer of activated B cells (NF-${\kappa}B$) signaling pathway. Furthermore, DTOGG reduced bone resorbing activity of osteoclasts, compared to the vehicle-treated control. These results suggest that DTOGG could be a useful natural compound to manage osteoclast-mediated skeletal diseases.

• Natural Product Sciences
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• v.21 no.1
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• pp.14-19
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• 2015

Several $19{\alpha}$-hydroxyursane-type triterpenoids and hydrolysable tannins have beneficial effects on human health. Rubus crataegifolius (Rosaceae) has the cleft simple leaf whereas R. parvifolius has pinnate compound leaves. This research was aimed to find the variation in the contents of the triterpenoids and tannins between the infected versus uninfected leaves of R. coreanus and R. parvifolius and between young versus mature leaves. Triterpenoids and tannins were quantitatively analyzed by HPLC. Six triterpenoids including tormentic acid, euscaphic acid, 23-hydroxytormentic acid, coreanoside $F_1$, kaji-ichigoside $F_1$ and niga-ichigoside $F_1$ were used for standard compounds. Gallotannins and ellagitannins were quantitatively evaluated using the indicatives of methyl gallate and ellagic acid. The infected leaves of R. crataegifolius contained higher levels of triterpenoids and tannin than the uninfected leaves; however, lower quantity of total tannin was observed in the mature leaves than in the young leaves. Although the pinnate compound leaves of R. parvifolius exhibited similar tendency of those compositional variation with R. crataegifolius each other, its contents of triterpenoids do not considerably vary. Variation of the contents of triterpenoids and tannins were particularly distinct in R. crataegifolius by growth and infection.