• Applied Biological Chemistry
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• v.45 no.3
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• pp.168-172
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• 2002

Antioxidative activities of solvent fractions obtained from Korean Rhus vernicifera, being used in food industry and as a traditional medicine, were examined by the methods of DPPH scavenging activity, inhibitory effect on autooxidation of linoleic acid, nitrite scavenging activity and the inhibitory effect on xanthine oxidase activity. Ethyl acetate fraction showed potent antioxidative activities. Three compounds were isolated from the ethyl acetate fraction by rotatory locular counter current chromatography (RLCCC), Sephadex LH-20 column chromatography and HPLC. The isolated compounds were 1,2,3-trihydroxybezene, methyl 3,4,5-trihydroxybenzoate and 3,4,5-trihydroxybenzoic acid determined by GC/MS and, $^1H$ and $^{13}C$ NMR. Among the isolated compounds, methyl 3,4,5-trihydroxybenzoate showed the strongest antioxidative activity than artificial antioxidants, BHA and BHT in various methods. However, these isolated compounds did not show cytotoxicity effects on the human cancer cell lines. Therefore, we may suggest that methyl 3,4,5-trihydroxybenzoate can be used as a food additive possessing the potent antioxidative activity.

• Journal of the Korean Wood Science and Technology
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• v.31 no.6
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• pp.8-14
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• 2003

This study was carried out identify extractives of Amorpha fruticosa. In this study, one flavonoid glycoside, one ester and two rotenoids were isolated from fruits of A. fruticosa. The structures were determined as: kaempferol 7-O-α-L-rhamnopyranoside (I), methyl 3, 4, 5-trihydroxybenzoate (methyl gallate, II), tephrosin (III) and dalbinol (IV), respectively, on the basis of spectroscopic data.

• Journal of fish pathology
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• v.18 no.3
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• pp.227-237
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• 2005

To obtain antimicrobial compounds against fish pathogenic bacteria from natural products, 80% methanolic extracts from 14 species of medicinal plant were screened for antimicrobial activity against fish pathogenic bacteria, Edwardsiella tarda and Vibrio anguillarum. Among them, Glycyrrhiza glabra, Rhus vemiciflua and Sanguisorba officinalis were effective for growth inhibition of Gram-negative bacteria, both E. tarda YSF and V. anguillarum YSR. Through the activity-guided isolation for R. verniciflua extract that exhibited the highest antimicrobial activity among three extracts, one antimicrobial compound (1) was isolated and identified as methyl-3,4,5-trihydroxybenzoate, or methyl gallate. This compound significantly inhibited the growth of tested strains of both E. tarda and V. anguillarum exhibiting MIC of 1 mg/ml for each strain.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.190.4-191
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• 2003

This study was carried out to examine the constituents of Amorpha fruticosa (Leguminosae), a shrub originated from North Africa. Dried and ground fruit of A. fruticosa were extracted with methanol and then concentrated to give the crude extracts. The crude extracts was successively fractioned with organic sovents, such as n-hexane, CH$_2$Cl$_2$ and EtOAc. Seven compounds were isolated from the fruits of A. fruticosa. On the basis of spectrosopic data, the structures of these compounds were determined as: kaempferol 7-O-${\alpha}$-L-rhamnopyranoside (I), methyl 3,4,5- trihydroxybenzoate (methyl gallate, II), tephrosin (III), dalbinol (IV), gallic acid (V), 2",4",5",7-tetramethoxyisofavone (Ⅵ) and Dalbinol 2"-O-${\beta}$-D-Glucopyranoside (Ⅶ) respectively. (omitted)

• Natural Product Sciences
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• v.23 no.1
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• pp.5-8
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• 2017

An antimicrobial compound has been isolated from the leaves of Glochidion superbum. The compound was determined as methyl 3, 4, 5-trihydroxybenzoate (methyl gallate), based on ultraviolet (UV), infrared (IR), nuclear magnetic resonance (NMR) and mass spectroscopy (MS) analysis. The isolated compound exhibited potent antimicrobial activity against three clinical isolates of methicillin resistant Staphylococcus aureus (MRSA) by qualitative agar disc diffusion method and quantitative broth dilution method. Agar disc diffusion was done in a dose-dependent manner for each bacterial isolate at disc potencies of 25, 50, 100, and $150{\mu}g/disc$. The zones of inhibition were on average equal to 12.27, 14.20, 15.43, and 24.17 mm respectively. The inhibition zones were compared with that of vancomycin disc at $30{\mu}g$ as a reference standard. The MIC and MBC values were $50{\mu}g/ml$ and $100{\mu}g/ml$ respectively. The results of anti MRSA activity were analyzed using one-way ANOVA with Turkey's HSD and Duncan test. In conclusion, methyl gallate which was isolated from G. superbum showed the inhibition activity against methicillin resistant S. aureus.

• 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 Medicinal Crop Science
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• v.7 no.1
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• pp.51-57
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• 1999

To search for antioxidative compounds from plant resources, methanol extracts of 45 plant species were investigated using DPPH method. The highest activity was shown in the methanol extract of Acer ginnala($RC_{50}\;:\;15{\mu}g$), followed by Stewartia koreana($RC_{50}\;:\;28{\mu}g$) and Carpinus laxiflora($RC_{50}\;:\;33{\mu}g$). Two antioxidative compounds were isolated from the methanolic extract of Acer ginnala Max and identified as acertannin(2, 6-di-O-galloyl-1, 5-anhydro-D-glucitol) and gallicin (methyl-3, 4, 5-trihydroxybenzoic acid) on the basis of mass spectroscopy, $^1H-\;and\;^{13}C-NMR$ data. The DPPH free radical scavenging activities of acertannin($RC_{50}\;:\;3.5{\mu}g$) and gallicin($RC_{50}\;:\;2.8{\mu}g$) were more effective than those of BHA($RC_{50}\;:\;14{\mu}g$) and ${\alpha}-tocopherol$ ($RC_{50}\;:\;12{\mu}g$).

• Journal of Microbiology and Biotechnology
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• v.19 no.9
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• pp.987-996
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• 2009

Aspergillus niger GH1 previously isolated and identified by our group as a wild tannase producer was grown under solid-state (SSC) and submerged culture (SmC) conditions to select the enzyme production system. For tannase purification, extracellular tannase was produced under SSC using polyurethane foam as the inert support. Tannase was purified to apparent homogeneity by ultrafiltration, anion-exchange chromatography, and gel filtration that led to a purified enzyme with a specific activity of 238.14 IU/mg protein with a final yield of 0.3% and a purification fold of 46. Three bands were found on the SDS-PAG with molecular masses of 50, 75, and 100 kDa. PI of 3.5 and 7.1% N-glycosylation were noted. Temperature and pH optima were 600e and 6.0 [methyl 3,4,5-trihydroxybenzoate (MTB) as substrate], respectively. Tannase was found with a $K_M$ value of $0.41{\times}10^{-4}M$ and the value of $V_{max}$ was $11.03{\mu}$moL/min at $60^{\circ}C$ for MTB. Effects of several metal salts, solvents, surfactants, and typical enzyme inhibitors on tannase activity were evaluated to establish the novelty of the enzyme. Finally, the tannase from A. niger GH1 was significantly inhibited by PMSF (phenylmethylsulfonyl fluoride), and therefore, it is possible to consider the presence of a serine or cysteine residue in the catalytic site.