• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1549-1553
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• 2008

A molecular imprinted polymer (MIP) using (+)catechin ((+)C) as a template and acrylamide (AM) as a functional monomer was prepared. Acetonitrile was used as the porogen with ethylene glycol dimethacrylate (EGDMA) as the crosslinker and 2,2'-azobis(isobutyronitrile) (AIBN) as the initiator. The adsorption isotherms in the MIP were measured and the parameters of the equilibrium isotherms were estimated by linear and nonlinear regression analyses. The linear equation for original concentration and adsorpted concentrations was then expressed, and the adsorption equilibrium data were correlated into Langmuir, Freundlich, quadratic, and Langmuir Extension isotherm models. The mixture compounds of (+)C and epicatechin (EC) show competitive adsorption on specific binding sites of the (+)catechin-MIP. The adsorption concentrations of (+)C, epicatechin (EC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG), on the (+)catechin-molecular imprinted polymer were compared. Through the analysis, the (+)catechin-molecular imprinted polymer showed higher adsorption ability than blank polymer which was synthesized molecular imprinted polymer without (+)catechin. Furthermore, the competitive Langmuir isotherms were applied to the mixture compounds of (+)C and EC.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.230-234
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• 2001

The extract of Ulmus davidiana var. japonica cortex has known as natural anti-inflammatory substance in East Asia. For the identification of antimicrobial substance, it was extracted by using methanol and fractionated by using different organic solvents. The fraction of butanol was represented the highest antimicrobial activities. Therefore, the butanol fraction was purified and identified the chemical structure by $^1$H and $^{13}$ C-NMR spectra, FT-IR and EI/MS spectroscopies. The isolated antimicrobial substance was identified as cis-2-[3,4-dihydroxy phenyl]-3,4-dihydro-2H-1-benzopyran-3,5,7-triol, which has commonly known as (-)epicatechin. Its minimum inhibitory concentrations (MICs) against Staphylococcus aureus and Listeria monocytogenes were shown as 100 $\mu\textrm{g}$/mL, respectively.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.100-100
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• 2019

This study attempted to establish a High Performance Liquid Chromatography (HPLC) analysis method for the determination of (-)-epicatechin gallate as a part of the quality control for the development of functional cosmetic materials from Penthorum chinense Pursh extracts. HPLC was performed on a Unison US-C18 column ($4.6{\times}250mm$, $5{\mu}m$) with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methyl alcohol at a flow rate of 1.0 mL/min at $30^{\circ}C$. The analyte was detected at 280 nm. The HPLC method was performed in accordance with the International Conference on Harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.11 and 0.33 mg/mL, respectively. Calibration curves showed good linearity (r2 > 0.9999), and the precision of analysis was satisfied (less than 0.6%). Recoveries of quantified compounds ranged from 99.51 to 101.92%. This result indicates that the established HPLC method is very useful for the determination of marker compound in P. chinense Pursh extracts.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.209-216
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• 2012

In the continued research on natural fungicides for control of plant diseases by using plant-derived products, we found that Spatholobus suberectus Dunn had a strong fungicidal activity against several plant pathogens. S. suberectus (1 kg) was extracted with 80% aqueous MeOH and then the concentrated extract was partitioned with n-hexane, EtOAc, n-BuOH and $H_2O$ successively. The four layers were tested their disease contron efficacies against 6 plant diseases such as rice blast (RCB), rice sheath blight (RSB), tomato grey mold (TGM), tomato late blight (TLB), wheat leaf rust (WLR), and barley powdery mildew (BPM). The EtOAc fraction was highly active showing over 80% control against RCB, TGM, TLB, and BPM. By using silica gel chromatography, preparative TLC and HPLC, six compounds that were expected to have antifungal activity were separated. Their chemical structures were identified as ethanone, hydroxytyrosol, epicatechin, procyanidin B2, dimethoxy daizein and formononetin by ESI-MS, $^1H$-NMR, $^{13}C$-NMR, and 2D-NMR spectroscopic analyses. The chemicals except epicatechin were first reported in S. suberectus. Study on in vitro and in vivo antifungal activities of the isolated compounds is in progress.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.45 no.1
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• pp.87-93
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• 2019

This study attempted to eatablish a High Performance Liquid Chromatography (HPLC) analysis method for the determination of (-)-epicatechin gallate as a part of the quality control for the development of functional cosmetic materials from Penthorum chinense Pursh. HPLC was performed on a Unison $US-C_{18}$ column ($4.6{\times}250mm$, $5{\mu}m$) with a gradient elution of 0.05% (v/v) trifluoroacetic acid (TFA) and methyl alcohol at a flow rate of 1.0 mL/min at $30^{\circ}C$. The analyte was detected at 280 nm. The HPLC method was performed in accordance with the International Conference on Harmonization (ICH) guideline (version 4, 2005) of analytical procedures with respect to specificity, precision, accuracy, and linearity. The limits of detection and quantitation were 0.11 and 0.33 mg/mL, respectively. Calibration curves showed good linearity ($r^2$ > 0.9999), and the precision of analysis was satisfied (less than 0.6%). Recoveries of quantified compounds ranged from 99.51 to 101.92%. This result indicates that the established HPLC method is very useful for the determination of marker compound in P. chinense Pursh extracts.

• Preventive Nutrition and Food Science
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• v.12 no.3
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• pp.135-140
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• 2007

Antibacterial activities of the major phenolic components from Camellia sinensis L. were investigated against several pathogenic microorganisms including Gram-positive strains like Staphylococcus aureus ATCC 29213 and Streptococcus pyogens 308A; and Gram-negative strains like Escherichia coli ATCC 25922, Escherichia coli 078, Pseudomonas aeruginosa 9027, and Enterobacter cloacae 1321E. The MIC values demonstrate that both (-)-epicatechin and (-)-epigallocatechin were more considerably toxic against Staphylococcus aureus ATCC 29213 than the other two catechins like (-)-epicatechingallate and (-)-epigallocatechin-3-gallate. (-)-Epicatechingallate and (-)-epigallocatechin-3-gallate were most inhibitory against Escherichia coli ATCC 25922. As a result, (-)-epicatechin showed predominant antibacterial activities among tea varieties. The contents of major polyphenolic components such as four catechins, theaflavin, and quercetin were different according to fermentation processes. The total contents of four catechins were ranged from 13.81 to 1.33%, with (-)-epigallocatechin-3-gallate being dominant among tea varieties; theaflavin was found the characteristic pigment in fully-fermented black tea.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.285-290
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• 2002

From the fruits of Crataegus pinnatifide BUNGE ursolic acid (1), $quercetin-3-O-{\alpha}-L-rhamnopyranosyl(1{\rightarrow}6)-{\beta}-D-glucopyranoside$ (2), (-)-epicatechin (3), $quercetin-3-O-{\beta}-D-galactopyranoside$ (4) and quercetin (5) have been isolated and identified on the basis of their physicochemical properties and spectroscopic evidences in comparison with authentic samples. Among isolated compounds, quercetin showed significant inhibitory effect against MAO.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.267-271
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• 2002

Prunasin and pomolic acid together with a mixture of ursolic and oleanolic acids, (-)-epicatechin and ${\beta}-sitosterol$ glucoside were isolated from the roots of Chaenomeles japonica. Among these compounds, the isolation of pomolic acid and prunasin is the first report from the genus Chaenomeles.

• Korean Journal of Pharmacognosy
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• v.33 no.4 s.131
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• pp.404-410
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• 2002

Phytochemical examination of Barks of Ulmus macrocarpa has led to the isolation and characterization of two fla-vanonol, taxifolin $7-O-{\beta}-D-glucopyranoside$ (1), taxifolin $3'-0-7-{\beta}-glucopyranoside$ (2), two flavanone eriodictyol $7-O-{\beta}-D-glucopyranoside$ (3), nalingenin $7-O-{\beta}-D-glucopyranoside$ (4), three flavan 3-ol, (+)-catechin (5), (-)-epicatechin (6), (+)-catechin 7-O-{\beta}-D-glucopyranoside (7) and one proanthocyanidin, procyanidin B-1 (8). Antioxidative activity of these compounds was determined by measuring the radical scavenging effect on 1,1-diphenyl-2- picrylhydrazyl (DPPH) radicals . (+)-Catechin (5) , (-)-epicatechin (6), (+)-catechin $7-O-{\beta}-D-glucopyranoside$ (7) and procyanidin B-1 (8) showed significant antioxidative activity.

• Korean Journal of Pharmacognosy
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• v.42 no.1
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• pp.89-97
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• 2011

This study was conducted to investigate tyrosinase inhibitory effect, hyaluronidase inhibitory effect and antioxidant activity by DPPH radical scavenging method on the MeOH extract of 50 species medicinal plant for screening of functional properties. As a result, Chaenomeles sinensis Koehne extract among 50 species medicinal plant turned out to be having tyrosinase, hyaluronidase inhibitory effect and antioxidant activity. The major component of tyrosinase and hyaluronidase inhibitory effect was isolated from EtOAc extract of Chaenomeles sinensis Koehne. And the component of antioxidant activity was isolated from n-BuOH extract of Chaenomeles sinensis Koehne. Their structure of compounds were identified as oleanolic acid and (-)-epicatechin by spectroscopic evidence, respectively.