• Korean Journal of Materials Research
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• v.33 no.11
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• pp.458-464
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• 2023

In order to develop catechin patches for skin regeneration at wound sites, patches with varying concentrations of catechin and chitosan were manufactured. An optimal composition ratio was determined by adjusting the drug release rate and amount, to maximize efficiency. The catechin used in this study was extracted from green tea leaves using a solvent/ultrasonication method, and its characteristics were confirmed through Fourier transform-infrared spectroscopy (FT-IR) and high-performance liquid chromatography (HPLC) analyses. Patches were prepared with different concentrations of catechin and chitosan, and various properties were analyzed using techniques such as FT-IR, water contact angle analysis, and UV-Vis spectroscopy. It was observed that as the chitosan concentration increased, the release of catechin slowed down or almost ceased. A patch manufactured with 1.5 mg/cm² of catechin at a 1 % chitosan concentration exhibited a high initial release rate over 24 h and demonstrated cellular biocompatibility. Consequently, these patches, with tailored release characteristics based on the concentrations of chitosan and catechin, hold promise for use as drug delivery systems in wound healing applications.

• Toxicological Research
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• v.15 no.1
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• pp.19-25
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• 1999

(+)-Catechin inhibited the growth and induced the differentiation of HL-60 human leukimia cells. The degree of a differentiation by (+)-catechin during the differentiation, the expression assay, To understand the molecular mechanism of (+)-catechin during the differentiation, the expression level of oncogenes was detected by Northern blot analysis. c-Myc mRNA level was reduced after treatment with (+)-Catechin (10-4), however, the expression of c-jun was increased with a concentration dependent manner in HL-60 cells. These results showed that the differentiation and antiproliferation of HL-60 cells against (+)-Catechin was related to the reduction of c-myc and the induction of c-jun expression.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1580-1584
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• 2005

Antioxidative activities of catechin from green tea extracts were examined by the methods of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) electron donating ability, hydroxy scavenging activity and the inhibitory effect on xanthine oxidase activity. The resulted demonstrated the fact that Catechin one (containing Green tea extracts plus catechin 51%) of green tea extracts product showed at 65.5% in electron donating activity on the DPPH. The electron donating ability on the DPPH of Catechin one was increased to 10% than purified catechin. Catechin one showed the activity at 64.5% in scavenging activity using hydroxy radical method. To the Catechin one provided to increase the hydroxy scavenging activity up to 3 fold. Inhibitory effects of the catechin one measured with xanthine oxidase method was 6.5%. Although the antioxidative activity of catechin (98% purified) was lower than that of Catechin one (containing Green tea extracts plus catechin 51%) in same catechin concentrations ($5{\mu}g$, respectively). Therefore, we may suggest that Catechin one can be used as a functional food additive possessing the potent antioxidative activity.

• The Korean Journal of Food And Nutrition
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• v.31 no.3
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• pp.416-424
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• 2018

The physiologically advantageous aspects of green tea have been identified recently and green tea has been a favorite drink of many people. Due to the increased awareness of green tea's positive effects on human health, the demand for foods containing green tea has increased. This has led to the development of diverse green tea-related beverages; thereby many companies in Korea have put a wide variety of manufactured green tea beverages on the market. However, the components within green tea beverages have not been examined in Korea yet. In this study, we investigated the contents of the physiologically functional materials found in green tea, such as catechin, catechin gallate, epicatechin, epicatechin gallate, epigallocatecin gallate, gallocatechin gallate and caffeine. Fifty-six green tea products purchased from the local grocery stores and cafes were analyzed using high performance liquid chromatography (HPLC) analysis. As a result, all tested products contained catechin and caffeine, although the amount of each component was largely different. The total amount of catechin derivatives in the manufactured green tea beverages purchased from cafes was 263.17 mg/L, while they were 61.99 mg/L in the beverages purchased from the local grocery stores. And, to the almost samples the amount of caffeine was proportional to the amount of catechin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.386-389
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• 1992

The four main tea catechin components (-)-epicatechin (EC), (-)-epigallocatechin (EGC) , (-)-epicatechin gallate (ECg), and (-)-epigallocatechin gallate (EGCg) were analyzed quantitatively from commerical green teas by HPLC. CATechin of the most amounts in steamed and parched teas was EGcg (steamed 1st : 7.54% , parched 1st : 7.88%). Amounts of catechins decreased in the following order : EGCg > EGC>ECg>EC. Almost same tendency of catechin components change of 1st tea and 2nd tea differed to harvesting time being observed in steamed and parched teas. In 2nd tea, amounts of EGCg increased more than in 1st tea. It seems that this change effects on the quality of tea taste.

• Korean Journal of Pharmacognosy
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• v.46 no.3
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• pp.189-194
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• 2015

Validation and contents determination of (+)-catechin and diosgenin from Smilax china L. rhizome (SC) were confirmed using Ultra-Performance Liquid Chromatography (UPLC). (+)-Catechin was isolated from 60% prethanol SC extract and diosgenin was isolated by acid hydrolysis of saponin fraction from 60% prethanol extract of SC. Finally we have established the validation of the isolated compounds [(+)-catechin, diosgenin] and contents determinations of (+)-catechin and diosgenin by UPLC on 60% prethanol extract of SC [(+)-catechin: 0.06878%, diosgenin: 0.48169%], and on hot water extract of SC [(+)-catechin: 0.06584%, diosgenin: 0.42178%].

• KSBB Journal
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• v.23 no.1
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• pp.96-100
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• 2008

In this work, we describes analysis of the antioxidant potential of Korean green tea phenolics using an high-performance liquid chromatography (HPLC) on-line $ABTS^{+}$ antioxidant screening method. In conjunction with the analysis of their 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS+) radical scavenging ability, the extraction of catechine compounds from Korean green tea were performed by various temperature and time. The optimum operating conditions were experimentally determined to analyze the catechine compounds in the pretreatment extracts. From the results, the extraction temperature $60^{\circ}C$, time 3 min was selected as an optimal antioxidant activity condition. The analysis by $C_{18}$ column was performed, the flow rate of mobile phase and UV wavelength was fixed at 1.0 ml/min and 254 nm, respectively. the mobile phase was composed from acetonitrile and water, and the gradient elution mode were applied.

• Journal of Food Hygiene and Safety
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• v.34 no.5
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• pp.431-437
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• 2019

This study was conducted to develop a simultaneous analysis method for ferulic acid, caffeic acid, catechin and taxifolin from Health Functional Food (HFF) Pinus Pinaster bark extract. The simultaneous analytical method for ferulic acid, caffeic acid, catechin and taxifolin is carried out using UPLC-MS/MS. The method validation was performed to determine selectivity, linearity, accuracy, limit of detection (LOD), limit of quantification (LOQ) and precision for ferulic acid, caffeic acid, catechin and taxifolin. LC-MS/MS method was established using an Acquity UPLC BEH $C_{18}$ Column and was applied for these 4 compounds. Product-ion traces, at m/z $194.2{\rightarrow}133$, $180.2{\rightarrow}135$, $290.3{\rightarrow}245$, $304.3{\rightarrow}248$, were used for quantitative analysis of ferulic acid, caffeic acid, catechin and taxifolin, respectively. Excellent linearity ($r^2=0.999$) was observed for ferulic acid, caffeic acid, catechin and taxifolin in the concentration range (50-2500 mg/L). The observed recoveries of these 4 compounds were found to be between 84.9 and 104.9%, while precision was between 1.20 and 4.43% relative standard deviation (% RSD).

• Food Science and Preservation
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• v.20 no.2
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• pp.242-249
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• 2013

Thermal processing of (+)-catechin was carried out at $121^{\circ}C$ for different reaction times (1, 2, 3, 6, and 12 h). The reacted products, compounds (1) and (2), were isolated and quantified via HPLC analysis. The antioxidant properties of processed (+)-catechin and its isolated compounds for different reaction time was measured via radical scavenging assays using DPPH and $ABTS^+$ radicals. Additionally, the anti-obesity efficacy of the thermal treated (+)-catechin was evaluated via porcine pancreatic lipase assay. The reacted (+)-catechin for 3 h had a slightly higher antioxidant capacity than that the parent (+)-catechin. Products 1 and 2, which were isolated from the reacted mixture during 3 h, showed an antioxidant capacity, and these two compounds may be responsible for the antioxidant capacity of processed (+)-catechin. Simple thermal treatment of (+)-catechin can be used to produce (+)-epicatechin (1) and protocatechuic acid (2) with enhanced antioxidant and anti-adipogenic effects.

• 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.