• Food Science and Biotechnology
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• 제15권2호
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• pp.177-182
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• 2006

Polyphenol oxidase (PPO) was isolated from the flesh of Fuji apples by DEAE-Cellulose, ammonium sulfate precipitation, phenyl-Sepharose CL-4B, and Sephdex G-100 chromatography. The molecular mass of the purified PPO was estimated to be 40 kDa by SDS polyacrylamide gel electrophoresis. With regard to substrate specificity, maximum activity was achieved with chlorogenic acid as substrate, followed by catechin and catechol whereas, there was no detectable activity with hydroquinic acid, resorcinol, or tyrosine as substrate. The optimum pH and temperature with catechol as substrate were 6.5 and $35^{\circ}C$, respectively. The enzyme was most stable at pH 6.0 and unstable at acidic pH. The enzyme was stable when it was heated to $45^{\circ}C$ but heating at $50^{\circ}C$ for more than 30 min caused 50% loss of activity. Reduced $ZnSO_4$, L-cystein, epigallocatechin-3-o-gallate (EGCG), and gallocatechin gallate (GCG) also inhibited activity.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2007년도 학술발표회
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• pp.232.2-232.2
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• 2007

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.130.2-131
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• 2002

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.255.2-255.2
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• 2002

The present study was designed to investigate the effects of green tea extract (GTE) and epigallocatechin gallate (EGCG) on secretion of catecholamines (CA) in the isolated perfused rat adrenal gland. In the presence of GTE (100 ${\mu}$g/$m\ell$) into an adrenal vein for 60 min. CA secretory responses evoked by ACh (5.32 mM), high K＋ (56 mM) and Bay-K-8644 (10 ${\mu}$M for 4 min) from the isolated perfused rat adrenal glands were greatly inhibited in a time-dependent fashion. (omitted)

• 한국식품영양과학회지
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• 제32권4호
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• pp.501-505
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• 2003

프로폴리스를 이용하여 새로운 기능성 식품을 개발하기 위하여 프로폴리스 원괴와 그 추출물의 화학성분에 대하여 조사하였다. 일반성분은 조지방 86.41%, 가용성 무질소물 7.32%, 조단백질 2.71%, 회분 1.05% 및 조섬유 0.20%로 나타났다. 프로폴리스에 함유되어 있는 주요 무기성분은 Na(120.40 mg%), Ca(115.40 mg%) 및 K(105.87 mg%) 순으로 나타났으며, Ca 함량은 알콜 추출물보다 물 추출물에서 높게 나타났다. 유리당은 총 3종이 분리, 동정되었으며, 그 중 sucrose가 152 mg%로 높게 나타났고, glucose 114 mg% 및 fructose 6 mg%로 함유되어 있었다. 프로폴리스에 함유되어 있는 주요 아미노산으로는 lysine, cystine 및 glutamic acid로 나타났으며, 그 함량은 각각 395.29 mg%, 267.66 mg% 및 248.14 mg%로 나타났다. 지방산은 총 8종이 분리되었으며, 주요 지방산으로는 oleic acid (51.89%), myristic acid (20.86%) 및 palmitic acid (20.28%)로 나타났다. 프로폴리스의 flavonol 화합물을 분석한 결과 myricetin, quercetin, apigenin 및 kaempferol이 주요 flavonol화합물로 나타났으며, 총 flavonoid 함량은 다른 추출물보다 50% 에탄올 추출물에서 가장 높게 나타났다. 프로폴리스에 함유되어 있는 polyphenol 성분들은 gallic acid, chlorogenic acid, catechin, epigallocatechin gallate, epicatechin 및 epicatechin gallate로 확인되었다.

• 한국식품과학회지
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• 제37권6호
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• pp.976-982
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• 2005

Sprague-Dawley 계열의 흰쥐를 perfusion시킨 후 분리한 뇌조직을 이용하여 뇌의 산화적 손상을 억제할 수 있는 식물체 및 항산화제의 활성을 조사하였다. 뇌의 산화적 손상 유도를 위해서는 활성산소원으로 $2.5{\mu}M$ ferrous sulfate와 7.5mM hydrogen peroxide를 뇌조직 homogenate에 첨가하였으며 손상의 정도는 malondialdehyde와 4-hydroxyalkenal 총 함량으로 표현되는 지질 과산화도(LPO)를 이용하였다. $37^{\circ}C$에서 10분간의 처리 시 LPO는 4.1에서 6.9nmol/mg protein 증가하였다. 한편, 식물체들의 뇌 손상 억제 효과를 분석하기 위해, 68종의 식용식물체로부터 수용성 추출물을 조제한 후 이를 활성산소 처리 전에 뇌 조직 homogenate에 첨가함으로써 지질산화 억제 정도를 비교하였다. 그 결과 엽채류에서는 아욱, 열무잎, 비름, 무순, 셀러리 등이, 근채류에서는 조림감자, 생강, 고구마 등이 80% 이상의 LPO억제 효과를 나타냈다. 과채류와 과일에서는 풋고추, 꽈리고추, 쥬니키, 가지, 아보카도, 오렌지, 바나나 등이 60% 이상의 효과를 보였으며, 버섯류에서는 팽이버섯, 양송이버섯, 표고버섯, 새송이버섯, 느타리버섯 순으로 효과가 높게 나타났다. 한편, 32종의 항산화제 중에서는 (+)catechin(91%), (-)epigallocatechin gallate(85%), (-)epicatechin gallate(83%), kaempferol(83%), chlorogenic acid(78%), melatonin(75%), ${\alpha}-tocopherol(69%)$ 등이 산화적 뇌 손상 방어에 우수한 것으로 나타났다.

• 대한임상독성학회지
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• 제14권2호
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• pp.78-82
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• 2016

Purpose: Green tea is known as a potent anti-oxidant, anti-carcinogen, and genetic protector. Glyphosate (N-phosphonomethyl glycine) is a widely used non-selective herbicide that causes DNA damage. The present study was conducted to investigate the protective effects of green tea in human blood lymphocytes exposed to glyphosate using the Sister Chromatid Exchange (SCE) frequency method. Methods: Peripheral blood was obtained from 10 volunteers and cultured through four different conditions. Four groups were divided into control, glyphosate only (300 ng/mL), glyphosate and low ($20{\mu}m$) concentrations of epigallocatechin gallate (EGCG) and glyphosate and high ($100{\mu}m$) concentrations of EGCG. Results: The glyphosate exposed groups had a higher mean SCE frequency ($10.33{\pm}2.50$) than the control group ($6.38{\pm}2.28$, p<0.001). The low concentrations of EGCG groups had a lower mean SCE frequency ($9.91{\pm}1.93$) than the glyphosate-only group, although this difference was not significant (p=0.219). However, the high concentration group ($9.49{\pm}1.85$) had a significantly lower SCE frequency than the glyphosate-only group (p=0.001). Conclusion: EGCG has a gene protective effect in human lymphocytes exposed to the genotoxicity of glyphosate in the case of high concentrations.

• Natural Product Sciences
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• 제22권4호
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• pp.270-274
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• 2016

Green tea, the leaves of Camellia sinsneis (Theaceae), is generally acknowledged as the most consumed beverage with multiple pharmacological functions including antioxidant activity. This study was performed to analyze the effect of extraction conditions of green tea on its antioxidant effects using DPPH assay. Three extraction factors such as extraction solvent (EtOH, 0 - 100%), extraction time (3 - 15 min) and extraction temperature ($10-70^{\circ}C$) were analyzed and optimized extraction condition for antioxidant activity of green tea extract (GTE) was determined using response surface methodology with three-level-three-factor Box-Behnken design (BBD). Regression analysis showed a good fit of data and the optimal conditions of extraction were found to be 57.7% EtOH, 15 min and $70^{\circ}C$. Under this condition, antioxidant activity of experimental data was 88.4% which was almost fit to the ideal value of 88.6%. As epigallocatechin gallate (EGCG) is known for the major ingredient for antioxidant activity of green tea, we investigated the effect of EGCG on antioxidant activity of GTE. EGCG showed antioxidant activity with the $IC_{50}$ value of $4.2{\mu}g/ml$ and a positive correlation was observed between EGCG content and the antioxidant activity of GTE with $R^2=0.7134$. Interestingly, however, GTE with 50 - 70% antioxidant activity contain less than $1.0{\mu}g/ml$ of EGCG, which is much lower than $IC_{50}$ value of EGCG. Therefore, we suppose that EGCG together with other constituents contribute to antioxidant activity of GTE. Taken together, these results suggest that green tea is more beneficial than EGCG alone for antioxidant ability and optimal extraction condition of green tea will be useful for the development of food and pharmaceutical applications

• 한국염색가공학회지
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• 제28권1호
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• pp.1-13
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• 2016

Natural colorant extracts were obtained by extraction from tumeric root, gardenia seeds, mugwort and green tea using water, methanol, ethanol and acetone as extractants at room temperature for 3 hours under shaking condition(180rpm) with liquor ratio(solid:solvent; 1:100). The main pigment components of tumeric root, gardenia seeds, mugwort and green tea are known to be curcumin, crocin, chlorophyll b and epigallocatechin gallate, respectively. The effects of the kind of extractant and pH on the color characteristics of natural colorant extracts were investigated. The solubility parameters of pigment components were determined to find adequate extractant. The solubility parameters of curcumin, crocin, chlorophyll b and epigallocatechin gallate were found to be 27.85, 29.40, 19.48 and $37.97(J/cm^3)^{1/2}$. As expected, solvents that have a solubility parameter similar to that of pigment component were generally found to be effective to obtain pigment extracts having high visible absorbance(A). The extract(pigment/solvent) with high visible absorbance was generally found to have low $L^*$(lightness) and high Chroma($C^*$, purity).

• 대한의용생체공학회:의공학회지
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• 제34권3호
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• pp.111-116
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• 2013

Finite element analysis(FEA) has been extensively applied in the analyses of biomechanical properties of stents. Geometrically, a closed-cell stent is an assembly of a number of repeated unit cells and exhibits periodicity in both longitudinal and circumferential directions. This study concentrates on various parameters of the FEA models for the analysis of drug-eluting biodegradable polymeric stents for application to the treatment of coronary artery disease. In order to determine the mechanical characteristics of biodegradable polymeric stents, FEA was used to model two different types of stents: tubular stents(TS) and helicoidal stents(HS). For this modeling, epigallocatechin-3-O-gallate (EGCG)-eluting poly[(L-lactide-co-${\varepsilon}$-caprolactone), PLCL] (E-PLCL) was chosen as drug-eluting stent materials. E-PLCL was prepared by blending PLCL with 5% EGCG as previously described. In addition, the effects of EGCG blending on the mechanical properties of PLCL were investigated for both types of stent models. EGCG did not affect tensile strength at break, but significantly increased elastic modulus of PLCL. It is suggested that FEA is a cost-effective method to improve the design of drug-eluting biodegradable polymeric stents.