• 한국식품영양학회지
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• 제31권3호
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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 Wood Science and Technology
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• 제30권1호
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• pp.63-71
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• 2002

사시나무속의 현사시, 이태리포플러 및 양황철나무 수피를 아세톤-물(7:3)로 추출한 후 농축하고 헥산, 클로로포름, 에틸아세테이트 및 수용성으로 분획하여 동결건조하였다. 각 추출물은 메탄올 수용액 및 에탄올-헥산 혼합액을 사용하여 Sephadex LH-20 칼럼크로마토그래피로 화합물을 분리한 후 TBA 및 6% 초산으로 전개하는 셀룰로오스 박층크로마토그래피로 단리 여부를 확인하였다. 단리된 화합물의 구조는 ¹H, ¹³C 및 2D-NMR과 질량분석에 의하여 결정되었다. 사시나무속 수종의 추출성분은 주로 flavonoid와 salicin 파생물로 구성되어 있으며 세 종류의 수종에서 모두 15개의 화합물이 분리되었다. 현사시나무에서는 (+)-catechin, naringenin, eriodictyol, sakuranetin, aromadendrin, taxifolin, sakuranetin-5-O-𝛽-D-glucopyranoside. neosaturanin. p-coumaric acid, salireposide와 aesculin이 단리되어 가장 많은 종류의 화합물을 포함하고 있었으며 이태리포플러에서는 (+)-catechin, salireposide, populoside와 salicortin이, 양황철나무에서는 (+)-catechin, padmatin, quercetin, salireposide, populoside와 salicortin이 단리되었다.

• 한국식품저장유통학회지
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• 제18권3호
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• pp.328-334
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• 2011

폴리페놀화합물인 안토시아닌, 레스베라트롤, 쿼세틴, 카테킨, 에피카테킨류는 항암작용과 항산화작용을 하는 것으로 보고되고 있다. 본 연구에서는 다양한 국내 육성 포도 품종과 외국 도입 품종에 대하여 포도내 대표적인 폴리페놀계 화합물인 안토시아닌, 레스베라트롤, 쿼세틴, 카테킨, 에피카테킨류의 함량을 분석하였다. 전체적으로 카테킨 및 에피카테킨의 함량은 레스베라트롤과 쿼세틴보다 훨씬 높게 검출되었다. 폴리페놀계의 화합물은 과피색 간에 큰 차이는 보이지 않았으나, 동일 과피색내의 품종간에는 유의적인 차이를 나타냈다. 각 과피색 그룹에서 흑색 포도에서는 캠벨얼리, 청색 그룹에서는 세네카, 그리고 적색그룹에서는 베니가드 품종이 가장 높은 수치를 보였다. 성분별로 적게 함유하거나 전혀 검출되지 않는 품종도 일부 존재하였다. 이러한 결과는 향후 포도 육종개발 및 가공 분야에 응용되는 유용한 정보가 될 것으로 기대된다.

• Nutrition Research and Practice
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• 제9권2호
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• pp.137-143
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• 2015

BACKGROUND/OBJECTIVES: Mulberry leaves contain quercetin derivatives, which have the effects of reducing obesity and improving lipid and glucose metabolism in mice with obesity. It is not clear whether or not mulberry leaves can directly affect metabolic disorders, in the presence of obesity, because of the interaction between obesity and metabolic disorders. The aim of the current study was to assess the direct action of quercetin derivatives on metabolic disorders in non-obese conditions in short-term high-fat diet fed mice. MATERIALS/METHODS: C57BL/6N mice were fed a high-fat diet, supplemented with either 0% (control), 1%, or 3% mulberry leaf powder (Mul) or 1% catechin powder for five days. Anthropometric parameters and blood biochemistry were determined, and hepatic gene expression associated with lipid and glucose metabolism was analyzed. RESULTS: Body and white fat weights did not differ among the four groups. Plasma triglycerides, total cholesterol, and free fatty acids in the 1%, 3% Mul and catechin groups did not differ significantly from those of the controls, however, plasma glucose and 8-isoprostane levels were significantly reduced. Liver gene expression of gp91phox, a main component of NADPH oxidase, was significantly down-regulated, and PPAR-${\alpha}$, related to ${\beta}$-oxidation, was significantly up-regulated. FAS and GPAT, involved in lipid metabolism, were significantly down-regulated, and Ehhadh was significantly up-regulated. Glucose-metabolism related genes, L-PK and G6Pase, were significantly down-regulated, while GK was significantly up-regulated in the two Mul groups compared to the control group. CONCLUSIONS: Our results suggest that the Mul quercetin derivatives can directly improve lipid and glucose metabolism by reducing oxidative stress and enhancing ${\beta}$-oxidation. The 1% Mul and 1% catechin groups had similar levels of polyphenol compound intake ($0.4{\times}10^{-5}$ vs $0.4{\times}10^{-5}$ mole/5 days) and exhibited similar effects, but neither showed dose-dependent effects on lipid and glucose metabolism or oxidative stress.

• 대한화학회지
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• 제66권4호
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• pp.298-304
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• 2022

The present study was designed to investigate the molecular mechanisms of DK-5-62, a novel (-)-catechin derivative on HCT116 human colorectal cancer cells. DK-5-62 inhibited the proliferation in dose- and time-dependent manner accompanied by the morphological changes. Effects of DK-5-62 appeared to be mediated by the induction of apoptosis, as manifested through DNA-binding dye Hoechst 33258 staining. Analysis of the mechanism of these events indicated that DK-5-62-treated cells exhibited an increased ratio of Bax/Bcl-2, resulting in the activation of caspase-9, caspase-3, and poly-ADP-ribose polymerase in a dose-dependent manner. Moreover, DK-5-62-induced apoptosis was accompanied by phosphorylation of the mitogen-activated protein kinase family, c-Jun N-terminal kinase, p38, and extracellular signal-regulated kinase. These results suggest that HCT116 cells are moderately sensitive to growth inhibition by DK-5-62 via apoptosis, as evidenced by activation of ERK/p38/Bcl-2 family signaling, as well as alteration in caspase-9 and caspase-3.

• 한국식품과학회지
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• 제40권5호
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• pp.510-515
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• 2008

포도씨에 함유된 기능성 카테킨류를 효과적으로 추출하기 위해서 마이크로웨이브 에너지를 이용하였다. 에탄올의 마이크로웨이브 가열특성을 확인하였을 때 100W에서 3분 이내에 끓는점에 도달하였다. 중심합성계획에 따라 추출조건(microwave power 0-120W, 에탄올 농도 0-100%, 추출시간 1-5분)을 설계하고, 조건별 추출물의 카테킨류 함량을 회귀분석함으로써 최적 추출조건을 예측하였다. (+)-Catechin의 최적 추출조건은 microwave power 104.10W, 에탄올 농도 45.35%, 추출시간 4.89분으로, 예측된 정상점은 최대점을 보이면서 최대 추출 값이 137.99 mg%였다. Procyanidin $B_2$의 최적 추출조건은 133.16W, 46.16%, 4.49분이며, 최대 추출 값은 72.78 mg%으로 예측되었다. 또한 (-)-epicatechin은 136.00W, 41.37%, 4.39분에서 최대 222.38 mg%를 추출할 수 있으며, (-)-epicatechin gallate는 143.20W, 37.51% 및 1.88min에서 9.59mg%를 추출할 수 있는 것으로 예측되었다. 이때 (+)-catechin, procyanidin $B_2$ 및 (-)-epicatechin은 microwave power, 에탄올 농도, 추출시간 등 3가지 독립변수에 모두 유사하게 영향을 받았지만, (-)-epicatechin gallate는 microwave power에만 주로 영향을 받는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제33권10호
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• pp.1317-1328
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• 2023

Green tea (GT) polyphenols undergo extensive metabolism within gastrointestinal tract (GIT), where their derivatives compounds potentially modulate the gut microbiome. This biotransformation process involves a cascade of exclusive gut microbial enzymes which chemically modify the GT polyphenols influencing both their bioactivity and bioavailability in host. Herein, we examined the in vitro interactions between 37 different human gut microbiota and the GT polyphenols. UHPLC-LTQ-Orbitrap-MS/MS analysis of the culture broth extracts unravel that genera Adlercreutzia, Eggerthella and Lactiplantibacillus plantarum KACC11451 promoted C-ring opening reaction in GT catechins. In addition, L. plantarum also hydrolyzed catechin galloyl esters to produce gallic acid and pyrogallol, and also converted flavonoid glycosides to their aglycone derivatives. Biotransformation of GT polyphenols into derivative compounds enhanced their antioxidant bioactivities in culture broth extracts. Considering the effects of GT polyphenols on specific growth rates of gut bacteria, we noted that GT polyphenols and their derivate compounds inhibited most species in phylum Actinobacteria, Bacteroides, and Firmicutes except genus Lactobacillus. The present study delineates the likely mechanisms involved in the metabolism and bioavailability of GT polyphenols upon exposure to gut microbiota. Further, widening this workflow to understand the metabolism of various other dietary polyphenols can unravel their biotransformation mechanisms and associated functions in human GIT.

• Journal of Photoscience
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• 제9권2호
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• pp.424-426
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• 2002

Recently, much attention has been paid to the physiological functions of flavonoids associated with their antioxidant properties. However, there was a lack of information on the molecular mechanism at which flavonoids play the antioxidative role. We have already studied on the oxidation of quercetin with hydrogen peroxide and sodium hypochlorite in alcoholic aqueous solution and determined the oxidation products. Through the structural analysis of the oxidation products, it was clarified that the hydroxyl group at C-3 in the C ring plays the important role in the antioxidative action of quercetin. Successively, rutin and (+)-catechin were oxidized with sodium hypochlorite and their mono- and di-chlorinated derivatives were obtained. These facts indicate that these flavonoids can directly scavenge hypochlorous acid and the active site in this scavenging reaction is not the hydroxyl group at C-3.

• Journal of the Korean Wood Science and Technology
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• 제37권5호
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• pp.474-479
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• 2009

Pinus koraiensis inner bark was collected and extracted with 95% ethanol. The extracts were concentrated and then sequentially fractionated using n-hexane, $CH_2Cl_2$, EtOAc, and $H_2O$ to be freeze dried. A portion of EtOAc fraction (6.6 g) was chromatographed on a Sephadex LH-20 column using aqueous methanol to isolate (+)-catechin (1), (-)-epicatechin (2), and trans-pinostilbenoside (3). Resveratrol (4) and trans-pinostilbene (5) were isolated by column chromatography using EtOH-hexane mixture after purification with aqueous methanol. The structures of these stilbenosides and flavans were characterized by spectroscopic tools using NMR and MS.

• 임산에너지
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• 제21권1호
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• pp.56-64
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• 2002

측백나무 잎을 채취하여 건조시킨 후 분말로 제조하여 아세톤-물(7:3, v/v)로 추출하고 hexane, CH₂C1₂, EtOAc, 그리고 수용성으로 분획하여 동결건조 시켰다. 그 중에서 EtOAc 분획을 Sephadex LH-20으로 충진한 칼럼에서 메탄올과 에탄올-헥산 혼합액을 용리용매로 사용하여 칼럼크로마토그래피를 실시하였다. 단리된 화합물들은 TLC로 확인한 후 NMR스펙트럼을 사용하여 정확한 구조규명을 하였고 FAB-MS로써 분자량을 측정하였다. 주로 quercetin-3-O-a-L-rhamnopyranoside와 myricetin-3-O-α-L-rhamnopyranoside 같은 flavononol 유도체들이 다량으로 포함되어 있었으며 비교적 적은 양의 (+)-catechin과 (+)-gallocatechin 같은 flavan 화합물들도 함께 단리 되었다. 각 분획물들과 단리된 화합물들은 DPPH 라디칼 소거법을 이용하여 항산화실험을 실시하였으며, 모두 우수한 항산화 효능이 있는 것으로 나타났다.