• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.67-72
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• 2003

The leaves of D. racemosum showed strong DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and the order of the radical scavenging activity against DPPH radical is ethyl acetate (EtOAc) fraction>crude extracts>residue fraction>hexane fraction>ether fraction, under the experimental conditions. Since EtOAc fraction has highest antioxidative activity among these fractions, the isolation was performed from the EtOAc fraction of the leaves of D. racemosum and four phenolic compounds were isolated and identified as follows: methyl gallate, kaempferol, quercetin and quercitrin. The free radical scavenging activities of these compounds were 79.9%, 93.1%, 93.6% and 66.7% at 10 ㎍/ml, respectively. The IC₅₀ of compound 1, compound 2, compound 3 and compound 4 were 6.1, 4.1, 3.6 and 6.5 ㎍/ml, respectively. These compounds have higher antioxidative activity compared with reference compounds, ascorbic acid (IC₅₀ = 9.6 ㎍/ml).

• 한국약용작물학회지
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• 제14권2호
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• pp.77-81
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• 2006

As a result of cytotoxic compounds against cancer cell lines from natural sources, senven compounds were isolated from the leaf and twig of Acer okamotoanum Nakai. The compounds (1-7) were identified as ethyl gallate (1), methyl gallate (2), gallic acid (3), trans $resveratrol-3-O-{\beta}-D-glucopyranoside$ (4), acertannin (5), nikoenoside (6), and fraxin (7) by physicochemical and spectroscopic data (including mp, UV, IR, MS, $^1H-NMR,\;^{13}C-NMR$, DEPT, and HMBC) in comparison with those of published papers. All the compounds were tested for their cytotoxic activity against L1210, HL-60, K562, and B16F10 cancer cell lines in vitro by MTT assay method. Compounds 1-3 and 5 showed cytotoxic activity against all tested cell lines with $IC_{50}$ values ranged from 12.5 to $72.2\;{\mu}M$. Of the compounds, methyl gallate (2) exhibited the most potent cytotoxic activity against L1210, HL-60, K562, and B16F10 tumor cells with $IC_{50}$ values of 12.5, 48.3, 22.8, and $22.8\;{\mu}M$, respectively. Other compounds did not show any cytotoxic activity against four cancer cell lines.

• Natural Product Sciences
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• 제22권1호
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• pp.64-69
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• 2016

A method for simultaneously identifying antioxidative compounds was developed using time-based LC-MS coupled with DPPH assay regardless of the time consuming process. The methanolic extract of Polygonum aviculare (Polygonaceae) showed significant DPPH radical scavenging activity. Time-based DPPH assay for simultaneous identification of active compounds from the extracts of P. aviculare was used. Major peaks of ethyl acetate fraction of P. aviculare showed high DPPH radical scavenging activity. A simple phenolic compound (1) and six flavonoids (2-7) were isolated from the ethyl acetate fraction of P. aviculare by silica gel and sephadex LH-20 column chromatography. The structures of seven compounds were determined to be protocatechuic acid (1), catechin (2), myricitrin (3), epicatechin-3-O-gallate (4), avicularin (5), quercitrin (6), and juglanin (7) based on the analysis of the $^1H$-NMR, $^{13}C$-NMR and ESI-MS data. All compounds exhibited significant antioxidant activity on DPPH assay and active compounds were well correlated with predicted one.

• 한국식품과학회지
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• 제43권5호
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• pp.558-563
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• 2011

복분자 와인은 복분자 열매를 발효 숙성시켜 제조한 것으로, 소비자에게 널리 음용되고 있으나 그 원재료인 복분자 열매에 대한 연구에 비해 복분자 와인에 존재하는 성분들에 대한 체계적인 연구는 거의 전무한 실정이다. 최근 우리는 복분자주에 함유되어 있는 화합물들의 분자 수준에서의 연구를 통하여 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 4-(2-hydroxyethyl)-phenol, pyrocatechol, ethyl gallate 등의 5종의 저분자 페놀성 화합물을 단리 구조해석하여 보고한 바 있다. 그 연속된 연구로써 본 논문에서는 복분자주에 존재하는 성분들에 대한 추가적인 분리 및 구조해석을 행하였다. 제조된 복분자 와인(11 L, 복분자 열매 15.7 kg)을 용매분획하여 얻어진 EtOAc층(56.2 g)의 일부(20 g)를 silica gel column chromatography와 ODS-HPLC로 정제하여 5종의 화합물을 단리하였다. 이 화합물들을 대상으로 MS 및 NMR 등의 기기분석을 행한 결과, ethyl succinate(1, 13.1 mg), vanillic acid(2, 2.6 mg), ethyl 3,4-dihydroxybenzoate(3, 13. 1 mg), furan-2-ol(4, 1.3 mg), 그리고 4-(4-hydroxyphenyl) butan-2(S)-ol(5, 1.1 mg)로 동정하였다. 이 화합물들 대부분은 발효식품에서 향기성분으로 동정된 바 있으며, 화합물 2는 복분자 열매에 존재함이 이미 보고되어 있으나, 화합물 1과 3-5는 복분자 열매 및 복분자와인으로부터 처음으로 동정되었다.

• Restorative Dentistry and Endodontics
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• 제42권3호
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• pp.188-199
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• 2017

Objectives: This in vitro study evaluated the effect of dentin biomodifiers on the immediate and long-term bond strengths of a simplified etch and rinse adhesive to dentin. Materials and Methods: Flat coronal dentin surfaces were prepared in 120 extracted human molars. Teeth were randomly divided into 5 groups (n = 24) according to 5 different surface pre-treatments: No pre-treatment (control); 1M carbodiimide (EDC); 0.1% epigallocatechin-3-gallate (EGCG); 2% minocycline (MI); 10% sodium ascorbate (SA). After surface pre-treatment, adhesive (Adper Single Bond 2 [SB], 3M ESPE) was applied. Composite was applied into transparent plastic tubes (2.5 mm in diameter), which was placed over the bonded dentin surface. From each group, 10 samples were subjected to shear bond strength (SBS) evaluation at 24 hours (immediate) and remaining 10 samples were tested after 6 months (delayed). Additionally, 4 samples per group were subjected to scanning electron microscopic analysis for observation of resin-dentin interface. The data were statistically analysed with Shaperio-Wilk W test, 2-way analysis of variance (ANOVA), and post hoc Tukey's test. Results: At 24 hours, SBS of all surface pre-treatment groups were comparable with the control group, with significant differences found between EDC and SA groups only (p = 0.009). After 6 months storage, EDC, EGCG, and MI pre-treatments preserved the resindentin bond strength with no significant fall. Conclusions: Dentin pre-treatment with all the dentin biomodifiers except SA resulted in significant preservation of resin-dentin bond over 6 months storage period, without negatively affecting the immediate bond strength of the etch and rinse adhesive tested.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.272-281
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• 2023

작약 뿌리는 monoterpene glycoside계 물질을 함유하고 있으며, 이들 화합물은 항경련, 항염증, 항바이러스, 신경보호 및 진정효과를 나타내는 것으로 알려져 있다. 이번 연구에서는 작약 뿌리의 dichloromethane (CH₂Cl₂) 및 ethyl acetate (EtOAc) 가용성 분획으로부터 세포독성 물질을 탐색하고자 하였다. 그 결과, 총 13종의 화합물을 분리할 수 있었으며, 이들의 세포독성 평가를 위해 사람 유래 폐암 선암 세포주인 A549에 처리하여 세포생존율 변화를 관찰하였다. A549에 대한 세포독성은 gallic acid (8) > (2S)-naringenin (9) > methyl gallate (10) > 6'-Obenzoylpaeoniflorin (7) > palmitic acid (3) 순으로 나타났다. 특히, 7은 normal cell인 MRC-5에 대한 독성은 없는 것으로 확인되었으며, 7의 A549 및 MRC-5 세포생존율에 미치는 영향에 대한 보고는 이번이 처음이다. 향후 7에 대한 세포독성 메커니즘 및 선택성과 관련된 추가연구가 필요할 것으로 판단된다.

• Natural Product Sciences
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• 제17권4호
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• pp.279-284
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• 2011

Phytochemical studies on the whole extract of Sedum hybridum L., a Mongolian medicinal plant, has been undertaken to isolate active principles responsible for its anti-oxidative and antibacterial activities. Eighteen known compounds, i.e. (1) quercetin, (2) kaempferol, (3) herbacetin-8-O-${\beta}$-D-xylopyranoside, (4) myricetin, (5) gossypetin-8-O-${\beta}$-D-xylopyranoside, (6) gallic acid, (7) 2,4,6-tri-O-galloyl-D-glucopyranose, (8) 6-O-galloylarbutin, (9) myricetin-3-O-${\alpha}$-L-arabinofuranoside, (10) quercetin-3-O-${\alpha}$-L-arabinofuranoside, (11) caffeic acid, (12) ethylgallate, (13) (-) epigallocatechin-3-O-gallate, (14) palmitic acid, (15) stearic acid, (16) stearic acid ethyl ether, (17) ${\beta}$-sitosterol and (18) ${\beta}$-sitosteryl-O-${\beta}$-D-glucopyranose have been isolated and their molecular structures identified by spectroscopic analysis. Thirteen substances including seven flavonol components (1, 2, 3, 4, 5, 9 and 10), five gallic acid derivatives (6, 7, 8, 12 and 13) and caffeic acid (11) exhibited significant, dose-dependent, DPPH radical scavenging activity. Galloyl esters 12 and 13 were revealed to be main active principles for the antibacterial property of the extract of Sedum hybridum L.

• 한국식품과학회지
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• 제40권2호
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• pp.129-134
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• 2008

복분자 와인은 복분자 열매를 발효ㆍ숙성시켜 제조하기 때문에 그들 양자 간의 성분에는 차이가 있을 것으로 추측되었다. 그러나 복분자 와인의 음용률이 높음에도 불구하고 복분자 와인 중에 함유된 성분들에 관한 체계적인 연구는 거의 전무한 실정이다. 그래서 먼저 복분자 와인 중에 함유되어 있는 성분들의 chemical profile의 검토를 위해 항산화 활성에 초점을 맞추어 화합물의 단리ㆍ구조해석에 착수하였다. 복분자 와인 11 L(신선 복분자 열매 15.7 kg 상당량)의 농축액(928.3 g)을 용매분획한 후 얻어진 EtOAc층(20 g/56.2 g)을 대상으로 각종 column chromatography 및 HPLC를 행하여 5종의 항산화 활성 화합물을 단리하였다. 그들을 대상으로 $^1H$-NMR 분석 및 TMS 유도체화 후 GCMS 분석을 행한 결과, 4-hydroxybenzoic acid(1, 0.1 mg), 3,4-dihydroxybenzoic acid(2, 0.3 mg), 4-(2-hydroxyethyl)-phenol(3, 0.6 mg), pyrocatechol(4, 0.3 mg), 3,4,5-trihydroxybenzoic acid ethyl ester(5, 0.6 mg)로 동정하였다. 화합물 1과 2는 복분자 열매중에 존재함이 보고되어 있으나 화합물 3-5는 복분자 열매로부터 그 존재가 보고되어진 바 없으며, 이들 5종의 화합물 모두가 복분자 와인으로부터 동정되어진 것 또한 처음이다.

• 한국식품과학회지
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• 제45권6호
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• pp.777-784
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• 2013

본 연구는 항산화 활성이 뛰어난 작두콩의 메탄올 추출물을 대상으로 극성차를 이용한 용매분획을 행하여 n-hexane층, $CHCl_3$층, EtOAc층, butanol층, 그리고 $H_2O$층을 얻었다. 그중 활성이 가장 높은 EtOAc층을 대상으로 silica gel column chromatography 및 HPLC를 행하여 4종의 활성 화합물을 분리하고, MS 및 NMR분석을 통하여 구조해석을 행하였다. 그 결과 화합물 1-4는 methyl 3,4,5-trihydroxybenzoate (methyl gallate, 화합물 1), 3,4,5-trihydroxybenzoic acid (gallic acid, 화합물 2), 1,6-di-O-galloyl ${\beta}$-$\small{D}$-glucopyranoside (화합물 3), 그리고 1,4,6-tri-O-galloyl ${\beta}$-$\small{D}$-glucopyranoside (화합물 4)로 각각 동정되었다. 그리고 분리 화합물들의 DPPH radical-scavenging 활성은 화합물 4>화합물 3>화합물 2>화합물 1 순으로 평가되었다. 또 분리된 양을 기준으로 하였을 때, 화합물 1과 2는 작두콩 중에 다른 화합물들에 비해 다량으로 존재해있을 것으로 시사되었으며, 이들 화합물이 작두콩의 항산화 활성에 상당부분 기여하고 있는 것으로 판단되었다. 또한 화합물 4는 본 연구를 통해 작두콩으로부터는 처음 분리 동정되었다.

• Preventive Nutrition and Food Science
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• 제2권4호
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• pp.285-290
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• 1997

Previously, a 50% aqueous methanol extract of Galla rhois was shown to be the most potent tyrosinase inhibition activity with an {TEX}$IC_{50}${/TEX}(the concentration causing 50% inhibition of tyrosinase activity) of 0.2mg/ml of 205 crude drug extracts. To isolate tyrosinase inhibitors, the methanol extract was evaporated to a small volume in vacuo, and then partitioned stepwise with benzene and ethyl acetate(EtOAc). the EtOAc fraction was solubilized in 10% MeOH solution, and then fractionated successively by Diaion HP-20 and Sephadex LH-20 column chromatography, and preparative HPLC. Three phenolic compounds were isolated, and characterized as gallic acid(GA), methyl gallate(MG) and 1,2,3,4,6-penta-O-galloyl-$\beta$-D-glucose(PGG) by UV, IR, {TEX}${1}^H${/TEX}-&{TEX}${13}^C${/TEX}-NMR, and FAB-MS spectroscopy, PGG({TEX}$IC_{50}${/TEX}=50$\mu\textrm{g}$/ml) showed a considerable inhibitory effect against mushroom tyrosinase, while GA({TEX}$IC_{50}${/TEX}=1.6mg/ml) and MG({TEX}$IC_{50}${/TEX}=234$\mu\textrm{g}$/ml) did not show an appreciable effect. Meanwhile, MG inhibited greatly melanogenesis in a murine melanocyte cell line, Mel-Ab. MG and PGG showed typical noncompetitive inhibition patterns against mushroom tyrosinase. These results suggest that PGG and MG may be potentially useful as either anti-browning or anti-melanogenic agents in foods and cosmetics.