• Korean journal of food and cookery science
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• v.23 no.1 s.97
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• pp.19-24
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• 2007

This study investigated the antioxidant and synergistic effects and nitrite scavenging ability of some phenolic compounds(catechin, rutin, quercetin and naringin), The electron donating abilities of naringin, quercetin, rutin and catechin were 6.7%, 92.8%, 87.6% and 92.21%, respectively, The antioxidant activities in O/W emulsion substrates were in order of rutin > quercetin > catechin > naringin. The antioxidant effect of rutin was stranger than that of BHT or ${\alpha}$-tocopherol. ${\alpha}$-tocopherol showed synergistic effect with catechin and quercetin, but ascorbic acid not showed effect. The nitrite scavenging abilities of catechin, quercetin, rutin and naringin were 99.9%, 98.6%, 25.5% and 0.2%, respectively. The nitrite scavenging abilities of quercetin and actechin were very potent as compared with those of BHT and ascorbic acid.

• Natural Product Sciences
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• v.8 no.2
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• pp.62-65
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• 2002

Two lupane-type triterpenes, lupenone (1) and lupeol (2), a phytosterol, ${\beta}-sitosterol$ (3), two ursane-type triterpenes, $3{\beta}-acetoxy$ ursolic acid (4) and ursolic acid (5), a lignan, (-)-lyoniresinol $3a-O-{\beta}-D-xylopyranoside$ (6), and two flavanol glycosides, $catechin-7-O-{\beta}-D-xylopyranoside$ (7) and $catechin-7-O-{\beta}-D-apiofuranoside$ (8) were isolated from the stem bark of Sorbus commixta (Rosaceae). Their chemical structures were identified by physicochemical and spectroscopic methods.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.429-434
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• 2006

The dried needles (1.5 kg) of Picea abies Karsten were ground, extracted with acetone-$H_2O$ (7:3, v/v), concentrated, and fractionated with a series of n-hexane, methylene chloride, ethyl acetate and water on a separatory funnel. Each fraction was freeze dried, then a portion of ethyl acetate soluble powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-n-hexane mixture as eluents. The isolated compounds were identified by cellulose TLC, $^1H$-, $^{13}C$-NMR, FAB and EI-MS. (+)-catechin (compound I), (-)-epicatechin (compound II), kaempferol-3-O-${\beta}$-D-glucopyranoside (compound III), 4-hydroxyacetophenone (compound IV) were isolated from the ethyl acetate soluble fraction and (+)-catechin (compound I), protocatechuic acid (compound V) were isolated from the $H_2O$ soluble fraction of P. abies needle. The antioxidative activities of each fraction and the isolated compounds were tested by DPPH radical scavenging method, and EtOAc soluble fraction, (+)-catechin and (-)-epicatechin showed similar values to ${\alpha}$-tocopherol and BHT as controls.

• Korean Journal of Pharmacognosy
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• v.31 no.3
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• pp.357-363
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• 2000

The root of Actinidia arguta was extracted with methanol and the methanol extract was suspended in $H_2O$ and successively partitioned with n-hexane, $CH_2Cl_2$, EtOAc and n-BuOH. Repeated column chromatographic separation of the EtOAc extract resulted in the isolation of two flavonoids (compounds 2 and 3) and two triterpenes (compounds 1 and 4) and $CH_2Cl_2$, extract to afford three lignans (compounds 5-7). Their structures have been established by spectroscopic, means to be (+)-tormentoside(1), (-)-catechin(2), (-)-epicatechin(3), (+)-uscaphic $acid-28-O-[\beta}-D-glucopyranoside$(4), (+)-pinoresinol(5), (+)-medioresinol(6), and (-)-syringaresinol(7).

• Applied Biological Chemistry
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• v.41 no.1
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• pp.110-117
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• 1998

Seven kinds of polyphenol compounds having ACE activities were isolated and purified by Sephadex LH-20, MCI-gel CHP-20, ${\um}-Bondapak\;C_{18}$ and Fuji-gel ODS $G_3$ sucessively from cacao bean(Ghana). The chemical structures of each compound were determined and identified using analyzers such as $^1H-NMR$, $^{13}C-NMR$, IR, MS, polarimeter and Elemental Analysis. Inhibition effects of isolated polyphenols on angiotensin converting enzyme (concerned with hypertension) were also observed. The results obtained were as follows,; The compounds isolated and identified were confirmed and determined as compound 1 [(+)-catechin], compound 2 [(-)-epicatechin], compound 3 [procyanidin B-1 : (-)-epicatechin-$(4{\beta}{\rightarrow}8)$-(+)catechin], compound 4 [procyanidin B-2 : (-)-epicatechin-$(4{\beta}{\rightarrow}8)$-(-)-epicatechin], compound 5 [procyanidin B-7 : (-)-epicatechin-$(4{\beta}{\rightarrow}6)$-(+)-catechin], campound 6 (procyanidin B-2,3,3'-O -digallate), compound 7 [cinnamtannin A-2 : (-)-epicatechin-$(4{\beta}{\rightarrow}8)$-(-)-epicatechin-$(4{\beta}{\rightarrow}8)$-(-)-epicatechin-$(4{\beta}{\rightarrow}8)$-(-)-epicatechin]. In the inhibition effect on ACE, procyanidin B-2,3,3'-O-digallate (compound 6) showed a higher value of 94.6% for ACE in $100\;{\um}M$ than other compounds such as (+)-catechin (compound 1), (-)-epicatechin (compound 2), procyanidin B-1 (compound 3), procyanidin B-2 (compound 4), procyanidin B-7 (compound 5) and cinnamtannin A-2 (compound 7) showing 67.9%, 61.9%, 88.6%, 82.5%, 72.2% and 82.3% for ACE, respectively. Inhibition of $4{\beta}{\rightarrow}8$ in coupling bond on the ACE enzyme was more effective than that of $4{\beta}{\rightarrow}6$. Procyanidin containing gallate inhibited more effectively than those containing not any. It was also observed that a lot of hydroxy group in the compounds increased the inhibitory effect.

• Natural Product Sciences
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• v.7 no.1
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• pp.1-4
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• 2001

The antioxidant activity of Pinus densiflora was determined by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The methanol extract of P. densiflora showed strong antioxidant activity, and thus fractionated with several solvents. The antioxidant activity potential of the individual fraction was in the order of ethyl acetate>n-butanol>water>dichloromethane> n-hexane fraction. The ethyl acetate soluble fraction exhibiting strong antioxidant activity was further purified by repeated silica gel column chromatography. Antioxidant (+)-catechin was isolated as one of the active principles from the ethyl acetate fraction, together with the inactive components, dihydrokaempferol and 1-O-benzoylglucose. The radical scavenging effect of (+)-catechin on DPPH radical exceeded to that of L-ascorbic acid which is a well known antioxidant.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2004.11a
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• pp.118-118
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• 2004

• Journal of the Korean Society of Food Culture
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• v.18 no.5
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• pp.443-456
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• 2003

The lyophilization of the solution extracted from 60 percent of acetone applied to persimmon leaves, the compounding process in accordance with the solution's concentration, and the gel filteration through Sephadex G-50 of biologically activated substances obstructing enzyme activity, such as tyrosinase, xanthine oxidase, and angiotesin converting enzyme (ACE) led to the assumption that polyphenol was the compound serving as biologically activated substances obstructing enzyme activity. Xanthine oxidase involved in pruine metabolism oxidizes hypoxanthine to xanthine and xanthine to uric acid. In the continuous study for natural compound, nine flavan-3-ols have been isolated from the persimmon leaves. The structures of (+)-catechin, (+)-gallocatechin, procyanidin B-1, pyrocyanidin C-1, prodelphinidin B-3, gallocatechin-$(4{\alpha}{\rightarrow}8)$-catechin, procyanidin B-7-3-O-gallate, procyanidin C-1-3'-3'-3'-O-trigallate and (-)-epigallocatechin-$(4{\alpha}{\rightarrow}8)$-epigallocatechin-$(4{\alpha}{\rightarrow}8)$-catechin were established by NMR and their inhibitory effect on xanthine oxidase activity was investigated. Procyanidin B-7-3-O-gallate, (-)-epigallocatechin-$(4{\alpha}{\rightarrow}8)$-epigallocatechin-$(4{\alpha}{\rightarrow}8)$-catechin and procyanidin C-1-3'-3'-3'-O-trigallate showed 94%, 90.69%, 80.90% inhibition at $100\;({\mu})M$ and inhibited on the angiotensin converting enzyme respectively. Procyanidin B-7-3-O-gallate and procyanidin C-1-3'-3'-3'-O-trigallate showed 66%, 63% inhibition at $100\;({\mu})M$ and inhibited on the xanthine oxidase competitively. Procyanidin C-1-3'-3'-3'-O-trigallate showed 70% inhibition at $100\;({\mu})M$ and inhibited on the tyrosinase competitively.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.191.3-192
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• 2003

Alnus japonica (Betulaceae) has been traditionally used for purifying blood, and curing feces containing blood, enteritis, diarrhea, alcoholism and cut wounds. In the current work, activity guided isolation of the butanol fraction of the Alnus japonica bark led to the isolation of catechin-7-O-${\beta}$-D-apiofuranoside. Anti-inflammatory activity was determined with carrageenan-induced paw edema in mice as an acute inflammation, complete Freund's adjuvant-induced arthritis as a chronic inflammation. Carrageenan- induced paw edema in mice was significantly inhibited at 0.5, 1, 2, and 3 hr after carrageenan injection by administration of the flavonoid glycoside at the dose of 150mg/kg. (omitted)

• Natural Product Sciences
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• v.21 no.2
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• pp.76-81
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• 2015

Diospyros burmanica Kurz. is an evergreen deciduous tree distributed in Mandalay of Myanmar, which belongs to the family of Ebenaceae. In Myanmar, it has been used to treat diarrhea, diabetes, diabetes and also as lumbers. In this study, seven flavonoids (1 - 7), a phenolic compound (8), and five triterpenes (9 - 13) were isolated from the barks of D. burmanica and their chemical structures were elucidated. Isolates were identified to be (+)-catechin (1), (+)-catechin 3-O-$\alpha$-L-rhamnopyranoside (2), (+)-catechin 3-O-gallate (3), (-)-epicatechin (4), (-)-epicatechin 3-O-gallate (5), (+)-afzelechin 3-O-$\alpha$-L-rhamnopyranoside (6), (+)-2,3-trans-dihydrokaempferol 3-O-$\alpha$-L-rhamnopyranoside (7), methyl gallate (8), lupeol (9), methyl lup-20(29)-en-3-on-28-oate (10), $\beta$-amyrin (11), $\alpha$-amyrin (12), $3\beta$-hydroxy-D:B-friedo-olean-5-ene (13) through MS, ¹H NMR and ¹³C NMR spectroscopic evidences.