• Korean Journal of Pharmacognosy
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• v.29 no.2
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• pp.142-145
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• 1998

Two phenylpropanoids and one flavan 3-ol were isolated from Lepisorus thunbergianus (Polypodiaceae, fern), which is used as folkmedicine. Phenylpropanoids were identified as caffeic acid and chlorogenic acid, and flavan 3-ol was elucidated as (-)-epicatechin 7-O-${\beta}$-D-glucoside by physico-chemical and spectral evidences (HMQC, NOESY).

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1084-1088
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• 1996

As a series of study for an anti-gout agent, two flavan-3-ols have been isolated from Oolong tea. They showed positive reaction in $anisaldehyde-H_2SO_4$ solution and $FeCl_3$, which were able to be confirmed in TLC with dimeric flavan-3-ols. The components were identified as procyanidin B-2 and procyanidin B-2-O-3, 3'-di-gallate by spectroscopic analysis. Their inhibitory effect on xanthine oxidase was also investigated and procyanidin B-2-O-3, 3'-digallate showed 60.6% inhibition at $50\;{\mu}mole$. The compound competitively inhibited the xantine oxidase and dimeric flavan-3-ols contanining gallate had higher inhibition activity.

• Journal of the Korean Wood Science and Technology
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• v.48 no.6
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• pp.888-895
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• 2020

Ulmus genus has excellent various physiological activities, including anti-ulcer, antioxidant, antibacterial, anti-cancer, immunity, and homeostasis maintenance effects, and it is known to have many additional drug effects And one of reasons for these excellentbiological activities is a flavan-3-ol chemical group in Ulmus genus. In this study a new flavan-3-ol compound was identified in Ulmus davidiana var. japonica. A flavan-3-ol,(2R,3S)-7-[(2S,3R,4R)-3,4-dihydroxy-4-(hydroxymethyl)oxolan-2-yl]oxy-2-(3,4-dihydroxyphenyl)-3,4-dihydro-2H-chromene-3,5-diol, named as catechin 7-O-beta-D apiofuranoside, was isolated from the stems and barks of Ulmus davidiana var. japonica for. suberosa, which is a species belonging to the genus Ulmus, growing throughout the Korea peninsula. The structure was elucidated by various spectroscopic methods including high-resolution TOF mass spectrometry, ¹H-NMR and ¹³C-NMR spectrometry and comparison with chemical structures of defined compounds.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.558-562
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• 1992

Xanthine oxidase involved in pruine metabolism oxidizes hypoxanthine to xanthine and xanthine to uric acid. The derangement of pruine metabolism results in gout that associates painful deposit of monosodium urate in the cartilage of joints. In the continuous study for natural compound, six flavan-3-ols have been isolated from the leaves of Oolong tea. The structures of procyanidin B-1, B-3, procyanidin B-3-3-O-rhamnose, procyanidin B-1-3-O-gallate, (-)-epicatechin, (-)-epicatechin-3-O-gallate were established by NMR and their inhibitory effect on xanthine oxidase activity was investigated. Flavan-3-ols containing the gallate had a high inhibitory capacity. Procyanidin B-1-3-O-gallate showed complete inhibition at $50\;{\mu}M$ and inhibited on the xanthine oxidase competitively.

• KSBB Journal
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• v.8 no.1
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• pp.69-74
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• 1993

For an anti-plaque agent, two flavan-3-ols isolated from Theobroma cacao bean husk showed positive reactions with $H_2SO_4$-anisaldehyde solution, $FeCl_3$, and were identified as monomeric, dimeric flavan-3-ots in TLC. They were (-)-epicatechin and procyanidin B-2(epicatechin-(4$\beta$$\rightarrow$8)-epicatechin). The structures were established by spectroscopic and chemical methods. (-)-Epicatechin had moderate inhibitory activity on GTase at concentration of 1.0mM while procyanidin B-2 showed complete inhibition activity at the same concentration. The hydroxyl group of flavan-3-ol was supposed to be the essential element for inhibition on GTase.

• Applied Biological Chemistry
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• v.41 no.4
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• pp.265-269
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• 1998

Several flavonoid dimers were isolated and elucidated from the bark of Korean pine tree (Pinus densiflora). One of them was postulated to be a compound, epicatechin $(4{\rightarrow}7)$ 5,8,3',4'-tetrahydroxy-(2R,3R)-flavan-3-ol, whose structural determination was carried out by diverse NMR techniques.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1304-1308
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• 1997

In the course of studies for anti-plaque agents, novel procyanidin structure isolated from Artocarpus heterophyllus folium was established by thiolysis and spectroscopic analysis. The chemical structure was identified for $(-)-epiafzelecin-(4{\beta}{\rightarrow}8)-afzelecin-(4{\alpha}-8)-catechin$ containing the trimeric flavan-3-ols and molecular weight was 833[M-H] by FAB-MS negative ion method. The inhibitory effect on the glucosyltransferase activity was investigated, novel compound showed complete inhibition at 1.0 mM and inhibited on the glucosyltransferase noncompetitively.

• Journal of Korea Foresty Energy
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• v.21 no.1
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• pp.56-64
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• 2002

2kg of the dried leaves of Thuja orientalis Linnaeus were ground, extracted with acetone-$H_2O$(7:3, v/v), concentrated, and fractionated with a series of hexane, $CH_2C1_2$ EtOAc and water on a separators funnel. Each fraction was freeze dried to give dark-brown powder and a EtOAc soluble portion. of the powder was chromatographed on a Sephadex LH-20 column using a series of aqueous methanol and ethanol-hexane mixture as eluents. Spectrometric analyses such as NMR and FAB-MS including TLC were performed to characterize the structures of isolated compounds. The leave of Thuja orientalis Linnaeus contained a large amount of flavononol derivatives such as quercetin-3-O-$\alpha$-L-rhamnopyranoside and myricetin-3-O-$\alpha$-L-rhamnopyranoside in addition to a small amount of flavan compounds such as (+)-catechin and (+)-gallocatechin. The antioxidative activities of each fractions and isolated compounds were done by DPPH radical scavenging test, and all of them were indicated strong antioxidative activities.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.1001-1012
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• 2009

A total of 49 phenolic compounds were identified from the aged red wines made from Cabernet Gernischt (Vitis vinifera L. cv.) grapes, a Chinese characteristic variety, including 13 anthocyanins, 4 pryanocyanins, 4 flavan-3-ol monomers, 6 flavan-3-ol polymers, 7 flavonols, 6 hydroxybenzoic acids, 5 hydroxycinnamic acids, 3 stilbenes, and 1 polymeric pigment. Evolution of these compounds was investigated in wines aged 1 to 13 months. Variance analysis showed that the levels of most phenolics existed significant difference in between wines aged 3 and 9 months. Cluster analysis indicated that 2 groups could be distinguished, one corresponding to wines aged 1 to 3 months and the other to wines aged 4 to 13 months. It was thus suggested that there were 2 key-stages for the development of fine wine quality, at the aged 3 and 9 months, respectively. This work would provide some helpful information for quality control in wine production.

• Natural Product Sciences
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• v.16 no.1
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• pp.10-14
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• 2010

Phytochemical examination of the barks of Pinus densiflora Siebold et Zuccarini has led to the isolation of one phenylpropanoid, one lignan, one flavonoid, one flavan 3-ol and two procyanidins : 4-O-$\beta$-D-glucopyranosyl-p-coumaric acid (1), 2,3-dihydro-2-(4-methoxy)-7-hydroxy-3-hydroxymethyl-5-(3-hydroxy propyl)-benzofuran 3-O-$\alpha$-D-glucopyranoside (2), taxifolin 3'-O-$\beta$-D-glucopyranoside (3), (+)-catechin (4), procyanidin B1 (5) and epicatechin-($4{\beta}$-8)-catechin-($4{\alpha}$-8)-catechin (6). Among them, Compound 4, 5 and 6 showed potent anti-oxidative activities and these anti-oxidative activities were significantly different compared with ascorbic acid as positive control.