• Journal of the Korean Wood Science and Technology
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• v.28 no.2
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• pp.42-48
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• 2000

Two stilbenoids and two flavonoids were isolated from ethylacetate fraction of ethanol extract of Morns bombycis heartwood. These four compounds were identified 2',3,4',5-tetrahydroxystilbene(oxyresveratrol), 3,4',5-trihydroxystilbene (resveratrol) as stilbenoids, and 2',3,4',5,7-pentahydroxyflavone(morin), 3,4',5,7-tetrahydroxyflavan((+)-afzelechin) as flavonoids by Mass and NMR spectroscopic analysis.

• Biomolecules & Therapeutics
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• v.32 no.1
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• pp.162-169
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• 2024

Particulate matter (PM) constitutes a hazardous blend of organic and inorganic particles that poses health risks. Inhalation of fine airborne PM with a diameter of ≤ 2.5 ㎛ (PM_2.5) can lead to significant lung impairments. (+)-afzelechin (AZC), a natural compound sourced from Bergenia ligulata, boasts a range of attributes, including antioxidant, antimicrobial, anticancer, and cardiovascular effects. However, knowledge about the therapeutic potential of AZC for patients with PM_2.5-induced lung injuries remains limited. Thus, in this study, we investigated the protective attributes of AZC against lung damage caused by PM_2.5 exposure. AZC was administered to the mice 30 min after intratracheal instillation of PM_2.5. Various parameters, such as changes in lung tissue wet/dry (W/D) weight ratio, total protein/total cell ratio, lymphocyte counts, levels of inflammatory cytokines in bronchoalveolar lavage fluid (BALF), vascular permeability, and histology, were evaluated in mice exposed to PM_2.5. Data demonstrated that AZC mitigated lung damage, reduced W/D weight ratio, and curbed hyperpermeability induced by PM_2.5 exposure. Furthermore, AZC effectively lowered plasma levels of inflammatory cytokines produced by PM_2.5 exposure. It reduced the total protein concentration in BALF and successfully alleviated PM_2.5-induced lymphocytosis. Additionally, AZC substantially diminished the expression levels of Toll-like receptors 4 (TLR4), MyD88, and autophagy-related proteins LC3 II and Beclin 1. In contrast, it elevated the protein phosphorylation of the mammalian target of rapamycin (mTOR). Consequently, the anti-inflammatory attribute of AZC positions it as a promising therapeutic agent for mitigating PM_2.5-induced lung injuries by modulating the TLR4-MyD88 and mTOR-autophagy pathways.

• Biomolecules & Therapeutics
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• v.32 no.4
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• pp.467-473
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• 2024

In this study, we investigated the potential protective effects of (+)-afzelechin (AZC), a natural compound that is derived from Bergenia ligulata, on lipopolysaccharide (LPS)-induced inflammatory responses. AZC is known to have antioxidant, anticancer, antimicrobial, and cardiovascular protective properties. However, knowledge regarding the therapeutic potential of AZC against LPS-induced inflammatory responses is limited. Thus, we investigated the protective attributes of AZC against inflammatory damage caused by LPS exposure. We examined the effects of AZC on heme oxygenase (HO)-1, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) in LPS-activated human umbilical vein endothelial cells (HUVECs). In addition, the effects of AZC on the expression of iNOS, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β were analyzed in the lung tissues of LPS-injected mice. Data revealed that AZC promoted the production of HO-1, inhibited the interaction between luciferase and nuclear factor (NF)-κB, and reduced the levels of COX-2/PGE2 and iNOS/NO, thereby leading to a decrease in the signal transducer and activator of transcription (STAT)-1 phosphorylation. Moreover, AZC facilitated the nuclear translocation of Nrf2, increased the binding activity between Nrf2 and the antioxidant response elements (AREs), and lowered the expression of IL-1β in the LPS-treated HUVECs. In the animal model, AZC significantly reduced the expression of iNOS in the lung tissue structure and the TNF-α level in the bronchoalveolar lavage fluid. These findings demonstrate that AZC possesses anti-inflammatory properties that regulate iNOS through the inhibition of both NF-κB expression and p-STAT-1. Consequently, AZC has potential as a future candidate for the development of new clinical substances for the treatment of pathological inflammation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.321-328
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• 2016

In this study, we investigated identification of anti-oxidative constituents from Ficus erecta var. sieboldii King (F. erecta) leaves. DPPH and $ABTS^+$ radical scavenging activities were screened for the ethanol extract and solvent fractions, and ethyl acetate fraction showed the most potent scavenging activities. Five constituents were isolated from the ethyl acetate fraction of F. erecta leaves; monoolein (1), oleic acid (2), lutein (3), afzelechin (4), catechin (5). The chemical structures of the isolated compounds were elucidated based on the spectroscopic data including NMR spectra, as well as comparison of the data to the literature values. As far as we know, all of the compounds 1 ~ 5 were isolated for the first time from this plant. Studies on DPPH and $ABTS^+$ radical scavenging activities were conducted for the isolated compounds. Among them, afzelechin (4) and catechin (5) showed strong DPPH and $ABTS^+$ radical scavenging activities, whose activities were comparable to a positive control vitamin C. Also, the content of catechin isolated from this plant was determined by HPLC and it was about 3.8 mg/g for the 70% ethanol extract and 20.8 mg/g for the ethyl acetate fraction. From these results, F. erecta leaves extract could be potentially applicable as anti-oxidant ingredients in cosmetic industries.

• Journal of Applied Biological Chemistry
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• v.58 no.2
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• pp.189-194
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• 2015

Ten compounds were isolated from the ethanolic extract of the leaves of Acacia catechu (Fabaceae), and their structures were identified as nine flavonoids [(+)-catechin (1), (-)-epicatechin (2), (+)-afzelechin (3), (-)-epiafzelechin (4), (+)-mesquitol (5), kaempferol (6), quercetin (7), quercetin 3-methyl ether (8), and caryatin (9)] and an ellagic acid (10). The chemical structures of these compounds were identified on the basis of spectroscopic methods (mass spectrometry, 1D and 2D nuclear magnetic resonance) and comparison with literature values. This is the first time that the isolation of caryatin (9) has been reported from Acacia genus.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.804-809
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• 2005

The EtOAc-soluble fraction from a methanolic extract of Hovenia dulcis Thunb. exhibited neuroprotective activity against glutamate-induced neurotoxicity in mouse hippocampal HT22 cells. The neuroprotective activity-guided isolation resulted in 8 phenolic compounds (1-8), such as vanillic acid (1), ferulic acid (2), 3,5-dihydroxystilbene (3), (+)-aromadendrin (4), methyl vanillate (5), (-)-catechin (6), 2,3,4-trihydrobenzoic acid (7), and (+)-afzelechin (8). Among these, compounds 6 and 8 had a neuroprotective effect on the glutamate-induced neurotoxicity in HT22 cells. Furthermore, compound 6 had a DPPH free radical scavenging effect with an $IC_{50}$ value of $57.7{\mu}M$, and a superoxide anion radical scavenging effect with an $IC_{50}$ value of $8.0{\mu}M$. Both compounds 6 and 8 had ABTS cation radical scavenging effects with $IC_{50}$ values of $7.8{\mu}M\;and\;23.7${\mu}M$, respectively. These results suggest that compounds 6 and 8 could be neuroprotectants owing to their free radical scavenging activities.

• 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.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1199-1203
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• 2003

Polyphenols were isolated from Korean green tea using Sephadex LH-20 and HPLC. The isolated polyphenols were procyanidin B-4, procyanidin B-2-3,3'-digallate, prodelphinidin C-2-3,3'-di-O-digallate, (+)-catechin-3-O-rhamnose, procyandin B-5, procyanidin B-7-3-0-gallate, gallate, epiafzelechin-$(4{\beta}{\rightarrow}8)$-epiafzelechin, procyanidin B-3-3-O-rhamnose, afzelechin-$(4{\alpha}{\rightarrow}8)$-catechin, prodelphinidin B-5-3,3'-di-O-digallate and (+)-taxifolin-3-O-D-xyloside. The inhibitory effects of prodelphinidin C-2-3,3'-di-O-gallate and procyanidin B-2-3,3'-digallate $(at\;100{\mu}M)$ on angiotensin.converting enzyme were 68.8 and 54.6%, respectively, while the inhibitory effects of prodelphinidin C-2-3,3'-di-O-gallated and procyanidin B-2-3,3'-digallate $(at\;100{\mu}m)$ on xanthine oxidase were 54.5 and 38.2%, respectively. Lastly, the inhibitory activities of prodelphinidin C-2-3,3'-di-O-gallate $(at\;100{\mu}m)$ on tyrosinase was 42.1%.

• 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.

• Journal of the Korean Wood Science and Technology
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• v.28 no.3
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• pp.70-77
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• 2000

Among four compounds such as oxyresveratrol, resveratrol, morin and afzelechin isolated from the heartwood of Morns bombycis, oxyresveratrol and resveratrol which belong to stilbenoid indicated high antioxidative and antimicrobial activity, respectively. Based on this result, this experiment was carried out to elucidate the relationship between biological activities of stilbenoids and their chemical structures using two isolated and six synthesized ones prepared by Wittig reaction. Antimicrobial activity of 3,5-dihydroxystilbene(pinosylvin) devoid of hydroxyl group of B-ring was the best among the tested stilbenoids. Antimicrobial activities of the stilbenoids showed negative dependency on the number of hydroxyl groups of B-ring, that is, the fewer number of hydroxyl groups of B-ring, the higher antimicrobial activity. On the other hand, antioxidative activities of the stilbenoids indicated a positive relationship with the number of hydroxyl groups of B-ring. In tetrahydroxystilbenoids, antioxidative activities of the compounds possessing ortho-diphenol structure, 2',3,3',5- and 3,3',4',5-tetrahydroxystilbene, were superior to the others. As a result, it was concluded that resveratrol and oxyresveratrol isolated from the heartwood of M. bombycis had antimicrobial and high antioxidative activities, and these activities of stilbenoids were also dependent on the number and position of hydroxyl groups of B-ring.