• Food Science and Biotechnology
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• v.16 no.6
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• pp.988-993
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• 2007

The protective effect of the water extract of Fraxinus rhynchophylla leaves (FLE) was determined using an animal model of acetaminophen (AAP)-induced nephrotoxicity. The BALB/c male mice used in this study were divided into 3 groups; the normal, AAP-administered, and FLE-pretreated AAP groups. A single dose of AAP induced necrosis of renal tubules and congestion along with edema to a remarkable degree as observed by hematoxylin and eosin stain, and also increased the numbers of terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL)-positive renal tubular epithelial cells. Blood urea nitrogen and plasma creatinine levels were determined to be significantly higher in the AAP group than in the normal group. However, FLE pretreatment resulted in an attenuation of renal tubule necrosis. Regeneration and dilatation of renal tubules were noted, and the numbers of TUNEL-positive cells were reduced in the FLE-pretreated groups. In an effort to detect the bioactive compounds exerting protective effects in FLE, the analysis of phenolic compounds via gas chromatography/mass spectrometry (GC/MS) were performed, and identified esculetin and esculin. The present study indicates that these compounds may exert a protective effect against AAP-induced nephrotoxicity.

• The Korean Journal of Ecology
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• v.21 no.1
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• pp.73-80
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• 1998

Peroxidase has been isolated to apparent homogeneity from earthworm, Lumbricus rubellus, using ammonium sulfate fractionation, Sephacryl S-2000 gel filtration, CM-cellulose cation exchange chromatography and native-PAGE elution. Some of its enzymatic characteristics were examined. The optimum pH for gruaiacol oxidation of earthworm peroxidase was determined to be 6.0, and the $K_{m}$ values against guaiacol and $H_2O_2$ were 1.25 mM and 3.4mM, respectively. When various compounds were tested as the possible substrates of the enzyme, o-dianisidine was used as the substrate. However, earthworm peroxidase could not oxidize esculetin and ferulic acid as substrates, suggesting the different characteristics of the enzyme from plant peroxidases. The optimum pH for veratryl alcohol and $H_2O_2$ oxidation was determined to be 2.5 when lignin peroxidation activity was examined. The $K_{m}$ values for veratryl alcohol and $H_2O_2$ were 0.02 mM and 0.13 mM, respectively. Furthermore, the earthworm peroxidase could oxidize phenoxyherbicides such as 2,4-D, 2,4-DP and MCPA as substrates. The optimum pHs for 2,4-D, 2,4-DP and MCPA were determined to be 4.0, 2.0 and 2.0, respectively. The most available substrate was 2,4-DP, followed by MCPA and 2,4-D when their peroxidation activities were compared.

• Journal of Applied Biological Chemistry
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• v.63 no.4
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• pp.335-338
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• 2020

Artemisia iwayomogi (Compositae), a perennial mugwort, is native to Korea and widely distributed in Japan, Russia, and China. A. iwayomogi and A. capillaris are similar in morphology and pharmacological activity and have been used for the same medicinal purposes in Korea. While various ingredients such as coumarins and flavonoids and their activity studies have been reported for A. capillaris, few studies have been conducted on the pharmacologically active components of A. iwayomogi. In Korea, A. capillaris is not economical because only young leaves are used as a medicinal material. Because of this, A. iwayomogi is frequently used in Korea, indicating the need to study its pharmacologically active components. Therefore, a phytochemical study was initiated to isolate active compounds from the aerial parts of A. iwayomogi. Finally, four coumarins, umbelliferone (1), esculetin (2), grevillone (3), and scoparone (4) were isolated for the first time from the aerial parts of A. iwayomogi in this study.

• Korean Journal of Pharmacognosy
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• v.54 no.2
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• pp.53-60
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• 2023

Athyrium acutipinnulum, called as Ulleungdo ladyfern (Seom-go-sa-ri), is a native plant of South Korea. A. acutipinnulum has been consumed as foods and also traditionally used for the treatment of epilepsy, gonorrhea and nerve disorder. The methanolic extract and EtOAc soluble fraction of A. acutipinnulum showed the antioxidant activity. Fractionation using various chromatographic techniques resulted in the isolation of 13 compounds. The structures were elucidated on the basis of spectroscopic methods as seven phenolic compounds, methyl 2-hydroxy-3-phenylpropanoate (1), protocatechualdehyde (2), caffeic acid (3), trans-p-coumaric acid (4), (-)-4-E-caffeoyl-L-threonic acid (5), 5-O-caffeoyl shikimic acid (6) and 5-O-caffeoyl quinic acid (7), three flavonoids, quercetin 3-O-β-glucoside (8), naringenin-7-O-β-glucoside (9) and sutchenoside A (10), two steroids, ponasterone A (11) and ecdysone (12) and a coumarin, esculetin (13). Among them, compounds 5 and 10 were first reported from Athyrium spp and compounds 2, 5, 6 and 7 showed the antioxidant activity.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8041-8046
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• 2014

In-depth analysis of how TRAIL signals through death receptors to induce apoptosis in cancer cells using high throughput technologies has added new layers of knowledge. However, the wealth of information has also highlighted the fact that TRAIL induced apoptosis may be impaired as evidenced by experimental findings obtained from TRAIL resistant cancer cell lines. Overwhelmingly, increasing understanding of TRAIL mediated apoptosis has helped in identifying synthetic and natural compounds which can restore TRAIL induced apoptosis via functionalization of either extrinsic or intrinsic pathways. Increasingly it is being realized that biologically active phytochemicals modulate TRAIL induced apoptosis, as evidenced by cell-based studies. In this review we have attempted to provide an overview of how different phytonutrients have shown efficacy in restoring apoptosis in TRAIL resistant cancer cells. We partition this review into how the TRAIL mediated signaling landscape has broadened over the years and how TRAIL induced signaling machinery crosstalks with autophagic protein networks. Subsequently, we provide a generalized view of considerable biological activity of coumarins against a wide range of cancer cell lines and how coumarins (psoralidin and esculetin) isolated from natural sources have improved TRAIL induced apoptosis in resistant cancer cells. We summarize recent updates on piperlongumine, phenethyl isothiocyanate and luteolin induced activation of TRAIL mediated apoptosis. The data obtained from pre-clinical studies will be helpful in translation of information from benchtop to the bedside.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1214-1221
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• 2020

Esculetin 6-O-β-D-arabinofuranosyl-(1 → 6)-β-D-glucopyranoside (EAG) is a coumarin glycoside isolated from the stem bark of Fraxinus rhynchophylla. This study scrutinized the anti-proliferative activity of EAG on blood cancer-derived Jurkat leukemic cells. Cell viability assays in leukemic cancer cells determined that EAG possesses potent anti-proliferative effects. Moreover, treatment with EAG increased the proportion of apoptotic cells, resulted in cell cycle arrest being induced at the subG0/G1 phase, and reduced the proportion of cells present in the S phase. In addition, mitochondrial membrane potential was reduced by EAG in Jurkat cells. Additionally, EAG triggered apoptosis that was mediated by the downregulation of BCL-XL, p-IκBα, and p-p65 expressions in addition to the upregulation of cleaved Caspase 3 and BAX expressions. These findings revealed that the toxic effect of EAG was mediated by intracellular signal transduction pathways that involved a mechanism in which reactive oxygen species (ROS) were upregulated. Thus, this study concludes that EAG could potentially serve as a therapeutic agent for leukemia.

• Natural Product Sciences
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• v.12 no.4
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• pp.221-225
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• 2006

Phytochemical examination of the fruits of Actinidia arguta has led to the isolation three organic acids, one coumarin, and three flavonoids. Structures of these compounds were elucidated as protocatechuic acid (1), caffeic acid (2), $caffeoyl-\beta-D-glucopyranoside$ (3), esculetin (4), quercetin (5), quercetin $3-O-\beta-D-galactopyranoside$ (6), and quercetin $3-O-\alpha-L-rhamnopyranosyl$ $(1\rightarrow6)-O-\beta-D-glucopyranoside$ (7) by comparisons with previously reported spectral data. To investigate the anti-inflammatory and anti-oxidative effects of these compounds, nitric oxide production inhibitory activity in LPS-stimulated RAW 264.7 cells and DPPH radical scavenging activities were examined. Nitric oxide productions were reduced significantly by the addition of compounds $[1(IC_{50}=59.27{\mu}g/ml),\;2(IC_{50}=27.95{\mu}g/ml),\;3(IC_{50}=73.09{\mu}g/ml),\;4(IC_{50}=67.44{\mu}g/ml),\;5(IC_{50}=17.40{\mu}g/ml),\;6(IC_{50}=41.99{\mu}g/ml),\;7(IC_{50}=54.46{\mu}g/ml)]$, and extracts $(IC_{50}=56.21{\mu}g/ml)$ compared with positive control, L-NMMA $(IC_{50}=14.48{\mu}g/ml)$. The phenolic compounds also showed anti-oxidative activities. Especially, Compounds $1(IC_{50}=8.87{\mu}g/ml),\;4(IC_{50}=3.41{\mu}g/ml),\;and\;5(IC_{50}=6.06{\mu}g/ml),\;$, showed potent anti-oxidative activities similar to L-ascorbic acid $(IC_{50}=5.89{\mu}g/ml)$.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.463-470
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• 2009

Sixteen antioxidative active compounds isolated from the EtOAc layer of MeOH extracts of kochujang, Korean fermented red pepper paste, were structurally elucidated as fumaric acid, methyl succinate, succinic acid furan-2-yl ester methyl ester (gochujangate, a novel compound), 2-hydroxy-3-phenylpropanoic acid, 3,4-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 6,7-dihydroxy-2H-chromen-2-one (esculetin), caffeic acid, cis-p-coumaric acid, trans-p-coumaric acid, daidzin, genistin, apigenin 7-O-$\beta$-D-apiofuranosyl($1{\rightarrow}2$)-$\beta$-D-glucopyranoside, apigenin 7-O-$\beta$-Dglucopyranoside, and quercetin 3-O-$\alpha$-L-rhamnopyranoside by mass spectrometry (MS) and nuclear magnetic resonance (NMR) experiments. These compounds were analyzed for the first time as antioxidants from kochujang.

• Journal of Ginseng Research
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• v.30 no.2
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• pp.82-87
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• 2006

Quantitative difference in five phenolic acids between white and red ginsengs was measured in this study. As the results, white ginseng has higher contents of cinnamic acid, quercetin and p-coumaric acid than red ginseng. Maltol was mainly included in red ginseng. These five compounds were recently reported to have tyrosinase inhibitory effects. These reports led us to investigate the de-pigmenting effect of ginseng products. In our examination of effect on tyrosinase activity, UV-protection and melanin production in melan-a cells, ethyl acetate traction of white ginseng extract and cinnamic acid showed potent de-pigmenting properties. The results indicated that white ginseng might be useful as skin whitening material and cinnamic acid proved to be one of active ingredient.