• Archives of Pharmacal Research
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• v.27 no.2
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• pp.169-172
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• 2004

Activity-guided fractionation of the EtOAc-soluble extract of the stems of Couepia ulei, using a bioassay based on the induction of quinone reductase (QR) in cultured Hepa 1c1c7 mouse hepatoma cells led to the isolation of two active compounds, a new natural product, erythro-2,3-bis(4-hydroxy-3-methoxyphenyl)-3-ethoxypropan-1-o1 (1), and a known compound, evofolin-B (2), along with five inactive compounds all of known structure, viz., betulinic acid, oleanolic acid, pomolic acid, ($\pm$)-syringaresinol, and ursolic acid. These isolates were identified by analysis of physical and spectral data. Compounds 1 and 2 exhibited QR inducing activity, with observed CD (concentration required to double induction) values of 16.7 and 16.4 $\mu\textrm{M}$, respectively.

• Korean Journal of Pharmacognosy
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• v.36 no.3 s.142
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• pp.240-244
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• 2005

The methanol extract of the seed of Myristica fragrans (myristicaceae) demonstrated a potent inhibition on the proliferation of cultured human tumor cells such as A549 (non small cell lung), SK-OV-3 (ovary), SK-MEL-2(melanoma), XF498 (central nerve system) and HCT-15(colon). The MeOH extract was fractionated into three portions by serial solvent partition i,e., EtOAc soluble part, BuOH soluble part and remaining water layer. Among them, the EtOAc soluble part of the extract demonstrated a potent inhibition on the proliferation of cultured human tumor cells, Bioassay-guided fractionation of the EtOAc soluble part led to the isolation of six lignan constituents, i.e., safrole(1), machilin A (2), licarin B (3), macelignan (4), mesodihydroguaiaretic acid (5) and myristargenol A (6) as well as a large amount of myristic acid as active ingredients. Structures of the isolated active components (1-6) were established by chemical and spectroscopic means.

• Journal of Microbiology and Biotechnology
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• v.30 no.12
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• pp.1885-1895
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• 2020

Rumex japonicus Houtt (RJH) is a valuable plant used in traditional medicine to treat several diseases, such as scabies and jaundice. In this study, Jurkat cell growth inhibitory extracts of R. japonicus roots were subjected to bioassay-guided fractionation, resulting in the isolation of three naphthalene derivatives (3-5) along with one anthraquinone (6) and two phenolic compounds (1 and 2). Among these compounds, 2-methoxystypandrone (5) exhibited potent anti-proliferative effects on Jurkat cells. Analysis by flow cytometry confirmed that 2-methoxystypandrone (5) could significantly reduce mitochondrial membrane potential and promote increased levels of mitochondrial reactive oxygen species (ROS), suggesting a strong mitochondrial depolarization effect. Real-time quantitative polymerase chain reaction (qPCR) analysis was also performed, and the results revealed that the accumulation of ROS was caused by reduced mRNA expression levels of heme oxygenase (HO-1), catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD). In addition, 2-methoxystypandrone (5) triggered strong apoptosis that was mediated by the arrest of the G0/G1 phase of the cell cycle. Furthermore, 2-methoxystypandrone (5) downregulated p-IκB-α, p-NF-κB p65, Bcl2, and Bcl-xl and upregulated BAX proteins. Taken together, these findings revealed that 2-methoxystypandrone (5) isolated from RJH could potentially serve as an early lead compound for leukemia treatment involving intracellular signaling by increasing mitochondrial ROS and exerting anti-proliferative effects.

• Food Science and Preservation
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• v.16 no.3
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• pp.435-441
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• 2009

Activity-guided isolation from the ethylacetate (EtOAc)-soluble portion of a methanolic extract of the seeds of Eriobotrya japonica, using several bioassays, led to the isolation and identification of six phenolic compounds of previously known structure: benzaldehyde (1), chlorogenic acid (2), caffeic acid (3), benzoic acid (4), ferulic acid (5), and amygdalin (6). Of these, benzaldehyde (1) exhibited tyrosinase inhibitory activity in a bioassay. In addition, chlorogenic acid (2) and caffeic acid (3) were found to have strong antioxidative effects on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and superoxide dismutase (SOD)-like activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.7
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• pp.1090-1099
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• 2015

Among the four different parts of mulberry (Morus alba L.) tree, ethanol extract of Morus root bark showed the highest ${\alpha}$-glucosidase inhibitory activity ($IC_{50}=12.01{\mu}g/mL$). Bioassay-guided fractionation of the ethanolic extract of root bark by Diaion HP-20, silica gel, ODS-A, and Sephadex LH-20 column chromatographies led to the isolation of four compounds, including Compound (Comp.) 1 ($IC_{50}=5.22{\mu}g/mL$), Comp. 2 ($IC_{50}=1.78{\mu}g/mL$), Comp. 3 ($IC_{50}=2.94{\mu}g/mL$), and Comp. 4 ($IC_{50}=1.54{\mu}g/mL$) with strong ${\alpha}$-glucosidase inhibitory activities. Their chemical structures were elucidated as morusin (Comp. 1), kuwanon H (Comp. 2), chalcomoracin A (Comp. 3), and chalcomoracin B (Comp. 4) by UV and NMR spectral analyses. These results suggest that prenylflavonoid and mulberrofuran of Morus root bark may be useful as potential therapeutic agents for diabetes.

• Herbal Formula Science
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• v.16 no.1
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• pp.117-130
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• 2008

Korean traditional medicine has been used for the treatment of the various diseases based on both oriental medicinal theory and clinical trials. Thus, the prescriptions of Korean traditional medicine would be useful for the development of new therapeutics. This research focuses on the fundamental study in Korean traditional prescriptions for the development of new hepatoprotective agents. We found two prescriptions. Injinho-Tang and Osumogwa-Tang, showed the significant DPPH free radical scavenging and hepatoprotective effect, respectively. It is well-known that free radical scavenging effect is related to the prevention of various pathological events including liver injury. This paper deals with hepatoprotective effects on tacrine-induced cytotoxicity in Hep G2 cells, free radicals scavenging on both DPPH and superoxide of above two prescriptions. Hot water extract of Injinho-Tang did not show the significant hepatoprotective effect on tacrine-induced cytotoxicity in Hep G2 cells, however, it shows the significant scavenging effects for both DPPH and superoxide radicals. On the other hand, all of the hot water extracts of constituent herbal drugs in Injinho-Tang exhibited the promising protective effect on tacrine-induced cytotoxicity in Hep G2 cells. Of these, water extract of Rhei Rhizoma showed the most prominent effect on tacrine-induced cytotoxicity in Hep G2 cells. Bioassay-guided fractionation of Rhei Rhizoma extract has furnished four compounds, and their chemical structures have been identified by comparison of their spectral data with those of literature as chrysophanol (1), emodin (2), 3,5-dihydroxy-4'- methoxystilbene (3), and rhapontigenin (4), respectively. Among the isolated compounds, compounds 2-4 revealed the significant hepatoprotective effect in vitro when their $EC_{50}$ values compare with that of silybin, as a positive control. It also exhibited that emodin possessed the most hepatoprotective effect among these active compounds. In case of Osumogwa-Tang, its hot water extract showed the moderate protective effect on tacrine-induced cytotoxicity in Hep G2 cells. Hot water extract of Chaenomelis Fructus, one of the constituent herbal drug of this prescription, exhibited the significant hepatoprotective effect with $EC_{50}$ value of $7.8{\pm}0.1\;{\mu}g/ml$, however, it showed strong cytotoxicity in Hep G2 cells above the concentration of $25\;{\mu}g/ml$. It was revealed that both hot water extract of Evodiae Fructus and its butanol soluble fraction showed the moderate hepatoprotective effect but concentration-dependent activity in Hep G2 assay system. Two quinolone alkaloids, evocarpine and dihydroevocarpine, also tested for their hepatoprotective effects on tacrine-induced cytotoxicity in Hep G2 cells, however, these two compounds derived from the Evodiae Fructus as the major constituents did not show in vitro hepatoprotective effect. From these results, it would be necessary to further isolation of its hepatoprotective compounds from the butanol soluble fraction of the hot water extract of Evodiae Fructus.

• Applied Biological Chemistry
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• v.50 no.4
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• pp.262-267
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• 2007

To access the natural product antibiotics produced by uncultured microorganisms, six cosmid libraries of DNA extracted directly from soil samples (environmental DNA, eDNA) were constructed and screened for the production of antibacterial active molecules. Of the approximately 60,000 clones screened, one antibacterial clone (YS92B) was detected. Ethyl acetate extracts of clone YS92B showed antibacterial activity against various pathogenic bacteria (Listeria monocytogenes, Bacillus subtilis, Pseudomonas syringae, Xanthomonas campestris pv. oryzae, Staphylococcus epidemis). Active constituents from cultures of YS92B were isolated and purified using a bioassay-guided fractionation against B. subtilis through a series of procedures (ethyl acetate extraction, Sephadex LH20 column chromatography, High Performance Liquid Chromatography). NMR (Nuclear Magnetic Resonance) spectral analysis of a major antibacterial active YS92B-VII indicated that it is a lauric acid linked to tyrosine. This report describes the characterization of antibacterially active long chain N-acyl derivatives of tyrosine that are produced by eDNA clones hosted in Escherichia coli from Korean soils.

• Archives of Pharmacal Research
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• v.26 no.8
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• pp.585-590
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• 2003

Activity-guided fractionation of the EtOAc-soluble extract of the whole plants of Sida acuta using a bioassay based on the induction of quinone reductase (OR) in cultured Hepa 1c1c7 mouse hepatoma cells, led to the isolation of ten active compounds of previously known structure, quindolinone (1), cryptolepinone (2), 11-methoxyquindoline (3), N-trans-feruloyltyramine (4), vomifoliol (5), loliolide (6), 4-ketopinoresinol (7), scopoletin (8), evofolin-A (9), and evofolin-B (10), along with five inactive compounds of known structure, ferulic acid, sinapic acid, syringic acid, ($\pm$)-syringaresinol, and vanillic acid. These isolates were identified by physical and spectral data measurement. A new derivative of quindolinone, 5,10-dimethylquindolin-11-one (1a) was synthesized and characterized spectroscopically. Of the active substances, compounds 1-3 and 1a exhibited the most potent QR activity, with observed CD (concentration required to double induction) values ranging from 0.01 to 0.12 $\mu$ g/mL. Six compounds were then evaluated in a mouse mammary organ culture assay, with cryptolepinone (2), N-trans-feruloyltyramine (4), and 5,10-dimethylquindolin-11-one (1a) found to exhibit 83.3, 75.0, and 66.7% inhibition of 7,12-dimethylbenz[a]anthracene-induced preneoplastic lesions, respectively, at a dose of 10 $\mu\textrm{g}$/mL.