• Proceedings of the PSK Conference
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• 2003.10b
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• pp.212.2-212.2
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• 2003

In the course of searching for BACE1 (${\beta}$-secretase) inhibitors from natural products, the ethyl acetate soluble fraction of green tea, which was suspected to be rich in catechin content, showed potent inhibitory activity. (-)-Epigallocatechin gallate, (-)-epicatechin gallate, and (-)-gallocatechin gallate ware isolated with IC$\_$50/ values of 1.6${\times}$10$\^$-6/ M, 4.5${\times}$10$\^$-6/ M, and 1.8${\times}$10$\^$-6/ M, respectively. Seven additional authentic catechins were tested for a fundamental structure-activity relationship. (-)-Catechin gallate, (-)-gallocatechin, and (-)-epigallocatechin significantly inhibited BACE1 activity with IC$\_$50/ values of 6.0${\times}$10$\^$-6/ M, 2.5${\times}$10$\^$-6/ M, and 2.4${\times}$10$\^$-6/ M, respectively. (omitted)

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.320.2-320.2
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• 2002

Macrophages activated by lipopolysaccharide (LPS) are known to induce several proinflammatory proteins including COX-2. iNOS and TNF which produce chemical mediators involved in inflammatory response. Sophoricoside and its analogs (genistin, genistein and orobol) from Sophora japonica (Leguminosae) showed differential inhibitory effects on COX-1 and 2 activities. Sophoricoside and genistin shwoed IC50 values of 4 uM and 6 uM on COX-2 activity and of 1,497 uM and 135 uM on COX-1 activity, respectively. Genistein and orobol showed IC50 values of 3 uM on COX-2 activity and of 28 uM and 18 uM on COX-1 activity. respectively. Therefore. the legume isoflavonoids to be selective COX-2 inhibitors. However. sophoricoside and its analogs did not show inhibitory effects of COX-2, iNos and TNF transcripts. which were identified by the RT-PCR.

• Natural Product Sciences
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• v.28 no.3
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• pp.115-120
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• 2022

Ten compounds, consisting of neoflavonoids (1-5), isoflavonoids (6 and 7), flavanone (8), and chalcones (9 and 10) were isolated from the ethyl acetate and n-butanol-soluble fractions of the heartwood of Dalbergia melanoxylon. The chemical structures were identified on the basis of spectroscopic evidence and compared to previously reported spectra. Compounds 1-10 were evaluated for cytotoxicity against HCT116 human colorectal cancer, MDA-MB-231 human metastatic breast cancer, and A2058 human melanoma cell lines. Among them, compounds 3 and 10 showed the strongest cytotoxic activity with IC₅₀ values of 11.92±1.07 μM, 10.83±1.02 μM, and 14.37±1.02 μM, 13.62±1.09 μM against HCT116 and MDA-MB-231 cell lines, respectively. Compounds 9 and 10 also had cytotoxic activity with IC₅₀ values of 13.49±1.18 μM and 9.82±0.91 μM against A2058 cell lines, respectively. To the best our knowledge, compounds 2 and 5-10 were isolated from this source for the first time.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.657-662
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• 2007

Antioxidant properties of Artemisia princeps Pamp were determined using in vitro assay systems against 1,1-diphenyl-picrylhydrazyl (DPPH) radical, superoxide ($O_2{^-}$), hydrogen peroxide ($H_2O_2$), hydroxyl radical ($HO{\cdot}$) and nitric oxide (NO) radical, as well as rat liver microsomal lipid peroxidation. Among the five solvent fractions, ethyl acetate fractions showed the highest total polyphenol and flavonoid contents at $311.35{\mu}g/mg\;and\;92.73{\mu}g/mg$, respectively. Ethyl acetate fractions, except for $H_2O_2$ scavenging activity, also showed the highest scavenging activity; the 50% inhibitory concentration ($IC_{50},\;{\mu}g/mg$) values for DPPH, superoxide, $HO{\cdot}$ and NO radical scavenging were 52.71, 26.47, 58.92 and 65.94, respectively. Additionally, the highest inhibition of rat liver microsomal lipid peroxidation was observed by ethyl a cetate fraction.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.187-190
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• 2018

Two curcumin derivatives, demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC), isolated from Curcuma longa were analyzed for their inhibitory activities against two isoforms of monoamine oxidase (MAO), which is involved in the catalysis of neurotransmitting monoamines. In the study, DMC and BDMC potently inhibited human MAO-B, with $IC_{50}$ values of 2.45 and $2.59{\mu}M$, respectively, and both compounds showed effective inhibitory activities against human MAO-A, with $IC_{50}$ values of 3.24 and $3.09{\mu}M$, respectively. The inhibitory activities of the two compounds were higher than those of curcumin. The removal of the methoxy or dimethoxy groups in curcumin might increase the inhibitory activities against human MAO-A and MAO-B. The inhibited activities were recovered to almost the values of the reversible references in the dialysis experiments with DMC and BDMC. DMC and BDMC showed competitive inhibition for MAO-A and MAO-B, respectively, with $K_i$ values of 0.91 and $0.80{\mu}M$, respectively. These results suggest that the two curcumin derivatives may be useful or lead compounds in the treatment of related disorders as potent reversible MAO inhibitors.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.50.2-50.2
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• 2021

There is increasing evidence that the convective mixing length (α) in stellar evolution models depends on metallicity of stars. In order to confirm a more precise metallicity-dependent mixing length trend, we investigate the effective temperature and metallicity of 14 red supergiant stars (RSGs) in the irregular dwarf galaxy IC 1613 using the near-infrared spectra observed with the MMIRS on the MMT telescope. From the synthetic spectral fitting to the observed spectra, we find that the mean metallicity is about [Fe/H]=0.69 with a weak bimodal distribution. We also find that the effective temperature of RSGs in IC 1613 is higher by about 250 K than that of the SMC on average. We compare the RSG position with stellar evolutionary tracks on the HR diagram, finding that models with α = 2.2-2.4 H_p can best reproduce the effective temperatures of the RSGs in IC 1613. It is evident that the mixing length values for IC 1613 is lower than that of the Milky Way. This result supports our previous study on a metallicity-dependent mixing length: mixing length decreases with decreasing metallicity of host galaxies. However, this dependency becomes relatively weak for RSGs having a metallicity equal to or less than the SMC metallicity.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.1
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• pp.199-203
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• 2014

Background: Rosuvastatine, doxazosin, repaglinide and oxcarbazepin are therapeutic drugs available in the market for the treatment of different diseases. Potential to display antitumor activities has also been suggested. The aim of the current study was to evaluate their in vitro effects on some human transformed cell lines. Materials and Methods: Cytotoxicity of the four drugs was tested in MCF-7, HeLa and HepG2 cells by the neutral red assay method and also the effect of rosuvastatine and doxazosin against Ehrlich Ascities Carcinoma Cells (EACC) by trypan blue assay. Results: Rosuvastatine exerted the greatest cytotoxic effect against HepG2 cells with an $IC_{50}$ value of $58.7{\pm}69.3$; in contrast doxazosin showed least activity with $IC_{50}=104.4{\pm}115.7$. Repaglinide inhibited the growth of both HepG2 and HeLa cells with $IC_{50}$ values of $87.6{\pm}117.5$ and $89.3{\pm}119.5$, respectively. Oxcarbazepine showed a potent cytotoxicity against both HeLa ($IC_{50}=19.4{\pm}43.9$) and MCF7 cancer cells (($IC_{50}=22{\pm}35.7$).On the other hand the growth of EACC was completely inhibited by doxazosine (100% inhibition) while rosuvastatine had weak inhibitory activity (11.6%). Conclusions: The four tested drugs may have cytotoxic effects against hepatic, breast and cervical carcinoma cells; also doxazosine may inhibit the growth of endometrial cancer cells. Further investigations in animals are needed to confirm these results.

• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1681-1686
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• 2014

A series of hybrid molecules between (${\alpha}$)-lipoic acid (ALA) and 4-amino-1-benzyl piperidines were synthesized and their in vitro cholinesterase (acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)) inhibitory activities were evaluated. Even though the parent compounds did not exhibit any inhibitory activity against cholinesterase (ChE) with the exception of compound 14 ($IC_{50}=255.26{\pm}4.41$ against BuChE), all hybrid molecules demonstrated BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, compound 17 was shown to be an effective inhibitor against both AChE ($IC_{50}=1.75{\pm}0.30{\mu}M$) and BuChE ($IC_{50}=5.61{\pm}1.25{\mu}M$) comparable to galantamine ($IC_{50}=1.7{\pm}0.9{\mu}M$ against AChE and $IC_{50}=9.4{\pm}2.5{\mu}M$ against BuChE). Inhibition kinetic studies using compound 17 indicated a mixed inhibition type for AChE and a noncompetitive inhibition type for BuChE. Its binding affinity ($K_i$) values to AChE and BuChE were $3.8{\pm}0.005{\mu}M$ and $7.0{\pm}0.04{\mu}M$, respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5659-5665
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• 2014

Background: To investigate the antioxidant value and anticancer functions of mitragynine (MTG) and its silane-reduced analogues (SRM) in vitro. Materials and Methods: MTG and SRM was analyzed for their reducing power ability, ABTS radical inhibition and 1,1-diphenyl-2-picryl hydrazylfree radicals scavenging activities. Furthermore, the antiproliferation efficacy was evaluated using MTT assay on K 562 and HCT116 cancer cell lines versus NIH/3T3 and CCD18-Co normal cell lines respectively. Results: SRM and MTG demonstrate moderate antioxidant value with ABTS assay (Trolox equivalent antioxidant capacity (TEAC): $2.25{\pm}0.02$ mmol trolox / mmol and $1.96{\pm}0.04$ mmol trolox / mmol respectively) and DPPH ($IC_{50}=3.75{\pm}0.04mg/mL$ and $IC_{50}=2.28{\pm}0.02mg/mL$ respectively). Both MTG and SRM demonstrate equal potency ($IC_{50}=25.20{\pm}1.53$ and $IC_{50}=22.19{\pm}1.06$ respectively) towards K 562 cell lines, comparable to control, betulinic acid (BA) ($IC_{50}24.40{\pm}1.26$). Both compounds showed concentration-dependent cytototoxicity effects and exert profound antiproliferative efficacy at concentration > $100{\mu}M$ towards HCT 116 and K 562 cancer cell lines, comparable to those of BA and 5-FU (5-Fluorouracil). Furthermore, both MTG and SRM exhibit high selectivity towards HCT 116 cell lines with selective indexes of 3.14 and 2.93 respectively compared to 5-FU (SI=0.60). Conclusions: These findings revealed that the medicinal and nutitional values of mitragynine obtained from ketum leaves that growth in tropical forest of Southeast Asia and its analogues does not limited to analgesic properties but could be promising antioxidant and anticancer or chemopreventive compounds.

• Preventive Nutrition and Food Science
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• v.11 no.3
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• pp.191-197
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• 2006

Matrix metalloproteinase-2 (MMP-2) is a key enzyme involved in tumor invasiveness. The plant of Magnolia officinalis Rehd. et Wils. is often included as an ingredient in various herbal remedies recommended for cancer theraphies in Korea. Various extracts prepared from stems of M. officinalis were tested for cytotoxic activity on human hepatocellular carcinoma cell line, SK-Hep cells using the XTT assay method. Then, the inhibitory effect was examined on MMP-2 activity using gelatin zymography. Methanol (MeOH) extract of M. officinalis caused the strongest inhibition of the MMP-2 activity, as measured by gelatin zymography method for enzyme activity. $IC_{50}$ values of fractions on MMP-2 activity were in a range of $4.9{\sim}11.3\;{\mu}g/mL$. Among each fraction, butanol and ethylacetate (EtOAc) fractions showed the strong inhibitory activities ($IC_{50}=10.7\;and\;4.9\;{\mu}g/mL$, respectively). When the M. officinalis's constituents such as magnolol, honokiol, (-)-epigallocatechin gallate (EGCG) and ovovatol were examined for inhibitory effects on MMP-2 activity, EGCG showed strong inhibitory activity. However, MeOH extract of M. officinalis was dose-dependently inhibited to MMP-2 activity. The MeOH extract, hexane and EtOAc fractions $(IC_{50}\;of\;>200\;{\mu}g/mL)$ exhibited weak cytotoxicity activity, while butanol $(IC_{50}=80\;{\mu}g/mL)$ and chloroform fractions $(IC_{50}=90\;{\mu}g/mL)$ exhibited relatively strong cytotoxic activity. From these results, M. officinalis could be suitable for cancer treatment and chemopreventive drugs.