• Journal of the Korean Chemical Society
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• v.24 no.1
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• pp.1-7
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• 1980

Solvolysis rate constants for methylchloroformate, methylthionochloroformate, methylthiolchloroformate and methyldithiochloroformate have been determined conductometrically in methanol, ethanol and ethanol-water mixtures and activation parameters have been derived. Results show that methylchloroformate solvolyzes through $S_N2$ process while methyldithiochloroformate solvolyzes by $S_N1$ process in all the solvent systems. The rate of hydrolysis decreased in the order, $CH_3S(CS)Cl>CH_3S(CO)Cl>CH_3O(CS)Cl>CH_3O(CO)Cl$ which corresponds to the order of decreasing $S_N1$ character. In methanol, $CH_3S(CS)Cl$ solvolyzed via the $S_N1$ mechanism while the others solvolyzed via the $S_N2$ process. In ethanol, however, $S_N2$ character was dominant for all the compounds, except methyldithiochloroformate, for which $S_N1$ character was still strong enough to accelerate the rate of ethanolysis. In ethanol-water mixtures, $CH_3S(CS)Cl$ and $CH_3S(CS)Cl$ solvolyzed via $S_N2$ process in ethanol-rich region while the $S_N1$ character increased greatly in water-rich region for the solvolysis of these compounds. The order of $S_N1$ character for solvolysis in water-rich region was the same as the order of hydrolysis rate.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.25-31
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• 2017

Objectives : Mori Radicis Cortex (MRC), the root epidermis of Morus alba L., has been traditionally used to treat lung-related diseases in Korean Medicine. The common of MRC is Mulberry bark Morus bark, and it's pharmaceutical properties and taste are known as sweet and cold, and it promotes urination and reduce edema by reducing heat from the lungs and soothe asthma. In the present study, anti-apoptotic mechanism of MRC in middle cerebral artery occlusion (MCAO) model in mice. Methods : Two-hundred grams of MRC was extracted with methanol at room temperature for 5 days, and this was repeated one time. After filtration, the methanol was removed using vacuum evaporator, then stored at $-20^{\circ}C$ until use. C57BL/6 male mice were housed in an environment with controlled humidity, temperature, and light cycle. In order to determine beneficial effects of MRC on ischemia induced brain damage, infarct volume, neurological deficit scores, activities of several apoptosis-related proteins such as caspase-8, -9, Bcl-xL in MCAO-induced brains of mice were analyzed. Mice in MRC-treated groups were orally administered 30, 100, or 300 mg/kg of body weight for three consecutive days before commencing the MCAO procedure. Results : Pre-treatment of MRC significantly reduced infarct volume in MCAO subjected mice applied with 300 mg/kg of MRC methanol extract, and MRC effectively inhibited Bcl-xL reduction and caspase-9 activation caused by MCAO-induced brain damage. Conclusions : MRC showed neuro-protective effects by regulating apoptosis-related protein signals, and it can be a potential candidate for the therapy of ischemia-induced brain damage.

• Journal of Life Science
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• v.25 no.4
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• pp.441-449
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• 2015

Endlicheria anomala, a neotropical plant, is found in northern South America and the Amazon region. It is traditionally used to remove poisons and cure gangrene. According to recent data, this plant has diverse biological properties such as anti-oxidative, anti-inflammatory and anti-melanogenic properties. However, the anti-cancer effect of E. anomala and its molecular mechanisms remain unclear. In this study, we examined the anti-cancer effect and the active mechanism of methanol extract of E. anomala (MEEA) in human lung adenocarcinoma cells (A549) and human liver cancer cells (HepG2). Our data revealed that MEEA showed cytotoxic activity in a dose-dependent manner and induced apoptosis both in A549 and HepG2 cells. We verified evidences of apoptosis via formation of chromatin condensation, apoptotic body and accumulation of cells in the subG1 phase. Following observed apoptosis-related phenomena, we found that the induction of apoptosis by MEEA was associated with the increase of tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 (WAF1/CIP1) expression. Furthermore, MEEA-induced apoptosis was characterized with proteolytic activation of caspase-3, degradation of poly ADP ribose polymerase (PARP), and up-regulation of pro-apoptotic Bax expression. Taken together, these findings indicate that MEEA may have potential cancer therapeutic utility in A549 and HepG2 cells.

• Bulletin of the Korean Chemical Society
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• v.31 no.7
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• pp.1963-1967
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• 2010

The rates of solvolysis of 4-morpholinecarbonyl chloride (MPC) have measured at $35.0^{\circ}C$ in water, $D_2O$, $CH_3OD$, and in aqueous binary mixtures of acetone, ethanol, methanol, and 2,2,2-trifluoroethanol. An extended (two-term) Grunwald-Winstein equation correlation gave sensitivities towards changes in solvent nucleophilicity and solvent ionizing power as expected for a dissociative $S_N2$ and/or $S_N1$(ionization) pathway. For nine solvents specific rates were determined at two additional temperatures and higher enthalpies and smaller negative entropies of activation were observed, consistent with the typical dissociative $S_N2$ or $S_N1$(ionization) pathway. The solvent deuterium isotope effect values for the hydrolysis of MPC of $k_{H_2O}/k_{D_2O}$ = 1.27 and for the methanolysis of MPC of $k_{MeOH}/k_{MeOD}$ = 1.22 are typical magnitudes of the $S_N1$ or ionization mechanism.

• Biomolecules & Therapeutics
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• v.22 no.4
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• pp.334-340
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• 2014

In this study, 23 oleanane-type triterpenoid saponins were isolated from a methanol extract of the roots of Pulsatilla koreana. The NF-${\kappa}B$ inhibitory activity of the isolated compounds was measured in $TNF{\alpha}$-treated HepG2 cells using a luciferase reporter system. Compounds 19-23 inhibited $TNF{\alpha}$-stimulated NF-${\kappa}B$ activation in a dose-dependent manner, with $IC_{50}$ values ranging from $0.75-8.30{\mu}M$. Compounds 19 and 20 also inhibited the $TNF{\alpha}$-induced expression of iNOS and ICAM-1 mRNA. Moreover, effect of the isolated compounds on PPARs transcriptional activity was assessed. Compounds 7-11 and 19-23 activated PPARs the transcriptional activity significantly in a dose-dependent manner, with $EC_{50}$ values ranging from $0.9-10.8{\mu}M$. These results suggest the presence of potent anti-inflammatory components in P. koreana, and will facilitate the development of novel anti-inflammatory agents.

• Natural Product Sciences
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• v.4 no.2
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• pp.100-104
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• 1998

The antimutagenic activity of a methanol extract of roasted Cassia tora seed against aflatoxin $B_1(AFB_1)$ was demonstrated with the Salmonella typhimurium assay. The numbers of revertants per plate decreased significantly when this extract was added to the assay system using Salmonella typhimurium TA100 and or TA98. The MeOH extract was then sequentially partitioned with $CH_2Cl_2$, EtOAc, n-BuOH, and $H_2O$. The $CH_2Cl_2$ and n-BuOH fractions possessed antimutagenic activity, but the EtOAc and $H_2O$ fractions were inactive. Both the MeOH extract and its fractions were capable of inhibiting the indirect-acting mutagen $AFB_1$, suggesting that these fractions may prevent the metabolic activation of $AFB_1$, or scavenge the electrophilic intermediate capable of inducing mutations. Column chromatography using silica gel yielded pure alaternin from the $CH_2Cl_2$ a fraction, and adenosine and isorubrofusarin gentiobioside from the n-BuOH fraction. Alaternin and isorubrofusarin gentiobioside demonstrated significant antimutagenic activities.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3371-3376
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• 2015

Pigmented rice bran has been suggested to be a valuable source of beneficial phytochemicals. We investigated genotoxic and anti-genotoxic effects of purple rice bran extract (PRBE) in rats using a liver micronucleus assay. Purple rice bran was extracted with methanol, obtaining large amounts of phenolic compounds, including anthocyanins and small amounts of gamma-oryzanol. The experimental protocols were divided into two sets. Male rats were divided into three groups. Group 1 was a negative control, while Groups 2 and 3 were fed with 100 and 500 mg/kg bw of PRBE, respectively, for 28 days. PRBE had no effect on micronucleus formation or xenobiotic metabolizing enzymes in rat liver. Experiments concerning the effect of PRBE on $AFB_1$ showed that PRBE significantly lessened the amount of micronucleated hepatocytes in $AFB_1$ treated rats. Furthermore, it modulated metabolic activation of $AFB_1$ metabolism in the liver by suppressing activity and protein expression of CYP1A2, CYP3A and CYP 450 reductase, and enhancing phase II enzymes including GST and UGT. Overall, purple rice bran extract was not genotoxic in rats. It exhibited anti-genotoxicity by modulation some xenobiotic enzymes active in $AFB_1$ metabolism.

• Advances in Traditional Medicine
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• v.10 no.2
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• pp.51-58
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• 2010

Vitex rotundifolia (V. rotundifolia) has been used for treating headache, dizziness, toothache and removal of fever as a traditional medicine in Korea. In the present study, we examined the antioxidant and anti-inflammatory activities of 85% methanol extract of V. rotundifolia. In various radical scavenging assays, V. rotundifolia exhibited strong scavenging effect on 1, 1-diphenyl-2-picrylhydrazyl free radical, superoxide radical, nitric oxide. To elucidate the anti-inflammatory properties of V. rotundifolia, we investigated the inhibition effects of nitric oxide production in IFN-gamma and LPS-stimulated mouse peritoneal macrophages. V. rotundifolia suppressed nitric oxide production, iNOS and COX-2 expression dose-dependently through suppression of NF-$\hat{e}B$ activation without notable cytotoxicity. These findings mean that V. rotundifolia may be beneficial in oxidative stress-mediated inflammatory disorders.

• The Journal of Internal Korean Medicine
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• v.29 no.1
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• pp.42-66
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• 2008

Aconiti Tuber is a traditional medicinal plant generally used in Oriental medicine therapy. In this study, we investigated the biochemical mechanisms of anti-proliferative effects by the methanol extract of Aconiti tuber (MEBJ) in Caki-1 human renal cell carcinoma cells. It was found that MEBJ could inhibit, in a dose-dependent manner, cell growth which was associated with apoptotic cell death such as formation of apoptotic bodies, DNA fragmentation and increased populations of apoptotic-sub G1 phase. Apoptosis of Caki-1 cells by MEBJ was associated with an up-regulation of pro-apoptotic Bax expression, and a down-regulation of anti-apoptotic Bcl-2 in a dose-dependent manner; however, the levels of IAP family were not affected. MEBJ treatment also induced the proteolytic activation of caspase-3 and -8, and a inhibition of poly(ADP-ribose) polymerase (PARP) and $PLC{\gamma}1$ protein. Furthermore, MEBJ treatment caused a dose-dependent inhibition of iNOS and cyclooxygenase-2 (Cox-2). Though further studies will be needed to identify the active compounds that confer the anti-cancer activity of MEBJ, the present findings provide important new insights into the possible molecular mechanisms of the apoptotic activity of MEBJ in cancer cells.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.4
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• pp.1073-1077
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• 2005

Oxidative stressand glia-associated chronic inflammation have been linked to the pathophysiology of Alzheimer's disease. Rhei rhizoma has been commonly used as a purgative and a haemostatic agent in traditional oriental medicine. Recently, the methanol extract from a dried root of Rheum undulatumhas been shown to have anti-allergic and anti-inflammatory effects. In this study, we tested the potential of the extract of Rheum undulatum for neuroprotective agent. The aqueous extract of Rheum undulatum reduced cell death and p53 phosphorylation in neuronal cells and attenuated levels of cyclooxygenase-2 and inducible nitric oxide synthase mRNAs in BV2 microglial cells treated with $amyloid-\beta$