• Title/Summary/Keyword: Methyl transferase

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Identification of Higenamine nad its Metabolites in Rat by Gas Chromatography/Mass Spectrometry

  • Ryu, Jae-chun;Song, Yun-Seon;Kim, Myung-Soo;Cho, Jung-Hyuck;Yunchoi, Hye-Sook
    • Archives of Pharmacal Research
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    • v.16 no.3
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    • pp.213-218
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    • 1993
  • ($\pm$)-Higenamine is known as a cardiotonic principle of aconite root (root of Aconitum spp., Ranunculaceae). A simple and sensitive detection method for higenamine was developed by using gas chromatography-mass spectrometry (GC/MS). The recovery of higenamine after extraction and concentration with XAD-2 resin column was around 95% from rat biological fluids such as bile, plasma and urine. The limits of detection of higenamine in these biological fluids were approximately 0.1 ng/ml each. It has well been suggested that tetrahydroisoquinolines possessing catechol moiety such as higenamine should be subjected to the catechol-O-methyl transferase (COMT) activity in vivo. We detected two major peaks of presumed metabolites of higenamine in the total ion chromatogram obtained from the rat urine sample after the oral adminstration of ($\pm$)-higenamine. The scan mass spectrum of one of the metabolties coincided with those obtained from coclaurine $(C_6$-O-methyl higenamine) and those of the other metabolite are suggestive of isococlaurine $(C_7$-O-methyl higenamine).

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Novel DOT1L ReceptorNatural Inhibitors Involved in Mixed Lineage Leukemia: a Virtual Screening, Molecular Docking and Dynamics Simulation Study

  • Raj, Utkarsh;Kumar, Himansu;Gupta, Saurabh;Varadwaj, Pritish Kumar
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.9
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    • pp.3817-3825
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    • 2015
  • Background: The human protein methyl-transferase DOT1L catalyzes the methylation of histone H3 on lysine 79 (H3K79) at homeobox genes and is also involved in a number of significant processes ranging from gene expression to DNA-damage response and cell cycle progression. Inhibition of DOT1L activity by shRNA or small-molecule inhibitors has been established to prevent proliferation of various MLL-rearranged leukemia cells in vitro, establishing DOT1L an attractive therapeutic target for mixed lineage leukemia (MLL). Most of the drugs currently in use for the MLL treatment are reported to have low efficacy, hence this study focused on various natural compounds which exhibit minimal toxic effects and high efficacy for the target receptor. Materials and Methods: Structures of human protein methyl-transferase DOT1L and natural compound databases were downloaded from various sources. Virtual screening, molecular docking, dynamics simulation and drug likeness studies were performed for those natural compounds to evaluate and analyze their anti-cancer activity. Results: The top five screened compounds possessing good binding affinity were identified as potential high affinity inhibitors against DOT1L's active site. The top ranking molecule amongst the screened ligands had a Glide g-score of -10.940 kcal/mol and Glide e-model score of -86.011 with 5 hydrogen bonds and 12 hydrophobic contacts. This ligand's behaviour also showed consistency during the simulation of protein-ligand complex for 20000 ps, which is indicative of its stability in the receptor pocket. Conclusions: The ligand obtained out of this screening study can be considered as a potential inhibitor for DOT1L and further can be treated as a lead for the drug designing pipeline.

Protective Effect of Pterocarpus santalinus on Galactosamine Induced Liver Damage

  • Dhanabal, S.P.;Syamala, G.;Elango, K.;Suresh, B.
    • Natural Product Sciences
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    • v.12 no.1
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    • pp.8-13
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    • 2006
  • The present study was carried out to investigate the hepatoprotective effect of the extract of Pterocarpus santalinus Linn on acute hepatotoxicity induced in Wistar albino rats by a single dose of Galactosamine (400 mg/kg). Suspensions of methanolic extract of heartwood of P. santalinus (200 and 400 mg/kg) in 0.3% Carboxy Methyl Cellulose (CMC) were administered p.o. to experimental animals and hepatoprotective activity was monitored by estimating aspartate amino transferase (ASAT, GOT), alanine amino transferase (ALAT, GPT), alkaline phosphatase (ALP), total bilirubin (TB), lactate dehydrogenase (LDH), total cholesterol (TC), triglycerides (TGL), albumin, total protein (TP) levels. The methanolic extract significantly reduced the elevation of serum transaminases and alterations of biochemical parameters induced by hepatotoxin, and alleviated the degree of liver damage. The results were supported by histopathological studies of liver samples showing regeneration of hepatocytes in treated animals. Silymarin (25 mg/kg), a known hepatoprotective drug was used for comparison. Based on the results obtained, it can be concluded that P. santalinus exerts hepatoprotective activity and may serve as a useful adjuvant in several clinical conditions associated with liver damage.

Effects of Polyacetylenes in Ginseng on Activity of Enzymes Related to Post-translational Modification of Ras Protein and Effects of Petroleum Ether Extract of Ginseng on Progression of Cell Cycle (인삼의 polyacetylene 계 성분이 Ras 단백질 변형 효소의 활성에 미치는 영향과 인삼의 석유에텔 추출물이 세포주기에 미치는 영향)

  • 김동청;이지영;인만진;채희정;황윤경;황우익
    • Journal of Ginseng Research
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    • v.25 no.4
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    • pp.156-161
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    • 2001
  • We investigated the effects of polyacetylenes of ginseng on farnesyl protein transferase (FPTase) and carboxyl methyl transferase (CMTase) activities related to post-translational modification of Ras protein. We also investigated the effect of petroleum ether extract (PEE) of ginseng on progression of cell cycle. FPTase activity was respectively inhibited 16.2% by 10mM panaxynol and 21.3% by 10mM panaxydol, whereas CMTase activity was not inhibited by panaxynol or panaxydol. Treatment of PEE significantly reduced the numbers and size of human colon cancer cell (HT-29) and human liver cancer cell(HepG2) cultured, respectively. To investigate the mechanism of growth inhibition by PEE of ginseng, we analyzed the cell cycle progressions of PT-29 and HepG2 cells, respectively. We found that PEE significantly inhibited progression of cell cycle from G1 to S phase. These results suggest that anticancer effects of PEE were derived from the arrest of G1 phase in cell cycle progression.

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Mechanisms of Parathion Resistance in a Ethyl Fenitrothion-Selected Yumenoshima III Strain of House Flies (페니트로치온 도태 Yumenoshima 저항성 집파리에 있어서의 파라치온 저항성 메카니즘)

  • ;;Toshio SHONO
    • Korean journal of applied entomology
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    • v.35 no.3
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    • pp.254-259
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    • 1996
  • The biochemical factors responsible for parathion resistance in a ethyl fenitrothion-selected Yumenoshima I11 (EF-30) strain of the housefly were examined. Great difference (167-fold) in the Iso was observed between the resistant EF-30 (R) and susceptible SRS (S) strains in vitro, suggesting that altered acetylcholinesterase (AChE) in the housefly strain was an important factor in the resistance. The in vitro degradative activity of parathion and paraoxon in both strains was associated with the microsomal and soluble fractions and required NADPH and reduced glutahione (GSH), respectively. The R strain possessed higher activity for GSH S-transferase than the S strain, and this enzyme appears to be important in the resistance mechanism. The R strain was highly resistant to parathion (101,487-fold), but substitution of the methoxy group for ethoxy group decreased the resistance level (25,914-fold) and parathion could be a substrate of GSH S-transferase. It is concluded that the combination of some factors (altered AChE, and enhanced activity of cytochrome P450 dependent monooxygenase and GSH S-transferase) could be sufficient to account for the extremely high level of resistance to parathion and parathion-methyl, although a possible involvement of other factor(s) can not be excluded.

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Glutathione-S-transferase Activity and its Changes to Chemical Pollution in Edible Shells and Fishes (식용 어패류 조직중의 glutathione S-transferase 활성과 화학물질 오염에 의한 변화)

  • Song, Mi-Ran;Choe, Sun-Nam;Park, Kwan-Ha
    • Korean Journal of Food Science and Technology
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    • v.30 no.1
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    • pp.206-212
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    • 1998
  • This study was undertaken to explore the applicability of glutathione S-transferase (GST) activity as a predictable indicator to monitor chemical pollution in shells and fishes utilized for food. There were some variations in the basal level of GST activity depending on species tested. Ark shells, Anadara satowi, showed the highest normal enzyme activity, followed by catfish and marine mussels, Mytilus coruscus. White clams, Meretrix lusoria, Israeli carp and catfish had lower activity. When A. satowi was exposed to 3-methyl-cholanthrene (3-MC), a prototypic polycyclic aromatic hydrocarbon for 1 week, GST activity decreased by about 30%. This reduction in GST activity induced by 3-MC did not recover until two weeks after the cessation of exposure. GST activity increased in response to 3-MC in most of the other species studied. The GST elevation in M. coruscus attained its maxinum of about 200% at the termination of 3-MC exposure maintaining this level up to 2 weeks, and declined gradually thereafter. 3-MC also induced GST activity in lsraeli carp in a similar fashion to M. coruscus. Phenobarbital induced GST activity both in M. coruscus and lsraeil carp. Other chemicals. such as clofibrate, butylated hydroxyanisole. hexachlorobenzene, and oxolinic acid did not change the enzyme activity significantly in most speciel. Phenol depressed GST activity only in lsraeli carp. These results suggest that the basal level of GST activity is somewhat variable and that the direction of change in response to chemicals seems to be related to its normal activity. The change in enzyme activity can be a preditable indicator of some environmental chemicals such as PAHs and phenol.

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Glutamate Receptor-interacting Protein 1 Protein Binds to the Armadillo Family Protein p0071/plakophilin-4 in Brain (Glutamate receptor-interacting protein 1 단백질과 armadillo family 단백질 p0071/plakophilin-4와의 결합)

  • Moon, Il-Soo;Seog, Dae-Hyun
    • Journal of Life Science
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    • v.19 no.8
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    • pp.1055-1061
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    • 2009
  • ${\alpha}$-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors are widespread throughout the central nervous system and appear to serve as synaptic receptors for fast excitatory synaptic transmission mediated by glutamate. Their modulation is believed to affect learning and memory. To identify the interaction proteins for the AMPA receptor subunit glutamate receptor-interacting protein 1 (GRIPl), GRIP1 interactions with armadillo family protein p0071/plakophilin-4 were investigated. GRIP1 protein bound to the tail region of p0071/plakophilin-4 but not to other armadillo family protein members in a yeast two-hybrid assay. The "S-X-V" motif at the carboxyl (C)-terminal end of p0071/plakophilin-4 is essential for interaction with GRIP1. p0071/plakophilin-4 interacted with the Postsynaptic density-95/Discs large/Zona occludens-1 (PDZ) domains of GRIPI in the yeast two-hybrid assay, as is indicated also by Glutathione S-transferase (GST) pull-down, and co-immunoprecipitated with GRIP1 antibody in brain fraction. The findings of this study provide evidence that p0071/plakophilin-4 is an interactor of GRIP1.

Antioxidant Activities of Citrus unshiu Extracts obtained from Different Solvents (추출용매에 따른 진피 추출물의 항산화 활성)

  • Lee, Sung-Gu;Oh, Sung-Cheon;Jang, Jae-Seon
    • The Korean Journal of Food And Nutrition
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    • v.28 no.3
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    • pp.458-464
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    • 2015
  • In this study, the total polyphenol content, electron donating ability (EDA) and inhibitory activity of glutathione S-transferase (GST) of freeze-dried Citrus unshiu extracts were examined. The Citrus unshiu extracts was obtained from four solvents such as ethyl acetate, acetone, methyl chloride and methanol, to evaluate its functional properties. Total polyphenol contents were measured in the two different extracts, and the extracts were screened for their potential antioxidant activities using tests such as electron donating ability (EDA), glutathione S-transferase (GST). The total polyphenol contents of Citrus unshiu extracts were $928.48{\pm}1.19{\mu}g\;GAE/mL$ in ethyl acetate (EA), $886.03{\pm}0.44{\mu}g\;RE/mL$ in acetone (AC), $413.08{\pm}1.39{\mu}g\;GAE/mL$ in methylene chloride (MC), $12,648.60{\pm}0.56{\mu}g\;GAE/mL$ in methanol (MeOH), respectively. Also, the total polyphenol contents of EtOH Citrus unshiu extracts were $664.64{\pm}0.74{\mu}g\;GAE/mL$ in EA, $702.67{\pm}0.85{\mu}g\;RE/mL$ in AC, $429.64{\pm}0.61{\mu}g\;GAE/mL$ in MC, $16,108{\pm}0.73{\mu}g\;GAE/mL$ in MeOH, respectively. The total polyphenol contents were significantly difference (p<0.05) between the solvents. The electron donating ability of Citrus unshiu extracts were $62.80{\pm}0.36%$ in EA, $97.43{\pm}0.51%$ in AC, $52.20{\pm}0.30%$ in MC, $97.63{\pm}0.46%$ in MeOH, respectively. Also, the electron donating ability of EtOH Citrus unshiu extracts were $51.49{\pm}0.26%$ in EA, $63.17{\pm}0.31%$ in AC, $67.68{\pm}0.55%$ in MC, $96.18{\pm}0.41%$ in MA, respectively. The electron donating ability were significantly difference (p<0.05) between the solvents. The inhibitory activity of glutathione S-transferase in Citrus unshiu extracts were $76.22{\pm}0.65%$ in EA, $31.73{\pm}0.48%$ in MC, $97.48{\pm}0.56%$ in MeOH, respectively. Also, inhibitory activity of glutathione S-transferase in EtOH Citrus unshiu extracts were $75.54{\pm}0.55%$ in EA, $73.53{\pm}0.38%$ in MC, $48.70{\pm}0.46%$ in MeOH, respectively. The inhibitory activity of glutathione S-transferase were significantly difference (p<0.05) between the solvents. These results indicated that the Citrus unshiu extracts is a high-valued food ingredient and the extraction with methanol will be useful as a nutritional source with natural antioxidant activities. Considering high consumer demand beneficial health effects, Citrus unshiu extracts can be utilized to develop functional food health- promoting and natural antioxidant agents.

Detection of Multi-class Pesticide Residues Using Surface Plasmon Resonance Based on Polyclonal Antibody

  • Yang, Gil-Mo;Kang, Suk-Won
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.547-552
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    • 2008
  • The detection of carbamate (carbofuran, carbaryl, benfracarb, thiodicarb, and methomil) and organophosphate (diazinon, cadusafos, ethoprofos, parathion-methyl, and chlorpyrifos) pesticide residues with very low detection limits was carried out using surface plasmon resonance (SPR) based equipment. The capacity to develop a portable SPR biosensor for food safety was also investigated. The applied ligand for the immunoassays was polyclonal goat anti-rabbit immunoglobulin (IgG) peroxidase conjugate. Concentration tests using direct binding assays showed the possibility of quantitative analysis. For ligand fishing to find a proper antibody to respond to each pesticide, acetylcholinesterase (AChE), and glutathione-S-transferase (GST) were tested. The reproducibility and precision of SPR measurements were evaluated. With this approach, the limit of detection for pesticide residues was 1 ng/mL and analysis took less than 11 min. Thus, it was demonstrated that detecting multi-class pesticide residues using SPR and IgG antibodies provides enough sensitivity and speed for use in portable SPR biosensors.

The Effect of Pyrogallol on the Pharmacological Action of Ephedrine and Epinephrine (Ephedrine 및 Epinephrine 의 작용(作用)에 미치는 Pyrogallol 의 영향(影響))

  • Lim, Zoo-Taek
    • The Korean Journal of Pharmacology
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    • v.4 no.1 s.5
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    • pp.41-44
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    • 1968
  • Pyrogallol is recently known to be a inhibitor of catechol-o-methyl transferase (COMT) and increase the action of epinephrine on the isolated rabbit atria. In this experiment, the author attempated to investigate the influence of pyrogallol on the effect of ephedrine and epinephrine on the blood pressure of the rabbit and isolated atria and excised intestine of the rabbit. The results obtained were summarized as follows; 1. Pyrogallol tends to increase the blood pressure and respiration of the rabbit. But it has no significant effect on the excised rabbit atria and intestine. 2. The effect of ephedrine on the blood pressure and respiration, isolated atria and excised intestine of the rabbit were not influenced by the pretreatment with pyrogallol. 3. The effect of epinephrine on the blood pressure and isolated atria of the rabbit is potentiated with pyrogallol pretreatment.

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