Research result 
해외 논문
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Synthesis of 2'-Deoxyisoguanosine 5'-Triphosphate and 2'-Deoxy-5- methylisocytidine 5'-Triphosphate
2023-07-27 10:36
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PCR amplification of DNA containing non-standard base pairs by variants of reverse transcriptase from Human Immunodefiency Virus-1
2023-07-27 10:36
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Influences of surface capping on particle size and optical characteristics of ZnS : Cu nanocrystals
ZnS:Cu nanocrystals were prepared by solution synthesis technique in thi s study, and the systematic investigation was carried outfor the surfac e capping effect in which the particle size could be controlled and the particle agglomeration could be reduced. The optical characteristics su ch as photoluminescence (PL) intensity and emission wavelength were also enhanced with surface capping. Sodium polyphosphate (SPP) was used as t he surface capping agent, and the new results about the effects of SPP c apping on structural and optical properties of ZnS:Cu nanocrystals were obtained as follows. ZnS nanoparticles had the cubic structure (beta-Zn S), and the crystal structure was not changed with the input of SPP. The particle morphology was spherical, and grain size was decreased and par ticle agglomeration was reduced with an increase of SPP input amount. Th e position of UV absorption edge was found to depend upon the SPP input amount, and it was decreased from 340 to 280 nm with the increase of SP P from 0.0 to 1.89 g, clearly showing the remarkable blue-shift phenomen on. PL intensities were also dependent upon the amount of capping agent, and the highest PL intensity was obtained for the sample capped with SP P 1.13 g in this study. PL emission wavelength was also blue-shifted, an d it was decreased from 518 to 462 nm with the increase of SPP from 0.0 to 1.89 g. (c) 2005 Elsevier B.V. All rights reserved.
2023-07-27 10:35
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Three-Dimensional Hierarchically Organized Magnetic Nanoparticle Polymer Composite: Achievement of Monodispersity and Enhanced Tensile Strength
2023-07-27 10:34
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Tris(2-methoxyphenyl)phosphine as a Highly Active Ligand for the Synthesis of Biaryls by Suzuki Coupling Reaction
2023-07-27 10:34
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Hybrid Photoreactive Magnet Obtained from Fe3O4/TiO2 Composite Nanoparticles
2023-07-27 10:33
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Cobalt-Manganese Oxide/Carbon-nanofiber Composite Electrodes for Supercapacitors
Composite electrodes consisting of Mn-Co oxide and high electrical conductive carbon nanofibers(vapor grown carbon nanofiber, VGCF)(CoMnO2/VGCF) were prepared by thermally decomposing manganese and cobalt nitrates directly onto the pore ofa porous nickel foam substrate as a current collector to form manganese and co balt oxides, and their supercapacitiveproperties were investigated us ing cyclic voltammetry in 1M KOH aqueous solution. The CoMnO2/VGCF e lectrodes exhibitedhigh specific capacitance value of 630 F/g at 5 mV/s and excellent capacitance retention of 95% after 10(4) cycles .
2023-07-27 10:31
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Electrocatalytic Properties of Carbon Nanofiber Web-Supported Nanocrystalline Pt Catalyst as Applied to Direct Methanol Fuel Cell
Carbon nanofibers (CNFs) web supported platinium nanoparticles were prepared by an electrochemical deposition method at sweeptimes of 5, 10, 20 and 40. Structure, composition and surface morphology of Pt incorporated CNF were analyzed by using X-ray diffraction (XRD), E nergy dispersive x-ray spectroscopy (EDX), Field emission scanning elect ron microscopy (FE-SEM) and High resolution transmission electron microscopy (HR-TEM) techniques. Structural analysis by XRD sh owed face centered cubic crystal structure of Pt. Particle size and loa ding level (wt%) of Pt were found to increase from 10.7 to 18.6 nm and 3 .3 to 7.0 6%, respectively with the increase of sweep times. SEM images showed that the Pt nano particles were agglomerated and effectively adhered on CNF with increase of sweep times. Nanocrystalline Pt and its FCC structure were also confirmed by using HR-TEM. Electrocataly tic activity of the nano Pt/CNF composite was demonstrated by li near voltammetrty, cyclic voltammetry and impedance spectra. The results showed increment in catalytic activity with the increase of sweep time.
2023-07-27 10:31
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Nafion-Doped Polypyrrole as a Supercapacitor Electrode in Ionic Liquid
The supercapacitive properties of flexible Nafion-doped polypyrrole(PPy/Nafion) electrodes prepared using a fle xible gold coated porous PVDF substrate were investigated in the p resence of an ionic liquid, N-methyl-N-propylpyridiniumtrifluorometh anesulfonyl imide(P1, 3TFSI), by means of cyclic voltammetry for su percapacitors. The PPy/Nafion showed capacitance values in the range o f 350-450 F/g at the scan rates of 50-300 mV/s, indicating the ionic liq uid is suitable for the electrolyte in supercapacitor.
2023-07-27 10:30
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Photoelectrochemical Cell Study on Closely Arranged Vertical Nanorod Bundles of CdSe and Zn doped CdSe Films
Closely arranged CdSe and Zn doped CdSe vertical nanorod bundles were grown directly on FTO coated glass by using electrodeposition method. Structural analysis by XRD showed the hexagonal phase without any precipitates related to Zn. FE-SEM image showed end capped vertic ally aligned nanorods arranged closely. From the UV-vis transmittance spectra, band gap energy was found to vary between 1.94 and 1.98 eV due to the incorporation of Zn. Solar cell parameters were obtained by assembling photoelectrochemical cells using CdSe and CdSe:Zn photoanodes, Pt cathode and polysulfide (1M Na2S + 1M S + 1M NaOH) electrolyte. The efficiency was found to increase from 0.16 to 0.22 upon Zn doping. Electrochemical impedance spectra (EIS) ind icate that the charge-transfer resistance on the FTO/CdSe/polysulfide interface was greater than on FTO/CdSe:Zn/polysulfide. Cyclic voltam metry results also indicate that the FTO/CdSe:Zn/polysulfide showed high er activity towards polysulfideredox reaction than that of FTO/CdSe/p olysulfide.
2023-07-27 10:30
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Preparation and enhanced stability of flexible supercapacitor prepared from Nafion/polyaniline nanofiber
Polyaniline nanofibers were used to produce a flexible supercapacitor electrode with a specific capacitance of 235 F g(-1). Cycle life and energy density were enhanced after encapsulating the polyaniline nanofiber electrode in Nafion. A specificcapacitance of 195 F g (-1) was obtained over 10,000 charge-discharge cycles. A fully flexib le, stand alone capacitor comprising two polyaniline nanofiber based electrodes and a PVDF separator was constructed. An initial spec ific capacitance of 125 F g(-1) (100 mV s(-1)) was obtained. This dec reased to 95 F g(-1) over 10,000 cycles. (C) 2009 Elsevier B.V. All rig hts reserved.
2023-07-27 10:29
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Cyclosporine A Reduces Dendritic Outgrowth of Neuroblasts in the Subgranular Zone of the Dentate Gyrus in C57BL/6 Mice
In the present study, we observed the effects of cyclosporine A (CsA), an efficient immunosuppressant, on cell proliferation andneuroblast differentiation in the subgranular zone of the dentate gyrus (SZDG) in normal C57BL/6 mice using Ki67 and doublecortin (DCX) immunohistochemical staining, respectively. At 8 week s of age, vehicle (physiological saline) orCsA was daily administered (40 mg/kg, i.p.) for 1 week. Animals were sacrificed at 2 weeks after last administration. CsA treatment did not show any influ ences in neurons, astrocytes and microglia based on immunohistochemist ry for its markers, respectively. However, in the CsA-treated group, Flu oro-Jade B, a marker for neurodegeneration, positive cells were fo und in the SZDG, not in the vehicle-treated group. In the vehicle-tre ated group, Ki67 immunoreactive ((+)) nuclei were clustered in the SZ DG, whereas in the CsA-treated group Ki67(+) nuclei were scattered in t he SZDG, showing no difference in cell numbers. Numbers of DCX+ neurobla sts with well-developed processes (tertiary dendrites) were m uch lower in the CsA-treated group than those in the vehicle-treated group; however, numbers of DCX+ neuroblasts with secondary dendrite s were similar in both the groups. These results suggest that CsA sig nificantly reduces dendritic outgrowth and complexity from neuroblasts in the SZDG without any affecting in neurons, astrocytes and microglia in normal mice.
2023-07-27 10:29
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Anti-HIV-1 efficacy of extracts from medicinal plants
The anti-HIV-1 activities of butanol, hexane, chloroform and water extracts from four widely used folk medicinal plants (Sophora flavescens, Tulipa edulis, Herba ephedra, and Pachyma hoelen Rumph) were evaluated in this study. The hexane extract of Pachyma hoelen Rumph, PH-4, showed effective inhibition against HIV-1. The 50% effective concentration (EC50) of PH-4 was 37.3 mu g/ml in the p24 antigen assay and 36.8% in the HIV-1 recombinant RT activi ty test (at 200 mu g/ml). In addition, the PH-4 showed the protective effect on the infected MT-4 cells, with a 58.2% rate of protection. The 50% cytotoxic concentration (CC50) of PH-4 was 100.6 mu g/ml. These res ults suggest that PH-4 from Pachyma hoelen Rumph might be the candidat e for the chemotherapy agent against HIV-1 infection with further s tudy.
2023-07-27 10:29
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Proliferating Neural Progenitors in the Developing CNS of Zebrafish Require Jagged2 and Jagged1b
In the central nervous system (CNS), giving rise to the diversity and the complexity of neurons is the spatial and temporal differentiation of neural stem cells and/or neural precursors. Here, we investigated the role of Jagged-mediated Notch signaling in the maintenance and differentiation of progenitor cells during late neurogenesis by analyzing the expression patterns of zebrafish jagged homologue s, and by injecting their morpholinos. Expression of both jagged2 and jagged1b mRNA in the CNS suggested that they might be involved in contr ol of differentiating neural progenitors in which they are involved later in development. In Jagged2 and Jagged1b knock-down embryos, the overall rate of cell division dramatically decreased, and the ectopi c VeMe neurons were generated. The results suggest that Jagged-Notc h signaling plays a critical role in the maintenance of proliferating ne ural precursors, and that the generation of late-born neurons, es pecially VeMe neurons, is regulated by the interplay between Jagged2 and Jagged1b.
2023-07-27 10:28
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Comparison of Newly Generated Doublecortin-immunoreactive Neuronal Progenitors in the Main Olfactory Bulb among Variously Aged Gerbils
In the present study, we investigated age-related differences in neuronal progenitors in the gerbil main olfactory bulb (MOB) usi ng doublecortin (DCX), a marker for neuronal progenitors which differentiate into neurons in the brain. No difference in t he number of neuronal nuclei (NeuN)-immunoreactive neurons was found in the MOB at variously aged gerbils. At postnatal month (PM) 1, DCX imm unoreaction was detected in all layers of the MOB except for the olfac tory nerve layer. Atthis time point, DCX-immunoreactive cells (neuro nal progenitors) were very abundant; however, they did not hav e fully developed-processes. From PM 3, the number of DCX-immunore active neuronal progenitors was decreased with age. At PM 6, DCX-immunoreactive cells showed very well-developed p rocesses. In western blot analysis, DCX protein level in the MOB w as highest at PM 1. Thereafter, levels of DCX protein were decreased w ith age. In the subventricular zoneof the lateral ventricle, the num ber of Ki-67-immunoractive cells (proliferating cells) was a lso significantly decreased with age. In addition, increases of alpha-synuclein-immunoreactive structures wer e observed in the MOB with age. These results suggest that decrease in D CX-immunoreactive neuronal progenitors and its protein levels in the MOB with age may be associated with reduction of cell proliferati on in the SVZ and with an increase in alpha- synuclein in the MDS
2023-07-27 10:27
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COMPARISON OF PHOSPHORYLATED EXTRACELLULAR SIGNAL-REGULATED KINASE 1/2 IMMUNOREACTIVITY IN THE HIPPOCAMPAL CA1 REGION INDUCED BY TRANSIENT CEREBRAL ISCHEMIA BETWEEN ADULT AND AGED GERBILS
In this study, the authors examined the difference of phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2) in the hippocamp al CA1 region (CA1) between adult and aged gerbils after 5 min of transient cerebral ischemia. Delayed neuronal death in the CA1 of the aged group was much slower than that in the adult group after ischemia/reperfusion (I/R). pERK1/2 immunoreaction was observ ed in the CA1 region of the sham-operated adult gerbil. pERK1/2 immunor eactivity and protein levels in the ischemic CA1 region of the adult gr oup were markedly increased 4 days after I/R, and then reduced up to 1 0 days after I/R. In contrast, pERK1/2 immunoreaction was hardly det ected in the CA1 region of sham-operated aged gerbils, and the immunor eactivity increased from 1 day after the ischemic insult, and still obs erved until 10 days post-ischemia. In addition, pERK1/2-immunoreact ion was expressed in astrocytes in the ischemic CA1 region: The expre ssion in the ischemia-operated aged gerbils was later than that in the ischemia-operated adult gerbils. These results indicate that different patterns of ERK1/2 immunoreactivity may be associated with d ifferent processes of delayed neuronal death in adult and aged animal s.
2023-07-27 10:27
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COMPARISON OF GLUCOCORTICOID RECEPTOR AND IONIZED CALCIUM-BINDING ADAPTER MOLECULE 1 IMMUNOREACTIVITY IN THE ADULT AND AGED GERBIL HIPPOCAMPUS FOLLOWING REPEATED RESTRAINT STRESS
Stress leads to changes in homeostasis and internal balance of the body and is known to be one of important factors in the development of several diseases. In the present study, we investigated changes i n glucocorticoid receptor (GR) and ionized calcium-binding adapter molecule 1 (Iba-1) immunoreactivity in the adult and aged gerbil hippocampus after chronicrestraint stress. Serum corticosterone level was much higher in both the stress-groups than the control group s. No neuronal death was found in all hippocampal subregions of the ad ult and aged gerbil after chronic restraint stress. GR immunoreactivity was decreased in both the adult and aged groups after repeated rest raint stress; however, GR immunoreactivity in the adult-stress-group was decreased much more than that in the aged-stress-group. Iba-1 immunoreactive microglia were hypertrophied and activated in the adult group after repeated restraint stress; in the aged-stress-gr oup, there was no any significant change in Iba-1 immunoreactive microg lia. In brief, level of GR, not Iba-1, in the hippocampus was much d ecreased in theadult gerbil compared to the aged gerbil following chron ic restraint stress.
2023-07-27 10:27
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TIME COURSE OF POSTNATAL DISTRIBUTION OF DOUBLECORTIN IMMUNOREACTIVE DEVELOPING/MATURING NEURONS IN THE SOMATOSENSORY CORTEX AND HIPPOCAMPAL CA1 REGION OF C57BL/6 MICE
In this study, we observed neuroblast differentiation in the somatosensory cortex (SSC) and hippocampal CA1 region (CA1), which is vulnerable to oxidative stress, of the mouse at various earl y postnatal days (P) 1, 7, 14, and 21 using doublecortin (DCX, a marker for neuroblasts). Cresyl violet and NeuN (Neuronal Nuclei) stai ning showed development of layers as well as neurons in the SSC and CA1 . At P1, DCX-positive neuroblasts expressed strong DCX immunoreactiv ity in both the SSC and CA1. Thereafter, DCX immunoreactivity was decre ased with time. At P7, many DCX-immunoreactive neuroblasts were well detected in the SSC and CA1. At P14, some DCX-positive neuroblasts wer e found in the SSC and CA1: The immunoreactivity was weak. At P21, DC X immunoreactivity was hardly found in cells in the SSC and CA1. These results suggest that DCX-positive neuroblasts were signif icantly decreased in the mouse SSC and CA1 from P
2023-07-27 10:26
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EFFECTS OF A NEW SYNTHETIC BUTYRYLCHOLINESTERASE INHIBITOR, HBU-39, ON CELL PROLIFERATION AND NEUROBLAST DIFFERENTIATION IN THE HIPPOCAMPAL DENTATE GYRUS IN A SCOPOLAMINE-INDUCED AMNESIA ANIMAL MODEL
2023-07-27 10:24
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PT-NI ALLOY NANOPARTICLES SUPPORTED ON CNF AS CATALYST FOR DIRECT ETHANOL FUEL CELLS
Carbon nanofiber (CNF) network supported Pt and Pt-Ni alloy nano particle catalysts were prepared by electrochemical deposition a t different deposition cycles. Structure, composition and surface morphology of the Pt/CNF and Pt-Ni/CNF were analyzed using X-ra y diffraction, Energy dispersive X-ray spectroscopy and field emi ssion scanning electron microscopy. Structural analysis by XRD reveal ed a face centered cubic crystal structure for Pt and its alloy. SEM images have shown that the Pt-Ni nanoparticles distributed evenly on t he CNF network. The electrocatalytic activity of the Pt/CNF and Pt-Ni/ CNF electrodes was verified using an electrochemical linear voltamm etrty (ELV), cyclic voltammetry (ECV) and electrochemicalimpedance spectroscopy (EIS) in an alkaline solution containing 1 M C2H 5OH + 1 M KOH. The results show increased catalytic activity with enhan cement of the Pt-Ni alloy formation. (C) 2011 Elsevier B.V. All rights reserved.
2023-07-27 10:23
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PROTECTIVE EFFECTS OF A NOVEL SYNTHETIC ALPHA-LIPOIC ACID-DECURSINOL HYBRID COMPOUND IN EXPERIMENTALLY INDUCED TRANSIENT CEREBRAL ISCHEMIA
Alpha-lipoic acid (ALA), a natural antioxidant, is widely used for the treatment of some diseases including diabetes, and decursinol (DA), a constituent of root of Angelica gigas Nakai, has some pharmacological activities including anti-inflammatory function. In this study, we synthesized a novel synthetic alpha-lipoic acid-decursinol (ALA-DA ) hybrid compound, and compared neuroprotective effects of ALA, DA o r ALA-DA against ischemic damage in the gerbil hippocampal CA1 regio n induced by 5 min of transient cerebral ischemia. In the 10 and 20 mg/kg ALA-, DA- and 10 mg/kg ALA-DA-pre-treated-ischemia-groups, there were no neuroprotective effects against ischemic damage 4 days after ischemic injury. However, 20 mg/kg ALA-DA pre-treatment protect ed pyramidal neurons from ischemic damage in the CA1 region. In ad dition, 20 mg/kg ALA-DA pre-treatment markedly decreased the activation of astrocytes and microglia in the CA1 region 4 days after ischemi c injury. On the other hand, post-treatment with the same dosages of them did not show any neuroprotective effect against ischemic damage . In brief, these findings indicate that pre-treatment with ALA-DA, not ALA or DA alone, can protect neurons from ischemic damage in the hippocampus induced by transient cerebral ischemia via the d ecrease of glial activation.
2023-07-27 10:23
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SUPERCAPACITIVE PROPERTIES OF CO-NI MIXED OXIDE ELECTRODE ADOPTING THE NICKEL FOAM AS A CURRENT COLLECTOR
Three-dimensional porous nickel foam was used as a current collector to prepare a Co-Ni oxide/Ni foam electrode for a supercapacitor. The synthesized Co-Ni oxide was proven to consist of mixed oxide phas es of Co3O4 and NiO. The Co-Ni oxide/Ni foam electrode prepared was characterized by morphological observation, crystalline prope rty analysis, cyclic voltammetry, and impedance spectroscopy. Cyc lic voltammetry for the electrode showed high specific capacitanc es, such as 936 F g(-1) at 5 mV s(-1) and 566 F g(-1) at 200 mV s(-1), and a comparatively good cycle performance. These improved results were mainly due to the dimensional stability of the nickel foam a nd its high electrical contact between the electrode material and the cu rrent collector substrate.
2023-07-27 10:23
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NEUROPROTECTION OF A NOVEL SYNTHETIC CAFFEIC ACID-SYRINGIC ACID HYBRID COMPOUND AGAINST EXPERIMENTALLY INDUCED TRANSIENT CEREBRAL ISCHEMIC DAMAGE
We investigated effects of caffeic acid, syringic acid, and their synthesis on transient cerebral ischemic damage in the gerbil hippocampal CA1 region. In the 10 mg/kg caffeic acid-, syring ic acid-, and 20 mg/kg syringic-treated ischemia groups, we did not fin d any significant neuroprotection in the ischemic hippocampal CA re gion. In the 20 mg/kg caffeic acid- and 10 mg/kg caffeic acid-syringic acid- treated ischemia groups, moderate neuroprotection was found i n the hippocampal CA1 region. In the 20 mg/kg caffeic acid- syringi c acid- treated ischemia group, a strong neuroprotective effect was f oundin the ischemic hippocampal CA1 region: about 89% of hippocampal CA1 region pyramidal neurons survived. We also observedchanges i n glial cells (astrocytes and microglia) in the ischemic hippocampal CA1 region in all the groups. Among them, the distribution pattern of t he glial cells was only in the 20 mg/kg caffeic acid- syringic acid- treated ischemia group brief, 20 mg/kg caffeic acid-syringic acid s howed a strong neuroprotective effect with an inhibition of glia ac tivation in thehippocampal CA1 region induced by transient cerebral is chemia.
2023-07-27 10:22
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SYNTHESIS OF SELECTIVE BUTYRYLCHOLINESTERASE INHIBITORS COUPLED BETWEEN ALPHA-LIPOIC ACID AND POLYPHENOLS BY USING 2-(PIPERAZIN-1-YL)ETHANOL LINKER
In the previous paper (Bull. Korean Chem. Soc., 2011, 32, 2997), the hybrid molecules between a-lipoic acid (ALA) and polyphenols (PPs) connected with neutral 2-(2-aminoethoxy)ethanol linker (linker-1) showed new biological activity such as butyrylcholinesterase (BuC hE) inhibition. In order to increase the binding affinity of the hybr id compounds to cholinesterase (ChE), the neutral 2-(2-aminoethoxy)e thanol (linker 1) was switched to the cationic 2-(piperazin-1-yl)ethanol linker (linker 2). The IC50 values of the linker-2 hybrid molecul es for BuChE inhibition were lower than those of linker-1 hybrid molecul es (except 9-2) and they also had the same great selectivity for BuC hE over AChE (> 800 fold) as linker-1 hybrid molecules. ALA-acetyl c affeic acid (10-2, ALA-AcCA) was shown as an effective inhibitor of BuCh E (IC50 = 0.44 +/- 0.24 mu M). A kinetic study using 7-2 showed tha t it is the same mixed type inhibition as 7-1. Its inhibition constant (Ki) to BuChE is 4.3 +/-0.09 mu M.
2023-07-27 10:22
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NEUROPROTECTIVE EFFECT OF A NEW SYNTHETIC ASPIRIN-DECURSINOL ADDUCT IN EXPERIMENTAL ANIMAL MODELS OF ISCHEMIC STROKE
Stroke is the second leading cause of death. Experimental animal models of cerebral ischemia are widely used for researching mechanisms of ischemic damage and developing new drugs for the prevention and treatment of stroke. The present study aimed to comparatively investigate neuroprotective effects of aspirin (ASA), decursi nol (DA) and new synthetic aspirin-decursinol adduct (ASA-DA) against transient focal and global cerebral ischemic damage. We found that tre atment with 20 mg/kg,not 10 mg/kg, ASA-DA protected against ischemia-in duced neuronal death after transient focal and global ischemic dam age, and its neuroprotective effect was much better than that of ASA or DA alone. In addition, 20 mg/kg ASA-DA treatment reduced the ischemia-induced gliosis and maintained antioxidants leve ls in the corresponding injury regions. In brief, ASA-DA, a new syn thetic drug, dramatically protected neurons from ischemic damage, and neuroprotective effects of ASA-DA may be closely related to the attenuation of ischemia-induced gliosis and maintenance of antioxidants.
2023-07-27 10:22
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DEVELOPMENT OF CHOLINESTERASE INHIBITORS USING (A)-LIPOIC ACID-BENZYL PIPERAZINE HYBRID MOLECULES
A series of hybrid molecules between (alpha)-lipoic acid (ALA) and benzyl piperazines were synthesized and their in vitro cholinester ase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibitory activities were evaluated. Even though the parent co mpounds did not show any inhibitory activity against cholinesterase (Ch E), all hybrid molecules showed BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specificall y, ALA-1-(3-methylbenzyl)piperazine (15) was shown to be an effec tive inhibitor of both BuChE (IC50 = 2.3 +/- 0.7 mu M) and AChE (IC 50 = 30.31 +/- 0.64 i mu M). An inhibition kinetic study using comp ound 15 indicated a mixed inhibition type. Its binding affinity (K-i) value to BuChE is 2.91 +/- 0.15 mu M.
2023-07-27 10:21
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A NOVEL CAFFEIC ACID-L-PIPERONYLPIPERAZINE HYBRIDIZATION COMPOUND HBU-47 INHIBITS LPS-MEDIATED INFLAMMATION IN RAW264.7 MACROPHAGE CELLS
In the present study, we synthesized a new hybrid compound by coupling caffeic acid and 1-piperonylpiperazine. The synthetic compound, acetyl-caffeic acid-1-piperonylpiperazine (HBU-47), showed pote nt anti-inflammatory effects inhibiting lipopolysaccharide (LPS)-i nduced production of nitric oxide (NO) in RAW264.7 macrophage cells. H BU-47 inhibited LPS-caused induction of inducible NO synthase (iNOS), cyclooxygenase-2, interleukin-6 and interleukin-1 beta in RAW26 4.7 cells in time- and dose-dependent manner. Compared to HBU-47, n either caffeic acid nor 1-piperonylpiperazine displayed significant in hibition of LPS responses. HBU-47 did not affect LPS-caused activation o f mitogen-activated kinases (MAPKs) or I kappa B-alpha. degradati on. Instead, LPS-mediated NF-kappa B activation and DNA bindings of p65, p50 and c-Rel to the NF-kappa B binding site of iNOS promoter w ere inhibited by HBU-47. Overall, our data suggest that the novel c affeic acid hybrid compound downregulates inflammatory responses throu gh inhibition of NF-kappa B and NE-kappa B-dependent gene expressi ons, thus, further suggesting its efficacy as a promising therapeuti c agent. (C) 2014 Elsevier B.V. All rights reserved.
2023-07-27 10:21
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NEUROPROTECTION OF POSTTREATMENT WITH RISPERIDONE, AN ATYPICAL ANTIPSYCHOTIC DRUG, IN RAT AND GERBIL MODELS OF ISCHEMIC STROKE AND THE MAINTENANCE OF ANTIOXIDANTS IN A GERBIL MODEL OF ISCHEMIC STROKE
Risperidone, an atypical antipsychotic drug, has been discovered to have some beneficial effects beyond its original effectiveness. The present study examines the neuroprotective effects of risperidone against ischemic damage in the rat and gerbil induced by transien t focal and global cerebral ischemia, respectively. The results sho wed that pre- and posttreatment with 4 mg/kg risperidone significantl y protected against neuronal death from ischemic injury. Many NeuN-immunoreactive neurons and a few F-J B-positive cells were found in the rat cerebral cortex and gerbil hippocampal CA1 regi on (CA1) in the risperidone-treated ischemia groups compared with thos e in the vehicle-treated ischemia group. In addition, treatment wit h risperidone markedly attenuated the activation of microglia in the ger bil CA1. On the other hand, we found that treatment with risperidone s ignificantly maintained the antioxidants levels in the ischemic gerbil CA1. Immunoreactivities of superoxide dismutases 1 and 2, cata lase, and glutathione peroxidase were maintained in the stratum pyr amidale of the CA1; the antioxidants were very different from those in t he vehicle-treated ischemia groups. In brief, our present fi ndings indicate that posttreatment as well as pretreatment with risperidone can protect neurons in the rat cerebral cortex and gerbi ls CA1 from transient cerebral ischemic injury and that the neuropro tective effect of risperidone may be relatedto attenuation of microgli al activation as well as maintenance of antioxidants. (c) 2014 Wiley P eriodicals, Inc.
2023-07-27 10:21
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DEVELOPMENT OF CHOLINESTERASE INHIBITORS USING 1-BENZYL PIPERIDIN-4-YL (ALPHA)-LIPOIC AMIDE MOLECULES
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 butyrylcholinest erase (BuChE)) inhibitory activities were evaluated. Even though the p arent compounds did not exhibit any inhibitory activity against cholinesterase (ChE) withthe exception of compound 14 (I C50 = 255.26 +/- 4.41 against BuChE), all hybrid molecules demonstrate d BuChE inhibitory activity. Some hybrid compounds also displayed AChE inhibitory activity. Specifically, compound 17 was shown to be an effective inhibitor against both AChE (IC50 = 1.75 +/- 0 .30 mu M) and BuChE (IC50 = 5.61 +/- 1.25 mu M) comparable to galantam ine (IC50 = 1.7 +/- 0.9 mu M against AChE and IC50 = 9.4 +/- 2.5 mu M ag ainst 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 BuC hE were 3.8 +/- 0.005 mu M and 7.0 +/- 0.04 mu M, respectively.
2023-07-27 10:20
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Supercapacitive properties of composite electrode consisting of activated carbon and a quinone-containing conducting additive
"A quinone-containing conducting additive, 2,5-bis((2-(1H-indol-3-yl)ethyl)amino)cyclohexa 2,5-diene-1,4-dione (HBU) is synthesized and mixed with activated carbon as an active material to yield a composite supercapacitor electrode. Due to the extra redox reaction of hydroquinone/quinone couple, the supercapacitor adopting the composite electrode shows the enhancement of the electrochemical specific capacitance up to about 130 F g(-1) in the scan range of 100-1000 mV s(-1) and over the repeated redox processes for 1000 cycles at 100 mV s(-1), compared to the case of activated carbon electrode alone (about 100 F g(-1)). The composite with the HBU is also electrochemically stable in the charge/discharge process and thereby can be highly recommended for supercapacitor electrode additive. (C) 2015 Elsevier B.V. All rights reserved."
2023-07-27 10:20
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A DOPAMINE-ALPHA-LIPOICACIDHYBRIDIZATIONCOMPOUND AND ITSACETYLATEDFORMINHIBITLPS-MEDIATEDINFLAMMATION
2023-07-27 10:20
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(S)-ALLYL CYSTEINE DERIVATIVES AS A NEW-TYPE CHOLINESTERASE INHIBITOR
2023-07-27 10:19
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SUPERCAPACITIVE PROPERTIES OF COMPOSITE ELECTRODE CONSISTING OF ACTIVATED CARBON AND DI(1-AMINOPYRENE)QUINONE
Di(1-aminopyrene)quinone (DAQ) as a quinone-containing conducting additive is synthesized from a solution reaction of 1-aminopyrene and hydroquinone. To utilize the conductive property of DAQ and its compatibility with activated carbon, a composite electrode for a supercapacitor is also prepared by blending activated carbon a nd DAQ (3:1 w/w), and its supercapacitive properties are characterize d based on the cyclic voltammetry and galvanostatic charge/discharge. As a result, the composite electrode adopting DAQ exhibits superio r electrochemical properties, such as a higher specific capacit anceof up to 160 F.g(-1) at 100 mV.s(-1), an excellent high-rate capabi lity of up to 1,000 mV.s(-1), and a higher cycling stability with a capa citance retention ratio of 82% for the 1,000th cycle.
2023-07-27 10:18
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SUPERCAPACITIVE PROPERTIES OF ACTIVATED CARBON-QUINONE DERIVATIVE COMPOSITE ELECTRODE IN DIFFERENT HYDROGEN ION CONDUCTING ELECTROLYTES
A composite electrode (CE) consisting of activated carbon and quinine derivative 2-((2-(1H-indol-3-yl) ethyl) amino) naphthalene-1, 4-dione (HBU-551) was probed in different hydrogen ion conducting electrolyte s such as sulfuric acid (H2SO4), hydrochloric acid (HCl), Phosphoric ac id (H3PO4) and ammonium chloride (NH4Cl). The electrochemical performanc es of the CE in the electrolytes were investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and charge-discharge. The different hydrogen ion conductin g electrolytes with different ionic conductivity induce different ele ctrochemical properties in the CE. The specific capacitance is in t he order of H2SO4 > H3PO4 > HCL > NH4Cl at 100 mV/s and a potential rang e of -0.2 - 0.8 (V vs Ag/AgCl).
2023-07-27 10:18
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SUPERCAPACITIVE PROPERTIES OF COMPOSITE ELECTRODES CONSISTING OF ACTIVATED CARBON AND 1,4-DIHYDROXYNAPHTHALENE DERIVATIVES
Two 1,4-dihydoxynaphthalene (PhQH(2))-based derivatives (coded as HBU-551 and HBU-552) are synthesized by reacting with different a mines (i.e., tryptamine and phenethylamine, respectively) to use as org anic additives of activated carbon supercapacitors. The composite elec trodes with HBU-551 and HBU-552 are also prepared by blending with the r atio of 70:25 w/w, and their supercapacitive properties are investigat ed in terms of redox behaviors and specific capacitance evolutions agai nst scan rateand cycle life. The organic additives and their composi tes with activated carbon are dominantly characterized by PhQ-PhQH(2) redox transition accompanying a two-electron two-proton process, and we akly affected by reversible redox reaction of nitrogen in the -NH grou p, which involves an additional one-electron one-proton process. Thu s, the composite electrodes show higher specific capacitance over 210 F g(-1) due to the synergistic effect between activated carbon (pseudocapacitance)and organic additives (redox behav ior). Cycle performance and high-rate capability can also be enhan ced by the adoption of PhQH(2)-based organic additives for their pore-filling morphology to increase the packing density of composi te electrodes. (C) 2016 Elsevier B.V. All rights reserved.
2023-07-27 10:18
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Cu-Pd Bimetallic Catalyst for Electrocatalytic Reduction of Nitrates in Water
2023-07-27 10:17
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SYNTHESIS OF BENZOISOXAZOLE DERIVATIVES AND EVALUATION OF INHIBITORY POTENCY AGAINST CHOLINESTERASE FOR ALZHEIMER'S DISEASE THERAPEUTICS
To improve Alzheimer's disease (AD) therapeutics, we have designed and synthesized new benzoisoxazole derivatives that are potent inhibitors of cholinesterase (acetylcholinesterase [AChE] and butyrylcholinesterase [BuChE]). Since inhibition o f cholinesterase (ChE) is still considered to be one of the most ef fective ways of treating AD patients, many new classes of ChE inhi bitors have been synthesized. To identify a new type of cholinergic drug, the benzoisoxazole moiety which is the pharmacophore m oiety of Risperidone was coupled with natural antioxidants. Some benzoi soxazole derivatives (26-28 and 30) were found to effectively inhibit B uChE (IC50 < 20 mu M), and some (20 and 26-28) to moderately in hibitAChE (IC50 < 100 mu M). Furthermore, compound 28 showed be tter inhibitory activity against BuChE (IC50 = 0.72 +/- 0.11 mu M) than galantamine (IC50 = 8.4 +/- 0.1 mu M). The new benzoisoxazole derivati ves showing BuChE inhibitory activity represent a new class of ChE inhibitor and can be used to create novel compound derivative drug s for treating AD patients.
2023-07-27 10:15
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INHIBITION OF TYROSINASE ACTIVITY AND MELANIN PRODUCTION BY THE CHALCONE DERIVATIVE 1-(2-CYCLOHEXYLMETHOXY-6-HYDROXY-PHENYL)-3(4-HYDROXYMETHYL-PHENYL)-PROPENONE
Abnormal accumulation of melanin pigments in the skin can be lead to hyperpigmentation disorders and melanoma. Melanin biosynthesis is ultimately regulated by the rate-limiting enzyme tyrosinase. In t he present study, we synthesized chalcone derivatives and identified 1-(2-cyclohexylmethoxy-6-hydroxyphenyl)-3-(4-hydroxymethyl-phenyl )-propenone (chalcone-21) as an anti-melanogenic substance in B16F10 mel anoma cells. Chalcone-21 strongly inhibited cellular melanin production and tyrosinase activity in B16F10 melanoma cells stimulated with a-melanocyte stimulating hormone (alpha-MSH) or protoporphyr in IX. In addition, the compound suppressed not only the expression of tyrosinase, tyrosinase-related protein-1 (TRP-1), TRP-2, and microphthalmia-associated transcription factor (MITF), but a lso the transcriptional activity of tyrosinase and MITE Our results demonstrated chalcone-21 to be an effective depigmenting ag ent. (C) 2016 Elsevier Inc. All rights reserved.
2023-07-27 10:15
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A tryptamine-paeonol hybridization compound inhibits LPS-mediated inflammation in BV2 cells
In the present study, we synthesized and evaluated the anti-inflammatory effects of three tryptamine (Trm) hybrid compounds, HBU-375, HBU-376 and HBU-379. The Click reaction between the azido-Trm and 2-or 4-propazylated paeonol moiety resulted in HBU-376 and HBU-375, respectively. HBU-379 was generated by hybridizing Trm with propazylated acetyl-syringic acid. HBU-376 and HBU-375 dose dependently inhibited LPS and caused nitric oxide (NO) generation in BV2 cells, whereas HBU-379 minimally inhibited NO generation, indicating that the paeonol unit plays an important role in the anti-inflammatory effect of Trm hybrid compounds. Although HBU-375 and HBU-376 demonstrated a similar inhibitory effect on LPS-induced NO generation, HBU-376 resulted in less cellular toxicity presumably due to the free phenolic hydroxyl group of paeonol. Therefore, HBU-376 may be a promising anti-inflammatory agent conferring minimal cytotoxicity. HBU-376 significantly and dose-dependently inhibited LPS-induced NO products, NO synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6, MCP-1 and interleukin-1 beta mRNA expressions and iNOS and COX-2 protein expressions: However, at the same concentrations, Trm or paeonol individually did not inhibit LPS-mediated production of inflammatory molecules. HBU-376 inhibited both LPS-induced STAT-3 phosphorylation and nuclear factor kappa B (NF-kappa B) activation. Furthermore, LPS-mediated DNA binding of c-Rel, p50 and p52 to the NF-kappa B binding site of the iNOS promoter was inhibited by HBU-376, whereas Trm and paeonol did not inhibit LPS-induced NF-kappa B activation and DNA binding of c-Rel, p50 and p52. Overall, our data suggest that the Trm-paeonol hybrid compound down-regulates inflammatory responses by inhibiting NF-kappa B and NF-kappa B dependent gene expression. This suggests that it is a potential therapeutic agent for inflammatory diseases of the central nervous system. (C) 2016 Elsevier Ltd. All rights reserved.
2023-07-27 10:15
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3,4-DIHYDROQUINAZOLINE DERIVATIVES INHIBIT THE ACTIVITIES OF CHOLINESTERASE ENZYMES
A series of 3,4-dihydroquinazoline derivatives consisting of the selected compounds from our chemical library on the diversity ba sis and the new synthetic compounds were in vitro tested for their inhib itory activities for both acetylcholinesterase (AChE, from electric ee l) and butyrylcholinesterase (BChE, from equine serum) enzymes. It was discovered that most of the compounds displayed weak AChE and s trong BuChE inhibitory activities. In particular, compound 8b and 8d were the most active compounds in the series against BChE with IC50 val ues of 45 nM and 62 nM, as well as 146- and 161-fold higher affinity to BChE, respectively. To understand the excellent activity of these c ompounds, molecular docking simulations were performed to getbetter in sights into the mechanism of binding of 3,4-dihydroquinazoline deriv atives. As expected, compound 8b and 8d bind to both catalytic anionic s ite (CAS) and peripheral site (PS) of BChE with better interaction ener gy values than AChE, in agreement with our experimental data. Furthermo re, the non-competitive/mixed-type inhibitions of both compounds furt her confirmed their dual binding nature in kinetic studies. (C) 2 017 Elsevier Ltd. All rights reserved.
2023-07-27 10:14
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LITHIUM BIS(OXALATE)BORATE AS AN ELECTROLYTE SALT FOR SUPERCAPACITORS IN ELEVATED TEMPERATURE APPLICATIONS
The electrolyte plays one of the most significant roles in the performance of electrochemical supercapacitors. Most liquid or ganic electrolytes used commercially have temperature and potential range constraints, which limit the possible energy and power output of the supercapacitor. The effect of elevated temperature on a lithi um bis(oxalate)borate(LiBOB)salt-based electrolyte was evaluate d in a symmetric supercapacitor assembled with activated carbon elec trodes and differentelectrolyte blends of acetonitrile(ACN) and propyle ne carbonate(PC). The electrochemical properties were investigat ed using linear sweep voltammetry, cyclic voltammetry, galvanostatic charge-discharge cycles, and electrochemical impedance spec troscopy. In particular, it was shown that LiBOB is stable at an operati onal temperature of 80 degrees C, and that, blending the solvent s helps to improve the overall performance of the supercapacitor. The cells retained about 81% of the initial specific capacitance aft er 1000 galvanic cycles in the potential range of 0-2.5 V. Thus, L iBOB/ACN:PC electrolytes exhibit a promising role in supercapacitor ap plications under elevated temperature conditions.
2023-07-27 10:14
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ANTICANCER ACTIVITY OF 2-AMINO-SUBSTITUTED-1,4-NAPHTHOQUINONE DERIVATIVES IN OVARIAN CANCER CELLS
2-Amino-substituted-1,4-naphthoquinone derivatives (10-17) were synthesized from coupling reaction between 1,4-dihydroxynaphtha lene and amines in the presence of catalyst CeCl(3)(.)7H(2)O. Their anti cancer activity was evaluated by using three ovarian cancer cells (A27 80, SKOV3, and OVCAR3). Among the eight compounds, compound 13 cont aining metal chelating moiety had a relatively potent cytotoxic activi ty (IC50 < 10 M) on all three ovarian cancer cells.
2023-07-27 10:14
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Supercapacitive properties of composite electrode consisting of activated carbon and quinone derivatives
2023-07-27 10:13
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A Novel Phenylsulfonamide Ameliorates the Cognitive Impairment in Mice Induced by Scopolamine
2023-07-27 10:13
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The Cytotoxic Activity of Honokiol-Triazole Derivatives in Ovarian Cancer Cells
Honokiol-triazole derivatives (4-17) were synthesized via click reactions between 2- or 4 -propargylated honokiol and azide compounds. Their anticancer activities were evaluated by using two ovarian cancer cells (A2780 and OVCAR3). Among the 14 compounds, compound 5 coupled with 4 -propargylated honokiol and benzyl azide exhibited relatively potent cytotoxic activity (IC50 = 5.5 +/- 0.5 mu M for A2780 and IC50 = 3.97 +/- 0.6 mu M for OVCAR3) but was less toxic to normal cells (IC50 = 18.90 +/- 0.9 mu M for IOSE80PC). The cytotoxic effect of compound 5 is associated with caspase-dependent apoptotic cell death via induction of intracellular reactive oxygen species.
2023-07-27 10:12
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Tryptamine-Triazole Hybrid Compounds for Selective Butyrylcholinesterase Inhibition
Tryptamine-triazole hybrid compounds (11-18) were synthesized via click reaction between tryptamine azide and propargylated natural compounds. Their cholinesterase inhibitory activity was evaluated. Among the eight compounds, compound 11 showed the most potent inhibitory activity [IC50 = 0.42 +/- 0.29 mu M for equine butyrylcholinesterase (BuChE) and 1.96 +/- 0.15 mu M for human BuChE]. From the molecular modeling study, compound 11 was bound to the catalytic anionic site, anionic subsite, peripheral anionic subsite, acyl-binding pocket, and oxyanion hole of human or horse BuChE by forming a hairpin or U-shaped structure. The Lineweaver-Burk plot of compound 11 against BuChE suggests a mixed type of inhibition which corresponds well with the molecular modeling study.
2023-07-27 10:12
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Naphthalene Derivative Supported Activated Carbon Composite Electrode with Enhanced Capacitance and Potential Window
A derivative of 1,4-Naphthoquinone coded HBU671 was synthesized and used in addition to activated carbon as composite electrode for supercapacitor application. From the electrochemical properties analysis, a specific capacitance of about 300 F g(-1) exhibited almost two times of that of activated carbon at a scan rate of 100 mV s(-1) and a potential window of - 0.2 - 1V. This improvement is due to the inherent redox reaction in HBU671. Cycle test also proved that this composite is still stable even after 1000 cycle within the applied potential window and it is highly recommended for practical application.
2023-07-27 10:11
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Phosphonamidate Compounds for Butyrylcholinesterase Selective Inhibitors
To find a new type of cholinergic drug, phosphonamidate compounds 18-32 were synthesized using a click reaction between propargylated-9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO, 2) and substituted benzyl azide. Their inhibitory activity against butyrylcholinesterase (BuChE) and acetylcholinesterase (AChE) was evaluated. Compound 31 was the most active of the 15 compounds (IC50 = 3.14 +/- 0.02 mu M for equine BuChE), whose IC50 value was slightly lower than the IC50 value of galantamine (IC50 = 9.4 +/- 2.50 for equine BuChE).
2023-07-27 10:10
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Novel structure of bacteria doped ZnO particles: Facile and green synthesis route to prepare hybrid material for supercapacitor electrodes
Zinc oxide (ZnO) nanostructures/bacteria (Escherichia coli, E. coli) composite material is successfully prepared via carbonization process. Morphological and electrochemical properties of nanostructure were studied as function of concentration of bacteria solution. Morphological properties of the composite material were investigated by scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET). The new approach of high-performance electrodes based on carbonization prepared from precursor and reductant of ZnO and bacteria resources. The ZnO nanostructures were reacted with the bacteria to introduce carbon (C) and nitrogen (N) for better electrochemical performance and an increased surface area. The bacteria doped ZnO electrode exhibited significantly enhanced specific capacitance (41 F g(-1)) at a discharge current density of 0.5 A g(-1), and cycling stability of 55% retention after 5000 cycles. Therefore, the bacteria as electrical dopant gave higher specific capacitance and cycle stability to the other metal oxide which could be a potential candidate in commercial applications of supercapacitors. (c) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
2023-07-27 10:10
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Effect of heteroatoms on the optical properties and enzymatic activity of N-doped carbon dots
Carbon dots (CDs) are attractive nanomaterials because of their facile synthesis, biocompatibility, superior physicochemical properties, and low cost of their precursors. Recent advances in CDs have particularly relied on the modulation of their properties by heteroatom doping (e.g., nitrogen). Although nitrogen-doped CDs (N-CDs) have attracted considerable attention owing to their different properties compared to those of the original CDs, the effects of the heteroatom content and types of bonding on the properties of N-doped CDs remain underexplored. In this work, we prepared N-CDs with controlled nitrogen contents, and fully examined their optical properties, enzymatic activity, and toxicity. We demonstrate that (i) the type of carbon-heteroatom bonding (i.e., carbon-oxygen and carbon-nitrogen bonds) can be altered by changing the ratio of carbon to heteroatom sources, and (ii) both the heteroatom content and the heteroatom-bonding character significantly influence the properties of the doped CDs. Notably, N-CDs exhibited higher quantum yields and peroxidase-like activities than the non-doped CDs. Furthermore, the negatively charged N-CDs exhibited negligible cytotoxicity. Such comprehensive investigations on the physicochemical properties of N-CDs are expected to guide the design of N-CDs for targeted applications.
2023-07-27 10:10
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Preparation of Vapor Grown Carbon Fiber/2-((4-dimethylamino) phenyl) amino) naphthalene-1, 4-dione Composites and their supercapacitor properties
In this work, a derivative of 1,4-dihydoxynaphthalene, 2-((4-dimethylamino) phenyl) amino) naphthalene-1,4-dione (HBU) was synthesized by reacting 1,4-dihydoxynaphthalene with N, N-Dimethyl-p-phenylenediamine. The supercapacitive properties of the electrodes containing various weights percent of vapor grown carbon fiber (VGCF) and HBU were probed in terms of redox behavior, the effect of VGCF, and specific capacitance. The VGCF created an excellent electronic pathway in the electrode, boosting the redox transition reaction in HBU involving a total of three-electron (3e(-))-three-proton (3H(+)) processes corresponding to 2,3-dihydro1,4-naphthoquinone-1,4-dihydroxynaphthalene and the aliphatic amine in the backbone of the substituted derivative of aniline. This led to a higher specific capacitance of 98 F/g for the HBU-VGCF electrode with a higher weight percent of HBU. The capacity retention of about 57% was observed for the HBU-VGCF electrodes after the 1000th cycle owing to the VGCF supporting the HBU by stabilizing its redox activity.
2023-07-27 10:09
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Synthesis of 4-substituted benzyl-2-triazole-linked-tryptamine-paeonol derivatives and evaluation of their selective inhibitions against butyrylcholinesterase and monoamine oxidase-B
Cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors are being used and developed to treat Alzheimers disease (AD), a major type of dementia patients. Fifteen 4-substituted benzyl-2-triazole-linked-tryptamine-paeonol derivatives were synthesized and evaluated for their inhibitory activities against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase-A (MAO-A), and B (MAO-B). Compound 896 was the most potent BChE inhibitor (IC50 = 0.13 mu M) with the selectivity index (SI) value of > 769.23 for BChE over AChE. Compound 897 was the most potent selective MAO-B inhibitor (IC50 = 0.73 mu M; SI = 20.45 for MAO-B over MAO-A). The meta-CF3 substituent of 896 increased BChE inhibitory activity and the para-CF3 substituent of 897 increased MAO-B inhibitory activity. Compound 896 was a reversible noncompetitive BChE inhibitor (K-i = 0.171 mu M) and 897 was a reversible competitive MAO-B inhibitor (K-i = 0.237 mu M). Compound 896 had a lower binding energy (-13.75 kcal/mol) to BChE than 897 (-11.29 kcal/mol), and 897 had a lower binding energy to MAO-B (-11.31 kcal/mol) than that to MAO-A (-6.72 kcal/mol). Little cytotoxicity was observed for 896 and 897 to normal cells (MDCK) and human neuroblastoma cells (SH-SY5Y). This study suggested that 896 and 897 are therapeutic candidates for various neurodegenerative disorders such as AD.
2023-07-27 10:09
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A Novel Aryl Hydrocarbon Receptor Antagonist HBU651 Ameliorates Peripheral and Hypothalamic Inflammation in High-Fat Diet-Induced Obese Mice
Obesity is a chronic peripheral inflammation condition that is strongly correlated with neurodegenerative diseases and associated with exposure to environmental chemicals. The aryl hydrocarbon receptor (AhR) is a ligand-activated nuclear receptor activated by environmental chemical, such as dioxins, and also is a regulator of inflammation through interacting with nuclear factor (NF)-kappa B. In this study, we evaluated the anti-obesity and anti-inflammatory activity of HBU651, a novel AhR antagonist. In BV2 microglia cells, HBU651 successfully inhibited lipopolysaccharide (LPS)-mediated nuclear localization of NF-kappa B and production of NF-kappa B-dependent proinflammatory cytokines, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, and IL-6. It also restored LPS-induced mitochondrial dysfunction. While mice being fed a high-fat diet (HFD) induced peripheral and central inflammation and obesity, HBU651 alleviated HFD-induced obesity, insulin resistance, glucose intolerance, dyslipidemia, and liver enzyme activity, without hepatic and renal damage. HBU651 ameliorated the production of inflammatory cytokines and chemokines, proinflammatory Ly6c(high) monocytes, and macrophage infiltration in the blood, liver, and adipose tissue. HBU651 also decreased microglial activation in the arcuate nucleus in the hypothalamus. These findings suggest that HBU651 may be a potential candidate for the treatment of obesity-related metabolic diseases.
2023-07-27 10:09
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New quinone-based electrode additives electrochemically polymerized on activated carbon electrodes for improved pseudocapacitance
Three quinone-based derivatives (HBU680, HBU888, and HBU889) are synthesized and separately mixed with activated carbon (AC) and electropolymerized to form a homogeneous composite electrode. The electrochemical properties of the composite electrodes are studied. The electrochemical properties are mainly characterized by PhQ-PhQH2 and Q-QH2 redox transitions. The composite electrodes show specific capacitance of 176 F/g, 262 F/g, and 145 F/g for HBU680, HBU888, and HBU889, respectively. The HBU888 shows the highest specific capacitance due to the fast PhQ-PhQH2 redox transition at a scan rate of 100 mV/s. The composite electrodes also show a 100% capacity retention over 10,000 cycles. These results show that the new quinone-based derivates can enhance pseudocapacitive behavior and warrant their use as electrode additives for supercapacitors.
2023-07-27 10:08
국내 논문
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Genetic Engineering of Escherichia coli for the Production of Precorrin-3 in Vivo and in Vitro.
2023-07-27 10:37
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New Cholinesterase Inhibitor, Lipoic Acid-Nitrone Derivatives
2023-07-27 10:35
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In Vitro Biosynthesis of Strictosidine Using Lonicera japonica Leaf Extracts and Recombinant Yeast
2023-07-27 10:35
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전해질염에 따른 EDLC 전기화학적 특성
2023-07-27 10:34
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PtCo/CNF web의 전기화학적 촉매 특성
2023-07-27 10:33
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Poly(vinyl alcohol)과 KOH로 제조 된 고체 전해질 필름에서 electrochemical double layer capacitors 특성
2023-07-27 10:32
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전착법으로 제조된 3성분계 PtCoNi/CNF web 촉매의 전기화학적 특성
2023-07-27 10:32
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전착에 의해 제조된 PtNi/CNF web의 전기화학적 특성
2023-07-27 10:32
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전해질 용매의 조성변화에 따른 염료감응태양전지의 광전환 효율특성 및 안정성 연구
2023-07-27 10:32
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이온 전해질에서 PANI Nanofiber의 전기화학적 특성
2023-07-27 10:31
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Electrochemical Performance of Lithium Sulfur Batteries with Plasticized Polymer Electrolytes based on P(VdF-co-HFP)
2023-07-27 10:28
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SELECTIVE BUTYRYLCHOLINESTERASE INHIBITORS USING POLYPHENOL-POLYPHENOL HYBRID MOLECULES
Polyphenols (PPs) are known as antioxidant compounds having benign biological activities. In this paper, a series of hybridmolecules between the free or acetyl protected poly phenol compounds were synthesized and their in vitro antioxidantactivity (DPPH assay) and cholinesterase [a cetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibition activities were evaluated. As expected, free phenolic hybrid compounds (6 and 8) showed better antioxidant activity than acetyl prote cted hybrid compounds (5 and 7) from DPPH assay. But the contrast result was obtained from BuChE inhibition assay. Acetylprotected hybrid compounds (5 and 7) showed better inhibition activity for BuChE than fre e phenolic hybrid compounds (6 and 8).Specifically, 10 (AcFA-AcFA) were shown as an effective inhibitor of BuChE (IC50 = 2.3 ± 0.3 μM) and also had a great selectivity for BuChE over AChE (more than 170 fold). Inhibition kinetic studies with acetyl protected compounds (5, 7, 9, and 10) indicated that 5, 7 and 10 are a h yperbolic mixed-type inhibition and 10 is a competitive inhibition type. The binding affinity (Ki) value of 10 to BuChE is 2.32 ± 0.15 μM.
2023-07-27 10:26
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DEVELOPMENT OF SELECTIVE BUTYRYLCHOLINESTERASE INHIBITORS USING (R)-LIPOIC ACID-POLYPHENOL HYBRID MOLECULES
A series of hybrid molecules between (R)-lipoic acid (ALA) and the acetylated or methylated polyphenol compounds were synthesized and their in vitro cholinesterase [acetylcholineste rase (AChE) and butyrylcholinesterase (BuChE)] inhibition activities were checked. The IC50 values of all hybr id molecules for a BuChE inhibition were lower than those of the single parent compounds. Specifically, ALA -acetyl protected caffeic acid (11, ALA-AcCA) was shown as an effective inhibitor of BuChE (IC50 = 0. 5 ± 0.2 μM) and also had a great selectivity for BuChE over AChE (more than 800 fold). Inhibition kinetic study indicated that 11 is a mixed inhibition type. Its binding affinity (Ki) value to BuChE is 1.52 ± 0.18 μM.
2023-07-27 10:24
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SYNTHESIS AND IN VITRO ASSAY OF NEW TRIAZOLE LINKED DECURSINOL DERIVATIVES SHOWING INHIBITORY ACTIVITY AGAINST CHOLINESTERASE FOR ALZHEIMER’S DISEASE THERAPEUTICS
With the goal of developing Alzheimer’s disease therapeutics, we have designed and synthesized new triazole linked decursinol derivatives having potency inhibitory activities against cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuC hE)]. Since inhibition of cholinesterase (ChE) is still considered to b e one of the most effective targets totreat AD patients, many new class es of ChE inhibitors have been synthesized. In an effort of identifyi ng new type of cholinergic drug, decursinol derivatives 11-17 have been synthesized between decursinol and other biological interesting compoun ds such as lipoic acid, polyphenols, etc by using the click reaction a nd then evaluated their biological activities. Compound 12 (IC50 = 5.89 ± 0.31 mM against BuChE) showed more effective inhibitory activit y against BuChE than galantamine (IC50 = 9.4�2.5 mM). Decursinol derivatives can be considered a new class inhibitor for BuChE and can be applied to be a novel drug candidate to treat AD patients.
2023-07-27 10:19
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Effects of Cleaning Chemicals on the Surfaces of Waste Halitios discus hannai Shells
2023-07-27 10:13
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전복껍질 메소절편 기반 복합소재 합판 제작및 이를 이용한 하이브리드 판재의 방탄특성
2023-07-27 10:12
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생체 내 경로에서 멜라닌 생성을 억제하는 타이로신 억제제로서의 코직산 유도체
코직산(Kojic acid)은 생리활성물질로서 많이 알려져 있으며 antibacterial, antifungal과 같은 효능을 나타낸다. 또한 티로시나아제(tyrosinase) 억제제로서 작용하여 멜라닌 생성을 저해시키기 때문에 화장품 산업에 있어서도 미백효과를 가지는 중요한 소재로서 각광받고 있다. 본 연구에서는 독립적으로 항산화 효과를 나타내는 유도체와 코직산(Kojic acid)을 연결하여 새로운 기능성을 가지는 신규 화합물을 발굴하고자 하였으며, 클릭 반응(Click reaction)을 통해 트리아졸(triazle)로 연결하여 신규 코직산 컨쥬게이트(conjugated) 화합물을 합성하였다. 먼저 신규 코직산 컨쥬게이트(conjugated) 화합물의 티로시나아제(tyrosinase) 억제 효과에 대해서 연구한 결과 대부분의 화합물이 코직산(Kojic acid)보다 우수한 티로시나아제(tyrosinase) 억제 효과를 나타냈다. 이와 같은 결과로 미루어 보아 신규 코직산 컨쥬게이트(conjugated) 화합물은 항산화용 건강보조식품 조성물 및 항산화 소재, 노화방지 및 미백 기능을 가진 피부외용제 조성물의 유효성분으로 개발될 가능성이 매우 높다고 사료된다.
2023-07-27 10:11
Research
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