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Laoratanakul P.,National Metal and Materials Technology Center | Yimnirun R.,Suranaree University of Technology | Yimnirun R.,Synchrotron Light Research Institute Public Organization | Wongsaenmai S.,Maejo University
Current Applied Physics | Year: 2011

In this work, the solid solution of (1-x)(Bi0.5Na 0.5)TiO3-(x)(K0.5Na0.5)NbO 3 ceramics with x = 0.00, 0.01, 0.03, 0.05, 0.07, 0.09 and 0.10 was prepared by a conventional mixed-oxide method. The structural phase formation, microstructure, dielectric properties were investigated. It was found that the BNT-KNN ceramics exhibited the perovskite structure with rhombohedral and pseudo-cubic symmetry. The microstructure showed grain shape depending upon compositions; i.e., the compositions of x < 0.05 the round shape grains were observed, while with x > 0.07 square or rectangular shape grains appeared. The addition of KNN into BNT ceramics resulted in the decrease of the phase transition temperature. More importantly, the dielectric properties also indicated the Morphotropic Phase Boundary (MPB) near the composition between x = 0.03 and x = 0.05. © 2011 Elsevier B.V. All rights reserved.


Chaodamrongsakul J.,Vongchavalitkul University | Klysubun W.,Synchrotron Light Research Institute Public Organization | Vao-Soongnern V.,Suranaree University of Technology
Materials Chemistry and Physics | Year: 2014

The atomistic solvation structure of tetraglyme:KSCN (TET:KSCN) electrolytes with various K+:ether oxygen (M:O) ratio were studied by a combination of molecular dynamic (MD) simulation and Extended X-Ray Absorption Fine Structure (EXAFS) called "MD-EXAFS" method. This method gives useful information at the atomistic scale including the average distance between atom pair around the probed ion (R0) and Coordination Number (N). MD simulation results suggest that K+ ions are mostly coordinated to ether oxygen and the conformation around C-C bond prefer the gauche state and TET becomes more compact shape. K+ ions are also coordinated to thiocyanate (SCN-) anion at both nitrogen and sulfur atoms due to strong electron delocalization over three atoms in SCN - (S, C and N). A comparison between MD-EXAFS with the experimental spectra gives an overall good agreement for both frequency and amplitude of the oscillations. © 2013 Elsevier B.V. All rights reserved.


Siritapetawee J.,Suranaree University of Technology | Thumanu K.,Synchrotron Light Research Institute Public Organization | Sojikul P.,Mahidol University | Thammasirirak S.,Khon Kaen University
Biochimica et Biophysica Acta - Proteins and Proteomics | Year: 2012

A protease was isolated and purified from Artocarpus heterophyllus (jackfruit) latex and designated as a 48-kDa antimicrobial protease (AMP48) in a previous publication. In this work, the enzyme was characterized for more biochemical and medicinal properties. Enzyme activity of AMP48 was strongly inhibited by phenylmethanesulfonyl fluoride and soybean trypsin inhibitor, indicating that the enzyme was a plant serine protease. The N-terminal amino acid sequences (A-Q-E-G-G-K-D-D-D-G-G) of AMP48 had no sequence similarity matches with any sequence databases of BLAST search and other plant serine protease. The secondary structure of this enzyme was composed of high α-helix (51%) and low β-sheet (9%). AMP48 had fibrinogenolytic activity with maximal activity between 55 and 60 °C at pH 8. The enzyme efficiently hydrolyzed α followed by partially hydrolyzed β and γ subunits of human fibrinogen. In addition, the fibrinolytic activity was observed through the degradation products by SDS-PAGE and emphasized its activity by monitoring the alteration of secondary structure of fibrin clot after enzyme digestion using ATR-FTIR spectroscopy. This study presented the potential role to use AMP48 as antithrombotic for treatment thromboembolic disorders such as strokes, pulmonary emboli and deep vein thrombosis. © 2012 Elsevier B.V. All rights reserved.


Sukwisute P.,Prince of Songkla University | Muensit N.,Prince of Songkla University | Soontaranon S.,Synchrotron Light Research Institute Public Organization | Rugmai S.,Synchrotron Light Research Institute Public Organization
Applied Physics Letters | Year: 2013

This work explores applications for poly(vinylidene fluoride hexafluoropropylene) or P(VDF-HFP). The P(VDF-HFP) with a 10 wt. % HFP can be prepared to exhibit the piezoelectricity and energy conversion ability. This was achieved by determining the nanostructural parameters by the Small Angle X-Ray Scattering. The unpoled sample gained linear crystallinity with drawing rate. The optimal conditions for poling process were 60 MV/m at 90°C. The piezoelectric coefficient d31 of 28.7 pC/N and FoM of 8.8 × 10-12 m2/N were obtained from the poled sample drawn at 45 mm/min. The piezoelectric P(VDF-HFP) was proven to deliver a microwatt energy essential for powering small-scale electronics. © 2013 AIP Publishing LLC.


Eumkeb G.,Suranaree University of Technology | Siriwong S.,Suranaree University of Technology | Thumanu K.,Synchrotron Light Research Institute Public Organization
Journal of Photochemistry and Photobiology B: Biology | Year: 2012

The purpose of this research was to investigate whether luteolin has antibacterial and synergistic activity against amoxicillin-resistant Escherichia coli (AREC) when use singly and in combination with amoxicillin. The primarily mode of action is also investigated. The susceptibility assay (minimum inhibitory concentration and checkerboard determination) was carried out by the broth macrodilution method's in Müeller-Hinton medium. MIC and checkerboard determination were carried out after 20 h of incubation at 35 °C by observing turbidity. The MICs of amoxicillin and luteolin against all AREC strains were >1000 and ≥200 μg/ml respectively. Synergistic activity were observed on amoxicillin plus luteolin against these strains. Viable count of this combination showed synergistic effect by reducing AREC cell numbers. The results indicated that this combination altered both outer and inner membrane permeabilisation. Enzyme assay showed that luteolin had an inhibitory activity against penicillinase. Fourier Transform-Infrared (FT-IR) spectroscopy exhibited that luteolin alone and when combined with amoxicillin caused increase in fatty acid and nucleic acid, but decrease in amide I of proteins in bacterial envelops compared with control. These results indicated that luteolin has the potential to reverse bacterial resistance to amoxicillin in AREC and may operate via three mechanisms: inhibition of proteins and peptidoglycan synthesis, inhibition of the activity of certain extended-spectrum β-lactamases and alteration of outer and inner membrane permeability. These findings offer the potential to develop a new generation of phytopharmaceuticals to treat AREC. © 2012 Elsevier B.V. All rights reserved.


Pengthaisong S.,Suranaree University of Technology | Withers S.G.,University of British Columbia | Kuaprasert B.,Synchrotron Light Research Institute Public Organization | Svasti J.,Mahidol University | Ketudat Cairns J.R.,Suranaree University of Technology
Protein Science | Year: 2012

Rice BGlu1 b-glucosidase nucleophile mutant E386G is a glycosynthase that can synthesize p-nitrophenyl (pNP)-cellooligosaccharides of up to 11 residues. The X-ray crystal structures of the E386G glycosynthase with and without a-glucosyl fluoride were solved and the a-glucosyl fluoride complex was found to contain an ordered water molecule near the position of the nucleophile of the BGlu1 native structure, which is likely to stabilize the departing fluoride. The structures of E386G glycosynthase in complexes with cellotetraose and cellopentaose confirmed that the side chains of N245, S334, and Y341 interact with glucosyl residues in cellooligosaccharide binding subsites 12, 13, and 14. Mutants in which these residues were replaced in BGlu1 b-glucosidase hydrolyzed cellotetraose and cellopentaose with kcat/Km values similar to those of the wild type enzyme. However, the Y341A, Y341L, and N245V mutants of the E386G glycosynthase synthesize shorter pNPcellooligosaccharides than do the E386G glycosynthase and its S334A mutant, suggesting that Y341 and N245 play important roles in the synthesis of long oligosaccharides. X-ray structural studies revealed that cellotetraose binds to the Y341A mutant of the glycosynthase in a very different, alternative mode not seen in complexes with the E386G glycosynthase, possibly explaining the similar hydrolysis, but poorer synthesis of longer oligosaccharides by Y341 mutants. Published by Wiley-Blackwell. © 2012 The Protein Society.


MacHana S.,Khon Kaen University | Weerapreeyakul N.,Khon Kaen University | Barusrux S.,Khon Kaen University | Thumanu K.,Synchrotron Light Research Institute Public Organization | Tanthanuch W.,Synchrotron Light Research Institute Public Organization
Talanta | Year: 2012

Apoptosis is the principal molecular goal of chemotherapeutics for effective anticancer action. We studied the effect of 50% ethanolic-water extracts of Pinus kesiya, Cratoxylum formosum ssp. pruniflorum and melphalan on cytotoxicity and apoptosis induction for human leukemic U937 cells, and explored the mode of action using FTIR microspectroscopy. The number of viable U937 cells in vitro was decreased in a concentration-dependent manner by all tested compounds, although potency differed between the U937 and Vero cells. Melphalan and the extract of C. formosum exhibited relatively lower IC 50 values (15.0 ± 1.0 and 82.7 ± 3.2 μg/mL respectively) and higher selectivity (selective index > 3) than the extract of P. kesiya (299.0 ± 5.2 μg/mL; selective index < 3) on the U937 cells. All three compounds significantly induced apoptosis through the late stage - seen by the indicative DNA ladder - with the most effective being melphalan, then the P. kesiya and C. formosum extracts. FTIR microspectroscopy revealed that all three compounds raised the intensity of the β-pleated sheet - higher than that of the untreated U937 cells - corresponding to a shift in the α-helix band associated with an alteration in the secondary structure of the protein band, confirming induction of apoptosis via pro-apoptotic proteins. The differences in intensity of the FTIR bands associated with lipids, proteins and nucleic acids were responsible for discrimination of the anticancer mode of action of each of the three compounds. The FTIR data suggest that the two plant extracts possessed anticancer activity with a different mode of action than melphalan. © 2012 Elsevier B.V. All rights reserved.


Sansenya S.,Suranaree University of Technology | Opassiri R.,Suranaree University of Technology | Kuaprasert B.,Synchrotron Light Research Institute Public Organization | Chen C.-J.,National Synchrotron Radiation Research Center | Ketudat Cairns J.R.,Suranaree University of Technology
Archives of Biochemistry and Biophysics | Year: 2011

Rice Os4BGlu12, a glycoside hydrolase family 1 (GH1) β-glucosidase, hydrolyzes β-(1,4)-linked oligosaccharides of 3-6 glucosyl residues and the β-(1,3)-linked disaccharide laminaribiose, as well as certain glycosides. The crystal structures of apo Os4BGlu12, and its complexes with 2,4-dinitrophenyl-2-deoxyl-2-fluoroglucoside (DNP2FG) and 2-deoxy-2- fluoroglucose (G2F) were solved at 2.50, 2.45 and 2.40 resolution, respectively. The overall structure of rice Os4BGlu12 is typical of GH1 enzymes, but it contains an extra disulfide bridge in the loop B region. The glucose ring of the G2F in the covalent intermediate was found in a 4C1 chair conformation, while that of the noncovalently bound DNP2FG had a 1S3 skew boat, consistent with hydrolysis via a 4H3 half-chair transition state. The position of the catalytic nucleophile (Glu393) in the G2F structure was more similar to that of the Sinapsis alba myrosinase G2F complex than to that in covalent intermediates of other O-glucosidases, such as rice Os3BGlu6 and Os3BGlu7 β-glucosidases. This correlated with a significant thioglucosidase activity for Os4BGlu12, although with 200- to 1200-fold lower kcat/Km values for S-glucosides than the comparable O-glucosides, while hydrolysis of S-glucosides was undetectable for Os3BGlu6 and Os3BGlu7. © 2011 Elsevier Inc. All rights reserved.


Plaimee P.,Khon Kaen University | Weerapreeyakul N.,Khon Kaen University | Thumanu K.,Synchrotron Light Research Institute Public Organization | Tanthanuch W.,Synchrotron Light Research Institute Public Organization | Barusrux S.,Khon Kaen University
Cell Proliferation | Year: 2014

Objectives: Anti-cancer effects of melatonin (N-acetyl-5-methoxytryptamine, an indole-amine), have been widely reported, however, little has been known, regarding its mechanism(s) of action in lung cancer. Thus, we investigated its induction of apoptosis through biomolecular changes (lipid, protein and nucleic acid/DNA) in the SK-LU-1 human lung cancer cell line. Materials and methods: We used Fourier transform infrared (FTIR) microspectroscopy, and conventional methods, to confirm changes in lipid (annexin V/PI staining for membrane alteration), protein (caspase-3/7 protein activity) and DNA (DAPI staining for DNA fragmentation). Results: We observed from FTIR data that melatonin increased lipid content and reduced intensity of nucleic acid/DNA, confirmed by annexin V/PI and DAPI respectively. Secondary protein structure at 1656 cm-1 (α-helix) was reduced and peak position of β-sheet structure (1637 cm-1) was shifted to lower frequency. Alteration in apoptotic proteins was demonstrated via caspase-3/7 activity induction. Conclusions: High melatonin concentration exerted anti-cancer effects by changing biomolecular structure of lipids, nucleic acids and proteins, supporting its enhancement of apoptotic induction. © 2014 John Wiley & Sons Ltd.


Merat K.,Suranaree University of Technology | Chaodamrongsakul J.,Suranaree University of Technology | Tanthanuch W.,Synchrotron Light Research Institute Public Organization | Vao-Soongnern V.,Suranaree University of Technology
Journal of Non-Crystalline Solids | Year: 2013

Molecular Dynamics (MD) simulation and the extended X-ray absorption fine structure (EXAFS) spectroscopy were employed to obtain the atomistic solvation structure of calcium (Ca2 +) ion in poly(vinyl alcohol) (PVA). From MD simulation results, it is obvious that there is only one dominant shell from oxygen atoms around calcium ion. The distance between the calcium ion and oxygen atoms in the first shell is in good agreement with experiment within 0.1 Å. For the Ca K-edge EXAFS spectrum of CaCl2/PVA sample, there is no evidence for the formation of significant numbers of Ca 2 +-Cl- contact ion pairs. Ca2 + ion can induce the conformational changes of PVA backbone compared to those of neat PVA. The MD and EXAFS technique is a powerful method to elucidate the detailed solvation structure of the probed ion in polymer matrix at the atomistic scale. © 2013 Elsevier B.V.

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