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Bangkok, Thailand

Chokpaiboon S.,Chulalongkorn University | Unagul P.,National Science and Technology Development Agency | Kongthong S.,National Science and Technology Development Agency | Danwisetkanjana K.,National Science and Technology Development Agency | And 3 more authors.
Tetrahedron Letters | Year: 2016

The novel compounds, astronypyrone, astronyquinone, and astronyurea, together with three known compounds, xestodecalactone A, ent-coryoctalactone B, and dimethoxy-O-methylpulvinone were isolated from the marine-derived fungus Astrosphaeriella nypae BCC 5335. Their structures were elucidated on the basis of NMR spectroscopy and mass spectrometry data. Astronypyrone possesses a 2-pyrone derivative fused with a tetrahydrofuran moiety via a dihydropyran unit, while the 2-pyrone ring is substituted by a naphthoquinone skeleton in astronyquinone. © 2016 Elsevier Ltd. All rights reserved. Source

Jang K.S.,Chonnam National University | Shin D.S.,Sogang University | Srisook E.,Burapha UniversityChonburi | Song H.-C.,Chonnam National University | Chi D.Y.,Sogang University
Tetrahedron | Year: 2016

Divergent functionalized 8-methoxyquinaldines were synthesized via regioselective debromination, 1,3-bromine shift process, aromatization with treatment of a strong base, nucleophilic substitution reaction at the C7 position using amines and cyanide as a nucleophile in the absence of a metal source and a catalyst from an unusual electrophilic aromatic addition (AdEAr) reaction products 7 and 8. In addition, quinaldine-7,8-dione was prepared by presence of CAN (ceric ammonium nitrate) in AcOH and H2O for 10 min at room temperature from N-(alkylamino)-8-methoxyquinalidines. During the AdEAr reaction, new stereoselective dearomatized addition products were generated via discriminative reaction routes depending on the methoxy and bromine occupancy position. The AdEAr reaction not only allowed for the functionalization of electron rich-fused heterocyclic arenes, but also provided a new synthetic route to an alternative mechanism for electrophilic aromatic substitution reactions. © 2016 Source

Subongkot T.,Burapha UniversityChonburi | Ngawhirunpat T.,Silpakorn UniversityNakhon Pathom
International Journal of Nanomedicine | Year: 2015

The purpose of this study was to investigate the effect of ultradeformable liposome components, Tween 20 and terpenes, on vesicle fluidity. The fluidity was evaluated by electron spin resonance spectroscopy using 5-doxyl stearic acid and 16-doxyl stearic acid as spin labels for phospholipid bilayer fluidity at the C5 atom of the acyl chain near the polar head group (hydrophilic region) and the C16 atom of the acyl chain (lipophilic region), respectively. The electron spin resonance study revealed that Tween 20 increased the fluidity at the C5 atom of the acyl chain, whereas terpenes increased the fluidity at the C16 atom of the acyl chain of the phospholipid bilayer. The increase in liposomal fluidity resulted in the increased skin penetration of sodium fluorescein. Confocal laser scanning microscopy showed that ultradeformable liposomes with terpenes increase the skin penetration of sodium fluorescein by enhancing hair follicle penetration. © 2015 Subongkot and Ngawhirunpat. Source

Sirisamut T.,Chulalongkorn University | Sirisamut T.,Mahidol University | Chinvarun Y.,Pramongkutklao Hospital | Tantisira M.H.,Chulalongkorn University | Tantisira M.H.,Burapha UniversityChonburi
Journal of the Medical Association of Thailand | Year: 2014

Effects of valproic acid (VPA) and phenytoin (PHT), as monotherapy, on cognitive functions and mood of Thai epileptic patients were investigated. Thai Mental Status Examination (TMSE) and Alcohol Use Disorder Identification Test (AUDIT) were used to screen for eligible subjects. Cognitive performance was assessed by neuropsychological tests including Stroop Color Word Test (SCWT), Wechsler Abbreviated Scale of Intelligence (WASI®) test, Profiles of Mood States (POMS®) and Adverse Event Profiles (AEP). Thirty epileptic patients, 15 taking PHT and 15 taking VPA, and 15 age and sex matched normal comparators were enrolled. In contrast to the effects of VPA, a statistically significant difference in T-score of WASI®- similarities and WASI®-matrix reasoning subtests was observed between PHT, and normal comparator group indicating poorer performance in intellectual functioning especially in executive function of the brain in patients taking PHT. Vigor is the only mood dimension that demonstrated significant difference between epileptic patients and normal comparators. VPA appears to be more appropriate than PHT when executive brain function is mostly concerned, however, further investigation is needed to gain better insight into the effects of AEDs on cognitive domain of the Thai epileptic patients. © 2014, Medical Association of Thailand. All Rights Reserved. Source

Chindaprasirt P.,Khon Kaen University | Rattanasak U.,Burapha UniversityChonburi
Construction and Building Materials | Year: 2016

Cement pipes have been used to transfer the domestic sewage and industrial wastewater due to its cost effectiveness. However, they faced the acid attack problem owing mainly to the high content of calcium compounds in the composite. Coating of cement pipes is one of the methods to protect the cement pipe surface from acid attack. An alumino-silicate geopolymer provides excellent mechanical properties and resistance to severe environments. Therefore, this research proposed the covering of cement-based materials with geopolymer. The covered specimens were immersed in deionized water (pH = 6.1), 0.005% H2SO4 (pH = 3), 5% MgSO4 (pH = 7.7) and 3% H2SO4 (pH = 0.3, representing the worst condition in the wastewater system). The pH and Ca2+ content of immersion solutions were measured. In addition, mechanical and chemical properties of geopolymeric-covering material were tested after the immersion in solutions for 30 and 90 days. © 2016 Elsevier Ltd. All rights reserved. Source

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