排序方式: 共有27条查询结果,搜索用时 15 毫秒
1.
Sunisa Boontom Kanokthorn Boonkitpatarakul Mongkol Sukwattanasinitt Nakorn Niamnont 《Tetrahedron》2017,73(17):2483-2487
A novel thiosemicarbazone fluorophore (3) was successfully synthesized in 3 steps via Sonogashira coupling and Knoevenagel condensation using baker's yeast (Saccharomyces cerevisiae) as a biocatalyst. Compound 3 contains triphenylacetylene, which acts as a fluorophore, and thiosemicarbazone, which acts as a copper probe. Compound 3 exhibited highly selective detection of Cu2+ ions based on photoinduced electron transfer (PET) in 10 mM HEPES buffer pH 7.4/propylene glycol (70% (v/v)). A linear relationship was observed for Cu2+ concentrations between 0.1 nM and 10 μM, and the detection limit of the method was 0.14 nM. Additionally, 3 was utilized to detect Cu2+ in wastewater with satisfactory results, which highlighted its potential for real sample applications. 相似文献
2.
Mongkol Thirabunyanon Penrat Hongwittayakorn 《Applied biochemistry and biotechnology》2013,169(2):511-525
The activities and modes of probiotic action of lactic acid bacteria isolated from infant feces were investigated for alternative application in the prevention and biotherapy of colon cancer. From a total of 81 isolates of Gram-positive rod and cocci bacteria obtained from healthy infants, only 15 isolates had the probiotic criteria which included growth inhibition against eight food-borne pathogens, no blood hemolysis, and tolerance to gastrointestinal tract properties such as pH?2.5 and 0.3 % bile salt. Four probiotic bacteria showed antiproliferation of colon cancer cells with the use of MTT and Trypan blue exclusion assay at the rates of 17–35 %. Through comparison of probiotic 16S rRNA sequences, they were identified as Pediococcus pentosaceus FP3, Lactobacillus salivarius FP25, L. salivarius FP35, and Enterococcus faecium FP51. Finding the mechanism of proliferative inhibition of colon cancer cells in this study indicated synergic induction by probiotic bacteria directly adhered to these cancer cells and triggered the bioproduction of short-chain fatty acids, mainly butyric and propionic acids. This study suggested that the use of these probiotics may be suitable as an alternative bioprophylactic and biotherapeutic strategy for colon cancer. 相似文献
3.
Diggle SP Lumjiaktase P Dipilato F Winzer K Kunakorn M Barrett DA Chhabra SR Cámara M Williams P 《Chemistry & biology》2006,13(7):701-710
Pseudomonas aeruginosa synthesizes diverse 2-alkyl-4(1H)-quinolones (AHQs), including the signaling molecule 2-heptyl-3-hydroxy-4(1H)-quinolone (PQS), via the pqsABCDE locus. By examining the genome databases, homologs of the pqs genes were identified in other bacteria. However, apart from P. aeruginosa, only Burkholderia pseudomallei and B. thailandensis contained a complete pqsA-E operon (termed hhqA-E). By introducing the B. pseudomallei hhqA and hhqE genes into P. aeruginosa pqsA and pqsE mutants, we show that they are functionally conserved and restore virulence factor and PQS production. B. pseudomallei, B. thailandensis, B. cenocepacia, and P. putida each produced 2-heptyl-4(1H)-quinolone (HHQ), but not PQS. Mutation of hhqA in B. pseudomallei resulted in the loss of AHQ production, altered colony morphology, and enhanced elastase production, which was reduced to parental levels by exogenous HHQ. These data reveal a role for AHQs in bacterial cell-to-cell communication beyond that seen in P. aeruginosa. 相似文献
4.
Pumtang S Siripornnoppakhun W Sukwattanasinitt M Ajavakom A 《Journal of colloid and interface science》2011,364(2):366-372
A well known unique property of polydiacetylenes (PDAs) is the colorimetric response to external stimuli making it one of the most studied conjugated polymers for sensing applications. Here we report the synthesis of a novel series of diacetylene acids from the condensation of pentacosa-10,12-diynylamine (PCDAmine) and dicarboxylic acid or its anhydrides. One of these diacetylene lipids, 4-(pentacosa-10,12-diynylamino)-4-oxobutanoic acid (PCDAS), is used in combination with pentacosa-10,12-diynoic acid (PCDA) for dropcasting on pieces of filter paper which are consequently irradiated by UV light to generate a paper based sensor array for solvent detection and identification. Upon the exposure to various types of organic solvents, the blue colored sensors colorimetrically respond to give different shades of colors between blue to red. The color patterns of the sensor array are recorded as RedGreenBlue (RGB) values and statistically analyzed by principal component analysis (PCA). The PCA score plot reveals that the array is capable of identifying eleven common organic solvents. 相似文献
5.
Rojrit Rojanathanes Thawatchai Tuntulani James B. Orton Michael B. Hursthouse Mongkol Sukwattanasinitt 《Tetrahedron》2005,61(5):1317-1324
Photo-switchable calixarenes consisting of a stilbene or azobenzene bridge, spanning the narrow rim as a switching unit, were synthesized through reductive coupling of o-, m- and p-bis-benzaldehyde and bis-nitrobenzene-substituted calix[4]arenes. Both cis- and trans-stilbenes were produced from the reductive coupling of the o- and m-bis-benzaldehyde with the cis isomer being predominant for both regioisomers, whilst the coupling of p-bis-benzaldehyde gave only cis product. On the other hand, the only isolable product obtained from the reductive coupling of bis-o- and bis-m-nitrobenzene was the corresponding trans-azobenzene and the coupling product from bis-p-nitrobenzene was not stable. Each of the synthesized compounds showed a photostationary state in their cis-trans isomerization. The complexation of alkali metal ions was observed for only the o-azobenzene derivative suggesting that the lone pair of N-atom in the azo bridge participates in this process. 相似文献
6.
Chatphorn Theppitak Suwadee Jiajaroen Nucharee Chongboriboon Songwuit Chanthee Filip Kielar Winya Dungkaew Mongkol Sukwattanasinitt Kittipong Chainok 《Molecules (Basel, Switzerland)》2021,26(15)
Two new lanthanide-based coordination polymers, [Sm2(bzz)(ben)6(H2O)3]·0.5H2O (1) and [Eu(bbz)(ben)3] (2), were synthesized and characterized. The described products were formed from in situ-generated benzoate (ben) and N’-benzoylbenzohydrazide (bbz) ligands, which were the products of transformation of originally added benzhydrazide (bzz) under hydrothermal conditions. Compound 1 exhibits a one-dimensional (1D) double-chain structure built up from the connection of the central Sm3+ ions with a mixture of bzz and ben ligands. On the other hand, 2 features a 3D network with a 4-connected (66) dia topology constructed from dinuclear [Eu2(ben)6] secondary building units and bbz linkers. High-pressure CO2 sorption studies of activated 1 show that maximum uptake increases to exceptionally high values of 376.7 cm3 g−1 (42.5 wt%) under a pressure of 50 bar at 298 K with good recyclability. Meanwhile, 2 shows a typical red emission in the solid state at room temperature with the decay lifetime of 1.2 ms. 相似文献
7.
Natthakorn Phadungsak Filip Kielar Winya Dungkaew Mongkol Sukwattanasinitt Yan Zhou Kittipong Chainok 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(10):1372-1380
Over the past two decades, the development of novel inorganic–organic hybrid porous crystalline materials or metal–organic frameworks (MOFs) using crystal engineering has provoked significant interest due to their potential applications as functional materials. In this context, luminescent MOFs as fluorescence sensors have recently received significant attention for the sensing of ionic species and small molecules. In this work, a new luminescent heterometallic zinc(II)–barium(II)‐based anionic metal–organic framework, namely poly[imidazolium [triaqua(μ6‐benzene‐1,3,5‐tricarboxylato)bariumtrizinc] tetrahydrate], {(C3H4N2)[BaZn3(C9H3O6)3(H2O)3]·4H2O}n ( 1 ), was synthesized under hydrothermal conditions and characterized. Compound 1 presents a three‐dimensional framework with an unprecedented (3,5)‐connected topology of the point symbol (3.92).(33.42.5.93.10), and exhibits `turn‐off' luminescence responses for the Cu2+ and Fe3+ ions in aqueous solution based on significantly different quenching mechanisms. 相似文献
8.
Thitima Pewklang Sirawit Wet-osot Sirilak Wangngae Utumporn Ngivprom Kantapat Chansaenpak Chuthamat Duangkamol Rung-Yi Lai Parinya Noisa Mongkol Sukwattanasinitt Anyanee Kamkaew 《Molecules (Basel, Switzerland)》2021,26(16)
A hypoxia-responsive probe based on a flavylium dye containing an azo group (AZO-Flav) was synthesized to detect hypoxic conditions via a reductase-catalyzed reaction in cancer cells. In in vitro enzymatic investigation, the azo group of AZO-Flav was reduced by a reductase in the presence of reduced nicotinamide adenine dinucleotide phosphate (NADPH) followed by fragmentation to generate a fluorescent molecule, Flav-NH2. The response of AZO-Flav to the reductase was as fast as 2 min with a limit of detection (LOD) of 0.4 μM. Moreover, AZO-Flav displayed high enzyme specificity even in the presence of high concentrations of biological interferences, such as reducing agents and biothiols. Therefore, AZO-Flav was tested to detect hypoxic and normoxic environments in cancer cells (HepG2). Compared to the normal condition, the fluorescence intensity in hypoxic conditions increased about 10-fold after 15 min. Prolonged incubation showed a 26-fold higher fluorescent intensity after 60 min. In addition, the fluorescence signal under hypoxia can be suppressed by an electron transport process inhibitor, diphenyliodonium chloride (DPIC), suggesting that reductases take part in the azo group reduction of AZO-Flav in a hypoxic environment. Therefore, this probe showed great potential application toward in vivo hypoxia detection. 相似文献
9.
Treatment of oxidized cellulose fabric with chitosan and its surface activity towards anionic reactive dyes 总被引:5,自引:1,他引:4
Yupaporn Kitkulnumchai Anawat Ajavakom Mongkol Sukwattanasinitt 《Cellulose (London, England)》2008,15(4):599-608
The surface modification of cellulose fabric with chitosan was achieved through an oxidation of the fabric with KIO4 followed by reductive ammination with chitosan. The chitosan content in the fabric determined by Kjeldahl nitrogen analysis
technique was 1.69%. The scanning electron micrograph revealed submicron particles of chitosan attached on the fabric surface.
Dyeing of the modified fabrics with mono-chloro-triazine and vinyl sulfone anionic reactive dyes, showed vastly improved exhaustion
and color yield (K/S) indicating that this method of surface modification is effective for changing surface activity of the
fabric. The enhancement of the dye uptake brought about an improved dyeing process in which the dye and salt used could be
reduced by half and 14%, respectively. A Significant drop in burst strength upon the oxidation but no discernable adverse
color fastness property was observed for the chitosan-modified fabric. 相似文献
10.
Davis BW Niamnont N Dillon R Bardeen CJ Sukwattanasinitt M Cheng Q 《Langmuir : the ACS journal of surfaces and colloids》2011,27(10):6401-6408
This paper reports the fabrication of solid-state nanofiber sensor arrays and their use for detection of multiple proteins using principal component analysis (PCA). Four cationic and anionic fluorescently embedded nanofibers are generated by an electrospinning method, yielding unique patterns of fluorescence change upon interaction with protein samples. Five metal and nonmetal containing proteins, i.e., hemoglobin, myoglobin, cytochrome c, BSA, and avidin, have been investigated; and the results show that distinct fluorescent patterns can be formed upon the addition of protein samples to the array of solid nanofiber substrates, allowing their unambiguous identification. The nanofiber films are highly repeatable with a batch-to-batch variation of approximately 5% and demonstrated outstanding reusability with less than a 15% loss of fluorescence intensity signal after 5 regenerations of test cycles. For a more practical visualization, a cluster map was generated using PCA of the change-in-fluorescence (ΔI) composite patterns, demonstrating the potential of the method for diagnostic applications. 相似文献