bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bipyridine‐Modulated Palladium‐Catalyzed Oxidative Heck‐Type Reactions of Arylboronic Acids with Olefins
Authors: Hsu Chien‐Ming , Li Chih‐Bin , Sun Chia‐Hsing 
Published: May 2015

AbstractWe have demonstrated that 4,4′‐dimethyl 2,2′‐bipyridine as ligand for Pd(II) catalysts was very efficient for oxidative Heck‐type coupling reaction of arylboronic acids with olefins in DMA or CH3CN under atm air at 80 °C. The presence of chelated bipyridine ligand isindispensable to achieve high reaction yields and to suppress the formation of biphenyl as homocoupled byproduct.
A New Oligostilbenoid from Rhizomes of Curculigo Sinensis
Authors: Wang Tian‐Ming , Wang Kai‐Jin , Tang Jun , Li Ning 
Published: May 2015

AbstractCurcusinol (1), a new resveratrol trimer, was isolated and identified from the rhizomes of Curculigo sinensis (Hypoxidaceae), together with five known phenolic compounds: curcapital (2), pilosidine (3), crassifoside A (4), curculigoside I (5) and phegopolin (6). The new compound 1 was determined as an oligostilbenoid on the basis of various spectroscopic methods, especially intensive 2D‐NMR (COSY, HMQC, HMBC and NOESY) techniques.
Cyclic Voltammetrically Prepared MnO2‐Polyaniline Composite and Its Electrocatalysis for Oxygen Reduction Reaction (ORR)
Authors: Ding Ke‐Qiang 
Published: May 2015

AbstractThe composite of manganese dioxide‐polyaniline (MnO2‐PANI) was successfully prepared by cyclic voltammetry (CV) from a 0.5 M H2SO4 solution containing 0.2 M aniline and 0.5 M MnSO4. Scanning electron microscopy (SEM) images revealed that cauliflower like manganese dioxides entangled with PANI were generated. The spectra obtained from UV‐vis spectrophotometry (UV‐vis) and Fourier transform infrared spectrometry (FTIR) strongly demonstrated that this novel composite was composed by MnO2 and PANI, and also there was an interaction between MnO2 and PANI. Then, for the first time, this resultant composite was modified on a graphite electrode and employed in the oxygen reduction reaction (ORR), subsequently, the obtained cyclic voltammograms (CVs) verified that ORR could proceed on this resultant composite of MnO2‐PANI. Lastly, the possible catalysis mechanism of MnO2‐PANI towards ORR was proposed based on the results we acquired. Developing a novel substrate on which ORR could proceed is the main contribution of this work.
Liquid Phase Hydrogenation of t,t,c‐1,5,9‐Cyclododecatriene over Ni/MCM‐41 and Ni/SiO2 Catalysts
Authors: Hsu Chen‐Hun , Wang Yin‐Lan , Ko An‐Nan 
Published: May 2015

AbstractNi‐loaded pure siliceous and aluminosilicate MCM‐41 (Ni/MCM‐41) and nickel‐loaded silica (15Ni/SiO2) were synthesized via wet impregnation and were characterized by various techniques. The H2 consumption in the TPR analysis was found to be proportional to the Ni amount in the calcined samples. After reduction the average Ni particle sizes of 15Ni/MCM‐41 and 15Ni/SiO2 were 9–12 and 16 nm, respectively, by means of XRD and TEM measurements. All catalysts owned weak and intermediate Lewis acid sites that increased slightly with increasing the Ni amount and the Al content. In the liquid phase hydrogenation of t,t,c‐1,5,9‐cyclododecatriene over Ni/MCM‐41, the catalytic activity was parallel to the Ni content and enhanced slightly with the acid amount of the catalysts. Consequently, it was proposed that the Ni metallic sites contributed the major effect to the catalytic activity while the Lewis acid sites promoted a small but significant influence on the catalytic performance. It is noteworthy that all 15Ni/MCM‐41 catalysts exhibited remarkably higher activity than that of the conventional 15Ni/SiO2 catalyst.
Purification and Characterization of Bowman‐Birk Protease Inhibitor from Rice Coleoptiles
Authors: Yan Ker‐Ming , Chang Tschining , Soon Su‐An , Huang Fu‐Yung 
Published: May 2015

AbstractA 15 kDa rice Bowman‐Birk inhibitor from fast elongating coleoptiles has been purified and identified using partial N‐terminal sequence, LC‐MS, and MALDI‐TOF MS as a 133 amino acid polypeptide (BBIrc 1). The kinetic study shows this protease inhibitor displays competitive inhibition toward trypsin with Ki of 4.0 × 10−7 M and non‐competitive inhibition toward α‐chymotrypsin with Ki of 9.3 × 10−6 M. The Western blotting results of the anti‐sera raised against this 15 kDa protein showed that this anti‐serum recognized two BBI proteins with molecular size around 15 kDa (BBIrc 1) and 25 kDa (BBIrc2) and the quantity of the expression of 15 kDa was nearly constant under both aerobic and hypoxia conditions; however, the 25 kDa expression was greatly up‐regulated when the fast elongating coleoptiles were transferred from hypoxia conditions to the aerobic conditions. The results indicate that the expression pattern of BBIs proteins correlated to the developmental stage in terms of morphological changes. The partial N‐terminal sequence of the first 9 amino acids of 25 kDa was AEAPPRPPK, which is the same as the amino acid sequence of 37th to 45th of RBBI3‐1 and LC‐MS study shows that several mass fragments fit to RBBI3‐1. The 25 kDa protein also shows specific binding to bovine trypsin. This expression pattern demonstrates for the first time that environmental factor, oxygen, can select and enhance specific BBI gene expression. The results of this study suggest BBI proteins might play multiple biological functions inside rice coleoptiles.
Determination of Sulfur Compounds in Water Samples by Ion Chromatography Dynamic Reaction Cell Inductively Coupled Plasma Mass Spectrometry
Authors: Lin Liang‐Yen , Jiang Shiuh‐Jen 
Published: May 2015

AbstractAn ion chromatography‐inductively coupled plasma mass spectrometric (IC‐ICP‐MS) method for the speciation of sulfur compounds, namely sulfite [SO32−], sulfate [SO42−] and thiosulfate [S2O32−], was described. Ionic sulfur compounds were well separated in about 3 min by ion chromatography with a Hamilton PRP‐X100 column as the stationary phase and 60 mmol L−1 NH4NO3 and 0.1% v/v formaldehyde (HCHO) solution (pH = 7) as the mobile phase. The analyses were carried out using dynamic reaction cell (DRC) ICP‐MS. The sulfur‐selective chromatogram was determined at m/z 48 as 32S16O+ by using its reaction with O2 in the reaction cell. The method avoided the effect of polyatomic isobaric interferences at m/z 32 caused by 16O16O+ and 14N18O+ on 32S+ by detecting 32S+ as the oxide ion 32S16O+ at m/z 48, which is less interfered. The detection limit of various species studied was in the range of 3.6–4.6 ng S mL−1. The accuracy of the method has been verified by comparing the sum of the concentrations of individual sulfur compounds obtained by the present procedure with the total concentration of sulfur in several natural water samples. The recovery was in the range of 97–102% for various compounds studied.
Functional Dihydro‐1H‐Imidazole Derivatives for MALDI Signal Enhancement of a Lysine‐Specific Chemical Modification
Authors: Ho Ming‐Yi , Shieh Yu‐Tse , Liao Chung‐Lin , Chen Yau‐Hung , Cheng Chien‐Chung 
Published: May 2015

AbstractThe enhancement of signal sensitivity and quantification of low‐abundance proteins is of great importance in proteomic analysis. The preparation of 2‐methoxy‐4,5‐dihydro‐1H‐imidazole (MeO‐DHIM) derivatives was accomplished by one‐step synthesis of O‐methyl‐isourea. The signal enhancement induced by these attached moieties increases in an order of compound 1 ≈︁ 4 < 2 < 5 ≈︁ 6 < 3 in MALDI mass spectrometry. Peptide‐compound 3 adduct was approximately 20 times signal enhancement of the unmodified peptide and of 9 times of the peptide‐compound 1 adduct. This result demonstrates that the rational designed organic molecules are capable of providing a sensitive tool in the detection of low‐abundance proteins in proteomics.
A Simple and Efficient Procedure for Synthesis of Optically Active 1,2,4‐Triazolo‐[3,4‐b]‐1,3,4‐Thiadiazole Derivatives Containing l‐Amino Acid Moieties
Authors: Foroughifar Naser , Mobinikhaledi Akbar , Ebrahimi Sattar , Fard Mohammad Ali Bodaghi , Moghanian Hassan 
Published: May 2015

AbstractSome new and optically active 1,2,4‐triazolo thiadiazoles bearing N‐phthaloyl‐l‐amino acids were synthesized by reaction of 4‐amino‐5‐(3‐ or 4‐)pyridyl‐3‐mercapto‐(4H)‐1,2,4‐triazoles with N‐phthaloyl‐l‐amino acids in the presence of phosphorus oxychloride. All the newly synthesized compounds were confirmed by IR, 1H NMR, 13C NMR and elemental analysis.
Study on Electrocatalytic Activity of Platinum for Hydrogen Oxidation in Acidic Solution by Scanning Electrochemical Microscopy
Authors: Yin Yue‐Hua , Niu Lin , Cao Xiao‐Li 
Published: May 2015

AbstractThe electrocatalytic activity of platinum for hydrogen oxidation in 0.01 M H2SO4 + 0.1 MNa2SO4 solution has been investigated by scanning electrochemical microscopy (SECM) technique. The cyclic voltammogram (CV), approach curve, area scan imaging and chronoamperometric methods have been used. The results indicate that the imaging capability of the SECM feedback mode can be used more efficiently to visually identify materials' electrocatalytic activity, compared with the approach curve method for identification of the conductive or insulating nature of a surface. The SECM imaging method has demonstrated the effects of Pt substrate potential on the electrocatalytic oxidation of hydrogen under a constant tip potential. It is found that the more positive the Pt substrate potential, the lower the electrocatalytic activity of the Pt. Furthermore, the chronoamperometric results support the variation of the electrocatalytic activity with the Pt substrate potential as well.
Structures and Magnetic Properties of Two Copper(II) Complexes with 2,5‐Dichloro‐3,6‐Dihydroxy‐1,4‐Benzoquinone Dianionic and Tetrachloroquinone Ligand
Authors: Chung Yun‐Ho , Fang Szu‐I , Fang Shu‐Hui , Lin Hsin‐Huang , Liou Shyh‐Yeon 
Published: May 2015

AbstractThe polynuclear copper(II) complex [Cu2(Hdpa)2(μ‐ClDHBQ)(ClO4)2]n, 1 is bridged by ClDHBQ−2 (2,5‐dichloro‐3,6‐dihydroxy‐1,4‐benzoquinone dianionic) and 2,2′‐dipyridylamine (Hdpa). In the axial position, Cu is connected with the oxygen atom of ClO. The perchlorate anion may be envisaged as a monodentate O‐bound ligand. Through the bond bridge of O–Cu … O–Cl, the binuclear compound [Cu2(Hdpa)2(μ‐ClDHBQ)(ClO4)2] is strung together into a long chain compound. Tetrachlorocatechol underwent partial oxidation/hydrolysis/dechlorination processes to produce ClDHBQ−2.The other mononuclear complex [Cu(Hdpa)(TeCQ)](DMF), 2, in which tetrachloroquinone (TeCQ) was produced by oxidation of tetrachlorocatechol (TeCC), therefore complex 2 is in the quinone form.The magnetic susceptibility measurements show antiferromagnetic coupling with J = −11.9 cm−1, θ = 2.6 K, and g = 2.05 for complex 1. Complex 2 exhibits the typical paramagnetic behavior of s = 1/2.
Differential Pulse Polarographic Determination of Cd(II) and Pb(II) in Milk Samples after Solid‐Phase Extraction Using Amberlite XAD‐2 Resin Modified with 2,2′‐DPED3P
Authors: Sreedhar N. Y. , Prasad P. Reddy , Nayak M. Sankara , Rekha D. , Reddy C. Nageswara 
Published: May 2015

AbstractIn the present paper novel column solid phase extraction procedure was developed for the determination of Cd(II) and Pb(II) in cows', goats', ewes', buffalos' and humans' milk samples using newly synthesized reagent 2,2′‐DPED3P (2,2′‐{[1,2‐diphenylethane‐1,2‐diylidene]dinitrilo}diphenol) for preconcentration and separation prior to differential pulse polarography using amberlite XAD‐2 in the ranges of pH 4.0–5.0. The sorbed elements were subsequently eluted with 10 mL of 2 M HCl elutes were analysed by differential pulse polarography (DPP). The interference of foreign ions has also been studied. Effects of various instrumental parameters are investigated and received conditions are optimized. The total metal concentration of the milk samples in the study area were in the following ranges 0.030–0.090 μg L−1 of Cd(II), 0.009–0.026 μg L−1 of Pb(II) respectively. The limits of detections were found to be 0.020 and 0.024 μg L−1 for Cd(II) and Pb(II) respectively by applying a preconcentration factor ∼40. The proposed enrichment method was applied successfully for the determination of metal ions in cows', goats', ewes', buffalos' and humans' milk samples.
Chemical Oxidative Degradation of Acridine Orange Dye in Aqueous Solution by Fenton's Reagent
Authors: Chen Chiing‐Chang , Wu Ren‐Jang , Tzeng Yi‐You , Lu Chung‐Shin 
Published: May 2015

AbstractDegradation of acridine orange (AO) in aqueous solution by Fenton's reagent (Fe2+ and H2O2) was investigated. The effects of different reaction parameters such as initial AO concentration, pH value of solution, ferrous concentration, hydrogen peroxide concentration, and the presence of chloride ion on the oxidative degradation of AO were investigated. Under optimum conditions, 2 mM H2O2, 0.4 mM Fe2+ and pH 3.0, the initial 0.2 mM AO solution was reduced by 95.8% within 10 min. The primary intermediates of the degradation reaction of AO were identified. The analytical results indicated that the N‐de‐methylation degradation of AO dye took place in a stepwise manner to yield mono‐, di‐, tri‐, and tetra‐N‐de‐methylated AO species generated during the Fenton process. The probable degradation pathways were proposed and discussed.
A New Diterpenoid and other Constituents from Acanthopanax Brachypus Harms
Authors: Hu Hao‐Bin , Fan Jun 
Published: May 2015

AbstractPhytochemical investigation of the stem bark of Acanthopanax brachypus afforded a new labdanetype diterpene glycoside, 3α‐trans‐sinapoyloxy‐jhanol 18‐O‐β‐D‐glucopyranoside (1), together with four known compounds, including one diterpene acid, acanthoic acid (2), one coumarin, isofraxidin (3), one phenolic glycoside, sasanquin (4), as well as one chalcone glycoside, okanin 4‐methyl ether‐3′‐O‐β‐D‐glucopyranoside (5). All of the structures were characterized by means of spectroscopic methods, including 1H, 13C, 2D‐NMR and HR‐MS, as well as chemical methods and comparison with the literature data.
Reliable Technique for the Determination of Sodium Dodecyl Sulphate by Crystal Violet in Relation to the Effluents of Durg‐Bhilai Region
Authors: Sar Santosh K. , Verma Chanda , Pandey Piyush K. , Bhui Ashish 
Published: May 2015

AbstractA simple spectrophotometric method applicable to waste water bodies is developed for the determination of anionic surfactant (AS). An ion‐association complex is formed between an anionic surfactant Sodium dodecyl sulphate (SDS) and a cationic dye Crystal Violet (CV). The dark blue colored complex can be easily extracted in organic solvent benzene. The absorbance of the complex in benzene layer is measured spectrophotometrically at maximum wave length (λ max) of 565 nm. Under the optimal experimental conditions, absorbance of the organic extractant obeyed Beer's law over the range of 0.75–10.00 μg mL−1 of SDS and the LOD was 0.01312 μg L−1. It is noticed that the present method is much easier, less time consuming and applicable to accelerated urbanization and industrial development found in newly formed Chhattisgarh state in Central India.The validity of the method was tested in regionalized industrial and domestic waste water runoff.
Highly Efficient CuI‐Catalyzed N‐Arylation of Azaheterocycles with Aryl Iodides Using 1,1,1‐Tris(Hydroxymethyl)ethane as a Tridentate O‐Donor Ligand: A Shorter Route to Toloxatone and Formal Synthesis of Linezolid
Authors: Chen Hsin‐Hung , Huang Hua‐Min , Chen Shu‐Chih , Chen Yao‐Jung 
Published: May 2015

AbstractAn efficient copper‐catalyzed N‐arylation of azaheterocycles with aryl iodides using 1,1,1‐tris(hydroxymethyl)ethane as a tridentates O‐donor ligand has been accomplished in good to excellent yields. Moreover, this highly efficient catalyst system has been successfully demonstrated to one‐step synthesis of toloxatone and a shorter route to formal synthesis of linezolid in good yields.
Synthesis of 4‐Aryl‐3‐Methyl‐1‐Phenyl‐1H‐Benzo[h]Pyrazolo[3,4‐b]Quinoline‐5,10‐diones Using Diammonium Hydrogen Phosphate as an Efficient and Versatile Catalyst in Water
Authors: Wu Li‐Qiang , Dong Ruo‐Yi , Yang Chun‐Guang , Yan Fu‐Lin 
Published: May 2015

AbstractA simple and efficient synthesis of 4‐aryl‐3‐methyl‐1‐phenyl‐1H‐benzo[h]pyrazolo[3,4‐b]quinoline‐5,10‐diones has been accomplished by the one‐pot condensation reaction of 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐amine, aldehydes and 2‐hydroxynaphthalene‐1,4‐dione in water in the presence of diammonium hydrogen phosphate.
A Simple and Rapid High Performance Liquid Chromatographic Method with Fluorescence Detection for the Estimation of Amikacin in Plasma ‐ Application to Preclinical Pharmacokinetics
Authors: Chang Xiao‐Juan , Peng Jing‐Dong , Liu Shao‐Pu 
Published: May 2015

AbstractA simple and sensitive reversed‐phase liquid chromatographic method has been developed for the determination of amikacin by derivatization. The method is based on the pre‐column derivatization of amikacin with 9‐fluorenylmethyl chloroformate (FMOC‐Cl). Isepamicin was used as the internal standard. The derivatization reaction proceeds in aqueous solution at room temperature with a borate buffer of pH 7.3. The formation of the corresponding derivative of amikacin is instantaneous and it is stable for more than 48 h. Detection was performed by fluorescence. Several factors influencing the derivatization reaction yields were studied and optimized. The system offered the following analytical parameters: limit of detection (LOD) of 90 ng mL−1 (3σ), linear correlation coefficient of 0.9998 and linear range response from 0.45 to 21.60 μg‐mL−1. The precision of the method was < 6%. As a preliminary application, the method has been successfully applied to the amikacin determination in parenteral pharmaceutical formulations.
Aggregation Influence of Polyethyleneglycol Organic Solvents with Ionic Liquids BMIBF4 and BMIPF6
Authors: Wu Tzi‐Yi , Wang Hao‐Cheng , Su Shyh‐Gang , Gung Shr‐Tusen , Lin Ming‐Wei , Lin Cheng‐Bo 
Published: May 2015

AbstractPolyethyleneglycol (PEG, Mw = 200, 300, 400) and polyethyleneimine (PEI, Mw = 423) are used to investigate the ion‐ion interactions in liquids and physicochemical properties after the addition of PEG (or PEI) to ionic liquids 1‐butyl‐3‐methylimidazole tetrafluoroborate (BMIBF4) or 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BMIPF6). Nuclear magnetic resonance is used to investigate the effects of solvent content (x = 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) and temperature (303–338 K) on the diffusion coefficient, chemical shift, and two dimensional NOESY, HOESY spectra. HOESY spectra show that a hydrogen bond forms between the alkyl hydrogen of PEG and the 19F atom of BF4− and PF6−. After the addition of PEG to BMIBF4 (or BMIPF6), the aggregation is the dominant effect for the diffusion coefficient result. When the molecular weight and the concentration of PEG increase, the effect of coving generates larger clusters involving PEG, BMI+ and its counter anion. The BF4− group of the BMIBF4/PEG system is smaller than PF6−, it's easier to generate clusters in the BMIBF4/PEG system than it is in the BMIPF6/PEG system.
Simultaneous Quantitation of Captopril and NSAID's in API, Dosage Formulations and Human Serum by RP‐HPLC
Authors: Sultana Najma , Arayne M. Saeed , Naveed Safila 
Published: May 2015

AbstractAn accurate, sensitive and least time consuming reverse phase high performance liquid chromatographic (RP‐HPLC) method for the estimation of captopril in the presence of non steroidal anti‐inflammatory drugs in formulation and human serum has been developed and validated. Chromatographic separation was conducted on prepacked Purospher star C18 (5 μm, 25 × 0.46 cm) column at room temperature using methanol:water (80:20 v/v) as a mobile phase, pH adjusted at 2.8 with o‐phosphoric acid and at a flow rate of 1.0 mL min−1, while UV detection was performed at 227 nm. The limit of detection and quantification for captopril were 1 and 0.35 ng mL−1, while that for (NSAID's) i.e. flurbiprofen, ibuprofen, diclofenac sodium and mefenamic acid LOD were 0.2, 1, 2 and 0.4 ng mL−1 respectively and LOQ were 0.9, 2.9, 8 and 1 ng mL−1 Analytical recovery was > 98.1%. The method used for the quantitative analysis of commonly administered non steroidal anti‐inflammatory drugs (NSAID's) i.e. ibuprofen, flurbiprofen, diclofenac sodium and mefenamic acid alone or in combination with captopril from API (active pharmaceutical ingredients), dosage formulations and in human serum. The established method is rapid (RT < 12 min), accurate (recovery > 98.1%), selective (no interference of excepients and other commonly used drugs and food) and sensitive (LOQ 3.5 ng mL;‐1) and reproducible (SD ± 0.003).
Study on Separation/Enrichment and Determination of Mercury(II) using Microcrystalline Thymolphthalein Loaded with Ternary Association Complex
Authors: Chang‐Qing Tu , Xin‐Rong Wen 
Published: May 2015

AbstractThe paper presents a novel method for the separation/enrichment of Hg2+ using microcrystalline thymolphthalein loaded with ternary association complex prior to the determination by spectrophotometry. The effects of different parameters, such as the dosages of KI and dodecyl trimethyl ammonium bromide (DTAB) and thymolphthalein, various salts and acidity etc. on the enrichment yield of Hg2+ have been investigated to select the experimental conditions. The results showed that in the presence of 1.0 g NaCl, when the dosage of 0.1 M KI solution was 1.50 mL and 5.0 × 10−3 M dodecyl trimethyl ammonium bromide (DTAB) solution was 1.50 mL respectively, the water‐insoluble ternary association complex of (DTAB)2(HgI4) which produced by Hg2+ and I−, DTAB cation (DTAB+) was quantificationally absorbed on the surface of microcrystalline thymolphthalein Therefore, Hg2+ was separated completely from Zn2+, Mn2+, Ni2+, Co2+, Fe3+, Al3+, Pb2+, Bi3+ and Cr3+ etc. by contolling acidity. The possible enrichment mechanism of Hg2+ was deduced. The proposed method has been successfully applied to the determination of Hg2+ in the sample of industrial waster water, and the results agreed well with the dithizone method. The recoveries were 94.5%∼106.5%, and the RSD was 2.0%∼2.8%.
Electrocatalysis of Hemoglobin in ZnO Nanoparticle/Ionic Liquid Composite Film Modified Glassy Carbon Electrode
Authors: Wang Dan‐Dan , Liu He‐Jian , Zhao Chang‐Zhi , Hui Ni , Sun Wei 
Published: May 2015

AbstractA nanobiocompatible composite containing hemoglobin (Hb), ZnO nanoparticles (nano‐ZnO) and ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate (BMIMPF6) was fabricated and further modified on the glassy carbon electrode (GCE). The electrochemical behaviours of Hb in the composite film were carefully studied and a pair of quasi‐reversible redox peaks appeared in pH 7.0 phosphate buffer solution, which was attributed to the electrode reaction of Hb heme Fe(III)/Fe(II) redox couple. The presences of nano‐ZnO and BMIMPF6 in the film can retain the bioactivity of Hb and greatly enhance the direct electron transfer of Hb. The immobilized Hb showed high stability and good electrocatalytic ability to the reduction of hydrogen peroxide and O2.