bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Luminescence and Intramolecular Energy Transfer of Binary and Ternary Rare Earth Complexes with Aromatic Carboxylic Acids and 1, 10‐Phenanthroline
Authors: Yan Bing , Zhang Hong‐Jie , Wang Shu‐Bin , Ni Jia‐Zuan 
Published: May 2015

AbstractA series of binary and ternary rare earth complexes with para‐substitued benzoic acids and 1,10‐phenanthroline were synthesized. The phosphorescence spectra were measured and the lowest triplet state energies of ligands were determined, the phosphorescence lifetimes were obtained and intramolecular energy transfer mechanism between ligands was studied. The luminescence properties were also measured and were in agreement with the prediction. The energy match and intramolecular energy transfer process in these binary and ternary complexes were discussed in detail.
Synthesis of Dendramines, Dendramides and Their New Application in the Oil Industry
Authors: Katritzky Alan R. , Yang Baozhen , Tack Robert D. 
Published: May 2015

AbstractA series of dendramines and dendramides have been synthesized and some of their “anti‐freeze” properties in diesel fuels have been tested, showing that these compounds are good oil additives for reducing the wax‐like crystals which block the fuel filters.
Microwave Induced Synthesis of 3,4‐Dihydro‐2H‐pyran‐2‐carboxaldehyde: A Versatile Linker for Solid Phase Combinatorial Library
Authors: Hsieh Hsing‐Pang , Chen Shui‐Tein , Wang Kung‐Tsung 
Published: May 2015

AbstractProcedures for the dimerization of acrolein to form 3,4‐dihydro‐2H‐pyran‐2‐carboxaldehyde by microwave induced synthesis have been developed. Significant rate‐enhancement and yield increase were observed. 3,4‐Dihydro‐2H‐pyran‐2‐carboxaldehyde was obtained in 91% yield under microwave irradiation for 5 minutes instead of 39% yield by reacting at 190 °C for 40 min or at 160 °C for 4 hr.
Triplex Formation of an Oligonucleotide Containing 2′‐O‐methylpseudoisocytidine with Single and Double Stranded Nucleic Acids at Neutral pH
Authors: Ono Akira , Ts'o Paul O. P. , Kan L.‐S. 
Published: May 2015

AbstractAn oligonucleotide analog containing 2′‐O‐methylpseudoisocytidine (P) and 2′‐O‐methyluridine (X) in an alternated homopyrimidine sequence (P‐X‐)7P‐T can form triplexes with d‐A‐(G‐A‐)7G single strand and [d‐A‐(G‐A‐)7G]:[d‐C‐(T‐C‐)7T] duplex in neutral conditions. An UV mixing titration showed an end point of two units of (P‐X‐)7P‐T to one unit of d‐A‐(G‐A‐)7G. This indicates that a [(P‐X‐)7P‐T]·[d‐A‐(G‐A‐)7G]·[(P‐X‐)7P‐T] is formed. The [(P‐X‐)7P‐T]·[d‐A‐(G‐A‐)7G]·[(P‐X‐)7P‐T] triplex is stable in a 0.1 M NaCl solution at neutral pH. However, the formation of triplex with [(P‐X‐)7P‐T] and a duplex [d‐A‐(G‐A‐)7G]·[d‐C‐(T‐C‐)7T] can be accomplished in solution also containing 5 mM MgCl2. CD spectra of both triplexes showed large negative bands at wavelength 210–230 nm. Both triplexes can be detected by native gel electrophoresis. The thermal dissociation/association results indicate that this triplex dissociates to the single strands directly without going through a stable duplex intermediate.
Synthesis of 3,11‐Dioxatetracyclo[6.3.0.02,6.05,9]undecanes and 3,5,7‐Trioxapentacyclo[7.2.1.02,8.04,11.06,10]dodecane
Authors: Lin Hui‐Chang , Wu Chung‐Yi , Wu Hsien‐Jen 
Published: May 2015

AbstractThe synthesis of 3,11‐dioxatetracyclo[6.3.0.02,6.05,9]undecanes has been accomplished from furans in a short sequence by iodine‐induced cyclization reaction. The application of iodine‐induced cyclization reaction for the synthesis of 3,5,7‐trioxapentacyclo[7.2.1.02,8.04,11.06,10]dodecane itself was also demonstrated.
Large‐Scale Enantiomeric Enrichment via Solid State Extraction Using β‐Cyclodextrin Crystalline and Anhydrous Acetonitrile as Solid and Liquid Phases
Authors: Chen Shushi 
Published: May 2015

AbstractThe process‐scale enantiomeric enrichment of several adrenergic β‐blockers, atropine, and ruelene was accomplished through solid state extraction using anhydrous acetonitrile and β‐cyclodextrin crystalline as liquid and solid phases, respectively. This non‐chromatographic method has the advantages of easy, low cost operation, simplicity, and a high percentage of enrichment for some of the β‐blockers examined in a single batch. The percentage of enrichment in anhydrous acetonitrile was the best for all the racemates studied; however, it dropped dramatically when the extraction was carried out in a liquid phase of low polarity such as petroleum ether. No enantiomeric enrichment was observed in liquid phases that are polar and capable of participating in hydrogen bonding (e.g., methanol). Introducing additives (e.g., acetic acid, triethylamine) to the liquid phase also decreased the percentage of enrichment. Finally, lowering the operating temperature (0 °C) appeared to retard the enantiomeric extraction process, which could be restored to normal level by elevating liquid phase temperature to 28 °C.
Radical Complexes of Isomeric Tetramethyl Phenanthroquinone with Manganesedecacarbonyls
Authors: Ho Tong‐Ing , Pan Kai , Chen Cheu‐Pyeng 
Published: May 2015

AbstractA series of radical complexes containing manganese carbonyl, 1,3,6,8‐tetramethyl‐9,10‐phenanthroquinone (PQ1), 2,4,5,7‐tetramethyl‐9,10‐phenanthroquinone (PQ2) and triphenylphosphine are prepared and their ESR spectra are recorded and analyzed with computer simulations. From the analysis of the proton, manganese and phosphine hyperfine splitting constants, the nature of the orbital interaction and also the election transfer character are revealed. PQ1− and PQ2− Mn(CO)4 radicals are of more anion radical character than the unsubstituted PQ− Mn(CO)4 radical. The fact that the Mn and P hfsc increases and the proton hfsc decreases as the phosphine ligand increases indicated that an increasing interaction exists between the PQ pπ* and the Mn dπ orbitals with increasing phosphine number.
Separation of Nanostructured Gold Particles by Capillary Zone Electrophoresis
Authors: Wei Guor‐Tzo , Wang Churng‐Ren Chris , Liu Fu‐Ken , Chang Ser‐Sing 
Published: May 2015

AbstractThe feasibility of employing capillary zone electrophoresis to separate nanostructured gold particles was investigated. The optimal experimental conditions of rinsing procedure, type and concentration of cationic surfactant, buffer concentration, and pH value were identified for the separations. Under the optimal conditions — included rinsing capillary with 0.5 N NaOH, water, and buffer for 3 min in sequence, and running the experiment with 7.5 mM TTAB, 12.5 mM tetraborate, and pH 9.0 of buffer solution at 20 kV applied voltage — nearly resolved separation (Rs = 1.0) of gold particles with mean diameter differences as small as 1 nm was achieved.
Determination of Phenylenediamines in Oxidative Hair Dyes by Differential Pulse Voltammetry
Authors: Wang Lai‐Hao , Chen Zong‐Shion 
Published: May 2015

AbstractAromatic diamines — such as m‐, p‐phenylenediamine, 2‐nitro‐p‐, N‐phenyl‐p‐phenylenediamine, 2,4‐diaminoanisole, and 2,5‐diaminetoluene — were determined by differential pulse voltammetry (DPV) on a carbon paste electrode with acetate buffer/(pH 4.74). Some factors affecting the determination of dye intermediates were discussed. The method permitted determination of various types of dye intermediates without any pretreatment in commercial hair dyes. The results obtained were in good agreement with those of the high performance liquid chromatographic (HPLC) method.
Isolation and Characterization of an Antibacterial Substance from Citrus Plant
Authors: Ito Chihiro , Fujiwara Kazuko , Koizumi Meisaku , Furukawa Hiroshi 
Published: May 2015

AbstractCitrus bacterial canker caused by Xanthomomas campestris pv. citri (Hasse 1915) Dye 1978, a gram‐negative and rod‐shape bacteria, is one of the destructive diseases of Citrus. There is marked diversity in resistance to the disease among Citrus plants. Calamondin, Citrus madurensis Lour. (Shiki‐kitsu) is one of the highly resistant plants.1 In resistant plants bacterial multiplication is restrained by the embedding of electron dense materials in intercellular spaces.2 This suggests the presence of an antibacterial substance in resistant plants.The third author assayed the 85% ethanol extracts of Citrus leaves infected with bacterial canker for static activities to X. campestris. pv. citri. An active fraction was found in Calamondin. We further purified and characterized its ingredients on the basis of spectrometric analyses. Its structure was found to be identical with 3‐hydroxy‐5,6,7,8,3′,4′‐hexamethoxyflavone (1) isolated from Citrus natsudaidai Hayata. However, its antibacterial activity is first reported by us.
Effect of Temperature in micro‐HPLC Separation of PAHs under Isocratic Conditions Using Octadecyl and Alkylamide Phases
Authors: Gadzala‐Kopciuch Renata , Buszewski Boguslaw 
Published: May 2015

AbstractThe main difficulty in micro‐HPLC separation is the manipulation with the composition of the mobile phase (degassing of solvents and a slow establishment of equilibrium) but the problem of elution can be solved by temperature optimalization. The effect of temperature in micro‐HPLC separation of the 16 polycyclic aromatic hydrocarbons (PAHs) (mixture SRM 1647 of the US EPA) has been studied using conventional C18 and new developed AP phase (an amide group localized in the hydrophobic ligands). All the investigations have been performed under isocratic conditions (binary hydroorganic mobile phase: acetonitrile/water). The results have shown that, in the case of AP phase, application of temperature gradient (from 298 to 303 K), enabled the attainment of complete 16 PAHs separation (especially of the first 4 solutes).
Mechanism of Alkaline Hydrolysis of Diazepam
Authors: Yang Shen K. 
Published: May 2015

AbstractDiazepam (1) is a frequently prescribed hypnotic/anxiolytic drug in worldwide use. Compound 1 is hydrolyzed in alkaline medium to form 2‐methylamino‐5‐chlorobenzophenone imine (2) and 2‐methylamino‐5‐chlorobenzophenone (3); the ratio of 2:3 increases with increasing NaOH concentration (J. Pharm. Sci. 85, 745–748, 1996). The mechanism in the conversion of 1 to 2 and 3 via various intermediates is the subject of this report. Results of hydrolysis kinetics and structural identification of some intermediate products indicated an initial hydroxide attack at the C2‐carbonyl carbon of 1, resulting in the formation of a dioxide (7, 7‐chloro‐1,3‐dihydro‐1‐methyl‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2,2‐dioxide). Compound 7 was characterized by proton NMR spectroscopy and via its monomethyl ether (8, 7‐chloro‐1,3‐dihydro‐2‐hydroxy‐2‐methoxy‐l‐methyl‐5‐pheny]‐2H‐1,4‐benzodiazepine). The seven‐member diazepine ring of 7 opened at the N1‐C2 bond to form a glycinate [5, 2‐methylamino‐5‐chloro‐α‐(phenylhenzylidene)glycinate]. Compound 7 (and/or 5) underwent an additional hydroxide attack at the C5‐N4 imine bond to form a tetrahedral intermediate, which decomposed to form 2 and 3.
The Synthesis of 1‐Methyl‐6,7,8,8a‐tetrahydro‐5H‐indolizin‐3‐one by the Palladium‐Catalyzed Cyclization of N‐Bromoacetyl‐2‐vinylpiperidine
Authors: Yang Shyh‐Chyun , Shea Fang‐Rong , Chung Wen‐Hung 
Published: May 2015

AbstractN‐Bromoacetyl‐2‐vinylpiperidine underwent cyclization to give indolizidine derivative in the presence of a base and a catalytic amount of palladium trifluoroacetate.
Allene‐Eneyne Related Cycloaromatization: Design and Synthesis of New DNA‐Cleaving Compounds
Authors: Wu Ming‐Jung , Lin Chi‐Fong , Jing Pao‐Tzu , Chang Li‐Juan , Duh Tsai‐Hui , Lee Fang‐Chen , Chen Huey‐Ting 
Published: May 2015

Abstract(Z)‐7‐Sulfonyl‐3‐hexen‐1,5‐diyne containing molecules are stable at room temperature and isomerized to eneyne‐allene‐sulfones under alkaline conditions. These eneyne‐allene‐sulfones were not isolable, spontaneously cyclized to form biradical intermediates under mild conditions, and exhibited good DNA‐cleaving and human tumor cell line growth inhibition properties. Further studies indicated that compounds bearing on aromatic ring at C(3) and C(4), such as 25, proved to be more active against those tumor cell lines. Removal of acetylene unit at C(1) and C(2), made the resulting compound less active. A related compound, (Z,Z)‐12‐(2‐tetrahydropyranyl)oxy‐1‐phenylsulfonyldodeca‐4,8‐diene‐2,6,10‐triyne (37), was synthesized. Upon treatment of triethylamine at refluxing benzene, this compound undergoes double cycloaromatization to form a naphalene adduct, which possesses excellent DNA‐cleaving activity.
Aspartase‐Catalyzed Preparative Scale Synthesis of 15N‐Aspartic Acid
Authors: Sookkheo Boonyaras , Phutakul Suree , Chen Shui‐Tein , Wang Kung‐Tsung 
Published: May 2015

AbstractA preparative scale synthesis of 15N‐aspartic acid from fumarate and 15NH4OH catalyzed by immobilized aspartase has been developed. Immobilization of aspartase in membrane enclosed enzyme immobilization (MEEI) facilitates the separation of the enzyme from product and makes the enzyme stable and durable for multiple usage. A simple isolation procedure in total yield of 62% using perfusion ion exchange chromatography renders the procedure more practical.
A General Procedure for Synthesis of NG‐Alkyl, and NG‐Aryl‐L‐Arginines as Potential Nitric Oxide Synthase inhibitors
Authors: Chen Bor‐Cherng , Shiu Shi , Yang Ding‐Yah 
Published: May 2015

AbstractA general procedure for the synthesis of NG‐alkyl, and NG‐aryl‐L‐arginines with relatively high overall yield is reported. The key step involved the coupling of protected L‐ornithine 4 with isothiourea 7 to give the fully protected NG‐aryl‐L‐arginine derivative 8. Subsequent deprotection of 8 in acidic condition provided the final target compound 9 with an overall yield of more than 80%.
Design and Characterization of a Short HMG‐I/DAT1 Peptide that Binds Specifically to the Minor Groove of DNA
Authors: Cheng Chien‐Chung , Jian Yuan‐Hung , Lo Ching‐Jung , Cheng Jya‐Wei 
Published: May 2015

AbstractHigh mobility group protein (HMG) is known to be involved in the formation of high order structure of chromatin. HMGs with minor‐groove binding ability in the AT‐rich DNA region play a vital role in controlling gene transcription activity. In this report, a 18‐residue HMG‐I/DAT1 chimeric peptide, PRGRPKGKTLREPRGRPY, was designed and synthesized containing two repetitive PRGRP units and a linking peptide, KGKTLRE, as a targeted DNA‐binding peptide. The segment PRGRP is derived from HMG‐I while KGKTLRE is from the DAT1 peptide. Using gel‐mobility shift assay and 32P‐end labeled 27 bp AT‐rich DNA, the dissociation constant of this chimeric peptide was found to be 4.7 × 10−6 M, that is, 104 times stronger than that of the PRGRP segment stand alone (> 10−2 M). In addition, the binding constant was found to increase with the length of AT‐rich DNA. The possible DNA binding site of the HMG−1/DAT1 chimeric peptide is determined by footprinting experiments using a minor‐groove cleaving agent ruthenium(III)‐Schiff base complex and a 135‐bp 32P‐5′‐end‐labeled DNA restriction fragment of Hind III/Rsa I from plasmid pBR322 DNA. The major pattern protected by the HMG‐I/DAT1 chimeric peptide exhibits a preference for 5′‐AAAT‐3′ of the AT‐rich region. Therefore, this novel design HMG‐1/DAT1 chimeric peptide possesses not only a high affinity to AT‐rich DNA but also the sequence‐specific binding in the minor groove of DNA, which may further lead to the design of short synthetic peptides for therapeutic applications.
The Regioselective Methylation of Polycyclic Aromatic Hydrocarbons through Tricarbonylchromium Coordination
Authors: Own Z. Y. , Chiu Li‐Ting 
Published: May 2015

AbstractDeprotonation, methylation, and air oxidation of polycyclic arenes coordinated to chromium(0), (η6‐arene)Cr(CO)3, produced ring‐methylated products with high selectivity and in good yield. This procedure gave 3‐methylbenz[a]anthracene from (η6‐benz[a]anthracene)Cr(CO)3, 3‐methylphenanthrene from (η6‐phenanthrene)Cr(CO)3, 2‐acetyl‐6‐methylphenanthrene from (η6−2‐acetylphenanthrene)Cr(CO)3, and 3,7,12‐trimethylbenz[a]anthracene from (η6−7,12‐dimethylbenz[a]anthracene)Cr(CO)3.
Affinity Capillary Electrophoresis: From Binding Measurement to Combinatorial Library Screening
Authors: Chu Yen‐Ho , Zang Xu , Tu Jian 
Published: May 2015

AbstractAffinity capillary electrophoresis is a new procedure for receptor‐ligand binding studies. Since its introduction in the early 1990s, this method has proved valuable in chiral separation of racemates, the measurement of binding constants, the estimation of kinetic rate constants, the determination of stoichiometries, the investigation of electrostatic interactions, the estimation of effective charges and molecular weights of biomolecules, the characterization of enzymatic catalysis, and, most recently, combinatorial library screening in solutions. This technique demands small amounts of samples, involves no radiolabeled materials or chemically immobilized ligands, and does not require changes in spectroscopic characteristics upon binding. This paper reviews the most recent applications of affinity capillary electrophoresis in binding measurement and combinatorial library screening.
Studies of Silver Nanoparticles by Laser Ablation Method
Authors: Jeon Jiann‐Shing , Yeh Chen‐Sheng 
Published: May 2015

AbstractThe laser ablation technique has been employed to study silver colloidal formation. Laser intensities, irradiation wavelengths (1064 nm and 532 nm), and solvents (water, methanol, and isopropanol) were all considered. Changes of the maximum UV‐Visible absorbance of the solutions with laser intensities exhibited nonlinear behavior for 1064 nm and 532 nm and displayed better ablation efficiency at 532 nm. Larger mean sizes were observed at 532 nm or at higher pulse energy. For solvent effect, the bigger particle sizes were generated in H2O. As to colloidal stability, isopropanol, which has a lower dielectric constant than water, was found to stabilize Ag nanoparticles without protecting reagents over six months. Preliminary results in 2‐butanol suggested that the viscosity of solvent may need to be considered in addition to the dielectric constant.
Structure and Crystallographic Disorder of [Mo2(O2CCF3)2I4](HPPh3)2
Authors: Chiang Shih‐Fu , Wu Ying‐Yann , Chen Jhy‐Der , Keng Tai‐Chiun , Wang Ju‐Chun 
Published: May 2015

AbstractThe reaction of Mo2(O3CCF3)4 with (CH3)3SiI and PPh3 gave the title complex [Mo3(O2CCF3)2I4]‐(HPPh3)2 which was characterized by X‐ray crystallography. Crystal data for [Mo2(O2CCF3)2I4](HPPh3)2: space group \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm P}\bar 1 $\end{document}, a = 10.953(4) Å, b = 12.784(3) Å, c = 19.829(4) Å, α = 100.68(2)°, β = 91.16(2)°, γ = 112.98(2)°, V = 2498.6(10) Å3, Z = 2, with final residuals R = 0.0887 and Rw = 0.0965. There are two independent molecules in each asymmetric unit. The molybdenum, oxygen, and fluoride atoms in one of the two independent molecules are disordered, such that the primary set is 53% occupied, and the secondary set 47%.
Intramolecular Diels‐Alder Reaction of Furans with Allenyl Ethers Followed by Phenylthio and Trialkylsilyl Groups Rearrangement
Authors: Chuang Chi‐Te , Yen Chia‐Hui , Wu Hsien‐Jen 
Published: May 2015

AbstractA new reaction involving an intramolecular Diels‐Alder reaction of a furan diene with an allenyl ether dienophile followed by phenylthio group rearrangement was discovered. Treatment of the propargyl ethers 2a‐c with t‐BuOK in t‐BuOH at 85 ° C gave the phenylthio group rearrangement products 5a‐c and 6a‐c. A reaction involving an intramolecular Diels‐Alder reaction of a furan diene with an allenyl ether dienophile followed by trialkylsilyl group rearrangement is also demonstrated.
Towards a Fundamental Understanding of Urea and Thiourea inclusion Compounds
Authors: Harris Kenneth D. M. 
Published: May 2015

AbstractThis article reviews some of the fundamental scientific issues associated with solid inclusion compounds, and describes the approaches and strategies that may be used to investigate the structural, dynamic and chemical properties of these systems. Two particular families of solid organic inclusion compounds ‐ the urea and thiourea inclusion compounds ‐ are highlighted. In order to understand the fundamental nature of these solids, it has been necessary to apply a wide range of experimental, computational and theoretical approaches. Each technique provides information on a different aspect of the solid, and the combined information obtained from these complementary approaches allows a comprehensive understanding to be established. Several issues of contemporary interest for urea and thiourea inclusion compounds are described, and the approaches that have been taken towards a fundamental understanding of these systems are explained.
Chemotaxonomy of Triterpenoid Pattern of HPLC of Ganoderma lucidum and Ganoderma tsugae
Authors: Chen Deng‐Hai , Shiou Wen‐Yue , Wang Kuen‐Chern , Huang Shu‐Ying , Shie Yu‐Tsan , Tsai Chiou‐Man , Shie Jun‐Fa , Chen Kuan‐Dee 
Published: May 2015

AbstractThree strains of Ganoderma tsugae (CCRC36065, CCRC37034, CCRC37038) and three strains of Ganoderma lucidum (CCRC36021, CCRC37029, CCRC37033) were cultivated. Their triterpenoid patterns of the fruit body were analyzed by reverse phase HPLC using a gradient elution of acetonitrile/2% acetic acid (1/4 and 1/2). The triterpenoid patterns of G. tsugae and G. lucidum are different. But similar 2 and 3 dimensional patterns are obtained among three strains of G. tsugae. Different patterns are found among different strains of G. lucidum. Ganoderic acid A(1), B(2), C(3) and D(4) were isolated from the ethanol extract of G. tsugae.
Combinatorial Peptide Library for Probing the Selectivity of the s‐1 Subsite of Proteases
Authors: Lin I‐Chun , Sookkheo Boonyaras , Phutrakul Suree , Chen Shui‐Tein , Tseng Min‐Jen , Wang Kung‐Tsung 
Published: May 2015

AbstractA combinatorial tetrapeptide library, Suc‐Ala‐Phe‐Arg‐AA1‐OR, in which R = p‐formamidobenzyl ester and AA1 = 17 of the 20 natural occurring amino acids, has been synthesized chemically and separated by a reverse phase HPLC. The library was used to study the s‐1 subsite specificity of various proteases. The preferred substrate at the s‐1 subsite of chymotrypsin is in the order of Trp > Tyr > Phe > Met > Leu. This agreed with the reported data that the favored substrate at the s‐1 subsite for chymotrypsin‐catalyzed hydrolysis is an aromatic amino acid residue. The hydrophobic amino acid residues at this subsite can be hydrolysized after a longer incubating time. This procedure of selective hydrolysis of a peptide library was used to probe the selectivity of s‐1 subsites of four proteases isolated from Bacillus stearothermophilus, subtilisin Carlsberg, subtilisin BPN' and an engineered protease subtilisin 8397. The protease from Bacillus stearothermophilus favored the substrate with residue Lys, and Arg at the s‐1 subsite as a trypsin‐like protease. The relative reactivities of amino acid residues in the protease‐catalyzed hydrolysis of the library can be used as a fingerprint to identify the protease in a protease family.