bluuebunny/crossref_metadata_2025 huggingface dataset:
A Convenient Halogenation Procedure for the Preparation of α‐Halocarbonyl Compounds
Authors: Cheng Sheng‐Fan , Lin Ching‐Shan , Liu Lilian Kao
Published: May 2015

Except for substituted acetophenones (p‐Y‐C6H4COCH3, Y=H, Br, CH3O), simple ketones, β‐ketoesters and 1,3‐diketones reacted smoothly with a preformed homogeneous mixture of hydrochloric acid and potassium permanganate in acetonitrile to give moderate to good yields of the corresponding α‐chlorocarbonyl compounds. Mixtures of α‐chloro‐ and α,α‐dichlorocarbonyl compounds were obtained for substituted acetophenones. Brominations proceeded similarly with higher yields when the hydrochloric acid was replaced with hydrobromic acid.
Immobilized Aspergillus Oryzae Protease Catalyzed Formation of Peptide Bonds in Organic Solvent
Authors: Shih Ing‐Lung , Lin Yun‐Yin , Huang Hui‐Yao , Tai Dar‐Fu , Chen Kuan‐Chu
Published: May 2015

Immobilized Aspergillus oryzae protease (AOP) catalyzed the formation of peptide bonds between TV‐protected amino acids and amino acid esters or amides in ethyl acetate. The influences of pH and reaction time on the coupling of Boc‐L‐Tyr and Gly‐NH2 were studied. The optimal reaction condition for this enzyme catalyzed synthesis of Boc‐L‐Phe‐Gly‐NH2 (98.66%) was at pH 5.5 and a duration of 48 hours.
Protein Engineering III: Computer Aided Design of Disulfide‐Bond Free Cobra Venom Cardiotoxin with a Novel Conformation and Biological Activity from Synthetic Peptides
Authors: Chen Shui‐Tein , Yang Maw‐Tsiung , Wu Sung‐Yang , Wang Kung‐Tsung
Published: May 2015

Using the crystal structure of cobra venom cardiotoxin as a templet, a computer designed peptide with a novel conformation and biological activity has been synthesized chemically. The designed peptide utilized two calcium coordination sites instead of disulfide bridges to hold the conformation. The coordination sites were introduced at the cleft of three β‐sheet strands by replacing the residues of Leu‐1, Leu‐26, Ser‐28, Leu‐48, and Ser‐55 with Glu and using their γ‐carboxyl groups as legends. The residues of Cys at positions 3, 14, 21, 38, 42, 53, 54, and 59 of the four disulfide bridges were changed with Gly to remove all the disulfide bonds. Circular dichroism spectra showed that the synthesized peptide has a conformation similar to that of the native cardiotoxin of a defined structure only in aqueous solutions with the presence of calcium ions. Immunoprecipitation assay, using the anti‐cardiotoxin V, showed that in the presence of calcium ion the peptide had same cross reaction as that of native cardiotoxin. Hemolysis assay in the presence of calcium ion (150–250 mmol) and phospholipase A2 showed that the peptide had 65–70% as much cytolytic activity as the native toxin.
Structural Characterization of Venom Toxins by Physical Methods and the Perspectives on Structure‐Function Correlation of Proteins
Authors: Chiou Shyh‐Horng , Wu Shih‐Hsiung
Published: May 2015

This account describes work in our laboratories on the application of physical methods to the structural studies of various toxins during the past few years. A general review of background and the meaningful results obtained from these approaches are described. The results are compared with updated information on related subjects carried out at other laboratories. Examples of structural studies on some small toxins present abundantly in Formosan cobra (Naja naja atra), one of the indigenous toxic snakes in Taiwan, are given with the emphasis on the identification and characterization of complex toxic protein components based on near‐infrared Fourier transform Raman Spectroscopy. We will also describe our initial efforts in solving the solution structures of several small proteins and peptides by means of two‐dimensional nuclear magnetic resonance (2D‐NMR) and computer‐simulated modeling. The structural information obtained by these modem physical techniques provides the framework for unraveling the complex structure‐activity relationships engendered by these biomolecules.
Nucleophilic Addition Reactions of Tricarbonyl [η5−1‐(Phenylsulfonyl)cyclohexadienyl]iron(I) Complex
Authors: Chou Shang‐Shing P. , Hsu Chien‐Hung
Published: May 2015

Hydride abstraction of tricarbonyl[η4‐1‐(phenylsulfonyl)‐1,3‐cyclohexadiene]iron(0) complex 2 with Ph3C+PF6− regiospecifically provided the title compound 3 in excellent yield. Cationic complex 3 could react with a variety of nucleophiles in good yields. Soft nucleophiles prefer to attack at the C‐5 position, whereas hard nucleophiles such as methyllithium and the enolate of ethyl acetate gave the C‐5 as well as the C‐2 addition products. Some synthetic applications of the addition products were also studied.
Kaurane‐Type Diterpenoids from Liverworts
Authors: Liu Huei‐Ju , Tseng Shu‐Huey , Wu Jen‐Dar , Wu Chia‐Li
Published: May 2015

Seven kaurane‐type diterpenoids were isolated from the Taiwanese liverworts Jungermannia truncata. Among them, three are new structures. They are: ent‐16‐kauren‐3, 15‐dione (6), ent‐16(S)‐kauran‐3,15‐dione (7), and ent‐14α‐hydroxy‐16‐kauren‐15‐one (11). From Plagiochila pulcherrima, three known kaurane alcohols were also isolated along with sesquiterpenoids plagiochilines A, B, C and ent‐4β, 10α‐dihydroxyaromadendrane.
Effects on Coordination of Thioether Sites. 4. Structural Analysis of η3‐Tripodal Ligand Manganese(I) Complexes
Authors: Wang Hsin‐Ell , Huang Chi‐Tsuan , Yiin Lih‐Ming , Cheng Ming‐Chu , Peng Shie‐Ming , Liu Shiuh‐Tzung
Published: May 2015

Crystal structures of a series of manganese(I) complexes containing tripodal ligands were determined. For [η3‐{CH3C(CH2PPh2)2(CH2SPh)‐P,P′,S}Mn(CO)3]PF6 (1): a = 10.856(3) Å, b = 19.698(3) Å, c = 17.596(5) Å, β = 96.17(2)°, monoclinic, Z = 4, P21/c, R(Fo) = 0.068, Rw(Fo) = 0.055 for 3617 reflections with Io > 2σ(Io). For [η3‐{CH3C(CH2PPh2)(CH2SPh)2‐P,P′,S}Mn(CO)3]PF6 (2): a = 9.890(2) Å, b = 20.403(4) Å, c = 10.269(3) Å, β = 117.44(2)°, monoclinic, Z = 2, P2l, R(Fo) = 0.050, Rw(Fo) = 0.037 for 1760 reflections with Io > 2σ(Io). For [η3‐{CH3C(CH2PPh2)2(CH2S)‐P,P′,S}Mn(CO)3] (4): a = 8.191(7) Å, b = 10.495(3) Å, c = 19.858(6) Å, α = 99.61(2)°, β = 96.17(2)°, γ = 92.70(4)°, triclinic, Z = 2, P‐I, R(Fo) = 0.048, Rw(Fo) = 0.039 for 2973 reflections with Io > 2σ(Io). There is no significant difference in the bond lengths of Mn‐S bonds among three species in their crystal structures [2.325(2) Å in 1; 2.358(4) in 2; 2.380(2) in 4], but the better donating ability of thiolate in complex 4 appears on the lower frequencies of its carbonyl stretching absorptions.
Strong Antiferromagnetic Exchange Interactions in Cobalt(II) Complexes with 2‐Pyridyl Substituted Nitronyl Nitroxide Ligand
Authors: Huang Chian‐Feng , Wei Ho‐Hsiang
Published: May 2015

Three new complexes, [Co(hfac)2(NIToPy)] (1), [CoCl2(NIToPy)2] (2), and [Co(NIToPy)3](ClO4)2 (3), with NIToPy = 2‐(2‐Pyridyl)‐4,4,5,5‐tetramethyl‐4,5‐dihydro‐1H‐imidazolyl‐oxy‐3‐oxide, and hfac = hexafluoroacetylacetonate, have been synthesized. The compound 3 crystallized in the monoclinic space group P21, with two molecules in a unit cell of dimensions a = 10.565(4) Å, b = 14.714(9) Å, c = 14.596(7) Å, and β = 107.10(4)°. The temperature‐dependent magnetic susceptibility measurements (4.2 K‐300 K) for the complexes demonstrated strong antiferromagnetic exchange interaction between cobalt(II) ion and NIToPy radical spins with J = −140.1 cm−1 for 1, J = −94.2 cm−1 for 2, and J = −161.8 cm−1 for 3, respectively. The magneto‐structural correlation in these complexes has been discussed.
Crystal Structure of the Coordinatively Unsaturated 2‐Pyridylphosphine Pd(0) Complex Pd(PPh2Py)3
Authors: Su Chi‐Hung , Chiang Michael Y.
Published: May 2015

The three‐coordinate tris(2‐pyridylphosphine)palladium(0) complex is the first example of a group 10 metal complex bearing pyridine substituted phosphine ligand, whose crystal structure is determined. Pd(PPh2py)3 crystallizes in the triclinic space group \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm P}\bar 1 $\end{document}, with a = 12.874(4) Å, b = 14.162(3) Å, c = 14.912(3) Å, α = 87.76(2)°, β = 66.50(2)°, γ = 63.17(2)°, Z = 2, and V = 2191(1) Å3. Full‐matrix least‐squares refinement of 523 variables using 4911 data (F2o > 3σF2o) gave R = 0.033 and Rw = 0.033. The pyridine ring is disordered. Possible weak interactions among Ph rings or Py rings and Pd center are discussed. Close approach of the ortho hydrogen on phenyl rings to the Pd center may imply facile ortho metallation.
Orbital Interaction and the Mulliken‐Walsh Diagram for AH2 Systems
Authors: Chen Erh‐Hao , Chang Tse‐Chiang
Published: May 2015

We define θ‐ (or R‐) bonding (or antibonding) character of the molecular orbitals according to the slopes of the orbital energy curves when the internuclear angle (or internuclear distance) is varied. So far the slope of the orbital curve has only been accounted for by the qualitative argument based on two factors: the orbital overlap and the s‐p mixing.

We employ the bond orbitals instead of the usual atomic orbitals as the basis set to analysis the character of the molecular orbitals. The Fock matrix in the bond orbital basis can then quantitatively account for the effects of both the overlap and s‐p mixing factors.

Our analysis also show that a third factor, the orbital interaction, is essential to account for both the “typical” and “abnormal” behavior of the slopes.
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

A 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

A 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

Procedures 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

An 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

The 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

The 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

A 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

The 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

Aromatic 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

Citrus 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

The 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

Diazepam (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

N‐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

(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

A 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

A 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

High 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

Deprotonation, 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

Affinity 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

The 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

The 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

A 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

This 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

Three 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

A 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.
Crystal Structures and Magnetic Properties of Charge‐Transfer Salts: Cobaltocenium Bis(cis 1,2‐diphenylethene‐1,2‐dithiolato)metalates (Metal = Ni, Pd, Pt)
Authors: Sheu Chou‐Fu , Lee Jung‐Si
Published: May 2015

Charge‐transfer salts [Co(C5H5)2][M(dpt)2] (M = Ni and Pt; dpt = cis‐1,2‐diphenylethene‐1,2‐dithiolate) were synthesized and crystallographically characterized. [Co(C5H5)2][Ni(dpt)2] crystallizes in the monoclinic space group C2/c with a = 25, 607(3) Å, b = 9.4151(11) Å, c = 14.407(4) Å, β = 101.373(22)°, V = 3405.3(10) Å3 and Z = 4. [Co(C5H5)2][Pt(dpt)2] belongs to the triclinic space group \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm P}\bar 1 $\end{document} with a = 9.4666(11) Å, b = 13.9869(12) Å, c = 14.2652(9) Å, α = 99.983(6)°, β = 90.034(7)°, γ = 109.751(7)°, V = 1747.2(3) Å3 and Z = 2. Both structures consist of ··· D+A−D+A−D+A− ··· linear chains with the local C5 axis of the eclipsed [Co(C5H5)2]+ cation parallel to the best MS4 plane of the [M(dpt)2]− anion. Magnetic susceptibility measurements show that χM T values of the complexes [Co(C5H5)2][M(dpt)2] (M = Ni, Pd, and Pt) remain nearly constant in the temperature range 15–300 K, but decrease rapidly with further decreasing of temperature, indicating weak antiferromagnetic interactions at low temperatures.
Polar Chemical Constituents from Phoebe formosana
Authors: Wang Perng‐Haur , Lee Shoei‐Sheng
Published: May 2015

A chemical investigation on the H2O‐soluble constituents from the leaf of Phoebe formosana. led to the characterization often compounds including two C‐glycosylflavone — vitexin (1), isovitexin (2); six O‐glycosylflavonol — quercetin 3‐O‐galactoside (3), quercetin 3‐O‐α‐L‐arabinopyranoside (4), kaempferol 3‐O‐α‐L‐arabinofuranoside (5), kaempferol 3‐O‐α‐L‐rhamnoside (6), kaempferol 3‐O‐β‐D‐xylopyranoside (7); one dihydroflavonol ‐(+)‐dihydroquercetin (8) and two nucleosides ‐adenosine (9), and adenine (10). Their structures were determined on the basis of spectral analysis.
Interfacing ASE and HPLC for the Determination of PAH in Soil
Authors: Chen Chien Wen , Wang Yun Yuan , Wu Gaston J. C.
Published: May 2015

A method was developed to couple an accelerated solvent extraction system (ASE) with high performance liquid chromatography (HPLC) for the analysis of PAH in soil samples. The resolution of HPLC is well maintained while the advantages of ASE, fast extraction, less solvent consumption and ease of operation, are well expressed. The precision and accuracy of this method are verified by a series of analyses of reference material, and the precision of retention from multiple injection indicates minimum loss of chromatographic resolution by the interface of this technique. Detection limits for the studied PAH range from 0.07 ng/Kg to 0.21 ng/Kg with a fluorescence detector.
Chemical Constituents of a Formosan Soft Coral Sinularia sp.
Authors: Sheu Jyh‐Horng , Chang Kuie‐Chi , Sung Ping‐Jyun , Duh Chang‐Yih , Shen Ya‐Ching
Published: May 2015

A new marine sterol 7β‐hydroperoxy‐24‐methylenecholesterol (1) along with five known compounds sarcophytol A (2), (Z)‐N‐[2‐(4‐hydroxyphenyl)ethyl]‐3‐methyldodec‐2‐enamide (3), 5α,7αH‐eduesm‐11(13)en‐4α‐ol (4), 24‐methylenecholesterol (5) and 1β‐hydroxy‐α‐cyperone (6) have been isolated from a Formosan soft coral Sinularia sp. The structures of the above compounds were determined by spectral analyses. Cytotoxicity of compounds 1–6 toward various cancer cell lines also is reported.
A Model Calculation for the Isomerization and Decomposition of Chemisorbed HCN on the Si(100)‐2×1 Surface
Authors: Bacalzo‐Gladden F. , Musaev D. G. , Lin M. C.
Published: May 2015

Ab initio molecular orbital and hybrid density functional theory calculations have been performed to study the adsorption, isomerization, and decomposition of HCN on Si(100)‐2×1 using the Si9H12 cluster model of the surface. The results of our calculations indicate that the HCN can adsorb molecularly without a barrier onto the surface with both end‐on (LM1) and side‐on (LM2) positions. LM1 can isomerize to LM2 with a small barrier of 8 kcal/mol. The isomerization of LM2 by H‐migration from C to the N atom, requires 76 kcal/mol activation energy (c.f. 47.5 kcal/mol in the gas phase) because of surface stabilization. Both HCN(a) and HNC(a) end‐on adsorbates were found to dissociate readily, as concluded in our earlier experiment, to produce H and CN adspecies. The computed vibrational frequencies of HCN, CN, and also HCNH adspecies agree reasonably well with those observed experimentally. HCNH was found to be stable, with either the C or the N attaching to the surface.
On the Search for H5O2+centered Water Clusters in the Gas Phase
Authors: Chang Huan‐Cheng , Jiang Jyh‐Chiang , Chang Hai‐Chou , Wang Yi‐Sheng , Lin Sheng H. , Lee Yuan T.
Published: May 2015

In searching for H5O2+‐centered water clusters, we employed vibrational predissociation spectroscopy and ab initio calculations. Structures of the clusters were characterized by the free‐ and hydrogen‐bonded‐OH stretches of ion cores and solvent molecules. Systematic examination of H+(H2O)5–7 in a supersonic expansion reveals the presence of both cyclic and noncyclic forms of H5O2+‐centered water clusters. The proton transfer intermediate H5O2+(H2O)4 was identified, for the first time, by its characteristic hydrogen‐bonded‐OH stretches of the ion core at 3178 cm−1. Also discovered at n = 7 is the H5O2+‐containing five‐membered ring isomer, whose existence is evidenced by the observation of a bonded‐OH stretching doublet at 3544 and 3555 cm−1 of the solvent molecules. The observations are in accord with ab initio calculations which forecast that H5O2+(H2O)4 and H5O2+(H2O)5 are, respectively, the lowest‐energy isomers of protonated water hexamers and heptamers.
Total Synthesis of Dimethyl Glolosiphone A via α‐Carbonyl Radical Spiro‐Cyclization
Authors: Sha Chin‐Kang , Ho Wen‐Yueh
Published: May 2015

A general approach toward spiro[4.4]nonane structure based on the α‐carbonyl radical cyclization has been developed. Efficient total synthesis of dimethyl gloiosiphone A (2) was achieved. Thus, alkylation of the anion of dimethylhydrazone of cyclopentanone with 5‐iodopent‐1‐yne followed by hydrolysis gave ketone 4. Iodination of 4 via its TMS‐enol ether yielded iodo ketone 7. Radical spiro‐cyclization of 7 gave spiro ketone 10. Iodination of 10 afford iodo spiro ketone 23. Oxidation and iodination of 23 gave compound 24. Methylation of 24 furnished methoxy iodo enone 25. Substitution of iodide in 25 with methoxide produced dimethoxy enone 26. Allylic oxidation of 26 gave diketone 27. Treatment of 27 with OsO4 and N‐methylmorpholine N‐oxide gave dihydroxy ketone 28. Methylation of the primary alcohol group in 28 afforded dimethyl gloiosiphone A (2).
Sesquiterpenes from the Roots of Ligularia duciformis
Authors: Gao Kun , Yang Li , Jia Zhong‐Jian
Published: May 2015

Two new sesquiterpenes named liguducin‐A (1) and ‐B (4) were isolated from a Chinese medicinal plant, the dried roots of Ligularia duciformis, together with four known sesquiterpenes, 4α, 10β‐dihydroxy‐1β,5α‐H‐guai‐6‐ene (2), 4α‐hydroxy‐1β,5α,11α‐H‐guai‐9‐en‐12,8α‐olide (3), 1β‐hydroxyeudesm‐4,11‐dien‐3‐one (5) and 1β,6α‐dihydroxyeudesm‐4(15)‐ene (6). On the basis of the spectral evidence, their structures were determined.
Determination of Arsenic and Mercury in Various Environmental Matrices by Chemical Neutron Activation Analysis
Authors: Lo Jem‐Mau , Wei Ju‐Chin
Published: May 2015

Chemical neutron activation analysis was developed for determining trace amounts of arsenic and mercury in a variety of environmental matrices, including water, sediment, rock, plants, animal organs, etc: The adsorption procedure via magnesium oxide as the agent was applied to preconcentrate arsenic from the digested environmental matrices where arsenic in the form of As(V) ion could be highly efficiently adsorbed by hydrous magnesium oxide. On the other hand, the extraction procedure via lead diethyldithiocarbamate as the agent was applied to preconcentrate mercury from the digested environmental matrices where mercury in the form of Hg(II) ion could be highly efficiently extracted into the solution of lead diethyldithiocarbamte in dichloromethane. Both of the preconcentrated materials prepared ultimately in the solid states, i.e., arsenic in magnesium oxide and mercury in lead diethyldithiocarbamte were taken to be neutron irradiated. The γ spectra of the preconcentrated samples irradiated generally showed clear peaks of the product radionuclides from arsenic or from mercury by the different separation procedures. The possible interfering elements such as Na, Br, etc., were prominently minimized in respect of most of the preconcentrated samples. The reliability and accuracy of the proposed analytical methods for detecting arsenic and mercury can be confirmed by the assay of commercial standard reference materials including sediment, rock, plants, and animal organs.
Removal of Heavy Metals from Plating Wastewater by Crystallization/Precipitation of Gypsum
Authors: Huang Chein‐Ho , Wu Cheng‐Kwung , Sun Ping‐Ching
Published: May 2015

A high surface area was created during nucleation and crystal growth of gypsum by mixing calcium and sulfate ions, causing adsorption of heavy metals on the colloids of gypsum and capsulation in the subsequent precipitation process. In addition to the effect of surface area, zeta potential and surface pH of the gypsum colloids, ionic strength of solution, as well as solubility and particle size of the metal hydroxide influenced the extent of uptake of heavy metals from wastewater.
Enzymatic Reaction in Supercritical Fluid Carbon Dioxide Using Dry‐Ice
Authors: Yu Hui‐Ming , Lin Han‐Liang , Wu Chi‐Yue , Tseng Ming‐Jen , Chen Shui‐Tein , Jeyashoke Narumon , Krisnangkura Kanit
Published: May 2015

New enzymatic reactions in supercritical fluid carbon dioxide catalyzed by lipases (PPL, Lipase MY, Candida cylindracea Lipase), and Proteases (subtilisin Carlsberg, subtilisin 8397, immobilized papain) with high efficiency and yields in a simple high pressure reactor using readily available dry‐ice have been developed.
Inhibition of Trichothecin and Ergosterol Biosynthesis in Trichothecium roseum by Lovastatin
Authors: Huang Wan‐Ling , Lee Kuan Rong , Shiao Ming‐Shi
Published: May 2015

The effect of lovastatin, an HMG‐CoA reductase inhibitor, on the biosynthesis of trichothecin, ergosterol, and fatty acids in the fungus Trichothecium roseum was investigated. Treatment of lovastatin (50 μM) to a 5‐day‐old culture of T. roseum reduced the incorporation of [2‐14C]acetate into trichothecin by 79%, whereas the conversion of [5‐3H]mevalonate into this sesquiterpenoid mycotoxin was reduced by only 28%. In a parallel experiment, the incorporation of [2‐14C]acetate and [5‐3H]mevalonate into ergosterol were decreased by 78% and 17%, respectively. Meanwhile, the conversion of labeled acetate into fatty acids was not significantly affected. These results indicate that HMG‐CoA reductase is a major, but not strict, regulatory site in mevalonic acid pathway leading to the formation of trichothecin and ergosterol. No priority was found in utilization of a single, residual mevalonic acid pool in response to lovastatin inhibition for the biosynthesis of trichothecin and ergosterol. Inhibition of mevalonic acid formation does not significantly divert acetyl CoA into fatty acid synthesis.
Cu2+‐ATPases: Sequence Analyses and Implications in the Wilson Disease
Authors: Liaw Shwu‐Huey , Chuang Lee‐Ming
Published: May 2015

Wilson disease is an autosomal recessive disorder of copper metabolism, and the defective gene codes for a P‐type Cu2+‐ATPase. Sequence comparison revealed that the Cu2+‐ATPases were very distinct from the Ca2+‐, Na+‐ H+‐, and K+‐ATPases, which however, shared significant similarity to each other. The major difference may be due to the difference in metal ligand preference. Some novel conserved motifs in the Wilson disease protein were also identified, including a putative Walker A motif (GCGIGCKV, residues 1099–1106), and a Walker B motif (GDGVND, residues 1266–1271) for the cofactor ATP binding and hydrolysis, a unique KAPIQ motif (residues 910–914) in the transduction domain, and some motifs in the transmembrane segments probably for the substrate specificity. Combining with the previous genetic and biochemical data, some conserved residues could be assigned for possible functions. This information should provide a guide for designing future studies of structure‐function relationships in the Wilson disease gene. Sequence analysis is also useful in distinguishing whether the mutant residues are missense or polymorphism, such as T977M was identified as a missense mutation because only small amino acid residues appear at this position.
Solvolysis of 1‐Aryl‐1‐tert‐butylmethyl Bromides. Hammett‐Type Correlation Analysis and Revised YBnBr Scale
Authors: Liu Kwang‐Ting , Chin Chin‐Pu , Yu Der‐Gann , Duann Yeh‐Fang
Published: May 2015

The solvolysis of a series of 1‐aryl‐1‐tert‐butylmethyl bromides (1a–1g) in a variety of solvents were carried out. Linear relationships were observed from Hammett‐type analysis of logarithm of rate constants using single‐parameter Brown‐Okamoto equation (Eqn. 1) and dual‐parameter Yukawa‐Tsuno equation (Eqn. 2), respectively. The ρ values and the γ values were found to depend mainly on the range of substituents and not the type of solvents employed. The observation of an upward deviation for the data points of strongly deactivating substrates 1f and 1g could be interpreted by an electrophilic acceleration owing to the solvation of leaving group. It is likely an additional example of overshadowed solvent effect in the dual‐parameter treatment of rate data. Moreover, the variation of γ values was found contradicting the general consideration of resonance contribution. The observed excellent linear correlations with YBnBr and the good solubility in aqueous solution with high percentage of water made 1c a better reference standard than 2‐bromo‐2‐(4‐trifluormethyl)adamantane (3) for obtaining revised and extended YBnBr values. Correlation analysis using the single‐parameter Grunwald‐Winstein equation (Eqn. 3) with YBnBr was found to be superior over the dual‐parameter equation containing YBr and I (Eqn. 5).
Preparation and Properties of a New Chelating Resin Containing Sulfur and Nitrogen Donor Atoms
Authors: Chen Min‐Jane , Liu Chuen‐Ying
Published: May 2015

A novel chelating resin was obtained by incorporating 2‐mercaptoethylamine into polystyrene divinylbenzene copolymer. Conversion of functional groups of the resin was confirmed by IR spectra, elemental analysis, hydrogen capacity, and protonation constants. The functionality of the resin is 0.45 mmol g−1. The water regain as a function of pH was determined. The coordination behavior of the resin was investigated by IR, EPR and potentiometry. Effects of pH on adsorption of metal ions to the resin, both at large excess and limited amount of metal ions were examined. The resin exhibits exceptionally high affinity for soft metal ions, even in highly acidic aqueous media. EPR measurements at different copper loading were made. The results showed that the copper(II)‐resin complex might be distorted tetragonal. Protonation constants and stability constants of the resin were determined at 25 °C and ionic strength of 0.5 M KCl solution. The selectivity of the resin toward metal ions decreased in the order: Au(III) > Pt(IV) > Ag(I) > Pd(II) > Hg(II) > Fe(III) > Cu(II) > Zn(II) > Cd(II) > Ni(II) ≡ Co(II). Metal ion coordination occurs primarily at the nitrogen and sulfur donor atoms, but the polymeric backbone also makes significant contribution to metal binding. The resin demonstrated high promise for the collection and analysis of noble metal ions, especially from complex matrix samples.