bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Transformations of 3‐Aminothieno[2,3‐b]pyridine‐2‐carboxamides.
Authors: Kaigorodova E. A. , Vasilin V. K. , Osipova A. A. , Lipunov M. M. , Krapivin G. D. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Highly Selective Conversion of N‐Aroyl‐α‐dehydronaphthylalaninamides into 3,4‐Dihydrobenzoquinolinone Derivatives via Photoinduced Intermolecular Electron Transfer.
Authors: Maekawa Kei , Shinozuka Ayana , Naito Michiko , Igarashi Tetsutaro , Sakurai Tadamitsu 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Novel Aryloxy‐8‐azabicyclo[3.2.1]oct‐3‐enes with 5‐HT Transporter and 5‐HT1A Affinity.
Authors: Gilbert Adam M. , Coleman Thomas , Kodah Jason , Mewshaw Richard E. , Scerni Rosemary , Schechter Lee E. , Smith Deborah L. , Andree Terrance H. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 7‐Alkyl(aryl)‐6‐alkoxycarbonyl‐5‐fluoroalkyl‐1,2,4‐tri(tetr)azolo [1,5‐a]pyrimidines
Authors: Pryadeina M. V. , Burgart Ya. V. , Saloutin V. I. , Kodess M. I. , Ulomskii E. N. , Rusinov V. L. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Five‐Membered 2,3‐Dioxo Heterocycles. Part 47. Reaction of 5‐Aryl‐4‐phenyl‐2,3‐dihydrofuran‐2,3‐diones with Compounds Containing C=N and CN Bonds.
Authors: Vostrov E. S. , Leont'eva E. V. , Tarasova O. P. , Maslivets A. N. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Anellation of the Thiazole Ring to 1,2,4‐Triazines by Tandem AN—AN or SNH—SNH Reactions.
Authors: Mochul'skaya N. N. , Andreiko A. A. , Kodess M. I. , Vasil'eva E. B. , Filyakova V. I. , Gubaidullin A. T. , Litvinov I. A. , Sinyashin O. G. , Aleksandrov G. G. , Charushin V. N. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Some Reactions of 3,6‐Bis(4‐amino‐1,2,5‐oxadiazol‐3‐yl)‐1,4,2,5‐dioxadiazine.
Authors: Shaposhnikov S. D. , Romanova T. V. , Spiridonova N. P. , Mel'nikova S. F. , Tselinskii I. V. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Azaphilone Pigments from a Yellow Mutant of the Fungus Monascus kaoliang.
Authors: Jongrungruangchok Suchada , Kittakoop Prasat , Yongsmith Busaba , Bavovada Rapepol , Tanasupawat Somboon , Lartpornmatulee Nattapat , Thebtaranonth Yodhathair 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Enzymatic Formation of an Unnatural Novel Tetracyclic Sesterterpene by β‐Amyrin Synthase.
Authors: Noma Hisashi , Tanaka Hideya , Noguchi Hiroshi , Shibuya Masaaki , Ebizuka Yutaka , Abe Ikuro 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis, Structure, and Absolute Configuration of a New Cyclopropanic Compound Derived from the Sesquiterpene β‐Himachalene.
Authors: Ziyat Hossni , El Houssame Soufiane , Ali Mustapha Ait , Itto My Youssef Ait , Karim Abdellah , Wartchow Rudolf , Butenschoen Holger 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Spirovetivane Sesquiterpenes from Santonin. Synthesis of (+)‐Anhydro‐β‐rotunol and All Diastereomers of 6,11‐Spirovetivadiene.
Authors: Blay Gonzalo , Cardona Luz , Collado Ana M. , Garcia Begona , Morcillo Veronica , Pedro Jose R. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Oxidation of Betulin and Its Acetates with Dimethyldioxirane.
Authors: Ashavina Olga Yu. , Kabalnova Nataliya N. , Flekhter Oxana B. , Spirikhin Leonid V. , Galin Fanur Z. , Baltina Lidiya A. , Starikova Zoya A. , Antipin Mikhail Yu. , Tolstikov Genrikh A. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of the Bicyclic [7.3.0] Enediyne System of the Maduropeptin Chromophore: Remarkable Atropisomerism of Ansamacrolactam and Isomerization of the C4—C13 Double Bond.
Authors: Kato Nobuki , Shimamura Satoshi , Kikai Yoko , Hirama Masahiro 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Efficient Routes to Optically Active Azido‐, Amino‐, Di‐azido‐ and Di‐amino‐cyclitols with chiro‐ and allo‐Configuration from myo‐Inositol.
Authors: Sureshan Kana M. , Ikeda Kyoko , Asano Naoki , Watanabe Yutaka 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 4‐Deoxy‐L‐(and D‐)hexoses from Chiral Noncarbohydrate Building Blocks.
Authors: Caputo Romualdo , De Nisco Mauro , Festa Pasquale , Guaragna Annalisa , Palumbo Giovanni , Pedatella Silvana 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Stereospecific Uncatalyzed α‐O‐Glycosylation and α‐C‐Glycosidation by Means of a New D‐Gulal‐Derived α Vinyl Oxirane.
Authors: Di Bussolo Valeria , Caselli Micaela , Romano Maria Rosaria , Pineschi Mauro , Crotti Paolo 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of 3‐Methoxyolivacine and Olivacine by Friedel—Crafts Reaction of Indole‐2,3‐dicarboxylic Anhydride with 2,4,6‐Trimethoxypyridine.
Authors: Miki Yasuyoshi , Tsuzaki Yasuhiko , Hibino Hajime , Aoki Yoshiyuki 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Camptothecin Analogues with Bulky, Hydrophobic Substituents at the 7‐Position via a Grignard Reaction.
Authors: Manikumar Govindarajan , Wadkins Randy M. , Bearss David , Von Hoff Daniel D. , Wani Mansukhlal C. , Wall Monroe E. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Design, Synthesis, and Evaluation of Acyclic C‐Nucleoside and N‐Methylated Derivatives of the Ribitylaminopyrimidine Substrate of Lumazine Synthase as Potential Enzyme Inhibitors and Mechanistic Probes.
Authors: Chen Jinhua , Sambaiah Thota , Illarionov Boris , Fischer Markus , Bacher Adelbert , Cushman Mark 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Alkyl Lysophosphatidic Acid and Fluoromethylene Phosphonate Analogues as Metabolically‐Stabilized Agonists for LPA Receptors.
Authors: Xu Yong , Tanaka Masayuki , Arai Hiroyuki , Aoki Junken , Prestwich Glenn D. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
MPC1001 and Its Analogues: New Antitumor Agents from the Fungus Cladorrhinum Species.
Authors: Onodera Hideyuki , Hasegawa Atsuhiro , Tsumagari Noriko , Nakai Ryuichiro , Ogawa Tatsuhiro , Kanda Yutaka 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Kinetic and Equilibrium Deuterium Isotope Effects for C—H Bond Reductive Elimination and Oxidative Addition Reactions Involving the ansa‐Tungstenocene Methyl—Hydride Complex [Me2Si(C5Me4)2]W(Me)H
Authors: Janak Kevin E. , Churchill David G. , Parkin Gerard 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Molecular Aspects of the Transport and Toxicity of Ochratoxin A
Authors: Dai Jian , Park Gyungse , Perry Jennifer L , Il'ichev Yuri V. , Bow Daniel A. J. , Pritchard John B. , Faucet Virginie , Pfohl‐Leszkowicz Annie , Manderville Richard A. , Simon John D. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
New Schemes for the Synthesis of Glycolipid Oligosaccharide Chains
Authors: Nifantiev Nikolay E. , Sherman Andrei A. , Yudina Olga N. , Cheshev Pavel E. , Tsvetkov Yury E. , Khatuntseva Elena A. , Kornilov Andrey V. , Shashkov Alexander S. 
Published: January 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Bicelles as model membranes for solid‐ and solution‐state NMR studies of membrane peptides and proteins
Authors: Marcotte Isabelle , Auger Michèle 
Published: January 2005

AbstractBicelles are an attractive membrane mimetic system because of their planar surface and lipid composition, which resemble biological membranes. In addition, their orientation and morphologic properties make them amenable to solid‐ and solution‐state NMR. This article reviews the physical properties of bicelles, such as magnetic alignment and viscosity as well as the different models proposed in the literature to explain the bicelle morphology. The utility of bicelles for studying the interaction and structure of membrane peptides and proteins by solid‐ and solution‐state NMR is also presented, along with the advantages and limitations of bicelles. © 2005 Wiley Periodicals, Inc. Concepts Magn Reson Part A 24A: 17–37, 2005.
The concept of effective correlation times for describing backbone motions in proteins. Part I. A residue‐per‐residue self‐consistent analysis of multifield 15N relaxation parameters
Authors: Bouguet‐Bonnet Sabine , Mutzenhardt Pierre , Roumestand Christian , Canet Daniel 
Published: January 2005

AbstractThis study is an extension of a recent work (Canet D, Barthe P, Mutzenhardt P, Roumestand C. 2001. A comprehensive analysis of multifield 15N relaxation parameters in proteins: Determination of 15N chemical shift anisotropies. J Am Chem Soc 123:4567–4576) dealing with the exploitation of the three classical 15N relaxation parameters (the longitudinal relaxation rate, R1, the transverse relaxation rate, R2, and the 1H‐15N cross‐relaxation rate, σNH) measured at several magnetic fields (at least two) in uniformly 15N‐labeled proteins (the chosen example is the C12A‐p8MTCP1 protein whose relaxation parameters have been measured at five different fields). R2 is iteratively corrected for exchange, so that the three parameters provide consistently the NH dipolar and 15N csa (chemical shift anisotropy) contributions. The dipolar spectral densities are analyzed, residue by residue, according to the functional form $$a_d + { b_d \over {1 + \omega^{2}\tau^{2}_{e\!f\!f}}}$$ (d for dipolar), where τeff is an (effective) correlation time associated with the slow motion(s) sensed by the NH vector at the level of the residue to which it belongs. In comparison with the Lipari‐Szabo approach, the coefficient bd can be identified with 2KdτeffS2, S being the generalized order parameter and Kd reflecting the amplitude of the dipolar mechanism (which, besides constants, involves $$1/r^{6}_{NH}$$); ad is associated with fast local motions. The csa spectral densities appearing in the expressions of R1 and R2 can be analyzed according to $${b_{csa\hphantom{j}}} \over {1 + \omega^{2}\tau^{2\hphantom{T}}_{e\!f\!\!f}}$$; bcsa; is proportional to bd (the proportionality factor depending on molecular quantities) and can yield 15N csa values from the rNH value and from the knowledge of the angle between the two relevant tensors. Uncertainties are such that it is impossible (at least with the present data) to conclude about a possible variation of 15N csa values along the protein backbone. © 2005 Wiley Periodicals, Inc. Concepts Magn Reson Part A 24A: 1–9, 2005.
Synthesis of Chiral, Half‐Sandwich Ruthenium Complexes from Weakly Coordinated Solvent Species
Authors: Jekki Laetitia , Pala Corinne , Calmuschi Beatrice , Ganter Christian 
Published: January 2005

AbstractThe bis(acetonitrile) species 7 has been synthesized in a multistep protocol. This chiral phosphaferrocene‐containing, half‐sandwich ruthenium complex easily provides two coordination sites due to the high lability of the coordinated solvent molecules. Although complex 7 could not be isolated in pure form, it serves as a valuable starting material for the preparation of other half‐sandwich complexes with, for example, pyridine (8), tmeda (9), N‐(2‐dimethylaminoethyl)‐morpholine (10), or tricyclohexylphosphine (11) as ligands. Whereas the morpholine complex 10 was obtained as almost a 1:1 mixture of diastereomers, the mixed MeCN/PCy3 complex 11 was formed with a high level of diastereoselectivity (90% de). The molecular structures of complexes 8, 10, and the cyclopentadiene derivative 3a were determined by X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Mono‐, Di‐ and Polymeric Calcium and Gadolinium Complexes of the Tripodal Ligand 2,2′,2′′‐Nitrilotribenzoic Acid
Authors: Wörl Stefan , Fritsky Igor O. , Hellwinkel Dieter , Pritzkow Hans , Krämer Roland 
Published: January 2005

AbstractThree novel carboxylate‐bridged complexes incorporating the tripodal N,O ligand 2,2′,2′′‐nitrilotribenzoic acid H3L of formula [CaII(H2L)(OH2)4][(H2L)]·4H2O (1), [CaII(OH2)4]‐[CaII(L)(OH2)2]2·7H2O (2) and [GdIII(L)(OH2)3]2[GdIII(L)‐(OH2)4]2·13H2O (3) were synthesized and characterized by X‐ray crystallography. In all three complexes, the ligand H3L binds to the metal centre only by its three carboxylate donors, leaving the bridgehead nitrogen atom nonbonding. The calcium(II) ion in the monomeric complex 1 is distorted pentagonal‐bipyramidal coordinated, the +1 charge of the complex cation [CaII(H2L)(OH2)4]+ is balanced by an H2L– anion and both units are connected by hydrogen bonds. The polymeric compound 2 displays a one‐dimensional chain structure, in which two [CaII(L)]2– units form a dimeric structure and are connected by hydrated CaII ions. 3 contains two different [GdIII(L)(OH2)n] dimers. In one of them the two GdIII ions are linked by two monoatomic carboxylate O‐bridges showing a short Gd···Gd distance of 3.99 Å. In the second, a syn‐anti carboxylate 1,3‐bridge with a longer Gd···Gd distance of 4.96 Å is observed. Magnetic measurements of 3 show paramagnetic behaviour with weak antiferromagnetic coupling. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
The Reactions of Elemental Iron with Dipicolinic Acid (H2dipic) and Quinaldic Acid (Hquin) – X‐ray Crystal Structures of [C5H5NH][Fe(Dipic)(Hdipic)(C5H5N)2]·3C5H5N, [Fe2(µ‐O)(Dipic)2(C5H5N)4]·2C5H5N·2H2O and trans‐[Fe(Quin)2(MeOH)2]
Authors: Jain Sneh L. , Slawin Alexandra M. Z. , Derek Woollins J. , Bhattacharyya Pravat 
Published: January 2005

AbstractIron powder reacts with dipicolinic acid (H2dipic) in pyridine at 110 °C to give the heptacoordinate iron(II) complex [C5H5NH][Fe(dipic)(Hdipic)(C5H5N)2]; the (Hdipic)– ligand binds to the metal centre solely through the oxygen atoms of one carboxylate group, the first example of this coordination mode at iron. Upon dissolution in pyridine under aerobic conditions this complex transforms into the oxo‐bridged diiron(III) species [Fe2(μ‐O)(dipic)2(C5H5N)4], which possesses a linear Fe–O–Fe axis. Quinaldic acid (Hquin) reacts withiron powder in pyridine at 110 °C to give [Fe(quin)2(C5H5N)2],analogous to the corresponding reactivity of picolinic acid. This complex is converted into trans‐[Fe(quin)2(MeOH)2] or [Fe2(μ‐O)(quin)4(dmf)2] in methanol or DMF respectively. The formation of an iron(II) complex in the reaction with methanol differs markedly from the picolinate system. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Bis(1‐methylimidazol‐2‐yl)propionates and Bis(1‐methylbenzimidazol‐2‐yl)‐propionates: A New Family of Biomimetic N,N,O Ligands – Synthesis, Structures and CuII Coordination Complexes
Authors: Bruijnincx Pieter C. A. , Lutz Martin , Spek, Anthony L. , van Faassen Ernst E. , Weckhuysen Bert M. , van Koten Gerard , Klein Gebbink Robertus J. M. 
Published: January 2005

AbstractA general synthetic route towards new tridentate, tripodal N,N,O ligands, bearing one carboxylate group and two of the biologically relevant imidazole moieties, is presented. The parent compounds of this new family of ligands, A[MIm2Pr] (1) and A[BenzMIm2Pr] (2) (A = H, K, Bu4N) were synthesized in two steps and high overall yield. The structures of HMIm2Pr (1a) and HBenzMIm2Pr (2a) were confirmed by X‐ray crystal structure determination, both molecules forming infinite one‐dimensional hydrogen bonded chains. The synthetic route allows for the fine‐tuning of the physical properties of both ligand systems, e.g., solubility and ease of crystallization. The capability of the two ligands to coordinate facially through all donor atoms was investigated and two isostructural mononuclear copper(II) complexes of the type [CuL2] were obtained. Both [Cu(MIm2Pr)2]·2H2O (3) and [Cu(BenzMIm2Pr)2]·3.12(H2O)·1.74(C2H5OH) (4) have been characterized by X‐ray crystallography, ESI‐MS, elemental analysis, UV/Vis, IR, and EPR spectroscopy. In both structures the copper atoms are on an inversion center, which results in a tetragonally distorted octahedral coordination geometry. The CuN4O2 chromophores consist of four equatorially coordinated imidazole nitrogen atoms and two axially coordinated carboxylate groups. The non‐coordinated water molecules of both crystal structures are involved in a one‐dimensional hydrogen‐bonded network. Two neighboring octahedrons are connected by two water molecules, each water molecule forming two hydrogen bonds with the non‐coordinated oxygen atoms of the carboxylate group. This results in the formation of infinite one‐dimensional chains. EPR spectroscopy and ESI‐MS measurements provide evidence for the integrity of the complexes in solution. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Determination of Amino Acids at a Silver Oxide/Silver Phosphate Electrode and the Analysis of Structure‐Response Relationships
Authors: DeMott James M. , Jahngen Edwin G. E. 
Published: January 2005

AbstractWhen a silver electrode is conditioned in a solution of 0.5 M sodium hydroxide with added sodium phosphate and using a dual pulse (500 mV/750 mV vs. Ag/AgCl), a stable silver(I)/silver(II) oxide surface is formed. It has been previously shown that various moieties react with the silver(II) oxide in a chemical oxidation at the outer surface of the oxide layer. This is then followed by re‐oxidation of the silver with the generation of current at approximately 500 mV relative to the silver/silver chloride electrode. Previously we found the need to remove carbon dioxide from the base and condition the electrode in a solution containing phosphate ion in order to provide mechanical stability to the oxide layer. We have previously shown this electrode to be applicable to the detection of a variety of carbohydrates. The applicability of the silver oxide/silver phosphate electrode to the post‐chromatographic amperometric detection of amino acids was investigated. Calibration studies of amino acids representative of the various classes demonstrated good sensitivity and linearity in the 1–100 μM range. Responses of amino acids were measured using glucose as an external standard, in order to correct for variability of the oxide layer. Relative responses of the amino acids ranged from 3 down to 0.1. Correlation with structure suggested the importance of absorption in determining the rate of oxidation. Comparison of arginine with n‐benzoyl‐L‐arginine ethyl ester indicated that side chains as well as the backbone amino group can be oxidized. A Levitch plot of alanine was shown to be linear from approximately 30 to 300 radians per second spin rate at a scan rate of 50 mV per second. Application to post‐chromatographic detection was demonstrated.
A Nitric Oxide Biosensor Based on Myoglobin Adsorbed on Multi‐Walled Carbon Nanotubes
Authors: Zhang Li , Zhao Guang‐Chao , Wei Xian‐Wen , Yang Zhou‐Sheng 
Published: January 2005

AbstractMyoglobin (Myb) of horse heart is incorporated on multi‐walled carbon nanotubes (MWNTs) and immobilized at a glassy carbon (GC) electrode surface. Its electrochemical behavior and enzyme activity are characterized by employing electrochemical methods. The results indicate that MWNTs can obviously promote the direct electron transfer between Myb and electrode, and that the Myb on MWNTs behaves as an enzyme‐like activity towards the electrochemical reduction of nitric oxide (NO). Accordingly, an unmediated NO biosensor is constructed. Experimental results reveal that the peak current related to NO is linearly proportional to its concentration in the range of 2.0×10−7–4.0×10−5 mol/L. The detection limit is estimated to be 8.0×10−8 mol/L. Considering a relative standard deviation of 2.1% in seven independent determinations of 1.0×10−5 mol/L NO, this biosensor shows a good reproducibility. The biosensor based on Myb/MWNTs modified electrode can be used for the rapid determination of trace NO in aqueous solution with a good stability, nice selectivity and easy construction.
Electrochemical Impedance Characterization of Nafion‐Coated Carbon Film Resistor Electrodes for Electroanalysis
Authors: Gouveia‐Caridade Carla , Brett Christopher M. A. 
Published: January 2005

AbstractCarbon film disk electrodes with Nafion coatings have been characterized by electrochemical impedance spectroscopy (EIS) with a view to a better understanding of their advantages and limitations in electroanalysis, particularly in anodic stripping voltammetry of metal ions. After initial examination by cyclic voltammetry, spectra were recorded over the full potential range in acetate buffer solution at the bare electrodes, electrodes electrochemically pretreated in acid solution, and Nafion‐coated pretreated electrodes in the presence and absence of dissolved oxygen. EIS equivalent circuit analysis clearly demonstrated the changes between these electrode assemblies. In order to simulate anodic stripping voltammetry conditions, spectra were also obtained in the presence of cadmium and lead ions in solution at Nafion‐coated electrodes, both after metal ion deposition and following re‐oxidation. Permanent changes to the structure of the Nafion film occurred, which has implications for use of these electrode assemblies in anodic stripping voltammetry at relatively high trace metal ion concentrations.
Electrogenerated Chemiluminescence Determination of Dopamine and Epinephrine in the Presence of Ascorbic Acid at Carbon Nanotube/Nafion‐Ru(bpy)$\rm{ {_{3}^{2+}}}$ Composite Film Modified Glassy Carbon Electrode
Authors: Guo Zhihui , Dong Shaojun 
Published: January 2005

AbstractBased on the inhibition effect of dopamine and epinephrine on Ru(bpy)$\rm{ {_{3}^{2+}}}$‐tripropylamine electrogenerated chemiluminescence system, the excellent properties of carbon nanotube, and the cation permselectivity of Nafion film, an electrogenerated chemiluminescence inhibition method for determination of dopamine and epinephrine in the presence of ascorbic acid at carbon nanotube/Nafion‐Ru(bpy)$\rm{ {_{3}^{2+}}}$ composite film modified glassy carbon electrode was described. The results showed that the proposed method was sensitive and selective for the determination of dopamine and epinephine. The linear calibration range was from 1.6×10−9 M to 3.2×10−5 M and 5×10−8 M to 6×10−5 M for dopamine and epinephrine, respectively. 200‐fold excess of ascorbic acid did not interfere with the determination of 1 μM dopamine and epinephrine.
Electroanalytical Studies of Biologically Active Azosalicylic Acid at a Hanging Mercury Drop Electrode
Authors: Nigović Biljana , Komorsky‐Lovrić Šebojka , Šimunić Branimir 
Published: January 2005

AbstractThe electrochemical behavior of disodium 3,3′‐azobis‐(6‐hydroxy‐)benzoate (olsalazine sodium), 2‐hydroxy‐5‐[(4‐sulfophenyl)azo]benzoic acid and 2‐hydroxy‐5‐azo‐benzoic acid was studied as a simple model of the metabolic reduction of azosalicylic acids using cyclic and square‐wave voltammetry. The stability of the hydrazo intermediate generated in the electroreduction process is strongly dependent on pH and the effect of different substituents in the aromatic ring adjacent to the azo bridge. The electrode mechanism of azosalicylic acids at hanging mercury drop electrode exhibits characteristic properties of a surface redox reaction. The kinetic parameters of azo/hydrazo reduction, such as the standard redox reaction rate constant and the electron transfer coefficient were estimated applying the methods of a split SW peak and a quasireversible maximum. A sensitive analytical method for the determination of trace level of biologically active azosalicylic acids by square‐wave voltammetry based on adsorptive stripping technique is described.