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1.
Saito H Shirai T Kudo H Mitsubayashi K 《Analytical and bioanalytical chemistry》2008,391(4):1263-1268
A bioelectronic sensor for triethylamine (TEA) was developed with a flavin-containing monooxygenase type 3 (FMO-3). The TEA
biosensor consisted of a Clark-type dissolved-oxygen electrode and an FMO-3 immobilized membrane. The FMO-3 solution was mixed
with a poly(vinyl alcohol) containing stilbazolium groups (PVA-SbQ), coated on to the dialysis membrane, and the membrane
was irradiated with a fluorescent light to immobilize the enzyme. In order to amplify the biosensor output, a substrate regeneration
cycle, obtained by coupling the monooxygenase with l-ascorbic acid (AsA) as reducing reagent system, was applied. The effect of pH on the determination of TEA was studied. The
maximum response was achieved at pH >9.0. A drop of the phosphate buffer solution with the AsA was put on the sensing area
of the oxygen electrode, and the FMO-3 immobilized membrane was placed on the oxygen electrode and covered with a supporting
Nylon mesh net which was secured with a silicone O-ring. A measurement system for TEA solution was constructed using the FMO-3
biosensor, a personal computer, a computer-controlled potentiostat, and an A/D converter. The FMO-3 biosensor was used to
measure TEA solution from 0.5 to 4.0 mmol L−1 with 10.0 mmol L−1 AsA. The biosensor also had good reproducibility, for example a 6.31% coefficient of variation for five measurements, and
the output current was maintained over a few hours. In order to improve the selectivity of the TEA biosensor, three type of
biosensor with FMO isomer types 1, 3, and 5 were constructed and used to measure nitrogen and sulfur compounds. The outputs
of the isomer biosensors indicated individual patterns for each sample solution. The selectivity of TEA biosensor would be
improved, and determination of sulfur and nitrogen compounds would be possible, by using the different output of biosensors
prepared from different FMO isomers. 相似文献
2.
Jing F Jun L Wang Y Zhu M Yong Z Fei X Zhang J 《Applied biochemistry and biotechnology》2008,150(3):327-335
The aim of the study was to set up a novel fully enzymatic method for screening glucose and 1,5-anhydro-D-glucitol (1,5-AG) in one cuvette. We have determined glucose and 1,5-AG, based on glucokinase (GK) converting glucose to G6P, a compound that can be catalyzed ultimately into 6-PGA by G-6PD and its coenzyme NADP(+), and then calculated glucose concentration according to absorbance variety. Furthermore, pyranose oxidase was used to oxidize 1,5-AG with the formation of 1, 5-anhydro-fructose and H(2)O(2). Measurement was done according to Trinder's reaction principle. The mean within-run and day-to-day precision (CV) of this method for glucose was 0.88% and 1.4%, and also that for 1,5-AG was 1.05% and 1.94%, respectively. The mean recovery rate of two targets was 100.2% and 101.6%, respectively. The correlation (R(2)) between the results of 1,5-AG obtained with our proposed method (y) and those obtained with LanaAG method (x) was 0.999 (y=1.002x-0.675 micromol/l; n=86), and the correlation (R(2)) of glucose between the results obtained with our GK method (y) and those obtained with recommendatory hexokinase method (x) was 0.9999 (y=1.0043x+0.1229 mmol/l; n=86). The reference range (95%) of serological glucose and 1,5-AG was 3.7 to 5.7 mmol/l (4.70+/-0.51 mmol/l) and 83.1 to 240.7 micromol/l (161.9+/-40.2 micromol/l), respectively; and there was no difference with age and sex (P>0.05). This newly developed method was dependable and steady-going, with analysis automatization, and allows quicker and easier measurement of serum glucose and 1,5-AG in one identical reaction cuvette in-phase than previously described methods. 相似文献
3.
A chiral liquid chromatographic method for determination of the enantiomeric purity of both l-carnitine and acetyl-l-carnitine is described. Separation of the enantiomers of dl-carnitine and acetyl-dl-carnitine was achieved on a commercial chiral column (Chiralcel OD-R) after derivatization with (alpha-bromo)methyl phenyl ketone. Introduction of this lipophilic UV chromophoric group to the carnitine and acetylcarnitine molecules improved their retention, resolution, and UV detection. The mobile phase was 74:26 (v/v) 0.5 mol L-1 sodium perchlorate–acetonitrile, pH 3.8, and the flow rate was 0.4 mL min-1. Detection was performed at 235 nm. The method is selective and reliable for determination of the enantiomeric purity of bulk drug substances l-carnitine and acetyl-l-carnitine. 相似文献
4.
Pedraza A Sicilia MD Rubio S Pérez-Bendito D 《Analytical and bioanalytical chemistry》2007,389(7-8):2297-2302
A selective method for the determination of l-glutamate in foodstuffs has been developed. It was based on the competition established between the analyte and the dye Coomassie
brilliant blue G (CBBG) to interact with the surfactant didodecyldimethylammonium bromide (DDABr). The measurement parameter
was the amount of DDABr required to reach a given dye-to-surfactant binding degree. It was obtained by photometric titration
on the basis of the changes observed in the spectral characteristics of the dye when CBBG–DDABr aggregates were formed. The
calibration graph obtained was linear in the l-glutamate concentration interval 0.2–5 mM (detection limit 0.05 mM). The high selectivity of the proposed method (other amino
acids and food additives did not interfere at the concentrations present in foodstuffs) permitted the direct analysis of food
samples after dissolution of the analyte in hot water. The accuracy of the surfactant to the dye binding degree method was
demonstrated by determining l-glutamate in different kinds of foodstuffs (liquid and dried soups, seasonings, pasta sauces and dried mushroom creams) and
comparing the results obtained with those provided by the commercial Boehringer Mannheim essay. 相似文献
5.
L. O. Nindakova N. N. Chipanina V. K. Turchaninov M. V. Ustinov B. A. Shainyan 《Russian Chemical Bulletin》2005,54(10):2343-2347
The reaction of di-μ-chlorobis(1,5-cyclooctadiene)dirhodium with (4S, 5S)-2,2-dimethyl-4,5-bis(methylaminomethyl)-1,3-dioxolane (1) gave the complex [Rh(cod)(1)]Cl (cod is 1,5-cyclooctadiene). The composition of the complexes CoCl2 · L2 and [Rh(cod)(L2)]X (L2 = 1, (4S,5S)-2,2-dimethyl-4,5-bis(aminomethyl)-1,3-dioxolane, and (4S, 5S)-2,2-dimethyl-4,5-bis(dimethylaminomethyl)-1,3-dioxolane; X = Cl, TfO) was studied using IR and 1H NMR spectroscopy. In the RhI cyclooctadienediamine complexes, the diene molecule forms a stronger bond with the metal atom than that in the cyclooctadienediphosphine
analogs.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2270–2274, October, 2005. 相似文献
6.
E. K. Beloglazkina I. V. Yudin A. G. Mazhuga A. A. Moiseeva S. V. Zatonskii N. V. Zyk 《Russian Chemical Bulletin》2008,57(3):577-584
A series of the M(L)Cl2 · nH2O and {M(L)}2(OAc)4 complexes (M = NiII, CoII, and CuII; L is 3- and 4-(2-pyridyl)-1,3-benzothiazole) were synthesized by the reaction of L with MX2 · nH2O (X = Cl, OAc) in ethanol. The molecular and crystal structures of the CuL2(OAc)4 binuclear complex (L is 4-(2-pyridyl)benzothiazole) were determined by X-ray diffraction analysis. The copper atoms have a distorted tetragonal bipyramidal environment and are coordinated to the nitrogen atom of the pyridine moiety of the ligand and to two oxygen atoms of the bridging acetate ligands. The Cu-Cu distance is 2.6129(9) Å. The electrochemical behavior of the synthesized ligands and complexes was studied using the cyclic voltammetry and rotating disk electrode techniques in DMF solutions (0.1 M Bu4NClO4). The primary reduction of all the complexes under study is directed to the metal. 相似文献
7.
Application of l-cysteine-capped nano-ZnS as a fluorescence probe for the determination of proteins 总被引:1,自引:0,他引:1
Zhu CQ Zhao DH Chen JL Li YX Wang le Y Wang L Zhou YY Zhuo SJ Wu YQ 《Analytical and bioanalytical chemistry》2004,378(3):811-815
Nanometer-sized l-cysteine-capped ZnS particles have been synthesized and used as a fluorescence probe to investigate the effect of proteins on fluorescent intensity. With =190 nm, maximum and constant synchronous fluorescence enhancement was produced at 267 nm and pH 5.12 in the presence of proteins. A highly sensitive synchronous fluorescence method for the rapid determination of proteins has been developed. Under optimum conditions, calibration graphs are linear over the range 0.03–8.0 g mL–1 for bovine serum albumin (BSA), 0.01–6.0 g mL–1 for human serum albumin (HSA), 0.05–8.0 g mL–1 for -globulin (-G), and 0.04–4.0 g mL–1 for ovalbumin, respectively. The relative standard deviations of seven replicate measurements were 1.75% for 1.0 g mL–1 BSA, 1.90% for 1.0 g mL–1 HSA, 1.65% for 1.0 g mL–1 -G, and 2.32% for 1.0 g mL–1 ovalbumin. 相似文献
8.
T. N. Kropacheva V. I. Kornev D. A. Loginov V. I. Meshcheryakov E. V. Mutseneck D. V. Muratov D. S. Perekalin L. S. Shul’pina A. R. Kudinov 《Russian Chemical Bulletin》2005,54(10):2354-2358
New dinuclear ruthenium manganese complexes of general composition (bpy)2Ru(L)MnClx(H2O)2 (L is 1,10-phenanthroline-5,6-dione, 3,3′-dicarboxy-2,2′-bipyridyl, or bis(pyrazolyl); x = 2 or 4) were synthesized by the reaction of (bpy)2Ru(L) with MnCl2 · 4H2O. These compounds and the starting mononuclear ruthenium complexes were studied by spectrophotometric and electrochemical
methods in MeCN. The position of the charge-transfer band RuII → L in the spectra depends on the donor-acceptor characteristics of the ligand L. For the dinuclear complex under study,
the formal potentials of reversible one-electron oxidation of RuII are in the range of 0.9–1.2 V (vs. the standard hydrogen electrode), whereas oxidation of MnII occurs at more positive (by 0.1–0.2 V) potentials.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2281–2285, October, 2005. 相似文献
9.
G. Sankar P. R. Sarode A. Srinivasan C. N. R. Rao S. Vasudevan J. M. Thomas 《Journal of Chemical Sciences》1984,93(3):321-334
A detailed investigation of sulphided Co/Mo/Al2O3 catalysts, their oxide precursors and several model oxides and sulphides of cobalt and molybdenum has been carried out using
x-ray photoelectron spectroscopy and x-ray absorption spectroscopy (xanes andexafs). Octahedrally coordinated Co(II) and Mo(IV) are shown to be present in a sulphidic environment on the surfaces of these
catalysts. The surface species contain an excess of sulphur, probably involving disulphide linkages. The surface compositions
of the catalysts examined conform to the general formula Co11 Mo
2n
IV
(2n + 3)S
2
2−
(2n -2)S2−. 相似文献
10.
Zakir Hossain SM Shinohara H Wang F Kitano H 《Analytical and bioanalytical chemistry》2007,389(6):1961-1966
There is an increasing interest in new strategies to detect neurotransmitters released from nerve cells in real time for brain
science, drug assessment, and so on. Previously we reported real-time monitoring of dopamine release from nerve model cells
by enzyme-catalyzed luminescence measurement with tyramine oxidase and peroxidase. In the present study, the system was modified
with glutamate oxidase instead of tyramine oxidase to detect L-glutamate sensitively (≈ 10 nM) and rapidly with high temporal resolution (<1 s). We applied this modified method successfully
to perform real-time monitoring of L-glutamate release from brain model cell (C6 glioma cell) using a luminescence plate reader upon stimulation with high concentration
of KCl (>10 mM) or 5-hydroxytryptamine (>1 μM). The measurement solution was not toxic and therefore the L-glutamate release from the cell was measured by the second stimulation after exchanging the measurement solution. We conclude
that the developed monitoring system is suitable for real-time detection of dynamic L-glutamate release from nerve cells in vitro and will be suitable for application in assessment of drugs acting on the nervous
system.
Figure Enzyme luminescence detection of L-glutamate released from cells 相似文献
11.
E. K. Beloglazkina A. G. Majouga A. A. Moiseeva M. G. Tsepkov N. V. Zyk 《Russian Chemical Bulletin》2007,56(2):351-355
The reaction of 5-[2-(methylthio)ethyl]-3-phenyl-2-thioxoimidazolidin-4-one (LH) with salts MCl2· xH2O (M = Co, Ni, Cu; x = 2, 6) afforded the [M(L)Cl]n complexes of NiII, CoII, and CuII. The electrochemical behavior of the LH ligand and its complexes was studied using the cyclic voltammetry and rotating disk
electrode techniques. The structures of the synthesized compounds were determined by the data of UV—Vis and IR spectroscopy,
mass spectrometry, and electrochemical characteristics.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 339–343, February, 2007. 相似文献
12.
N. V. Zyk E. K. Beloglazkina S. E. Sosonyuk M. N. Bulanov R. L. Antipin 《Russian Chemical Bulletin》2005,54(6):1488-1491
Electrophilic sulfenylation, selenenation, and halogenation of bicyclo[2.2.1]heptenes containing CF3 or NO2 group in position endo-5 were studied. The sulfenylation and selenenation were accomplished by arylsulfene- and arylselenenamides activated by POHal3 (Hal = Br, Cl), and iodination was performed by KICl2. The reactions are regiospecific and involve an exo-attack of the electrophilic fragment (arylthio or arylseleno group or iodine) on the C=C bond atom located closer to the
CF3 or NO2 group.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1445–1448, June, 2005. 相似文献
13.
Zhenning Yan Xiaoge Wang Ronghua Xing Jianji Wang 《The Journal of chemical thermodynamics》2009,41(12):1343-1349
Densities and conductivity data for the sodium carboxylate (sodium acetate and sodium butyrate)–dipeptides {(glycyl-l-glutamine and l-alanyl-l-glutamine) + water} systems were determined at T = 298.15 K. The apparent molar volumes of the peptides and the molar conductivity (Λ) of sodium acetate and sodium butyrate have been calculated. These data have been utilized to deduce the standard partial molar volumes (), standard partial molar volumes of transfer for dipeptide from water to aqueous sodium carboxylate solutions (ΔtV°), volumetric interaction coefficient, the limiting molar conductivity (Λ°), and Walden product (Λ°η). Both and ΔtV° for the dipeptides increase with increasing concentration of sodium carboxylate. The interpretation is that this result arises from the dominant interactions of the sodium carboxylate with the charged group and polar groups of peptides. The decrease in Λ° of sodium carboxylate with increasing dipeptide concentration and nonconstant Walden product are attributed to the interactions of sodium carboxylate with peptide and friction resistance of the solvent medium. 相似文献
14.
An enzymatic method for determining L-malic acid in wine based on an L-malate sensing layer with nicotinamide adenine dinucleotide (NAD+), L-malate dehydrogenase (L-MDH) and diaphorase (DI), immobilized by sol-gel technology, was constructed and evaluated. The sol-gel glass was prepared
with tetramethoxysilane (TMOS), water and HCl. L-MDH catalyzes the reaction between L-malate and NAD+, producing NADH, whose fluorescence (λ
exc = 340 nm, λ
em = 430 nm) could be directly related to the amount of L-malate. NADH is converted to NAD+ by applying hexacyanoferrate(III) as oxidant in the presence of DI. Some parameters affecting sol-gel encapsulation and the
pH of the enzymatic reaction were studied. The sensing layer has a dynamic range of 0.1–1.0 g/L of L-malate and a long-term storage stability of 25 days. It exhibits acceptable reproducibility [s
r(%)≈10] and allows six regenerations. The content of L-malic acid was determined for different types of wine, and polyvinylpolypyrrolidone (PVPP) was used as a bleaching agent
with red wine. The results obtained for the wine samples using the sensing layer are comparable to those obtained from a reference
method based on UV-vis molecular absorption spectrometry, if the matrix effect is corrected for. 相似文献
15.
Zahradnícková H Husek P Simek P Hartvich P Marsálek B Holoubek I 《Analytical and bioanalytical chemistry》2007,388(8):1815-1822
A rapid and simple method was developed for the determination of free amino acids (AAs) released from cyanobacteria. The procedure
involves trapping of AAs from the centrifuged cyanobacterial culture fluid on a cation-exchange resin, their release together
with the resin by direct treatment with the reaction medium, followed by immediate derivatization with a corresponding chloroformate.
The extractive alkylation transfers the analytes into an organic phase, an aliquot of which is subjected to GC analysis. Identification
and quantification of AAs was performed by GC/MS and GC/FID, respectively, using propyl chloroformate (PCF) as the derivatization
reagent. For chiral analysis, the cyanobacteria extracts were treated with 2,2,3,3,3-pentafluoropropyl chloroformate (PFPCF)
to create more volatile analytes. Separation of the AA enantiomers was accomplished on a Chirasil-Val capillary column and
the D/L enantiomeric ratios were determined. AAs of cyanobacteria are considered to be important for the assessment of energy flow
in an aquatic food web, nutrition value of cyanobacteria in a food web and for cell–cell communication within cyanobacteria.
The highest levels of AAs were found in the summer period at the beginning of the season (July). In the September and October
samples, the amount of AAs was lower, the number of D-AAs decreased and the D/L ratio was higher than in the July sample. Based on the obtained results it can be assumed that young populations excrete
AAs in higher concentrations and a different composition compared to actively growing populations.
Figure PFPCF derivatization scheme 相似文献
16.
E. K. Beloglazkina A. G. Majouga A. A. Moiseeva I. V. Yudin F. S. Moiseev O. I. Shmatova N. V. Zyk 《Russian Chemical Bulletin》2008,57(2):358-363
Transition metal (NiII, CoII, and CuII) complexes with 1,2-bis[2-(3-pyridylmethylideneamino)phenylthio]ethane (1) and 1,2-bis[2-(4-pyridylmethylideneamino)phenylthio]ethane (2) were synthesized for the first time by slow diffusion of solutions of compounds 1 or 2 in CH2Cl2 into solutions of MX2 · nH2O (M = Ni, Co, or Cu; X = Cl or NO3; n = 2 or 6) in ethanol. The reactions with CoII and CuII chlorides afford complexes of composition M(L)Cl2 (L = 1 or 2). The reactions of compound 1 with NiII salts produce complexes with 1,2-bis(2-aminophenylthio)ethane. The molecular structure of dinitrato[1,2-bis(2-aminophenylthio)ethane]nickel(ii) was confirmed by X-ray diffraction. The ligands and the complexes were investigated by cyclic voltammetry and rotating disk
electrode voltammetry. The initial reduction of the complexes proceeds at the metal atom. The oxidation of the chlorine-containing
complexes proceeds at the coordinated chloride anion.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 350–355, February, 2008. 相似文献
17.
V. V. Potekhin 《Russian Chemical Bulletin》2007,56(5):875-882
The oxidation of lower aliphatic alcohols C1–C4 with dioxygen to form the corresponding carbonyl compounds in the presence of the PdII tetraaqua complexes and FeII-FeIII aqua ions in an aqueous medium was studied at 40–80 °C. The introduction of an aromatic compound (acetophenone, benzonitrile,
phenylacetonitrile, o-cyanotoluene, nitrobenzene) and FeII aqua ion instead of the FeIII aqua ion into the reaction system increases substantially the catalytic activity and the yield of the carbonyl compound.
The key role of the Pd species in the intermediate oxidation state stabilized by the aromatic additive in the catalytic cycle
of alcohol oxidation with dioxygen to the carbonyl compound was shown. An increase in the kinetic isotope effect with an increase
in the temperature of methanol oxidation indicates a change in the rate-determining step of alcohol oxidation with dioxygen
in the presence of PdII-FeII-FeIII and the aromatic compound. At temperatures below 60 °C, the catalytically active palladium species are mainly formed upon
the reduction of the PdII tetraaqua complex with the FeII aqua ion, whereas at higher temperatures the reaction between the alcohol and PdII predominates. The mechanism and kinetic equation of the process were proposed.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 842–848, May, 2007. 相似文献
18.
K. L. Tokarev M. A. Kiskin A. A. Sidorov G. G. Aleksandrov V. N. Ikorskii I. P. Suzdalev V. M. Novotortsev I. L. Eremenko 《Russian Chemical Bulletin》2008,57(6):1209-1214
The mononuclear complexes (η3-terpy)M(Piv)2·MeCN (M = Fe
ii
(3) and Co
ii
(4), and Piv is the pivalate anion) were synthesized by the reactions of polymeric iron(ii) and cobalt(ii) pivalates with 2,2′:6′,2″-terpyridine (terpy). The oxidation of compound 3 affords the pentanuclear heterospin iron(ii,iii) complex (η3-terpy)Fe5(μ4-O)(μ3-OH)(μ-OH)2(μ-Piv)7(η1-Piv)2 (5). All compounds were characterized by X-ray diffraction.
Dedicated to the 90th anniversary of the L. Ya. Karpov Institute of Physical Chemistry.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1186–1190, June, 2008. 相似文献
19.
A series of novel mono(2,2,2-trifluoroethyl) esters,mono L-amino acid ester prodrugs of acyclic nucleoside phosphonates was synthesized and their in vitro anti-HBVactivity was evaluated in HepG 2 2.2.15 cells.Compound 1d exhibited more potent anti-HBV activity and lower cytotoxicity than those of adefovir dipivoxil and alamifovir(MCC-478) with EC50 and CC50 values of 0.01μmol/L and >8000μmol/L respectively. 相似文献
20.
V. N. Leibzon L. V. Michalchenko M. Yu. Leonova V. P. Gultyai 《Russian Chemical Bulletin》2005,54(5):1203-1207
Small additives of iron(II) or copper(II) salts change the regioselectivity of 2,4,6-trinitrotoluene monoreduction with titanium(III) chloride affording predominantly less accessible 2-amino-4,6-dinitrotoluene over 4-amino-2,6-dinitrotoluene (from 25% when
the reduction occurs in the absence of the iron and copper salts to 70% in the presence of these salts). A possible mechanism
of the process is discussed.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1172–1176, May, 2005. 相似文献