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1.
The previously unknown ability of Zitrimin, the complex of tris(2-hydroxyethyl)amine with zinc(ii) bis(2-methylphenoxyacetate), to affect the activity of acid lipase of the aortic intima was studied. Daily administration of an aqueous solution of the tris(2-hydroxyethyl)amine complex with zinc bis(2-methylphenoxyacetate) in a dose of 10 mg kg?1 for 3 months to rabbilts with experimental atherosclerosis was found to decrease the cholesterol and total lipid levels in the aortic tissue and to decrease the degree of aortic damage with atherosclerotic plaques. According to the results of enzymatic analysis, development of atherosclerosis is accompanied by 68% increase in the activity of acid lipase in the intima of the aorta compared to the control. 相似文献
2.
Abstract An electrochemical method for a rapid assay of total cholesterol in serum using free cholesterol oxidase (EC 1.1.3.6) and cholesterol esterase (EC 3.1.1.13) is described. Hydrogen peroxide generated by cholesterol oxidase is amperometrically monitored at + 650 mV vs Ag/AgCl and two types of responses can be recorded : a steady-state response and a dynamic one. The dynamic response is obtained within one minute. Interfering species are detected prior measurement and a linear calibration curve can be obtained for total cholesterol in the sample in the range 0.4-8 mM useful for clinical analysis. 相似文献
3.
New N-(pyridin-3-ylmethyl)-2-aminothiazolines containing various substituents at the 5 position of the thiazoline ring and the 4- tert-butylbenzyl, 4-isopropylbenzyl, or 4-fluorobenzyl moiety at the nitrogen atom of the amino group were synthesized. The inhibitory activity of the synthesized compounds against human erythrocyte acetylcholinesterase (AChE, EC 3.1.1.7), equine serum butyrylcholinesterase (BChE, EC 3.1.1.8), and porcine liver carboxylesterase (CaE, EC 3.1.1.1) was evaluated and their antioxidant properties were studied by ABTS assay. N-(Pyridin-3-ylmethyl)-2-aminothiazolines proveded to be very weak AChE inhibitors, while their inhibitory activity against BChE and CaE was structure-dependent. 2-Aminothiazolines containing the 4- tert-butylbenzyl moiety are more efficient BChE inhibitors compared to the derivatives containing the 4-isopropylbenzyl or 4-fluorobenzyl substituent. An analysis of the dependence of the esterase profile of N-(pyridin-3-ylmethyl)-2-aminothiazolines on the structure of the substituent at the 5 position of the thiazoline ring of these compounds demonstrated that the derivatives containing the iodomethyl substituent possess the highest anti-BChE activity, the compounds with R 2 = H and R 3 = CH 2I have the optimal esterase profile. Regardless of the structure of the substituents in the benzyl moiety, all N-(pyridin-3-ylmethyl)-2-aminothiazolines containing the iodomethyl substituent at the 5 position of the thiazoline ring exhibited high radical scavenging activity comparable with that of the standard antioxidant Trolox. N-(Pyridin-3-ylmethyl)-2-aminothiazolines were shown to be a new promising class of compounds for the design of multifunctional agents for the treatment of neurodegenerative diseases. 相似文献
4.
Cholesterol oxidase (ChOx), cholesterol esterase (ChEt), and horseradish peroxidase (HRP) have been co-immobilized covalently
on a self-assembled monolayer (SAM) of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPTS) deposited on an indium–tin–oxide (ITO) glass surface. These enzyme-modified
(ChOx-ChEt-HRP/AEAPTS/ITO) biosensing electrodes have been used to estimate cholesteryl oleate from 10 to 500 mg dL −1. The sensitivity, K
m value, and shelf-life of these ChEt-ChOx-HRP/AEAPTS/ITO biosensing electrodes have been found to be 124 nA mg −1 dL, 95.098 mg dL −1 (1.46 mmol L −1), and ten weeks, respectively. The ChEt-ChOx-HRP/AEAPTS/ITO bio-electrodes have been used to estimate total cholesterol in
serum samples.
Figure Covalent immobilization of enzymes onto AEAPTS/ITO surface using EDC/NHS chemistry
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
ABSTRACT A new cholesterol flow injection analysis biosensor is described. It is based on a luminol/hydrogen peroxide electrochemiluminescence (ECL) reaction induced by a glassy carbon electrode polarised at + 425 mV vs a Pt pseudo reference. The cholesterol b8543158 sensing layer is based on cholesterol oxidase (COD) immobilised on either UltraBind TM membrane or Immunodyne membrane. The physicochemical properties of the UltraBind TM type membranes enable a high-performance biosensor to be obtained. A high salt concentration, 3 M NaCl, is shown to induce a 400% increase of the immobilised COD activity, and intermediate salt concentrations, from 1 to 1.5 M NaCl, induce a 230% increase of the H 2O 2 sensor performances. Both phenomena enable the achievement of a sensitive ECL cholesterol biosensor which exhibited a 800% increase of its performance in the presence of 2 M NaCl. In those optimised conditions, the determination of free cholesterol could be performed with a detection limit of 0.6 nmol and a detection ranging over at least two decades. When used in conjunction with a cholesterol esterase in solution, the biosensor enables the detection of free and total cholesterol in human sera, in 15 minutes with a good accuracy. The biosensor operational stability was satisfactory either with buffered standard solutions or with complex matrices since a total of 55 and 43 assays, respectively, could be performed with good reproducibility (CV = 4.8% and 8.3%) and without detectable loss of sensitivity. 相似文献
6.
Various 4-arylthiomethyl-2-oxo-1,3-dioxole derivatives IIIa-o were synthesized. Their hydrolysis rates by arylesterase (EC 3.1.1.2) and cholinesterase (EC 3.1.1.8) in human serum were evaluated. Some of them were not hydrolyzed by cholinesterase, but were hydrolyzed easily by arylesterase. Among the substrates, sodium 4-((5-methyl-2-oxo-1,3-dioxol-4-yl)methylthio)benzenesulfonate (IIIg) was selected for its substrate reactivity toward arylesterase and its good water solubility. In addition, neither aliesterase (EC 3.1.1.1), acetylesterase (EC 3.1.1.6) nor cholesterol esterase (EC 3.1.1.13) hydrolyzed the compound. IIIg is thus concluded to be a specific substrate for arylesterase. Our assay system for serum arylesterase using IIIg can be readily applied to an automatic analyzer in the diagnosis of liver cirrhosis. 相似文献
7.
The increasing clinical importance of drug-resistant fungal and bacterial pathogens has lent additional urgency to microbiological research and new antimicrobial compound development. For this purpose, new pyrazoline derivatives were synthesized and evaluated for antimicrobial activity. Some 1-[(N, N-disubstitutedthiocarbamoylthio)acetyl]-3,5-diaryl-2-pyrazolines derivatives were synthesized by reacting 1-(chloroacetyl)-3,5-diaryl-2-pyrazolines with appropriate potassium salts of secondary amine dithiocarbamic acids. The chemical structures of the compounds were elucidated by IR, 1 H-NMR, and FAB +-MS spectral data. Their antimicrobial activities against Staphylococcus aureus (B-767), Escherichia coli (B-3704), Pseudomonas aeruginosa (ATCC 27853), Proteus vulgaris (NRLL B-123), and Candida albicans (NRRL-27077) were investigated. The results showed that some of the compounds have notable activity against S. aureus and C. albicans. 相似文献
8.
At least three types of cholesterol-rich membrane domains have been described in biological membranes including cholesterol rafts, membrane caveolae and crystalline cholesterol domains,. While clear biological functions have been ascribed to both rafts and caveolae, little attention has been directed to the biological consequences of cholesterol enrichment of cell membranes and the formation of cholesterol domains. Elevated blood cholesterol levels have been shown to result in the enrichment of the cell plasma membrane with cholesterol in arterial smooth muscle cells (SMC), endothelial cells (EC) and cardiac myocytes. In the early period of cholesterol feeding (within days), the cell membrane enriches with cholesterol and membrane viscosity and membrane bilayer width increase. This latter effect severely alters membrane protein function, and recent data indicates that this induces the modulation of vascular cells (SMC and EC) to the atherosclerotic phenotype. In cardiac myocytes these membrane modifications appear to induce alterations in gene expression patterns that lead to the development of a heart failure phenotype. In addition, as the cholesterol content increases, phase separation of cholesterol occurs resulting in the formation of immiscible cholesterol domains within the membrane. These domains likely initiate nucleation of cholesterol crystals which would explain the origin of “cholesterol clefts” in atherosclerotic lesions. Taken together, these membrane alterations secondary to cholesterol enrichment constitute a “membrane lesion” which contribute to the very early pathogenic events underlying major human diseases including coronary artery disease, stroke and heart failure. 相似文献
9.
A new plasticized nanocomposite polymer electrolyte based on poly (ethylene oxide) (PEO)-LiTf dispersed with ceramic filler (Al 2O 3) and plasticized with propylene carbonate (PC), ethylene carbonate (EC), and a mixture of EC and PC (EC+PC) have been studied for their ionic conductivity and thermal properties. The incorporation of plasticizers alone will yield polymer electrolytes with enhanced conductivity but with poor mechanical properties. However, mechanical properties can be improved by incorporating ceramic fillers to the plasticized system. Nanocomposite solid polymer electrolyte films (200–600 μm) were prepared by common solvent-casting method. In present work, we have shown the ionic conductivity can be substantially enhanced by using the combined effect of the plasticizers as well as the inert filler. It was revealed that the incorporating 15 wt.% Al 2O 3 filler in to PEO: LiTf polymer electrolyte significantly enhanced the ionic conductivity [ σ RT (max)?=?7.8?×?10 ?6 S cm ?1]. It was interesting to observe that the addition of PC, EC, and mixture of EC and PC to the PEO: LiTf: 15 wt.% Al 2O 3 CPE showed further conductivity enhancement. The conductivity enhancement with EC is higher than PC. However, mixture of plasticizer (EC+PC) showed maximum conductivity enhancement in the temperature range interest, giving the value [ σ RT (max)?=?1.2?×?10 ?4 S cm ?1]. It is suggested that the addition of PC, EC, or a mixture of EC and PC leads to a lowering of glass transition temperature and increasing the amorphous phase of PEO and the fraction of PEO-Li + complex, corresponding to conductivity enhancement. Al 2O 3 filler would contribute to conductivity enhancement by transient hydrogen bonding of migrating ionic species with O–OH groups at the filler grain surface. The differential scanning calorimetry thermograms points towards the decrease of T g , crystallite melting temperature, and melting enthalpy of PEO: LiTf: Al 2O 3 CPE after introducing plasticizers. The reduction of crystallinity and the increase in the amorphous phase content of the electrolyte, caused by the filler, also contributes to the observed conductivity enhancement. 相似文献
10.
Abstract A simple, efficient, and environmentally benign methodology has been accomplished for the synthesis of α-aminophosphonates by one-pot three-component reaction of ethyl-2-amino- α-(methoxy-imino)-4-thiazoleacetate, aldehydes, and diethylphosphite by using Amberlyst-15 as catalyst at room temperature under solvent-free conditions. Their chemical structures were characterized by infrared (IR), NMR ( 1H, 13C & 31P), mass spectral, and elemental analysis. All the title compounds were screened for radical-scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitic oxide (NO), and hydrogen peroxide (H 2O 2) methods. Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and figures. 相似文献
11.
Abstract A new heterogeneous Mn(II) ion selective coated wire electrode (CWISE) based on tetrapyridine Mn(II) thiocynanate as electroactive material has been described. the working pH range of the electrode is 2.3 to 8.8. the electrode shows a linear response in the concentration range 1.0×10 ?1M to 1.0×10 ?6M. the response time of the electrode is 35 sec. the selectivity coefficient for different cations determined by mixed solution method are: Fe 2+(0.05), Cd 2+(0.05), Ni 2+(0.01), Co 2+(0.5), Pb 2+(0.5), Hg 2+(0.05), Sn 2+(0), Zn 2+(0) The electrode can be used for the electrometeric determination of Mn(II) ion. 相似文献
12.
We describe in this paper the lithium insertion/extraction behavior of a new NASICON type Li 2Co 2(MoO 4) 3 at a low potential and explored the possibility of considering this new oxyanion material as anode for lithium-ion batteries for the first time. Li 2Co 2(MoO 4) 3 was synthesized by a soft-combustion glycine-nitrate low temperature protocol. Test cells were assembled using composite Li 2Co 2(MoO 4) 3 as the negative electrode material and a thin lithium foil as the positive electrode material separated by a microporous polypropylene (Celgard® membrane) soaked in aprotic organic electrolyte (1 M LiPF 6 in EC/DMC). Electrochemical discharge down to 0.001 V from OCV (~3.5 V) revealed that about 35 Li + could possibly be inserted into Li 2Co 2(MoO 4) 3 during the first discharge (reduction) corresponding to a specific capacity amounting to 1,500 mAh g ?1. This is roughly fourfold higher compared to that of frequently used graphite electrodes. However, about 24 Li + could be extracted during the first charge. It is interesting to note that the same amount of Li + could be inserted during the second Li + insertion process (second cycle discharge) giving rise to a second discharge capacity of 1,070 mAh g ?1. It was also observed that a major portion of lithium intake occurs below 1.0 V vs Li/Li +, which is typical of anodes being used in lithium-ion batteries. 相似文献
13.
Isopropyl 3-(3,4-dihydroxyphenyl)-2-hydroxypropanoate (IDHP), a metabolite of Danshensu, from Salvia miltiorrhiza, has been proved to have potential as a novel drug for regulation of vasomotor activity in small-resistance vascular circulation. In this presentation we report a new specific method for analysis of IDHP in rabbit plasma. Plasma samples were pretreated with 1.5% formic acid in acetonitrile to remove the protein, and the resulting supernatant was extracted with ethyl acetate. Chromatographic separation was achieved on a C18 column with 15.0% acetonitrile in 0.3% aqueous formic acid (pH 2.2) as mobile phase. Multiple-reaction-mode ion-trap mass spectrometry was selected for accurate analysis of IDHP. The calibration plot was linear in the range 0.1–200.0 ng mL−1 for plasma samples. The detection limit was 0.02 ng mL−1. Intra-day and inter-day coefficients of variation were <13.0% and intra-day and inter-day accuracy was within ±8.0% of known concentrations. Finally, the method was used to investigate the pharmacokinetics of IDHP in rabbits; the results indicated IDHP was eliminated rapidly after oral administration. 相似文献
14.
In this study, we investigated the electrochemical intercalation of Ca2+ into graphite as an anode material for calcium-ion batteries (CIBs). The electrochemical intercalation of Ca2+ into a graphite electrode is possible when γ-butyrolactone (GBL) is utilized as a solvent, resulting in a reversible charge/discharge capacity. The GBL-based electrolyte allows a reversible redox reaction, thereby resulting in the intercalation and deintercalation of Ca2+ within the graphite electrode. Conversely, Ca2+ cannot be intercalated between the graphite layers in the ethylene carbonate–diethyl carbonate (EC–DEC)–based electrolyte. Analyses of the solution structures of both cases indicated that the interaction between the GBL solvent and Ca2+ was weak whereas that between the EC–DEC solvent and Ca2+ was strong. As a result of analyzing the surface of the negative electrode after charging and discharging from XPS, it was confirmed that a component that seems to be a solid electrolyte interphase (SEI) was confirmed in the graphite electrode using the GBL-based electrolyte. 相似文献
15.
Fabrication of an amperometric cholesterol biosensor by co-immobilization of cholesterol esterase (ChEt) and cholesterol oxidase (ChOx) onto conducting polypyrrole (PPY) films using electrochemical entrapment technique is described. Electrochemical polymerization was carried out using a two-electrode cell configuration at 0.8 V. Characterization of resulting amperometric biosensor for the estimation of cholesterol has been experimentally determined in terms of linear response range, optimum pH, applied potential, temperature, and shelf-life. These PPY/ChEt/ChOx electrodes can be used for cholesterol ester estimation from 1 to 8 mM and have shelf-life of about 4 weeks at 4 °C during which about 15 estimations of cholesterol ester could be made. The sensitivity of PPY/ChEt/ChOx electrode has been found to be 0.15 μA/mM and the apparent Km value for this electrode is 9.8 mM. Conductivity of the polymer films found to be about 3×10 −3 S/cm. 相似文献
16.
Abstract A new series of 2-substituted-3-((3-(6-nitrobenzo[d]thiazol-2-yl)-4-oxo-3,4-dihydroquinazolin-2-yl)methyl)-1,3,4-thiadiazol-3-ium-5-thiolate 6(a–j) was synthesized starting from anthranilic acid 1. The structures of the newly synthesized compounds were characterized by IR, 1H NMR, 13C NMR, mass spectra, and elemental analysis. The final compounds were tested for their antimicrobial activity against several microbes. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional text and tables.] 相似文献
17.
Abstract In this work we report the synthesis, characterization and electrochemistry of the complex trans-[RuCl 2(pmp) 4], where pmp=3-(pyrrol-l-ylmethyl)pyridine. The complex was characterize by electronic spectroscopy (Λ max = 404 nm and ε = 27000), vibrational FT-IR spectroscopy, 1H and 13C NMR, showing results typically in agreement with trans geometry. Cyclic voltammetry reveals a redox process centered on the Ru(II) center (E 1/2 = 0.53V vs. NHE), which is electrochemically and chemically reversible. Spectroelectrochemistry shows the progressive disappearance of bands at 404 and 475 nm and the appearance of a new band at 302 nm during the oxidation process. Cyclic voltammetric experiments were performed to characterize the redox properties of the ruthenium complex; its electropolymerization produced a strongly adhesive conducting polymeric film on platinum and palladium electrodes. 相似文献
18.
Abstract New metal complexes of Co(II), Cu(II), Ni(II), Zn(II), Mn(II), Fe(III), Ru(III), UO 2(II), and VO(II) with the Schiff base, 2-(5-((2-chlorophenyl)diazenyl)-2-hydroxy- benzylidene) hydrazine-carbothioamide ( H2L) have been prepared and characterized by elemental and thermal analyses, FT-IR, UV–Vis, mass spectra, 1H-NMR, and ESR as well as conductivity and magnetic moments measurements. The IR spectra showed that the ligand acts as neutral tridentate, neutral bidentate or monobasic tridentate ligand. The geometries of metal complexes were either octahedral or square pyramidal. The ESR spectra of the solid copper(II) complexes indicated an axial symmetry type of a d (x2-y2) ground state with considerably ionic or covalent environment. The effect of the presence of an azo group on the biological activity of the ligand was investigated. The ligand and its complexes are biologically inactive due to the presence of azo group. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the related elements to view the free supplemental file. 相似文献
19.
ABSTRACT A highly sensitive azo dye, 2-(5-nitro-2-pyridylazo)-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol (Nitro-PAPS), is used as a colorimetric reagent for the determination of tin(IV) content. Nitro-PAPS reacts with tin(IV) to form a water-soluble complex in 1.0 M acetic acid. Full color development is attained within 5 minutes, and maintains constant absorbance for at least 24 hours. The apparent molar absorptivity is 7.7 x 10 4 dm 3 mol ?1 cm ?1 at a maximum wavelength of 580 ran. Beer's law is obeyed for tin(IV) in the range of 0-1.2 μg ml ?1. The proposed method is successfully applied to the determination of trace amounts of tin in steels. 相似文献
20.
The new organophosphorus proligand (OPPh 2)(O 2SMe)NR (R = C 6H 3Pr i 2–2,6) (3) was prepared as a white crystalline solid by reacting the lithiated compound Li[Ph 2P(O)NR] with MeSO 2Cl in a 1:1 molar ratio. The precursor Ph 2P(O)NHR (1), as well as its thio analogue Ph 2P(S)NHR (2), were obtained in the reaction between the lithiated amine RNHLi and the corresponding organophosphorus chloride. All compounds were characterized by multinuclear ( 1H, 13C, and 31P) NMR spectroscopy. The molecular structures of 1–3 were established by single-crystal X-ray diffraction. A zigzag polymeric chain is formed in the crystals of 1 and 2 by hydrogen N–H···X (X = O, S) bonding, while the crystal of 3 contains discrete monomeric units with a syn–syn conformation of the O?P(C) 2–N–S(C)(?O) 2 skeleton. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
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