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51.
K. Chandra Babu Raman Vysabhattar K.S.V. Srinivas Satish Nigam G. Madhusudhan K. Mukkanti 《Tetrahedron: Asymmetry》2010,21(21-22):2619-2624
We report an asymmetric synthesis of (4S,5S)-2-oxo-4-phenyloxazolidine-5-carboxylic acid via stereoselective addition of phenylmagnesium bromide (PhMgBr) to an N-sulfinimine derived from (R)-glyceraldehyde acetonide. (S)- and (R)-Glyceraldehyde acetonides, important chiral synthons in synthetic organic chemistry, are prepared from the corresponding epichlorohydrin using an identical synthetic methodology. 相似文献
52.
Alfin D. N. Vaz Wei Wei Wang Andrew J. Bessire Raman Sharma Anne E. Hagen 《Rapid communications in mass spectrometry : RCM》2010,24(14):2109-2121
A simple procedure is described to identify acyl‐glucuronides by coupled liquid chromatography/mass spectrometry after derivatization to a hydroxamic acid with hydroxylamine. The reaction specificity obviates the need for isolation of the acyl‐glucuronide from an extract. Glucuronides derived from carbamic acids, and alkyl‐ and aromatic amines, are inert to the derivatization reaction conditions, making the hydroxamic acid derivative a fingerprint for acyl‐glucuronides. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
53.
In this paper, gold nanoparticles coated with palladium dots (Pd@Au) bimetallic nanostructures have been reported to have a peroxidase like activity which is not found in their monometallic counterparts. Based on this finding, we have developed an immunoassay in which antibody-modified Pd@Au nanostructure catalyzes the dimerization of a fluorogenic substrate for peroxidase, 3-(4-dihydroxy phenyl) propionic acid (HPPA), to generate high fluorescence signal. Specific antibodies against bensulfuron-methyl were generated by using a well characterized bensulfuron–protein conjugate as an immunogen, and the assay was performed in a competitive immunoassay format where Pd@Au nanostructure was bound to secondary antibody to show the peroxidase like activity. The developed immunoassay exhibited an excellent sensitivity showing a dynamic response range from 0.001 to 100 ng mL−1 for herbicide bensulfuron-methyl with a detection limit of 0.01 ng mL−1 (n = 3). The newly synthesized bimetallic nanostructure shows the advantages of low cost, easy synthesis and tunable catalytic activity, making it a promising substitution of enzyme peroxidase in different applications. 相似文献
54.
Two new iron nitrosyls derived from two designed pentadentate ligands N,N-bis(2-pyridylmethyl)-amine-N'-(2-pyridylmethyl)acetamide and N,N-bis(2-pyridylmethyl)-amine-N'-[1-(2-pyridinyl)ethyl]acetamide (PcPy(3)H and MePcPy(3)H, respectively, where H is the dissociable amide proton) have been structurally characterized. These complexes are similar to a previously reported (Fe-NO)6 complex, [(PaPy(3))Fe(NO)](ClO(4))(2) (1) that releases NO under mild conditions. The present nitrosyls, namely [(PcPy(3))Fe(NO)](ClO(4))(2) (2) and [(MePcPy(3))Fe(NO)](ClO(4))(2) (3), belong to the same (Fe-NO)6 family and exhibit (a) clean (1)H NMR spectra in CD(3)CN indicating S = 0 ground state, (b) almost linear Fe-N-O angles (177.3(5) degrees and 177.6(4) degrees for 2 and 3, respectively), and (c) N-O stretching frequencies (nu(NO)) in the range 1900-1925 cm(-)(1). The binding of NO at the non-heme iron centers of 1-3 is completely reversible and all three nitrosyls rapidly release NO when exposed to light (50 W tungsten bulb). In addition to acting as photoactive NO-donors, these complexes also nitrosylate thiols such as N-acetylpenicillamine, 3-mercaptopropionic acid, and N-acetyl-cysteine-methyl-ester in yields that range from 30 to 90% in the absence of light. The addition of alkyl or aryl thiolate (RS(-)) to the (Fe-NO)6 complexes in the absence of dioxygen results in the reduction of the iron metal center to afford the corresponding (Fe-NO)7 species. 相似文献
55.
Darr JA Guo ZX Raman V Bououdina M Rehman IU 《Chemical communications (Cambridge, England)》2004,(6):696-697
For the first time, the MOCVD technique has been used to deposit carbonated hydroxyapatite onto Ti6AL4V substrates using volatile monomeric (liquid) complexes [Ca(beta-diketonate)(2)(L)] and P(OEt)(3). 相似文献
56.
A self-consistent estimation method for the thermochemical properties of polycyclic aromatic hydrocarbons (PAH) is presented. This method is based on enthalpies of formation (DeltaHf(degrees), entropies (S(degrees)298, and heat capacities (C(degrees)p obtained from B3LYP/6-31G(d) calculations of the total energies and frequencies for 139 PAHs, including C(60) and C(70) fullerenes. The enthalpies of formation were calculated using an optimized set of homodesmic reactions given the available experimental DeltaHf(degrees) of PAHs. The theoretical entropies were compared with the existing experimental entropies, and some inconsistencies in the experimental data were identified. The estimation method presented here is a systematic extension of the widely employed atom-centered group additivity method originally proposed by Benson. This new method is based on bond-centered groups that define bonds linking two atom-centered groups and specify the size of the rings to which they belong. In addition, a term to describe the resonance energy is included. The thermochemical properties of PAHs up to C(70) fullerene are estimated with a mean average deviation of 2.8 kcal mol(-1) in DeltaHf(degrees), 0.7 cal K(-1) mol(-1) in S(degrees)298, and about 0.5 cal K(-1) mol(-1) in the C(degrees)p. This bond-centered group additivity method for the thermochemical properties of PAHs significantly expands both the range of systems that can be estimated and the accuracy of the estimations. The results of this work also allow us to assess the quality of available experimental data. For example, there are strong indications that the literature DeltaHf(degrees)of benzo[k]fluoranthene is about 10 kcal mol(-1) too low. 相似文献
57.
58.
Chemistry of hybrid nanocomposites depends mainly on their reactivity and structural relationship. This review mainly reports on the processing techniques of inorganic–organic hybrid nanocomposites and their natural reactivity. Herein, the structure, processing methods and properties of nanocomposites with three different types of matrices are discussed in general. The perusal of this review enables the researchers to design a novel and simple route in processing the hybrid nanocomposites. 相似文献
59.
Raman Natarajan Kulandaisamy Antonysamy Thangaraja Chinnathangavel Jeyasubramanian Kadarkaraithangam 《Transition Metal Chemistry》2003,28(1):29-36
Neutral tetradentate chelate complexes of CuII, NiII, CoII, MnII, ZnII and VOII have been prepared in EtOH using Schiff bases derived from acetoacetanilido-4-aminoantipyrine and 2-aminophenol/2-aminothiophenol. Microanalytical data, magnetic susceptibility, i.r., u.v.–vis., 1H-n.m.r. and e.s.r. spectral techniques were used to confirm the structures of the chelates. Electronic absorption and i.r. spectra of the complexes suggest a square-planar geometry around the central metal ion, except for VOII and MnII complexes which have square-pyramidal and octahedral geometry respectively. The cyclic voltammetric data for the CuII complexes in MeCN show two waves for copper(II) copper(III) and copper(II) copper(I) couples, whereas the VOII complexes in MeCN show two waves for vanadium(IV) vanadium(V) and vanadium(IV) vanadium(III) couples. The e.s.r. spectra of the CuII, VOII and MnII complexes were recorded in DMSO solution and their salient features reported. The in vitro antimicrobial activity of the investigated compounds was tested against the microorganisms such as Salmonella typhi, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis, Shigella flexneri, Pseudomonas aeruginosa, Aspergillus niger and Rhizoctonia bataicola. Most of the metal chelates have higher antimicrobial activity than the free ligands. 相似文献
60.
Point‐of‐Care Amperometric Testing of Diabetic Marker (HbA1c) Using Specific Electroactive Antibodies 下载免费PDF全文
Specific immune detection of glycated hemoglobin is still a great challenge owing to the small epitopic difference between Hemoglobin (Hb) and HbA1c. We report a new electrochemical immunoassay format for point of care testing of HbA1c. A conducting self‐assembled monolayer of mercaptophenyl boronic acid (MPBA) was used as a capture layer for binding of glycated proteins and ferrocene tagged anti‐HbA1c antibody (FcAb) as a tracer molecule on a gold screen printed electrode. Validation of the new HbA1c assay was carried out using 6 clinical samples with known HPLC values and a correlation coefficient of 98 % was observed. 相似文献