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11.
The low-resolution mass spectra of 13 trifluoromethyl and/or methyl sulfur-containing compounds (CF3SnCF3, CF3SnCH3, CH3SnCH3, CF3SmCl, and CH3SmCl; n = 1, 2, 3; m = 1, 2) are reported and discussed. There is a considerable similarity between the fragmentation pattern of compounds with the same terminal groups. However, with a fluorinated and a non-fluorinated methyl group, the major fragmentation products produced are similar to those for the dimethyl compounds. 相似文献
12.
James N. Sturgis C. Neil Hunter Robert A. Niederman 《Photochemistry and photobiology》1988,48(2):243-247
Abstract— Membranes from Rhodobacter (formerly Rhodopseudomonas) sphaeroides mutant strains that lack one or more of the bacteriochlorophyll a (BChl)-protein complexes were used to obtain spectra and molar extinction coefficients of the near-IR absorption bands. The strains examined were NF57 which lacks the B875 light-harvesting and reaction center complexes, and M21 which lacks the B800–850light-harvesting complex. The extinction coefficients obtained for the B800, B850 and B875 bands were 226 ± 10, 170 ± 5, and 118 ± 5 m M -1 cm-1 , respectively, in reasonable agreement with values reported for detergent-isolated complexes (Clayton, R. K. and B. J. Clayton, Proc. Natl. Acad. Sci. USA 78 ,5583–5587, 1981). The results also demonstrated that detergent solubilization altered the spectra, causing a band broadening on the blue side of the B875 and B800 peaks. The data obtained from the analysis of the mutant strains were used for deconvolution of the BChl species in membranes of the wild-type. A short BASIC computer program for performing this deconvolution is included. 相似文献
13.
The synthesis and chemical properties of a series of amino acid derivatives containing the thiolsulphonate functionality are described. 相似文献
14.
Neil Bricklebank Simon J. Coles Michael B. Hursthouse Peter J. Skabara 《Journal of organometallic chemistry》2005,690(2):328-332
The title compound, Fc2(Ph)PS · I2, has been prepared and characterised in both the solid state and solution. Single crystal X-ray crystallography reveals that the adduct adopts a molecular charge-transfer structure in the solid state. Mössbauer spectroscopy confirms the presence of low spin Fe2+ but also indicates the presence of ca. 24% of an Fe3+ species. The electrochemistry of Fc2(Ph)PS · I2, Fc2(Ph)PS and Fc2(Ph)P has been studied using a combination of cyclic voltammetry and differential pulse voltammetry. The data for Fc2(Ph)PS · I2 show two redox processes, consistent with the sequential oxidation of the ferrocenyl groups to ferrocenium species. 相似文献
15.
Two reactions, catalyzed by lactate oxidase (LO) and peroxidase, are initiated by a single injection of the enzymes and the substrate 2,2'-azino-bis(3-ethylene-thiazoline-6-sulfonic acid) (ABTS) into the capillary previously filled with the sample (lactate or lactate-oxalate mixture) and the run buffer containing NADH. The oxidized ABTS product upon reaction with NADH is converted to NAD(+) which is separated and detected in less than 2 min at 266 nm with a sample throughput of 7 min (including wash steps between samples). Simplex trade mark software is used to optimize the enzyme concentrations and reaction temperature. Consumption of the more expensive LO enzyme is only 1.4 x 10(-3) U per assay assuming 27 nL per injection. Linearity is established within the range from 0.0025 to 1 mM with R(2) of 0.9982. Recoveries of lactate from five spiked serum samples averaged 101%. Application of this method for the determination of oxalate as an inhibitor of LO is demonstrated. 相似文献
16.
[reaction: see text] The title alkaloid was synthesized in racemic form from 3,7-diallyl-2,4,6,8-tetraoxo-3,7-diazabicyclo[3.3.1]nonane (7) by a regioselective diallylation reaction followed by double ring-closing olefin metathesis and exhaustive reduction. Tetraoxobispidine 7 was itself prepared in three simple operations from dimethyl malonate. The entire sequence to alpha-isosparteine was conducted on a multigram scale and proceeded without recourse to chromatography. 相似文献
17.
Recovery of intact proteins from silver stained gels 总被引:1,自引:0,他引:1
Silver stained proteins of a wide molecular weight (MW) range (20-116 kDa) were successfully recovered by both electroblot and electroelution. The recovery was demonstrated for nanogram loads of proteins separated by SDS-PAGE and visualized by silver staining methods compatible and incompatible with mass spectrometry (MS). It was shown that the alcohol/acid and glutaraldehyde fixation steps present in a number of staining procedures did not prevent recovery of intact proteins from gels. It was found that the recovery of intact proteins from silver stained gels was substantially increased upon pre-equilibration in a buffer containing the reducing agent, dithiothreitol (DTT). The effect of destaining on the recovery of silver stained proteins was also investigated. Comparable recovery of intact proteins within a wide MW range from silver stained gels with and without destaining step was demonstrated. Recovery of model proteins from gels visualized using silver staining method compatible with MS showed 52 to 76% yield of that from the unstained gel, depending upon method of the transfer. Comparison of the recovery of intact proteins from gels visualized using other staining procedures was also made. The above findings have implications as to the supposed irreversible nature of protein "fixation" inside polyacrylamide matrix, and confirm lack of binding of proteins in the gel to metal silver deposited on its surface. This method has the potential to be suitable for direct characterization of proteins by matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) without additional purification steps. 相似文献
18.
1-Phenyl-2-(benzenesulphonyl)-ethylene and 1-phenyl-2-(benzenesulphonyl)-prop-1-ene have been shown to undergo ,-photoisomerisation, whereas 2-benzenesulphonylindene readily forms [π2 + π2] photoadducts with 2,3-dimethylbut-2-ene, cyclopentene, and cyclohexene. 相似文献
19.
In this letter we describe the advantages of a dynamic optical interconnection system for parallel information processing applications. The system is based on a liquid crystal television which acts as a binary phase-only spatial light modulator. We describe example algorithms where reconfigurable interconnects would be useful and present results of several interconnection topologies which have been implemented.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994. 相似文献
20.
Serum proteins represent an important class of drug and imaging agent delivery vectors. In this minireview, key advantages of using serum proteins are discussed, followed by the particular advantages and challenges associated with employing soluble folate binding protein. In particular, approaches employing drugs that target folate metabolism are reviewed. Additionally, the slow-onset, tightbinding interaction of folate with folate binding protein and the relationship to a natural oligomerization mechanism is discussed. These unique aspects of folate binding protein suggest interesting applications for the protein as a vector for further drug and imaging agent development. 相似文献