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991.
Takefumi Momose Kikuo Masuda Sachiko Furusawa Osamu Muraoka Toshiyuki Itooka 《合成通讯》2013,43(13):1039-1046
Isotwistanones have been highlighted since their use in the sesquiterpene syntheses.1 Begley and coworkers reported a new access to this system via the postulated aldol cyclization of bicyclo [4.3.1]decane-2, 7-dione.2 We have found another novel path of a similar mode. 相似文献
992.
Kaori Tateishi Shiori Tsukagoshi Tsuyoshi Nakamura Shotaro Watanabe Vadim A. Soloshonok Osamu Kitagawa 《Tetrahedron letters》2013
We report here the theoretical design and proof of principle of the first example of a conceptually new approach for the preparation of enantiomerically pure compounds from the racemates by chiral initiator-induced Self-Disproportionation of Enantiomers (SDE) via achiral chromatography. 相似文献
993.
Yasuhiro Mie Keiko Kowata Yu Hirano Osamu Niwa Fumio Mizutani 《Analytical sciences》2008,24(5):577-582
Several redox enzymes were examined for enzymatic/electrochemical-recycling systems in order to measure p-aminophenol (PAP) with high sensitivity. Glucose oxidase (GOD) and diaphorase (DI) worked well as catalysts for recycling electrode systems: these enzymes effectively reduced p-iminoquinone (PIQ), the electrochemically-oxidized form of PAP, and caused an enhancement in the electrochemical signals (anodic currents in the voltammogram and amperogram) by approximately 100 fold. The lower detection limits for PAP were estimated to be 50 nM with the GOD system and 2 nM with the DI system. We combined the enzymatic-recycling electrode using DI with an enzyme immunoassay system to measure atrial natriuretic peptide (ANP), an important marker peptide hormone involved in heart diseases. ANPs from serum samples at ppt-levels were determined appropriately using the present assay system. 相似文献
994.
995.
Wakahara T D'Angelo P Miyazawa K Nemoto Y Ito O Tanigaki N Bradley DD Anthopoulos TD 《Journal of the American Chemical Society》2012,134(17):7204-7206
A novel supramolecular nanoarchitecture, comprising C(60)/Co porphyrin nanosheets, was prepared by a simple liquid-liquid interfacial precipitation method and fully characterized by means of optical microscopy, AFM, STEM, TEM, and XRD. It is established that the highly crystalline C(60)/Co porphyrin nanosheets have a simple (1:1) stoichiometry, and when incorporated in bottom-gate, bottom-contact field-effect transistors (FETs), they show ambipolar charge transport characteristics. 相似文献
996.
Janar J Nugroho AE Wong CP Hirasawa Y Kaneda T Shirota O Morita H 《Chemical & pharmaceutical bulletin》2012,60(1):154-159
Six new diterpenoids, sabiperones A-F (1-6) have been isolated from the aerial part of Juniperus sabina. Their structures were elucidated by spectroscopic methods including 2D NMR techniques. Sabiperone F showed moderate cell growth inhibitory activities against five human cancer cell lines. 相似文献
997.
Deguchi J Hirahara T Hirasawa Y Ekasari W Widyawaruyanti A Shirota O Shiro M Morita H 《Chemical & pharmaceutical bulletin》2012,60(2):219-222
Four new alkaloids, cassiarins G, H, J, and K (1-4) which showed moderate antiplasmodial activity against Plasmodium falciparum 3D7, were isolated from the leaves of Cassia siamea (Leguminosae) and the structures of 1-4 were elucidated by 1D- and 2D-NMR analysis and X-ray crystallographic analysis. 相似文献
998.
Neto Ade B Bustamante MC Oliveira JH Granato AC Bellão C Badino AC Badino AC Barboza M Hokka CO 《Applied biochemistry and biotechnology》2012,166(1):208-221
A study was made for purification of cephamycin C from fermentation of Streptomyces clavuligerus. Initially, the culture broth was clarified by microfiltration and ultrafiltration, after which the resulting permeates were
subjected to nonspecific adsorption and ion-exchange chromatography on resin columns. The antibiotic activity was measured
by the biological method at each stage by assaying its activity against the Escherichia coli ESS, super sensitive to β-lactam antibiotic. The purification processes were assessed in relation to the variables affecting
each step. The purification efficiency by nonspecific adsorption was monitored by UV spectrophotometry, while the ion-exchange
adsorption fractions were assessed by NMR spectroscopy. Some of the fractions obtained during purification were also analyzed
by mass spectrometry (LC/MS and LC/MS/MS) to identify the cephamycin C molecule. These preliminary results proved the process
feasibility. 相似文献
999.
Multiplexed assay for proteins based on sequestration electrochemistry using the protein binding electroactive magnetic microbeads 总被引:1,自引:0,他引:1
Kuramitz H Mawatari Y Ikeuchi M Kutomi O Hata N Taguchi S Sugawara K 《Analytical sciences》2012,28(1):77
The paramagnetic microbead-based electrochemical binding assay was demonstrated for detecting two kinds of protein simultaneously. The principle of this assay is based on the sequestration electrochemistry. The protein binding electroactive magnetic microbeads which are conjugated with an electroactive compound and a ligand to bind specifically with a target protein were prepared. The avidin-biotin and soybean agglutinin (SBA)-galactosamine were chosen as model protein-ligand systems. The avidin binding electroactive magnetic microbead (ABEMMb) and SBA binding electroactive magnetic microbead (SBEMMb) are constructed by biotin/thionine and galactosamine/ferrocene modified on paramagnetic microbeads. The voltammetric response for these functionalized microbeads was measured by the Nd-Fe-B magnet-incorporating carbon paste rotating disk electrode. The measurements were performed in a microliter droplet using a rotating disk electrode system. Avidin and SBA were simultaneously detected by the decrease in the current responses from the reduction of ABEMMb and SBEMMb that was caused by the binding with target proteins. The limits of detection for avidin and SBA were 4 × 10(-10) and 2 × 10(-10) M, respectively. 相似文献
1000.
Four novel megastigmanes, neosedumosides I (1), II (2), III (3), and IV (4) were isolated from the whole plant of Sedum sarmentosum (Crassulaceae). Absolute stereostructures of these constituents were determined on the basis of chemical and physicochemical evidence. Among them, 1-3 were found to show lipid accumulation inhibitory activity in HepG2 cells. Furthermore, 2 and 3 were found to also show lipid metabolism-promoting activity. 相似文献