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91.
Ando K Tsuji E Ando Y Kunitomo J Kobayashi R Yokomizo T Shimizu T Yamashita M Ohta S Nabe T Kohno S Ohishi Y 《Organic & biomolecular chemistry》2005,3(11):2129-2139
Variable benzo[b]furan derivatives having (E)- and (Z)-2-alkylcarbamoyl-1-methylvinyl groups at the 2-, 4- and 5-positions and a carboxylpropoxy or (1-phenyl)ethoxy group at the 7-position were prepared to find novel and selective leukotriene B4(LTB4) receptor antagonists. (E)-2-(2-diethylcarbamoyl-1-methylvinyl)-7-(1-phenylethoxy)benzo[b]furan (4v) showed selective inhibition to the human BLT2 receptor (hBLT2). On the other hand, (E)-2-acetyl-4-(2-diethylcarbamoyl-1-methylvinyl)-7-(1-phenylethoxy)benzo[b]furan (7v) inhibited both human BLT(1) receptor (hBLT1) and hBLT2. The (E)-2-(2-diethylcarbamoyl-1-methylvinyl) group lay on approximately the same plane as the benzo[b]furan ring, whereas the (E)-4-(2-diethylcarbamoyl-1-methylvinyl) group had the torsion angle (45.7 degree) from the benzo[b]furan ring plane. However, the (Z)-(2-alkylcarbamoyl-1-methylvinyl)benzo[b]furans were inactive. The inhibitory activity depended on the conformation of the 2-diethylcarbamoyl-1-methylvinyl group. 相似文献
92.
Jun-ichi Horinaka Atsushi Okuda Ryosuke Yasuda Toshikazu Takigawa 《Colloid and polymer science》2012,290(17):1793-1797
Dynamic viscoelasticity measurements were carried out for concentrated solutions of linear d-glucans in BmimCl to examine the effect of the linkage between repeating units of glucose on the rheological properties. The values of molecular weight between entanglements (M e) were determined for four d-glucans: curdlan, pullulan, cellulose, and amylose. From the concentration dependence of M e, the value of M e in the molten state (M e,melt) for each d-glucan was estimated as a material constant. The order of M e,melt became cellulose?<?pullulan?<?curdlan?<?amylose, indicating that the linkage is actually influential in M e,melt for the linear d-glucans. The relationship between M e,melt and the molecular structure of the d-glucans were discussed assuming that the values of M e,melt for the d-glucans primarily reflect the chain stiffness such as the characteristic ratio C ∞ on the analogy of synthetic polymers. Although the trend was not so clear, it was shown that N unit is a decreasing function of C ∞ . 相似文献
93.
Microwave spectrum of monodeuterated diacetylene (HCCCCD), which is nonpolar in the equilibrium configuration, was observed in various excited states of bending vibrations. Dipole moments in the ν6, 2ν6, and ν6 + ν9 vibrational states were determined from the Stark effect measurement to be 0.0907(6), 0.1681(14), and 0.0900(4) D with uncertainties in parentheses, where ν6 and ν9 denote respectively the CCH bending and lowest frequency bending vibrations. The l-type doubling constant in the ν6 state is 2.1316(28) MHz. Rotational constants were determined in MHz; ν6(Π), 4086.2165(44); 2ν6(Δ), 4087.6963(58); ν6 + ν9(Δ), 4097.7537(50); 2ν8(Δ), 4094.4786(103); ν6 + ν7(Δ), 4092.9074(176); ν7 + ν8(Δ), 4095.8925(354); 2ν6 + ν9(Φ), 4098.9505(339). 相似文献
94.
Chikara Tsutsumi Hajime Yasuda 《Journal of polymer science. Part A, Polymer chemistry》2001,39(22):3916-3927
Random copolymerizations of L ‐lactide with (R)‐, (S)‐, or rac‐1‐methyltrimethylene carbonate with bis(pentamethylcyclopentadienyl) samarium‐methyl tetrahydrofuranate [(C5Me5)2SmMe(THF)] as a novel initiator provided high molecular weight polymers with low polydispersities. Biodegradation of the resulting polymers with tricine and {N‐[tris(hydroxymethyl)methyl]‐2‐aminoethane sulfonic acid (TES) buffers as well as activated sludge showed only a small weight loss, whereas the polymer with proteinase K revealed high biodegradability independent of the optical activity of 1‐methyltrimethylene carbonate. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3916–3927, 2001 相似文献
95.
Negatively Charged π‐Electronic Systems by Deprotonation of Hydroxy‐Substituted Dipyrrolyldiketone Boron Complexes 下载免费PDF全文
Boron complexes of meso‐hydroxy‐substituted dipyrrolyldiketones, as the precursors of negatively charged π‐electronic systems, were synthesized via the oxidative introduction of an acetoxy unit at the meso position of dipyrrolyldiketones and subsequent hydrolysis. The anionic site formed upon deprotonation was moderately stabilized by hydrogen‐bond‐donating pyrrole NH, generating non‐complexing anionic species. 相似文献
96.
DC cathodic polymerization of trimethylsilane (TMS) was carried out in plasma reactors with and without using anode assembly. In DC cathodic polymerization, the TMS plasma polymers are mainly deposited on the cathode (substrate) surface. As a result, fast deposition of TMS plasma polymers was easily achieved in DC cathodic polymerization as compared with AF or RF plasma polymerization. DC cathodic polymerization without using anode assembly has its advantageous features that the size and number of substrates (as cathodes) are not restricted by the size and the location of anode assembly. It was found that the maximum deposition rate on the cathode surfaces was obtained without anode assembly. The DC cathodic polymerization of TMS was conducted also in a large volume reactor with multiple cathodes (substrates). The same deposition mechanisms for DC cathodic polymerization with a single cathode also apply to the multiple cathodes. Uniform deposition on each cathode could be obtained with appropriate spacing of multiple cathodes and by adjusting the operational parameters, which are based on the current density and the system pressure. 相似文献
97.
Masazumi Ishiguro Kensuke Harada Keiichi Tanaka Takehiko Tanaka 《Journal of Molecular Spectroscopy》1996,180(2)
Rotational transitions of fluoroacetylene in the ν1(CH stretch) vibrational state have been observed by the laser–microwave double resonance technique using a color center laser as a radiation source in the 3 μm region. The rotational constant and centrifugal distortion constant in the ν1state were determined to be 9684.310(16) MHz and 2.68(62) kHz, respectively, where the uncertainties given in parentheses correspond to 2.5 standard deviations. 相似文献
98.
The magnesium-butadiene 1 : 1 (1), 1 : 2 (II) and 1 : 3 addition compounds obtained by the direct metalation of butadiene with metallic magnesium were isolated. These compounds have a polymeric structure. Structural analysis of these compounds by NMR and IR methods was carried out. The process for the formation of II via I and III via II was investigated. The results of protolysis and alkylation of the above magnesium compounds corresponded well to those of crotylmagnesium compounds. 相似文献
99.
We present a new method for homocysteine quantitation in human plasma based on in-capillary reaction of homocysteine with 2,2′-dipyridyl disulfide. Homocysteine is in this so-called thiol-exchange reaction quantitatively transformed in mixed disulfide concomitantly with formation of an equimolar amount of 2-thiopyridone that is further separated by micellar electrokinetic chromatography and determined specifically at 343 nm. The concentration of homocysteine is thus estimated indirectly from the result of 2-thiopyridone determination. The linear detection range for concentration versus peak area for the assay was from 0.03–3 mM (correlation coefficient 0.994) with a detection limit of 6 μM and a limit of quantitation 20 μM. The inter-day reproducibility of the peak area and the migration time were 1.37% and 0.05%, respectively. The method is simple, relatively rapid and can be easily automated. Moreover the common capillary electrophoresis apparatus with a UV detector can be used to distinguish between normal and pathological hyperhomocysteinemia plasma samples. 相似文献
100.
Saito T Yasuda N Kataoka Y Nakanishi Y Kitagawa Y Kawakami T Yamanaka S Okumura M Yamaguchi K 《The journal of physical chemistry. A》2011,115(22):5625-5631
The spin-unrestricted Hartree-Fock (UHF)-based coupled cluster singles and doubles (UHF-CCSD) and Mukherjee's state-specific multireference CCSD (MkCCSD) methods are applied to four ring-opening reactions. The spin-restricted Hartree-Fock (RHF)-based CCSD (RHF-CCSD) calculations are also performed for comparison. In the case of the UHF-CCSD method, an approximate spin-projection (AP) method is applied to the broken-symmetry (BS) singlet solution to remove the spin contamination effect. For potential energy curves (PECs) of all reactions presented in this study, the results of RHF-CCSD and UHF-CCSD are substantially different from those of MkCCSD, while the results after the AP method (AP-UCCSD) reproduce the MkCCSD results well. It strongly suggests that the spin contamination effect should be removed by the AP correction even at the UHF-CCSD level to predict reliable energetics of these reactions. 相似文献