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991.
992.
The selective detection of 8-oxo-2'-deoxyguanosine (8-oxo-dG) in DNA without chemical or enzymatic treatment is an attractive tool for genomic research. We designed and synthesized the non-natural nucleoside analogue, the adenosine-1,3-diazaphenoxazine (Adap) derivative, for selective recognition of 8-oxo-dG in DNA. This study clearly showed that Adap has a highly selective stabilizing effect on the duplex containing the Adap-8-oxo-dG base pair. Furthermore, the fluorescent property of Adap was shown to be useful for the selective detection of 8-oxo-dG in the duplex DNA. To the best of our knowledge, this is the first successful demonstration of a non-natural nucleoside with a high selectivity for 8-oxo-dG in DNA. 相似文献
993.
994.
An internally contracted multireference configuration interaction is developed which employs wave functions that explicitly depend on the electron-electron distance (MRCI-F12). This MRCI-F12 method has the same applicability as the MRCI method, while having much improved basis-set convergence with little extra computational cost. The F12b approximation is used to arrive at a computationally efficient implementation. The MRCI-F12 method is applied to the singlet-triplet separation of methylene, the dissociation energy of ozone, properties of diatomic molecules, and the reaction barrier and exothermicity of the F + H(2) reaction. These examples demonstrate that already with basis sets of moderate size the method provides near complete basis set MRCI accuracy, and hence quantitative agreement with the experimental data. As a side product, we have also implemented the explicitly correlated multireference averaged coupled pair functional method (MRACPF-F12). 相似文献
995.
We develop an explicitly correlated multireference configuration interaction method (MRCI-F12) with multiple reference functions. It can be routinely applied to nearly degenerate molecular electronic structures near conical intersections and avoided crossings, where the reference functions are strongly mixed in the correlated wave function. This work is a generalization of the MRCI-F12 method for electronic ground states, reported earlier by Shiozaki et al. [J. Chem. Phys. 134, 034113 (2011)]. The so-called F12b approximation is used to arrive at computationally efficient formulas. The doubly external part of the wave function is expanded in terms of internally contracted configurations generated from all the reference functions. In addition, we introduce a singles correction to the CASSCF reference energies, which is applicable to multi-state calculations. As examples, we present numerical results for the avoided crossing of LiF, excited states of ozone, and the H(2)?+?OH (A(2)Σ(+)) reaction. 相似文献
996.
Tomoki Saka Toru Okaki Shohei Ifuku Yukiko Yamashita Kasumi Sato Shota Miyawaki Akiko Kamori Atsushi Kato Isao Adachi Yasuhiro Tezuka Peter G. Kiria Osamu Onomura Daishiro Minato Kenji Sugimoto Yuji Matsuya Naoki Toyooka 《Tetrahedron》2013
Synthesis and inhibitory activities against α-l-fucosidase of phenylalkyl-substituted polyhydroxypiperidines have been described. Among the newly synthesized compounds, 2,4,6-trichloro derivative (16q) showed very high inhibitory activity against α-l-fucosidase with IC50 value of 0.005 μM, and Ki values of 0.0011 μM, respectively. 相似文献
997.
Masako Koyama Masaharu Shiraishi Koji Sasaki Kijiro Kon-no 《Journal of Dispersion Science and Technology》2013,34(9):1266-1271
Amino acids provide useful foods, medicines, health foods, and nutritional supplements. We studied the morphology control of alanine, an amino acid. We also studied the effects of amino acid addition on the dispersion stability of gold nanoparticles. We then studied hybridization between alanine crystals and arginine-capped gold nanoparticles. Alanine crystal growth in a supersaturated alanine solution was found to increase linearly over time, and alanine crystal growth stopped as supersaturation decreased. Alanine crystals with arginine grew toward the c-axis because arginine was adsorbed onto the face (120) of alanine crystals. Absorption wavelengths of colloidal solutions changed for gold nanoparticles with arginine, suggesting that arginine was adsorbed onto gold nanoparticles. The change in alanine crystal morphology was the same for alanine crystals with arginine-capped gold nanoparticles in that it grew toward the c-axis. Alanine crystals contained arginine-capped gold nanoparticles toward the c-axis. 相似文献
998.
Prof. Dr. Haruhiko Fuwa Masato Kawakami Kenkichi Noto Takashi Muto Yuto Suga Prof. Dr. Keiichi Konoki Prof. Dr. Mari Yotsu‐Yamashita Prof. Dr. Makoto Sasaki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(25):8100-8110
We describe herein a concise synthesis of (+)‐neopeltolide, a marine macrolide natural product that elicits a highly potent antiproliferative activity against several human cancer cell lines. Our synthesis exploited the powerful bond‐forming ability and high functional group compatibility of olefin metathesis and esterification reactions to minimize manipulations of oxygen functionalities and to maximize synthetic convergency. Our findings include a chemoselective olefin cross‐metathesis reaction directed by H‐bonding, and a ring‐closing metathesis conducted under non‐high dilution conditions. Moreover, we developed a 16‐member stereoisomer library of 8,9‐dehydroneopeltolide to systematically explore the stereostructure–activity relationships. Assessment of the antiproliferative activity of the stereoisomers against A549 human lung adenocarcinoma, MCF‐7 human breast adenocarcinoma, HT‐1080 human fibrosarcoma, and P388 murine leukemia cell lines has revealed marked differences in potency between the stereoisomers. This study provides comprehensive insights into the structure–activity relationship of this important antiproliferative agent, leading to the identification of the pharmacophoric structural elements and the development of truncated analogues with nanomolar potency. 相似文献
999.
Abstract A series of silicon-containing multifunctional oxetane monomers has been prepared and characterized. These monomers were compared among themselves and with other oxetane monomers with respect to their reactivity in photoinitiated cationic polymerization. 相似文献
1000.
Shigeyuki Yagi Ryuhei Yamada Norihiro Tsuji Shinji Murakami Toru Takagishi 《Supramolecular chemistry》2013,25(3):293-297
Abstract A porphyrin dimer with a polyether linkage was newly synthesized and its conformational change triggered by complexation with an sodium cation was examined. It was confirmed by 1H NMR titration experiments that the dimer bearing a pentaoxyehtylene linkage (1b) was effectively formed a 1:1 complex with a sodium perchlorate. A detailed investigation of the CIS values for the protons confirmed that the complex of 1b?Na+ adopts a slipped face-to-face conformation. 相似文献