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301.
We show the bursting process of dioleoylphosphatidylcholine (DOPC) liposomes in response to the addition of acetonitrile, a small toxic molecule widely used in the fields of chemistry and industry. The percentage of destroyed liposomes is reduced upon decreasing the acetonitrile fraction in the aqueous solution and vesicle bursting is not observed at volume ratios of 4:6 and below. This indicates that a high fraction of acetonitrile causes the bursting of liposomes, and it is proposed that this occurs through insertion of the molecules into outer leaflet of the lipid bilayer. The elapsed time between initial addition of acetonitrile and liposome bursting at each vesicle is also measured and demonstrated to be dependent on the volume fraction of acetonitrile and the vesicle size. 相似文献
302.
Osamu Takahashi Katsuyoshi Yamasaki Youji Kurihara Yoji Umezawa Motohiro Nishio 《Tetrahedron》2008,64(10):2433-2440
Ab initio MO calculations were carried out, at the MP2/6-311++G(d,p)//MP2/6-311G(d,p) level, to investigate the Gibbs free energy of the conformational isomers of 2-alkyl, 3-alkyl, and 4-alkyl cyclohexanones. The calculation gave results consistent with the general trend experimentally found. The genesis of stabilization of the axial conformers in 2- and 3-alkyl cyclohexanones, as compared to the structurally corresponding cyclohexane derivatives, was sought in the context of the attractive CH/π(CO) hydrogen bond. In support of this hypothesis, short nonbonded distances have been noted between CHs in the alkyl group and the carbonyl carbon in the relevant axial conformers. Calculations were also carried out to study the conformational energies of several terpenic ketones. For isomenthone, more than a half molecular fraction (ca. 55%) has been suggested to be in the isopropyl-axial conformation, while for isocarvomenthone ca. 77% has been suggested to be in the axial-isopropyl conformation; this is consistent with bibliographic experimental data. A crystallographic database search has provided results compatible with this conclusion. We suggest that the relative stability of the axial alkyl substituent, often observed in terpenic and steroidal ketones is rationalized in terms of an attractive molecular force, the CH/π(CO) hydrogen bond. 相似文献
303.
Nishio K Masaike Y Ikeda M Narimatsu H Gokon N Tsubouchi S Hatakeyama M Sakamoto S Hanyu N Sandhu A Kawaguchi H Abe M Handa H 《Colloids and surfaces. B, Biointerfaces》2008,64(2):162-169
We developed novel magnetic nano-carriers around 180 nm in diameter for affinity purification. Prepared magnetic nano-carriers possessed uniform core/shell/shell nano-structure composed of 40 nm magnetite particles/poly(styrene-co-glycidyl methacrylate (GMA))/polyGMA, which was constructed by admicellar polymerization. By utilizing relatively large 40 nm magnetite particles with large magnetization, the magnetic nano-carriers could show good response to permanent magnet. Thanks to uniform polymer shell with high physical/chemical stability, the magnetic nano-carriers could disperse in a wide range of organic solvent without disruption of core/shell structure and could immobilize various kinds of drugs. We examined affinity purification using our prepared magnetic nano-carriers with anti-cancer agent methotrexate (MTX) as ligand. Our magnetic nano-carriers showed higher performance compared to commercially available magnetic beads in terms of purification efficiency of target including extent of non-specific binding protein. 相似文献
304.
An efficient approach to benzoxazoles via tandem migration-carboalkoxylation of o-isocyanophenyl acetals has been developed. Both a Lewis acid and base are essential for this reaction, and the BF(3)·OEt(2)/2,4,6-collidine combination is the best choice for cooperative transformation. 相似文献
305.
Azuma S Nishio K Kubo K Sasamori T Tokitoh N Kuramochi K Tsubaki K 《The Journal of organic chemistry》2012,77(10):4812-4820
Three types of dimeric naphthoquinones, which possess structurally diverse skeletons, can be prepared in one step from 2-bromo-3-methyl-1,4-naphthoquinones. 2,2'-Dimeric naphthoquinones were prepared by a one-pot Stille-type reaction via vinylstannanes. Oxepines are formed by unexpected domino reactions via 1,4-dihydroxynaphthalene species. Epoxides are formed by a Michael/Darzens reaction via the o-quinone methides. 相似文献
306.
F. P. Heßberger S. Hofmann D. Ackermann S. Antalic B. Kindler I. Kojouharov P. Kuusiniemi M. Leino B. Lommel R. Mann K. Nishio A. G. Popeko B. Sulignano S. Saro B. Streicher M. Venhart A. V. Yeremin 《The European Physical Journal A - Hadrons and Nuclei》2006,30(3):561-569
The decay of the isotopes 255Rf, 251No and 247Fm produced in the reactions
, and
was investigated by means of α-γ spectroscopy. Previously observed γ transitions in coincidence with α decays of 255Rf were confirmed, their energies and line intensities were measured more precisely, and their multipolarities were determined
as E1. In 251No a new isomeric state at E
* > 1700keV with a half-life of ≈ 2μs was identified. The decay of 247Fm was measured more precisely. A partial level scheme of the daughter nucleus 243Cf could be established. 相似文献
307.
Kenta Itahashi Georg P. A. Berg Hiroyuki Fujioka Hans Geissel Ryugo S. Hayano Satoru Hirenzaki Natsumi Ikeno Naohito Inabe Satoshi Itoh Daisuke Kameda Toshiyuki Kubo Hiroaki Matsubara Shinichiro Michimasa Kenjiro Miki Hiroyuki Miya Masaki Nakamura Takahiro Nishi Shumpei Noji Shinsuke Ota Ken Suzuki Hiroyuki Takeda Koichi Todoroki Kyo Tsukada Tomohiro Uesaka Helmut Weick Koichi Yoshida 《Hyperfine Interactions》2012,209(1-3):51-56
308.
Dr. Yoshifumi Hashikawa Shumpei Sadai Shu Okamoto Prof. Dr. Yasujiro Murata 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202215380
Though [60]fullerene is an achiral molecular nanocarbon with Ih symmetry, it could attain an inherent chirality depending upon a functionalization pattern. The conventional chiral induction of C60 relies mainly upon a multiple addition affording a mixture of achiral and chiral isomers while their chiral function would be largely offset by the existence of pseudo-mirror plane(s). These are major obstacles to proceed further study on fullerene chirality and yet leave its understanding elusive. Herein, we showcase a carbene-mediated synthesis of C1-symmetric chiral open [60]fullerenes showing an intense far-red to near-infrared absorption. The large dissymmetry factor of |gabs|=0.12 was achieved at λ=820 nm for circular dichroism in benzonitrile. This is, in general, unachievable by other small chiral organic molecules, demonstrating the potential usage of open [60]fullerenes as novel types of chiral chromophores. 相似文献
309.