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711.
Kunihiko Takabe Yujiro Uchiyama Koichi Okisaka Takashi Yamada Takao Katagiri Tetuharu Okazaki Yoshiki Oketa Hidenori Kumobayashi Susumu Akutagawa 《Tetrahedron letters》1985,26(42):5153-5154
A stereospecific synthesis of (3R,7R)?3,7,11-trimethyldodecanal (2) with highly optical purity was achieved by utilizing the coupling reaction of the amino sulfone (9) with(R)?3,7-dimethyloctyl magnesium bromide (7), and the asymmetric isomerization of the resulting(E)-allylic amine (10). 相似文献
712.
Koichi Sasaki Minori Harada Yoshiki Miyashita Hiroshi Tagawa Akihiro Kishimura Takeshi Mori Yoshiki Katayama 《Chemical science》2020,11(12):3208
Redirecting endogenous antibodies in the bloodstream to tumor cells using synthetic molecules is a promising approach to trigger anti-tumor immune responses. However, current molecular designs only enable the use of a small fraction of endogenous antibodies, limiting the therapeutic potential. Here, we report Fc-binding antibody-recruiting molecules (Fc-ARMs) as the first example addressing this issue. Fc-ARMs are composed of an Fc-binding peptide and a targeting ligand, enabling the exploitation of endogenous antibodies through constant affinity to the Fc region of antibodies, whose sequence is conserved in contrast to the Fab region. We show that Fc-ARM targeting folate receptor-α (FR-α) redirects a clinically used antibody mixture to FR-α+ cancer cells, resulting in cancer cell lysis by natural killer cells in vitro. Fc-ARMs successfully interacted with antibodies in vivo and accumulated in tumors. Furthermore, Fc-ARMs recruited antibodies to suppress tumor growth in a mouse model. Thus, Fc-ARMs have the potential to be a novel class of cancer immunotherapeutic agents.Fc-binding antibody-recruiting molecules provide robust and sufficient opportunities to employ endogenous antibodies for anti-tumor immune responses. 相似文献
713.
Aratani N Takagi A Yanagawa Y Matsumoto T Kawai T Yoon ZS Kim D Osuka A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2005,11(11):3389-3404
On the basis of the Ag(I)-promoted coupling reaction of zinc(II)-5,15-bis(3,5-dioctyloxyphenyl)porphyrin Z1, chain elongation has been attempted by using a stepwise doubling approach, which provides Z2, Z4, Z8, Z16, Z32, Z64, Z128, Z256, Z384, and Z512. The porphyrin arrays up to Z128 are sufficiently soluble in CHCl3 and THF despite their very long molecular lengths and rodlike structures, while the arrays over Z128 show a significant drop in solubility and stability. The discrete porphyrin arrays thus isolated were characterized by means of (1)H NMR spectroscopy, matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, UV/Vis spectroscopy, gel-permeation chromatography (GPC), cyclic voltammetry (CV), single-crystal X-ray crystallography, scanning tunneling microscopy (STM), and atomic force microscopy (AFM). Contrary to expected linear conformations of the arrays Z n (where n is the number of porphyrins), the single molecular images of Z128, Z256, and Z512 revealed largely bent structures; this finding indicates the substantial conformational flexibility of Z n. We also exploited an effective synthetic route by means of which Z n can be fabricated with a thiol-protected aryl group to provide Z n S(2) through Z n Br(2), by bromination with N-bromosuccinimide and subsequent Pd-catalyzed Suzuki-Miyaura arylation. Finally, the reaction of Z256 provided Z512, Z768, and Z1024. Collectively, this work provides an important milestone in the preparation of sub-microscale discrete organic molecules and the fabrication of molecular-based materials, hence significantly contributing to device applications. 相似文献
714.
Masatomo Minagawa Kentaro Nouchi Masahiro Tozuka Riichiro Chujo Fumio Yoshii 《Journal of polymer science. Part A, Polymer chemistry》1995,33(4):665-671
Isotactic poly(acrylonitrile) (PAN) has been prepared by means of a conventional ultraviolet (UV) irradiation apparatus without γ-ray sources; an acrylonitrile-urea canal complex was directly formed at the surface of the UV (Hg) emission tube at low temperatures (~ ?78°C). When the complex was UV-irradiated at this temperature, a stereoregular polymer was formed in the canal. The 13C-NMR analyses indicate that (1) these PAN are rich in isotactic configuration, (2) the extent of the isotactic triad is in the range of 56?71%, and (3) the penultimate unit effect, 4 (mm) (rr)/(mr)2, is linearly correlated with the ultimate unit effect, (mm)/(rr). From the plots of log{4(mm)(rr)/(mr)2} vs log{(mm)/(rr)}, the anomaly in the polymerization of AN is discussed. The molecular characteristics of the UV canal PAN such as molecular weight, etc., were briefly noted. © 1995 John Wiley & Sons, Inc. 相似文献
715.
Paul J. Saines Brendan J. Kennedy Yoshiki Kubota Hiroko Hano Masaki Takata 《Journal of solid state chemistry》2007,180(11):3001-3007
The structures of eight members of the series of double perovskites of the type Ba2LnB′O6 (Ln=La3+-Sm3+ and Y3+ and B′=Nb5+ and Ta5+) were examined both above and below room temperature using synchrotron X-ray powder diffraction. The La3+ and Pr3+ containing compounds had an intermediate rhombohedral phase whereas the other tantalates and niobates studied have a tetragonal intermediate. This difference in symmetry appears to be a consequence of the larger size of the La3+ and Pr3+ cations compared to the other lanthanides. The temperature range over which the intermediate symmetry is stable is reduced in those compounds near the point where the preferred intermediate symmetry changes from tetragonal to rhombohedral. In such compounds the transition to the cubic phase involves higher order terms in the Landau expression. This suggests that in this region the stability of the two intermediate phases is similar. 相似文献
716.
717.
The plane structure and partial stereochemistry of a cytotoxic bromotriterpene polyether (+)-aurilol (1), isolated from the sea hare Dolabella auricularia, were mainly elucidated by NMR methods; however, determination of the entire stereochemistry has not been reached. Although there have also been many other types of triterpene polyethers, it is often difficult to determine their stereostructures even by the current highly advanced spectroscopic methods, especially in acyclic systems including quaternary carbon centers such as C10-C11, C14-C15, and C18-C19 in 1. In this paper, we report that the total assignment of the incomplete stereostructure of (+)-aurilol (1) to the structural formula 2 has been accomplished through its first asymmetric total synthesis featuring the highly regio- and stereocontrolled biogenetic-like A-D ether ring formations. 相似文献
718.
Masao Hisatome Yoshiki Kawajiri Koji Yamakawa Yoshinori Harada Yoichi Iitaka 《Tetrahedron letters》1982,23(16):1713-1716
Perbridged ferrocenes ( and : the title compound) have been synthesized and characterized by spectroscopies and X-ray diffraction, and an interesting rotational disorder has been found by the X-ray crystal analyses of both and . 相似文献
719.
Takayuki Chujo Isao Saraoka Shinobu Kato Hiroyasu Sato Koichi Fukuhara Hiroatsu Matsuura 《Journal of inclusion phenomena and macrocyclic chemistry》1994,20(2):173-190
Three sodium complexes (bromide, iodide an thiocyanate) of 4,13-diaza-18-crown-6 were studied using Raman and IR spectroscopy and normal coordinate calculations to probe the stoichiometry of the complexes and the variation in the conformation of azacrown moiety on complex formation. Complex formation is accompaniedby characteristic shifts of the bands, especially of those in the 800–900 cm–1 region. Complexes of both 1: 1 and 2:1 stoichiometry were observed. Normal coordinate calculations showed the reduction of symmetry of azacrown moiety toC
2
, in contrast to theC
2h
symmetry known for the parent azacrown and potassium thiocyanate complex. 相似文献
720.
Hiroaki Ogasawara Yoshiki Tanaka Masayasu Taki Shigehiro Yamaguchi 《Chemical science》2021,12(22):7902
Near-infrared (NIR) fluorescent molecules are of great importance for the visualisation of biological processes. Among the most promising dye scaffolds for this purpose are P O-substituted phospha-xanthene (POX) dyes, which show NIR emission with high photostability. Their practical utility for in vitro and in vivo imaging has recently been demonstrated. Although classical modification methods have been used to produce POX-based fluorescent probes, it is still a challenge to introduce additional functional groups to control the localisation of the probe in cells. Herein, we report on the development of POXs that bear a 4-ethynylphenyl group on the phosphorus atom. These dyes can subsequently be functionalised with azide-tagged biomolecules via a late-stage Cu-catalysed azide/alkyne cycloaddition (CuAAC) reaction, thus achieving target-selective labelling. To demonstrate the practical utility of the functionalised POXs, we designed a sophisticated NIR probe that exhibits a bell-shaped off–on–off pH-response and is able to assess the degree of endosomal maturation.A series of NIR-emissive phospha-xanthene dyes bearing an ethynyl group are reported. The late-stage functionalisation of the NIR dyes enables creation of multi-functionalised fluorescent probes that can be designed to target organelles of interest. 相似文献