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51.
Y Nishioka S Kyotani M Okamura M Miyazaki Y Sakamoto M Morita K Okazaki S Ohnishi Y Yamamoto K Ito 《Chemical & pharmaceutical bulletin》1992,40(1):267-268
Hepatic artery of dogs was embolized with cisplatin (CDDP) albumin microspheres containing chitin and chitosan to investigate the in vivo CDDP release kinetics from CDDP albumin microspheres, the CDDP cumulative characteristics in the liver, and the influence of microsphere administration on hepatic tissue. Results showed that changes in blood CDDP content were dependent on CDDP albumin microsphere type and that release kinetics were better sustained when chitin was added to the microspheres or when the microspheres were treated with chitosan. In particular, the administration of CDDP in the chitin-containing CDDP chitosan albumin microspheres showed a blood CDDP content of approximately 0.26 micrograms Pt/ml 14 d after administration. The administration of chitin-containing or chitosan treated CDDP microspheres showed a CDDP content in the hepatic tissue of 0.14 to 0.23 micrograms Pt/g 28 d after administration. They also showed better control of CDDP release than those without chitin or chitosan treatment. No CDDP influence on hepatic tissue was observed. We conclude that, even in vivo, chitin and chitosan are effective embolic materials. 相似文献
52.
H Hagiwara T Nagasawa K M Lodhi M Kozuka T Ito S Hirose 《Journal of chromatography. A》1992,597(1-2):331-334
Endothelin receptor was purified from bovine lung by affinity chromatography using biotinylated endothelin and avidin-agarose. Endothelin was biotinylated with sulphosuccinimidyl 2-(biotinamido)ethyl-1,3-dithiopropionate, a reactive form of biotin with a cleavable spacer arm containing a disulphide bond designed for a simple elution by thiols. Starting from 3.5 kg of bovine lung, about 200 micrograms of pure receptor were obtained. 相似文献
53.
Shibusawa Y Yanagida A Ito A Ichihashi K Shindo H Ito Y 《Journal of chromatography. A》2000,886(1-2):65-73
Apple procyanidins were separated by high-speed counter-current chromatography using a type-J multilayer coil planet centrifuge. Several two-phase solvent systems with a wide range of hydrophobicities from a non-polar hexane system to polar n-butanol systems were evaluated their performance in terms of the partition coefficient and the retention of the phase. The best separation of procyanidins B and C was achieved with a two-phase solvent system composed of n-butanol-methyl tert.-butyl ether-acetonitrile-0.1% trifluoroacetic acid (2:4:3:8) using the lower phase as a mobile at a flow-rate of 1.0 ml/min. 相似文献
54.
Kazuaki Ito Akane Suzuki Naoto Ito Hiroyuki Teraura Yoshihiro Ohba 《Journal of heterocyclic chemistry》2003,40(3):405-410
Dithia‐tetrahomodiaza‐calix[4]arenes were synthesized by the cyclization reactions of bis(3‐(chloro‐methyl)‐2‐hydroxyphenyl)sulfide with cystine peptides in moderate yields. Conformational analysis of the macrocycles by using nmr spectroscopy reveled that the cyclophanes adopt a cone‐like form as a preferable conformation and the cystine bridge moiety is incorporated in the cavity. The calixarene analogs can extract transion metals such as Zn2+ and Cu2+ ions from an aqueous phase into chloroform. 相似文献
55.
Toshio Koizumi Jun Sakamoto Yasuhiko Gondo Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2002,40(14):2487-2494
The palladium(0)‐catalyzed polyaddition of bifunctional vinyloxiranes [1,4‐bis(2‐vinylepoxyethyl)benzene ( 1a ) and 1,4‐bis(1‐methyl‐2‐vinylepoxyethyl)benzene ( 1b )] with 1,3‐dicarbonyl compounds [methyl acetoacetate ( 4 ), dimethyl malonate ( 6 ), and Meldrum's acid ( 8 )] was investigated under various conditions. The polyaddition of 1 with 4 was carried out in tetrahydrofuran with phosphine ligands such as PPh3 and 1,2‐bis(diphenylphosphino)ethane (dppe). Polymers having hydroxy, ketone, and ester groups in the side groups ( 5 ) were obtained in good yields despite the kinds of ligands employed. The number‐average molecular weight value of 5b was higher than that of 5a . The polyaddition of 1b and 6 was affected by the kinds of ligands employed. The corresponding polymer 7b was not obtained when PPh3 and 1,2‐bis(diphenylphosphino)ferrocene were used. The polyaddition was carried out with dppe as the ligand and gave polymer 7b in a good yield. The molecular weight of the polymer obtained from 1b and 8 was much higher than those of polymers 5b and 7b . The polyaddition with Pd2(dba)3 · CHCl3/dppe as a catalyst (where dba is dibenzylideneacetone) produced polymer 9b in a 92% yield (number‐average molecular weight = 45,600). The stereochemistries of all the obtained polymers were confirmed as an E configuration by the coupling constant of the vinyl proton. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2487–2494, 2002 相似文献
56.
Masahiro Murayama Ryoji Kanno Michihiko IrieShinya Ito Takayuki HataNoriyuki Sonoyama Yoji Kawamoto 《Journal of solid state chemistry》2002,168(1):140-148
The new lithium ionic conductors, thio-LISICON (LIthium SuperIonic CONductor), were found in the ternary Li2S-SiS2-Al2S3 and Li2S-SiS2-P2S5 systems. Their structures of new materials, Li4+xSi1−xAlxS4 and Li4−xSi1−xPxS4 were determined by X-ray Rietveld analysis, and the electric and electrochemical properties were studied by electronic conductivity, ac conductivity and cyclic voltammogram measurements. The structure of the host material, Li4SiS4 is related to the γ-Li3PO4-type structure, and when the Li+ interstitials or Li+ vacancies were created by the partial substitutions of Al3+ or P5+ for Si4+, large increases in conductivity occur. The solid solution member x=0.6 in Li4−xSi1−xPxS4 showed high conductivity of 6.4×10-4 S cm−1 at 27°C with negligible electronic conductivity. The new solid solution, Li4−xSi1−xPxS4, also has high electrochemical stability up to ∼5 V vs Li at room temperature. All-solid-state lithium cells were investigated using the Li3.4Si0.4P0.6S4 electrolyte, LiCoO2 cathode and In anode. 相似文献
57.
Fumoto M Hinou H Ohta T Ito T Yamada K Takimoto A Kondo H Shimizu H Inazu T Nakahara Y Nishimura S 《Journal of the American Chemical Society》2005,127(33):11804-11818
The chemoselective polymer blotting method allows for rapid and efficient synthesis of glycopeptides based on a "catch and release" strategy between solid-phase and water-soluble polymer supports. We have developed a heterobifunctional linker sensitive to glutamic acid specific protease (BLase). The general procedure consists of five steps, namely (i) the solid-phase synthesis of glycopeptide containing BLase sensitive linker, (ii) subsequent deprotections and the release of the glycopeptide from the resin, (iii) chemoselective blotting of the glycopeptide intermediates in the presence of water-soluble polymers with oxylamino functional groups, (iv) sugar elongations using glycosyltransferases, and (v) the release of target glycopeptides from the polymer platform by selective BLase promoted hydrolysis. The combined use of the solid-phase chemical syntheses of peptides and the enzymatic syntheses of carbohydrates on water-soluble polymers would greatly contribute to the production of complicated glycopeptide libraries, thereby enhancing applicative research. We report here a high-throughput synthetic system for the various types of MUC1 glycopeptides exhibiting a variety of sugar moieties. It is our belief that this concept will become part of the entrenched repertoire for the synthesis of biologically important glycopeptides on the basis of glycosyltransferase reactions in automated and combinatorial syntheses. 相似文献
58.
Synthesis and photochemical properties of photoactivated antitumor prodrugs releasing 5-fluorouracil
A new family of antitumor prodrugs (1-3) of 5-fluorouracil (5-FU) possessing photolabile 2-nitrobenzyl chromophores have been designed and synthesized to investigate the efficiency and mechanism of photoactivated 5-FU release upon UV-irradiation at lambda(ex)= 365 nm. The photoactivated prodrug 3 derived from conjugation of 2 with a tumor-homing cyclic peptide Cys-Asn-Gly-Arg-Cys (CNGRC) was so designed as to manifest a tumor-targeting function. 相似文献
59.
Ken-Ichi Ito Masamichi Nishimura Minoru Sashio Masahiro Tsunooka 《Journal of polymer science. Part A, Polymer chemistry》1994,32(11):2177-2185
It was found that amines were formed efficiently by the photolysis of O-acyloximes followed by hydrolysis in polystyrene films and the relationship between structures of O-acyloximes and yields of amines were investigated. O-phenylacetyl acetophenone oxime (PaApO), O-pivaloyl acetophenone oxime (PApO), and O-benzoyl acetophenone oxime (BApO) as monofunctional O-acyloximes and O,O′-succinyl diacetophenone oxime (SDApO) and O,O′-glutaryl diacetophenone oxime (GDApO) as bifunctional O-acyloximes were examined. The yields of amines for PaApO and SDApO under N2 were ca. 70%, which was the highest among O-acyloximes examined in this experiment. On the other hand, the yields for PApO, BApO, and GDApO were less than 15% and it was verified that the hydrogen abstraction by imino radicals via 6-membered cyclic intermediates resulted in the lowering of yields. Although the effect of oxygen under photolysis on the yields of amine for PaApO was negligible under 50% conversion of PaApO, the yield decreased with further increase in the conversion and was 50% at 90% conversion. © 1994 John Wiley & Sons, Inc. 相似文献
60.
Takeo Ito Hideki Shirakawa Sakuji Ikeda 《Journal of polymer science. Part A, Polymer chemistry》1974,12(1):11-20
A direct method of simultaneously polymerizing and forming acetylene monomer to produce uniformly thin films of polyacetylene was investigated in terms of catalyst system, catalyst concentration, and polymerization temperature. The best catalyst was a Ti(OC4H9)4–Al(C2H5)3 system (Al/Ti = 3–4) and the critical concentration was 3 mmole/l. of Ti(OC4H9)4. Below the critical concentration, only a solid or a powder was obtained. The configuration of the polymers obtained depends strongly upon the polymerization temperature. Thus an all-cis polymer was obtained at temperatures lower than ?78°C, whereas an all-trans polymer resulted at temperatures higher than 150°C. Observations either in an electron microscope by direct transmission or in a scanning electron microscope showed that the film is composed of an accumulation of fibrils about 200–300 Å in width and of indefinite length. 相似文献