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21.
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
22.
Takehiko Yamato Masashi Yasumatsu Yoshiyuki Saruwatari Louis Korbla Doamekpor 《Journal of inclusion phenomena and macrocyclic chemistry》1994,19(1-4):315-331
Novel macrocyclic compounds, hexahydroxy[1.0.1.0.1.0]- (2b) and octahydroxy[1.0.1.0.1.0.1.0]metacyclophane (2c) have been prepared in 50–70% yield by base-catalyzed condensation of 5,5-di-tert-butyl-2,2-dihydroxybiphenyl (1) with formaldehyde in refluxing xylene. An attempted alkylation of the flexible macrocycles2b and2c with ethyl bromoacetate in the presence of Cs2CO3 under acetonitrile reflux gave only one pure stereoisomer3 and4, respectively, while other possible isomers were not observed. The structural characterization of these products is also discussed. The two-phase solvent extraction data indicated that hexaethyl ester3 and octaethyl ester4 show strong metal affinity, comparable with that of the corresponding calix[n]arenes, and a high K+ selectivity was observed for octaethyl ester4.1H-NMR titration of hexaethyl ester3 and octaethyl ester4 with KSCN clearly demonstrate that a 11 complex is formed which is stable on the NMR time scale.This paper is dedicated to the commemorative issue on the 50th anniversary of calixarenes. 相似文献
23.
The structure and stereochemistry of scopadulin, a novel aphidicolane-type diterpene isolated from Scoparia dulcis L. have been established from spectral data and single-crystal X-ray analysis of its acetone solvate. 相似文献
24.
T Morita F Mikami A Kanagawa M Sera H Ueki 《Chemical & pharmaceutical bulletin》1991,39(12):3287-3289
Vanadate stimulated the release of rat hepatic lipase activity from liver slices into an incubation medium in a time- and dose-dependent manner. Insulin, however, failed to have this stimulatory action, and the release by heparin was recognized, but was not additive to that by vanadate. Amiloride, an inhibitor of tyrosine kinase in some receptors and of the Na+/H+ exchange system suppressed the vanadate-stimulated release. Biochanin A, a different type of tyrosine kinase inhibitor than amiloride, also suppressed the effect of vanadate. The stimulation by vanadate was clearly preserved in Na(+)-, K(+)-, or Ca(2+)-free medium, suggesting that neither the Na+/H+ exchange system, Na+, K(+)-adenosine triphosphatase, nor Ca(2+)-influx into cells is involved in the action of this substance. These results suggest that vanadate-stimulated release of the enzyme activity is associated with the activation of the tyrosine kinase activity. 相似文献
25.
Evaluation of the disintegration time of rapidly disintegrating tablets via a novel method utilizing a CCD camera 总被引:6,自引:0,他引:6
Morita Y Tsushima Y Yasui M Termoz R Ajioka J Takayama K 《Chemical & pharmaceutical bulletin》2002,50(9):1181-1186
Many kinds of rapidly disintegrating or oral disintegrating tablets (RDT) have been developed to improve the ease of tablet administration, especially for elderly and pediatric patients. In these cases, knowledge regarding disintegration behavior appears important with respect to the development of such a novel tablet. Ordinary disintegration testing, such as the Japanese Pharmacopoeia (JP) method, faces limitations with respect to the evaluation of rapid disintegration due to strong agitation. Therefore, we have developed a novel apparatus and method to determine the dissolution of the RDT. The novel device consists of a disintegrating bath and CCD camera interfaced with a personal computer equipped with motion capture and image analysis software. A newly developed RDT containing various types of binder was evaluated with this protocol. In this method, disintegration occurs in a mildly agitated medium, which allows differentiation of minor distinctions among RDTs of different formulations. Simultaneously, we were also able to detect qualitative information, i.e., morphological changes in the tablet during disintegration. This method is useful for the evaluation of the disintegration of RDT during pharmaceutical development, and also for quality control during production. 相似文献
26.
Yu Liu Bin Li Takehiko Wada Yoshihisa Inoue 《Journal of inclusion phenomena and macrocyclic chemistry》2000,36(3):311-325
The spectrophotometric titrations have beenperformed at 25–40 °C in aqueous solution to give the complexstability constants and the thermodynamic parametersfor the stoichiometric 1 : 1 inclusion complexation ofvarious aliphatic alcohols withmono[6-(phenylseleno)-6-deoxy]--cyclodextrin (2),mono[6-(o-, m-,p-tolylseleno)-6-deoxy]--cyclodextrin (3–5),mono[6-(p-chloro-phenyl-seleno)-6-deoxy]--cyclodextrin(6), mono[6-(benzylseleno)-6-deoxy]--cyclodextrin (7) and mono[6-(naphthaleneseleno)-6-deoxy]--cyclodextrin(8). On thebasis of the present and previous results, themolecular binding abilities and selectivities forguest aliphatic alcohols of the host -cyclodextrinderivatives (2–8) are discussed comparatively and globallyfrom the thermodynamic point of view. Thethermodynamic parameters obtained are criticalfunctions of the size/shape of aliphatic alcohols, andthe position and type of the substituent introduced tothe aromatic ring of -cyclodextrin's sidearm,which are elucidatedin terms of the conformational, electrostatic,hydrogen-bonding, and hydrophobic effects. 相似文献
27.
The bound site of Mo atoms and its local structure in a Mo/HY catalyst have been determined by detailed analysis of extended X-ray absorption fine structure (EXAFS). Molybdenum was introduced in the supercage of HY zeolite by cycles of saturated adsorption of Mo(CO)6 at room temperature and subsequent thermal decomposition at 573 K. Two Mo atoms per supercage were immobilized in each CVD-thermal treatment cycle. The Mo loading increased linearly with the cycles up to three cycles at saturation, where six Mo atoms were supported. Temperature-programmed decomposition of the adsorbed Mo(CO)6 was also characterized by GC, QMS, and FT-IR, respectively. The EXAFS analysis including multiple scattering based on theoretical calculations revealed that Mo bound with two oxygen atoms connects to Al, where one of the two oxygen atoms had been associated with a proton. The bound site is called the S(III)' site. The zeolite framework was significantly distorted by the introduction of low-valent Mo, resulting in isolation of the [MoO2Al] unit from the surrounding zeolite framework due to a quasi-disruption of Si-O bonds adjacent to the unit. In the mild oxidation of the low-valent Mo/HY sample two Mo=O bonds were newly formed and the position of Mo was displaced by 0.06 nm so that the distortion of zeolite framework around the Al atom was relieved. The structures were also supported by DFT calculations. This study is the first example that the position of metal cation in zeolite was determined unambiguously by the EXAFS analysis. 相似文献
28.
T. Takahagi I. Shimada M. Fukuhara K. Morita A. Ishitani 《Journal of polymer science. Part A, Polymer chemistry》1986,24(11):3101-3107
In the carbon fiber production process from polyacrylonitrile (PAN), PAN precursor is heated first in air to secure stabilization in the succeeding carbonization process at higher temperature. The mechanism of the stabilization reaction and chemical structure of the stabilized PAN have been examined by x-ray photoelectron spectroscopy and elemental analysis. The stabilized PAN was determined to have a ladderlike structure consisting of 40% acridone ring, 30% naphtyridine ring, 20% hydronaphtyridine ring, and others. This structure well explains the stability of the polymer in the succeeding carbonization process on carbon fiber production with conjugated π-electron systems over the whole polymer chain and intermolecular hydrogen bonds. A comonomer addition to the precursor was found to accelerate the dehydrogenation reaction in the stabilization process. 相似文献
29.
I. Shimada T. Takahagi M. Fukuhara K. Morita A. Ishitani 《Journal of polymer science. Part A, Polymer chemistry》1986,24(8):1989-1995
The stabilized fibers prepared by heating PAN and a PAN copolymer in air and under reduced pressure have been examined by FT-IR spectroscopy in order to determine their chemical structures. Three kinds of reactions, cyclization, dehydrogenation, and oxygen uptake are found to occur almost simultaneously in the stabilization process in air by digital difference spectrum method. The effect of the comonomer is confirmed to accelate the dehydrogenation reaction and also the formation of acridone ring in the thermal stabilization in air by kinetic study. 相似文献
30.
H Itokawa K Saitou H Morita K Takeya K Yamada 《Chemical & pharmaceutical bulletin》1992,40(11):2984-2989
Metabolites of antitumor cyclic hexapeptides, RA-VII and -X which were isolated from Rubia cordifolia were studied by hepatic microsomal biotransformation in rats and in bile juice of rabbits to which these drugs were administered intravascularly. Their structures and conformations were elucidated by two-dimensional nuclear magnetic resonance techniques, temperature effect on NH protons and nuclear Overhauser effect experiments. Specific N-demethylation of Tyr-3, O-demethylation and hydroxylation at aromatic rings of Tyr-3 and -5 were observed. Compared with metabolites of RA-VII, most of RA-X was excreted unchanged in the bile juice. Relationship among their structures, conformations and antitumor activities is also discussed. 相似文献