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101.
S Nakajima I Sakata Y Omote K Yamazaki T Maeda Y Kubo N Samejima T Takemura Y Shindo H Yamauchi 《Journal of photochemistry and photobiology. B, Biology》1991,8(4):409-417
Spectrofluorometry, radioisotope (RI) labelling and high performance liquid chromatography (HPLC) can be used to estimate photosensitizer concentrations. The biodistribution of porphyrins and metalloporphyrins containing the bifunctional chelating agent diethylenetriamine pentaacetic acid (DTPA) was examined in tumour-bearing mice by nitrogen-pulsed laser spectrofluorometry (PLS) and RI labelling. The biodistribution of metalloporphyrin amino acid derivatives containing alkoxyl groups was also examined by PLS and HPLC analysis using an acetone powder extraction method. Spectrofluorometry is useful for estimating the biodistribution of porphyrins in tumour, lung, kidney and serum, but not in liver. However, spectrofluorometry cannot be used to evaluate the concentration of certain metalloporphyrins such as manganese complexes. The concentrations of porphyrins in liver measured by PLS and two other methods showed remarkable differences. RI labelling and HPLC analysis are obviously tedious methods. Therefore it seems practical to screen for a number of compounds using the spectrofluorometric method (PLS). Subsequently, the porphyrins which give good results with PLS should be measured using RI labelling and HPLC. 相似文献
102.
Takehiko Nishio Naoko Nakajima Yoshimori Omote 《Journal of heterocyclic chemistry》1980,17(2):405-406
Irradiation of β-aminovinyl aryl thioketones ( 1a-b ) afforded β-aminovinyl aryl ketones ( 2a-b ). 2H-Thiopyran derivatives ( 4a-b ) were obtained when β-aminovinyl phenyl thioketone ( 1a ) was irradiated with methyl acrylate and acrylonitrile. 4H-Thiopyran derivatives ( 6,8 ) were also obtained thermally in the reaction of β-aminovinyl phenyl thioketone ( 1a ) and methyl propiolate and maleic anhydride. 相似文献
103.
In this work a gyroscope using a ferrofluidic mass as inertial mass is presented. The device consists of a glass plate filled with deionized water with an injected ferrofluidic drop, a electromagnetic driving system to move the ferrofluidic mass back and forward along the actuation axis and a differential inductive readout system to sense the motion of the ferrofluidic sphere. An angular rate imposed to the device produces a deviation of the ferrofluidic mass trajectory which is measured by the differential readout system. Experimental surveys have been performed to characterize both the driving system and the behavior of the device. 相似文献
104.
Photochemical behaviors of the pyrazinone derivatives 5,6,7,8-tetrahydroquinoxalin-2(1H)-ones 1a – c and 1,5,6,7,8,9-hexahydro-2H-cyclohepta[b]pyrazin-2-one 1d were investigated. Dye-sensitized photo-oxygenation of 1a-c gave the 1:1 adducts 5a – c of the corresponding 3,8a-epidioxy-3,5,6,7,8,8a-hexahydroquinoxalin-2(1H)-one 4 and H2O, whereas 1d gave 3,9a-epidioxy-1,3,5,6,7,8,9,9a-octahydro-2H-cyclohepta[b]pyrazin-2-one 4d (Scheme 2). The different kind of products was interpreted as being the result of the ring strain and steric hindrance of endoperoxides produced from 1a – d with singlet oxygen. Irradiation of 1a – b in the presence of alkenes gave tricyclic azetidine derivatives 9 by [2 + 2] cycloaddition of the C?N bond of 1 to the alkene. 相似文献
105.
106.
Generally 3-hetero-substituted 2-alken-1-ones were prepared from 1,3-alkanediones, 3-chloro-2-alken-1-ones, or conjugated ynones. The preparation of 3-hetero-substituted 2-alken-1-ones was subjected to some limitations by these methods. By the reaction of 3-(1-imidazolyl)-2-alken-1-ones (I) and 3-(3-oxo-1-alkenyl)-1-methylimidazolium iodides (II) with nucleophiles, 3-hetero-substituted 2-alken-1-ones could be obtained regioselectively in good yield under mild conditions. These results suggested that compounds I and II were concluded to be useful intermediates for the organic synthesis. 相似文献
107.
The NMR spectra of the benzohexahelicenes have been analyzed. The conformation of the helical structure is not changed to a large extent by the benzo-groups. Some flattening of a part of the helix results in a small downfield shift of the protons on the terminal rings and in a larger upfield shift of proton A in II ascribed to a change in the ring current in the pitch of the helix. A gradual upfield shift is found for protons of the terminal rings by an increase in overcrowding of the benzo-groups. 相似文献
108.
109.
Masaaki Omote 《Tetrahedron》2006,62(8):1886-1894
Axially dissymmetric ligands with perfluoroalkyl groups, (Ra)-2,2′-bis[(R)-1-hydroxy-1H-perfluorooctyl]biphenyl [(Ra)-(R)2-1c] and its enantiomer, have been synthesized successfully by the coupling reaction of the corresponding aryl bromide using Ni(COD)2. These ligands showed much higher asymmetric induction in the reaction of various aldehydes with diethylzinc than the trifluoromethyl (1a) or pentafluoroethyl (1b) analogues. Furthermore, 1c was recovered quantitatively by extraction with a fluorous solvent from the reaction mixture due to its high fluorine content. The recovered ligand 1c was pure enough to be reused without purification. The efficiency of 1c as the chiral ligand was not decreased at all even after seven times recycling. 相似文献
110.
“Truncated” [1.1.1.1] pagodanes like the [1.1.0.0] and [0.0.0.0] homologues3 and 4 (EStr = 146.1 – 171.5 kcal mol?1, MM2) are potential precursors of unusual unsaturated homoconjugated radical cations and σ-bishomoaromatic dications. Attempts are presented toward the synthesis of 3 - starting out from [1.1.1.1] pagodane-4,9-dione 9 and diaza [2.2.1.1] pagodadiene 11 by cycloelimination (unsuccessful) and by Favorskii-type ring contraction methodologies. Control experiments with the model diketone 19 documented the limitations for α,α′-difunctionalization of 9 as the prerequisite for one-pot double Favorskii-type ring contraction. A de novo synthesis for such α,α′-disubstituted derivatives of 9(54) was not sufficiently expeditious to open a practical access to 3. Sequential double bridgehead hydroxylation of 9, successfully practized with model 19, similarly suffered from inherent cage effects and allowed only limited yields of [1.1.1.0] pagodanone 10, the intermediate on the way to 3. 相似文献