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991.
Both the enantiomers of sclerosporin and sclerosporal were synthesized from (-)-carvone. (4R,9R,10S)-(+)-Sclerosporin and (4R,9R,10S)-(-)-sclerosporal were identified as the natural enantiomers by a comparison of their CD-spectra. An intramolecular Diels-Alder route was proved to be an efficient method of preparing sufficient amounts of (+)- for the biological study. 相似文献
992.
Yoshikata Koga 《Journal of Thermal Analysis and Calorimetry》1979,17(1):87-92
Some evidence is given for the presence of a solid phase just below the melting point of stearic acid. It is not certain whether the existence of this new phase is due to impurities or not.
I wish to express my sincere thanks to the following people: Dr. J. A. Morrison for kindly sending the sample and helpful discussion, Dr. D. Dolphin for making the LKB 8700 calorimeter available to me, Dr. L. G. Harrison for allowing the use of his facilities, and Mr. B. Greene, Mr. J. Edwards and Mr. B. Powell for their excellent technical assistances in modifying the apparatus. The financial support from the University of British Columbia is also acknowledged. 相似文献
Zusammenfassung Einige Beweise zur Gegenwart einer Festphase knapp unterhalb des Schmelzpunktes der StearinsÄure werden gegeben. Es ist nicht geklÄrt ob das Vorhandensein dieser neuen Phase auf Verunreinigungen zurückzuführen ist oder nicht.
Résumé On donne plusieurs preuves de la présence d'une phase solide juste au-dessous du point de fusion de l'acide stéarique. Il n'est pas certain que l'existence de cette phase nouvelle soit due à des impuretés ou non.
. , .
I wish to express my sincere thanks to the following people: Dr. J. A. Morrison for kindly sending the sample and helpful discussion, Dr. D. Dolphin for making the LKB 8700 calorimeter available to me, Dr. L. G. Harrison for allowing the use of his facilities, and Mr. B. Greene, Mr. J. Edwards and Mr. B. Powell for their excellent technical assistances in modifying the apparatus. The financial support from the University of British Columbia is also acknowledged. 相似文献
993.
Hasegawa T Haraguchi S Numata M Li C Bae AH Fujisawa T Kaneko K Sakurai K Shinkai S 《Organic & biomolecular chemistry》2005,3(24):4321-4328
Schizophyllan interacts with various 1,4-diphenylbutadiyne derivatives to induce their chirally-twisted packing. A series of referential experiments using other polysaccharides (amylose, pullulan, dextran, etc.) and a carbohydrate-appended detergent (dodecyl-beta-d-glucopyranoside) indicates that these 1,4-diphenylbutadiyne derivatives are accommodated within a tubular cavity constructed by a helical superstructure of schizophyllan. In these 1,4-diphenylbutadiyne derivatives, 1,4-bis(p-propionamidophenyl)butadiyne can be easily polymerized through UV-irradiation, in which schizophyllan acts as a one-dimensional mold to produce the corresponding poly(diacetylene)s with fibrous morphologies. Detailed investigations on this unique approach to prepare the nanofibers revealed that it includes two individual processes, that is, 1) UV-mediated polymerization of encapsulated 1,4-bis(p-propionamidophenyl)butadiyne to produce immature nanofibers and 2) their reorganization through hydrophobic interfiber interactions into ordered nanofibers. The other 1,4-diphenylbutadiyne derivatives could not be polymerized through UV-irradiation, indicating that the p-propionamido-functionalities play substantial roles for a suitable packing of the monomer for the polymerization. The other 1,4-diphenylbutadiyne derivatives, however, can be also polymerized through gamma-ray irradiation in the presence of schizophyllan to give the corresponding poly(diacetylene)-nanofibers, emphasizing the wide applicability of the schizophyllan-based strategy for polymerization of various 1,4-diphenylbutadiyne derivatives. 相似文献
994.
Fujiwara H Wada K Hiraoka T Hayashi T Sugimoto T Nakazumi H Yokogawa K Teramura M Yasuzuka S Murata K Mori T 《Journal of the American Chemical Society》2005,127(41):14166-14167
We report the crystal structure and physical properties of the 2:1 FeCl4- salt of a new donor molecule, EDO-TTFVO. Crystal structure analysis of this salt revealed that the donor molecules formed a beta' '-type two-dimensional conducting layer, and there is a short S...Cl contact between the donor molecules and the FeCl4- ions, which is expected to mediate a strong pi-d interaction. This salt showed a stable metallic conducting behavior down to 0.3 K and an antiferromagnetic ordering at TN approximately 3.0 K, indicating that this salt becomes a new antiferromagnetic molecular metal at ambient pressure. The appearance of the magnetic ordering is considered to originate from the strong pi-d interactions between the donor molecules and the FeCl4- ions because the field dependence of magnetoresistances was remarkably affected below the antiferromagnetic transition temperature. 相似文献
995.
The determination of acetaldehyde was achieved by monitoring the chemiluminescence emission from the luminol-potassium hexacyanoferrate (III) reaction in the presence of xanthine oxidase. The linear range was three orders of magnitude, the detection limit (2σ) was 4 × 10?7 M and the relative standard deviation (n = 5) was 10.6% for 4.3 × 10?7 M. No interference was observed from seven organic and inorganic species at a 1000-fold excess relative to a concentration of 1 × 10?5 M acetaldehyde. 相似文献
996.
Urinary metabolites 5-methyl-5-[2-(2,6,6-trimethyl -3-oxo-1-cyclohexen-1-yl)-vinyl]-2-tetrahydrofuranone (1) and 5-[2-(6-hydroxymethyl-2, 6-dimethyl-3-oxo-1- cyclohexen-1-yl)vinyl]-5-methyl-2-tetrahydrofuranone (2) of retinoic acid have been synthesized from 4-[2,2,6-trimethyl-3-(tetrahydro-2 H -pyran-2-yl)oxy-1-cyclohexen-1-yl]-3-buten-2-one (4) and methyl 2-(3,3-ethylenedioxy-1-butenyl)-1, 3-dimethyl-4-oxo-2-cyclohexene-1-carboxylate (5) . 相似文献
997.
Natural (?)-botryodiplodin() has been synthesized from an antibiotic methylenomycin A (). The absolute configurations of (?)-botryodiplodin( and methylenomycin A () have also been established as shown in and respectively. 相似文献
998.
Feng F Okuyama K Niikura K Ohta T Sadamoto R Monde K Noguchi T Nishimura S 《Organic & biomolecular chemistry》2004,2(11):1617-1623
Two non-natural fluorinated 2-N-acetamidosugar nucleotides, uridine 5'-diphosphate (UDP) 2-acetamido-2,4-dideoxy-4-fluoro-alpha-D-glucopyranose (UDP-4-FGlcNAc) 1 and its galacto isomer (UDP-4-FGalNAc) 2, were enzymatically constructed by treating chemically synthesized fluorinated 2-N-acetamidosugar 1-phosphates as the donor with UDP 2-acetamido-2-deoxy-alpha-D-glucopyranose pyrophosphorylase in the presence of uridine 5'-triphosphate (UTP). 相似文献
999.
Kakinoki K Yamane K Igarashi M Yamamoto M Teraoka R Matsuda Y 《Chemical & pharmaceutical bulletin》2005,53(7):811-815
To characterize the photocatalytic activity of TiO2 via solid-state reaction, the relationship between the physicochemical properties and photocatalytic activity of TiO2 was investigated and estimated from the results of photodegradation of nisoldipine. The photodegradation of nisoldipine was significantly enhanced by addition of TiO2. Two degradation products, nitroso-phenylpyridine derivative and nitro-phenylpyridine derivative, were formed. The degree of photocatalytic activity of TiO2 was quite different between the various types of TiO2 investigated, even when the crystalline phase was the same. As a result of the investigations into the relationship between the photocatalytic activity and physicochemical properties of TiO2, it was found that for the rutile form the photocatalytic activity has good correlation with specific surface area of TiO2, but poor correlation with water loss on drying of TiO2. However, for the anatase form, the photocatalytic activity has good correlation with water loss on drying of TiO2, but poor correlation with specific surface area. Moreover, it was found that the crystallinity of TiO2 has a moderate correlation with the photocatalytic activity of both crystal forms of TiO2. These results suggest that a degree of photocatalytic activity of TiO2 depends on the various physicochemical properties of each type of TiO2 investigated. 相似文献
1000.
Kenji Uchimura Megumi Morimoto-Tomita Annette Bistrup Jessica Li Malcolm Lyon John Gallagher Zena Werb Steven D Rosen 《BMC biochemistry》2006,7(1):2-13