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951.
We propose a conclusive difference observed between the excitation conditions required to observe porphyrins and copper-metallothioneins
in cells and/or tissues using an ordinary fluorescence microscope. We have emphasized the importance of examining the spectral
properties of the emissions to avoid any serious mistakes such as confusing porphyrins with copper-metallothioneins in the
liver and kidneys. However, microspectrophotometry is not a conventional method for either histochemical, cytochemical, or
pathological studies because microspectrophotometers are both expensive and difficult to operate. Therefore, we demonstrate
a simple comparative method using ordinary excitation filter arrangements. When using our technique, it becomes possible to
optically discriminate more accurately between the autofluorescence properties arising from porphyrins and those arising from
copper-metallothioneins. We would like to name our simple technique “Triple Observation Method (TOM)”. 相似文献
952.
Prof. Dr. Koji Kano Toshiro Ochi Sayuri Okunaka Yusuke Ota Keiichi Karasugi Takunori Ueda Dr. Hiroaki Kitagishi 《化学:亚洲杂志》2011,6(11):2946-2955
Poly(acrylic acid) (PAA) is modified by 5‐(4‐β‐alanylaminophenyl)‐10,15,20‐tris(4‐sulfonatophenyl) porphinatoiron(III) to yield iron porphyrin‐bearing PAAs (FeP(n)s) through a condensation reaction. FeP(n)s were further functionalized by Py3CD, which is a per‐O‐methylated β‐cyclodextrin (CD) dimer with a pyridine linker and includes the porphyrin pendants to form ferric hemoCD‐P(n)s. Ferrous hemoCD‐P(3), having three porphyrin chromophores in a polymer chain, is shown to bind molecular oxygen (P1/2=7.9±1.4 Torr) in aqueous solution at pH 7.0 and 25 °C, affording oxy‐hemoCD‐P(3). Oxy‐hemoCD‐P(3) is biphasically autoxidized to ferric hemoCD‐P(3), with 27 % of the dioxygen adducts being rapidly oxidized. The rate of autoxidation of oxy‐hemoCD‐P(15), having 15 porphyrin chromophores in a polymer chain, was much faster than that of oxy‐hemoCD‐P(3), thus suggesting self‐catalyzed autoxidation of oxy‐hemoCD‐P(n)s. Oxy‐hemoCD‐P(n)s are markedly stabilized by catalase, thereby indicating that hydrogen peroxide generated from oxy‐hemoCD‐P(n) accelerates the autoxidation. Most of the hemoCD‐P(3) molecules injected into the femoral vein of a rat remained in the body, though about 16 % of the hemoCD‐P(3) molecules were excreted in the urine as a carbon monoxide adduct. 相似文献
953.
Terada M Moriya K Kanomata K Sorimachi K 《Angewandte Chemie (International ed. in English)》2011,50(52):12586-12590
Syn-gled out: The syn diastereo- and enantioselective addition of azlactones to 3-vinylindoles was accomplished by using a chiral, binapthol-derived, Br?nsted acid catalyst (see scheme). This method enables facile access to tryptophan derivatives with adjacent quaternary and tertiary stereogenic centers, which are potentially useful for the synthesis of peptidomimetics. 相似文献
954.
A new arylbenzofuran, 3',5'-dihydroxy-6-methoxy-7-prenyl-2-arylbenzofuran (1), and 25 known compounds, including moracin R (2), moracin C (3), moracin O (4), moracin P (5), artoindonesianin O (6), moracin D (7), alabafuran A (8), mulberrofuran L (9), mulberrofuran Y (10), kuwanon A (11), kuwanon C (12), kuwanon T (13), morusin (14), kuwanon E (15), sanggenon F (16), betulinic acid (17), uvaol (18), ursolic acid (19), β-sitosterol (20), oxyresveratrol 2-O-β-D-glucopyranoside (21), mulberroside A (22), mulberroside B (23), 5,7-dihydroxycoumarin 7-O-β-D-glucopyranoside (24), 5,7-dihydroxycoumarin 7-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranoside (25) and adenosine (26), were isolated from Morus alba var. multicaulis Perro. (Moraceae). Their structures were determined by spectroscopic methods. The prenyl-flavonoids 11-14, 16, triterpenoids 17,18 and 20 showed significant inhibitory activity towards the differentiation of 3T3-L1 adipocytes. The arylbenzofurans 1-10 and prenyl-flavonoids 11-16 also showed significant nitric oxide (NO) production inhibitory effects in RAW264.7 cells. 相似文献
955.
A ruthenium-catalyzed hydrovinylation-type cross-coupling of ynamides and ethylene proceeds via ruthenacyclopentene to give 2-aminobuta-1,3-diene derivatives in a highly regioselective manner. It was also demonstrated that 2-aminobuta-1,3-diene derivatives reacted with various dienophiles or singlet oxygen to give a cyclic enamide derivative. 相似文献
956.
T. Ishikawa M. Hosoda A. Sorimachi S. Tokonami S. Katoh S. Ogashiwa 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(3):709-713
Nowadays, artificial “radon spa sources” for home baths are commercially available. Although these sources could give a potential
radiation exposure to the users, few studies have been reported on their radiological measurements. In the present study,
five types of radon spa sources were collected and their radiological characterization was investigated. The followings were
estimated for these samples: (1) radon emanation coefficients (dry and water-saturated conditions), (2) surface γ-ray dose
rate, (3) surface count rates for α- and β-rays, (4) activity concentrations of 226Ra, 232Th and 40K, and (5) concentrations of radon and thoron generated from the sources located in an air flow system. The activity concentrations
were very high (except for one sample (named “sample B”), although radon emanation coefficient was low compared with soil.
This leads to high concentrations of radon/thoron generated from the sample. The maximum surface γ-ray dose rate was observed
for sample A (2.7 μGy h−1). If people stay very close to the sample for a long time, the exposure might be significant. 相似文献
957.
Kazuhiro WatanabeTadashi Katoh 《Tetrahedron letters》2011,52(41):5395-5397
In this Letter, a selective deprotection of the alcohol protecting 3,4-dimethoxybenzyl (3,4DMB) group is described. The hypervalent iodine(III) reagent phenyliodine bis(trifluoroacetate) (PIFA) is found to be an efficient reagent for the chemoselective deprotection of 3,4DMB ethers in the presence of benzyl, p-methoxybenzyl, methoxymethyl, tert-butyldimethylsilyl, and tert-butyldiphenylsilyl ethers under mild conditions. This is the first example of the selective deprotection of the 3,4DMB group from a hydroxy group with PIFA. 相似文献
958.
Yoshio Nakahara Tsutomu Takeuchi Shoutaro Yokoyama Keiichi Kimura 《Surface and interface analysis : SIA》2011,43(4):809-815
Quantitative analysis of reacted silanol groups in silica nanoparticles modified chemically with monochlorosilanes was performed by 1H NMR after treatment with cesium fluoride. Silica nanoparticles were modified chemically by the reaction between the silanol groups and monochlorosilanes, and the structure of the organic moiety anchored onto the silica surface was confirmed with solid‐state 13C NMR. As monochlorosilanes react with silanol groups at 1:1 ratio unlike di‐ or trichlorosilanes, the number of the silanes introduced into silica nanoparticles equals that of reacted silanol groups. Organically modified silica nanoparticles were dissolved using cesium fluoride, and the amount of the soluble organic compounds originated from the introduced silanes was determined by a 1H NMR internal standard method using pyrene as the reference. Those values determined by 1H NMR were in good agreement with those determined by elemental analysis. Thus, the number of reacted silanol groups per one particle was calculated on the basis of the results obtained by the 1H NMR method, and the values were highly dependent on the steric structure of the introduced silanes. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
959.
We developed a novel hybrid sample injection mode (HSIM) that presents the combination of electrokinetic injection and vacuum injection to enhance detection sensitivity in CZE. Samples were introduced using both vacuum and electrokinetic injections simultaneously, with a water plug injected into the capillary prior to sample introduction (i.e. similarly to field-amplified sample injection, FASI). Using a sample mixture containing an anti-fouling agent applied to ship hulls, pyridine-triphenylborane and its degradation products (diphenylborinic acid, phenylboronic acid, and phenol) dissolved in ACN, the length of water plug, time, and voltage for sample introduction were optimized. The signal intensity (peak height) was found to be up to a 30-fold increased using HSIM by applying 4 kV for 4 s at the inlet end of the capillary as the cathode with supplementary vacuum in comparison with only vacuum injection for 4 s. The LODs (at a S/N of 3) for pyridine-triphenylborane, diphenylborinic acid, phenylboronic acid, and phenol were 0.88, 1.0, 21, and 23 μg/L, respectively. At the level of 0.04 mg/L, the RSDs (n=4, intra-day) for the above analytes were in the ranges of 1.9-11, 4.3-9.2, and 0.34-0.66% for peak area, peak height, and migration time, respectively. The HSIM is a simple and promising procedure useful for enhancing the sensitivity for both low-and high-mobility ions in CZE. 相似文献
960.