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1.
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
2.
A 1:1 inclusion complex (FeIIPImCD) of 5,10,15,20‐tetrakis‐ (4‐sulfonatophenyl)porphinatoiron(II) (FeIIP) and an O‐methylated β‐cyclodextrin dimer with an imidazole linker (ImCD) was found to bind dioxygen in aqueous solution. The half‐saturation pressure of dioxygen (P1/2O2) is 1.7 torr at 25 °C, which is 10 times lower than that for a previous myoglobin functional model (hemoCD) with a pyridine linker. Meanwhile, the half‐life of oxygenated FeIIPImCD is 3 h, which is 10 times shorter than that of oxygenated hemoCD. The covering of the iron(II) center by a microscopic environment is essential for preventing autoxidation of oxygenated ferrous porphyrin, which is promoted by nucleophilic attack of H2O and/or nucleophiles such as inorganic anions. Due to structural requirements, covering of the FeII center of FeIIPImCD is insufficient compared with the case of hemoCD. As a result, water molecules can penetrate more easily the cleft of the O2–FeIIPImCD complex and act as an autoxidation inducer. This structure also causes poorer selectivity against carbon monoxide (M=1040). In contrast, the dioxygen affinity of FeIIPImCD is much higher than that of hemoCD because the imidazole moiety is a stronger electron donor than pyridine. 相似文献
3.
Gold nanoparticles (AuNPs) prepared by citrate reduction of aurochloric acid (HAuCl4) were functionalized by tris(4‐sulfonatophenyl)porphinatoiron(III) (FeIIIP2) and poly(ethylene glycol) with thiolated arms (PEG‐SH). FeIIIP2 on the AuNP surface existed as its μ‐oxo dimer, which was reduced by Na2S2O4 to yield monomeric FeIIP2. FeIIP2‐bearing AuNPs were further functionalized through inclusion of two sulfonatophenyl groups of FeIIP2 by a per‐O‐methylated β‐cyclodextrin dimer with a pyridine linker (Py3CD) to obtain AuNPs capable of carrying diatomic molecules in the body. The resulting AuNPs (hemoCD‐AuNPs) bound O2 as well as CO in an aqueous solution. Although a noncolloidal 1:1 complex of 5,10,15,20‐tetrakis(4‐sulfonatophenyl)porphinatoiron(II) and Py3CD injected into the femoral vein of a rat was rapidly excreted in the urine, no excretion was observed with ferric hemoCD‐AuNPs, which were gradually accumulated in the spleen and liver of a rat. These results suggest that hemoCD‐AuNPs can be used as a carrier of diatomic molecules such as O2 and CO in vivo. 相似文献
4.
Intramolecular Oxidative O‐Demethylation of an Oxoferryl Porphyrin Complexed with a Per‐O‐methylated β‐Cyclodextrin Dimer
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The intramolecular oxidation of ROCH3 to ROCH2OH, where the latter compound spontaneously decomposed to ROH and HCHO, was observed during the reaction of the supramolecular complex (met‐hemoCD3) with cumene hydroperoxide in aqueous solution. Met‐hemoCD3 is composed of meso‐tetrakis(4‐sulfonatophenyl)porphinatoiron(III) (FeIIITPPS) and a per‐O‐methylated β‐cyclodextrin dimer having an ‐OCH2PyCH2O‐ linker (Py=pyridine‐3,5‐diyl). The O=FeIVTPPS complex was formed by the reaction of met‐hemoCD3 with cumene hydroperoxide, and isolated by gel‐filtration chromatography. Although the isolated O=FeIVTPPS complex in the cyclodextrin cage was stable in aqueous solution at 25 °C, it was gradually converted to FeIITPPS (t1/2=7.6 h). This conversion was accompanied by oxidative O‐demethylation of an OCH3 group in the cyclodextrin dimer. The results indicated that hydrogen abstraction by O=FeIVTPPS from ROCH3 yields HO‐FeIIITPPS and ROCH2.. This was followed by radical coupling to afford FeIITPPS and ROCH2OH. The hemiacetal (ROCH2OH) immediately decomposed to ROH and HCHO. This study revealed the ability of oxoferryl porphyrin to induce two‐electron oxidation. 相似文献
5.
The discovery of a novel superoxide dismutase (SOD) mimic which demonstrates SOD activity, chemical stability in H2O2 solution and long half‐life in circulation is reported. The SOD mimic consists of a manganese porphyrin (MnP) with SOD activity and a polymer (poly (styrene‐co‐maleic anhydride); SMA) with biological characteristics. The SOD activity of SMA‐MnP at pH = 8.1 measured using the stopped‐flow kinetic analysis technique to monitor the decay of superoxide directly was 1.1 (± 0.1) × 106 M‐1 sec‐1. It is postulated that the reduction by O2·− of the oxidized SMA‐Mn(III) is slow, while the oxidation of the reduced SMA‐Mn(II) by O2·− is very fast. The retention times of SMA‐MnP in the circulation of rabbits were determined. In vivo, SMA‐MnP that binds to the warfarin site on albumin showed an enhanced half‐life in the circulation. Additionally, in vitro SMA‐MnP indicated an excellent stability to H2O2. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
6.
Development of an Indirect Competitive ELISA Based on Polyclonal Antibody for the Detection of Diethylstilbestrol in Water Samples 总被引:3,自引:0,他引:3
An indirect competitive enzyme-linked immunosorbent assay (icELISA) based on polyclonal antibody for the estrogen diethylstilbestrol (DES) was developed. With this aim, two different haptens mono-O-3-carboxypropyldiethylstilbestrol (DES-CP) and mono-O-carboxymethyldiethylstilbestrol (DES-CM) with carboxylic group that preserve the molecular structure character of diethylstilbestrol were synthesized. The haptens were conjugated with the carder proteins bovine serum albumin (BSA) by mixed-anhydride method for immunogen and conjugated with ovalbumin (OVA) by active ester method for coating antigen. Polyclonal antibodies for diethylstilbestrol were raised by immunizing mice with immune antigen DES-CP-BSA. Under optimized system, the lowest limit of detection (LLD) of diethylstilbestrol was 0.01 ng/mL, and IC50= 1.02 ng/mL. Its analogs were tested and no obvious cross-reactivity was found to anti-diethylstilbestrol antibody. DES-fortified water samples were determined by simple dilution to diminish the matrix effect. The comparison between the amount of DES estimated by ELISA and the amount added indicates good agreement for all water samples tested, with mean recovery values ranging from 86% to 120.2%. 相似文献
7.
Biomineralization of Versatile CuS/Gd2O3 Hybrid Nanoparticles for MR Imaging and Antitumor Photothermal Chemotherapy
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Huai‐Xin Zhao Hong Wang Quan Zou Dr. Shao‐Kai Sun Prof. Chunshui Yu Prof. Xuejun Zhang Dr. Yan‐Yan Fu 《化学:亚洲杂志》2016,11(17):2458-2469
The versatile application of nanoparticles in integrating imaging and therapy has aroused extensive research interest in precision medicine. Of the various nanoparticles that have been studied, CuS has shown great potential in the construction of multifunctional agents, owing to its excellent photothermal heating properties. Herein, we report a facile one‐pot biomineralization approach for the preparation of versatile bovine‐serum‐albumin‐conjugated CuS/Gd2O3 hybrid nanoparticles (BSA?CuS/Gd2O3 HNPs), which simultaneously possessed strong longitudinal relaxivity, an outstanding photothermal effect, high drug‐loading capacity, and pH/temperature‐responsive drug release. The versatile nanoparticles were used for magnetic resonance imaging (MRI) and antitumor photothermal chemotherapy, both in vitro and in vivo. In vivo MRI showed that the BSA?CuS/Gd2O3 HNPs had a long circulation time and effective passive tumor‐uptake ability. More importantly, combined in vitro and in vivo therapy demonstrated that drug‐loaded BSA?CuS/Gd2O3 HNPs offered outstanding synergistic therapeutic efficacy for tumor inhibition. 相似文献
8.
The chemistry of the HC(O)CO radical, produced in the oxidation of glyoxal, has been studied under conditions relevant to the lower atmosphere using an environmental chamber/Fourier Transform infrared spectrometric system. The chemistry of HC(O)CO was studied over the range 224–317 K at 700 Torr total pressure and was found to be governed by competition between unimolecular decomposition [to HCO and CO, reaction (5)] and reaction with O2 [to form HO2 and 2CO, reaction (6a), or HC(O)C(O)O2, reaction (6b)]. The rate coefficient for decomposition relative to that of reaction with O2 increases with increasing temperature. Assuming a value for k6 of 10−11 cm3 molecule−1 s−1, the following expression for the unimolecular decomposition is obtained at 700 Torr, k5 = 1.4+9/−1.1 × 1012 exp(−3160 ± 500/T). The rate coefficients for reactions (6a) and (6b) are about equal, with no strong dependence on temperature. The reaction of HC(O)C(O)O2 with NO2 was also studied. Final product analysis was consistent with the formation of HCO, CO2, and NO3 as the major products in this reaction; no evidence for the PAN‐type species, HC(O)C(O)O2NO2, was found even at the lowest temperature studied (224 K). The UV‐visible absorption spectrum of glyoxal is also reported; results are in substantive agreement with previous studies. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 149–156, 2001 相似文献
9.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(6):742-751
The stoichiometry, X‐ray structures and stability of four pharmaceutical cocrystals previously identified from liquid‐assisted grinding (LAG) of 11‐azaartemisinin (11‐Aza; systematic name: 1,5,9‐trimethyl‐14,15,16‐trioxa‐11‐azatetracyclo[10.3.1.04,13.08,13]hexadecan‐10‐one) with trans‐cinnamic (Cin), maleic (Mal) and fumaric (Fum) acids are herein reported. trans‐Cinnamic acid, a mono acid, forms 1:1 cocrystal 11‐Aza:Cin ( 1 , C15H23NO4·C9H8O2). Maleic acid forms both 1:1 cocrystal 11‐Aza:Mal ( 2 , C15H23NO4·C4H4O4), in which one COOH group is involved in self‐catenation, and 2:1 cocrystal 11‐Aza2:Mal ( 3 , 2C15H23NO4·C4H4O4). Its isomer, fumaric acid, only affords 2:1 cocrystal 11‐Aza2:Fum ( 4 ). All cocrystal formation appears driven by acid–lactam R22(8) heterosynthons with short O—H…O=C hydrogen bonds [O…O = 2.56 (2) Å], augmented by weaker C=O…H—N contacts. Despite a better packing efficiency, cocrystal 3 is metastable with respect to 2 , probably due to a higher conformational energy for the maleic acid molecule in its structure. In each case, the microcrystalline powders from LAG were useful in providing seeding for the single‐crystal growth. 相似文献
10.
《中国化学会会志》2018,65(6):771-779
Inulin hydrolysis was performed by inulinase from Aspergillus niger covalently immobilized on magnetite nanoparticles (Fe3O4) covered with soy protein isolate (Fe3O4/SPI) functionalized by bovine serum albumin (Fe3O4/SPI/BSA) nanoparticles as a new bio‐functional carrier. The specific activity and protein content of the immobilized enzyme were 25.99 U/mg and 3.52 mg/mL, respectively, with 80% enzyme loading. The immobilized inulinase showed maximum activity at 45 °C, which is 5 °C higher than the optimum temperature of the free enzyme. Also, the optimum pH of the immobilized enzyme shifted from 6 to 5.5, which is more acidic compared to that of the free enzyme. The Km value of immobilized inulinase decreased to 2.03 mg/mL. Thermal stability increased considerably at 65 and 75 °C, and a 5.13‐fold rise was detected in the enzyme half‐life at 75 °C after immobilization. Moreover, 80% of initial activity of immobilized inulinase remained after 10 cycles of hydrolysis. 相似文献
11.
(4‐Carboxybutyl)carbamates 5 and 6 , as well as 10 , derived from 10‐O‐deacetylbaccatin III ( 1 ) and paclitaxel ( 2 ), respectively, were synthesized by reaction of unprotected 1 and 2′‐O‐(methoxyacetyl)paclitaxel ( 8 ), respectively, with trimethylsilyl 5‐isocyanatopentanoate in good yields. The carbamoyl‐taxoids were conjugated to bovine‐serum albumin and analyzed by MALDI‐TOF mass spectrometry. 相似文献
12.
A magnetically separable core–shell CoFe2O4@SiO2‐SO3H nanocatalyst has been successfully exploited as a heterogeneous acid catalyst in the synthesis of diversely substituted biologically important spiro fused pyrrolo/indolo[1,2‐a]quinoxaline derivatives through the condensation of N‐(2‐aminophenyl)pyrroles/indoles and various cyclic conjugated 1,2‐diones in ethanol under ultrasonic irradiation. Room temperature synthesis, short reaction time, wide substrate scope, good to excellent yield of products and use of a magnetically separable and recyclable nanocatalyst make this method attractive and practicable. 相似文献
13.
Haixia Zhong Khoa Hoang Ly Mingchao Wang Yulia Krupskaya Xiaocang Han Jichao Zhang Jian Zhang Vladislav Kataev Bernd Büchner Inez M. Weidinger Stefan Kaskel Pan Liu Mingwei Chen Renhao Dong Xinliang Feng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(31):10787-10792
Layered two‐dimensional (2D) conjugated metal–organic frameworks (MOFs) represent a family of rising electrocatalysts for the oxygen reduction reaction (ORR), due to the controllable architectures, excellent electrical conductivity, and highly exposed well‐defined molecular active sites. Herein, we report a copper phthalocyanine based 2D conjugated MOF with square‐planar cobalt bis(dihydroxy) complexes (Co‐O4) as linkages (PcCu‐O8‐Co) and layer‐stacked structures prepared via solvothermal synthesis. PcCu‐O8‐Co 2D MOF mixed with carbon nanotubes exhibits excellent electrocatalytic ORR activity (E1/2=0.83 V vs. RHE, n=3.93, and jL=5.3 mA cm?2) in alkaline media, which is the record value among the reported intrinsic MOF electrocatalysts. Supported by in situ Raman spectro‐electrochemistry and theoretical modeling as well as contrast catalytic tests, we identified the cobalt nodes as ORR active sites. Furthermore, when employed as a cathode electrocatalyst for zinc–air batteries, PcCu‐O8‐Co delivers a maximum power density of 94 mW cm?2, outperforming the state‐of‐the‐art Pt/C electrocatalysts (78.3 mW cm?2). 相似文献
14.
Photocatalytic Hydrogen Production Coupled with Selective Benzylamine Oxidation over MOF Composites
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Hang Liu Caiyun Xu Dr. Dandan Li Prof. Dr. Hai‐Long Jiang 《Angewandte Chemie (International ed. in English)》2018,57(19):5379-5383
Photocatalytic water splitting requires separation of the mixed H2 and O2 products and is often hampered by the sluggish O2‐producing half reaction. An approach is now reported to address these issues by coupling the H2‐producing half reaction with value‐added benzylamine oxidation reaction using metal–organic framework (MOF) composites. Upon MOF photoexcitation, the electrons rapidly reduce the protons to generate H2 and the holes promote considerable benzylamine oxidation to N‐benzylbenzaldimine with high selectivity. Further experimental characterizations and theoretical calculation reveal that the highly conjugated s‐triazine strut in the MOF structure is crucial to the efficient charge separation and excellent photocatalytic activity. 相似文献
15.
Jana Sopkov‐de Oliveira Santos Marc‐Antoine Bazin Jean‐Franois Lohier La?la El Kihel Sylvain Rault 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(7):o311-o313
The stilbene derivative 1,2,3‐trimethoxy‐4‐[(E)‐2‐phenylvinyl]benzene, C17H18O3, (I), and its homocoupling co‐product (E,E)‐1,4‐bis(2,3,4‐trimethoxyphenyl)buta‐1,3‐diene, C22H26O6, (II), both have double bonds in trans conformations in their conjugated linkages. In the structure of stilbene (I), the aromatic rings deviate significantly from coplanarity, in contrast with coproduct (II), the core of which is rigorously planar. The deviation in stilbene (I) seems to be driven by intermolecular electrostatic interactions. Diene (II) sits on a crystallographic inversion centre, which bisects the conjugated linkage. 相似文献
16.
Dr. Weiqi Wang Dr. Lei Wang Prof. Yubin Huang Prof. Zhigang Xie Prof. Xiabin Jing 《化学:亚洲杂志》2016,11(5):750-756
A metal–organic framework (MOF)–protein conjugate, NH2‐MIL‐125(Ti)‐hemoglobin [MIL‐125(Ti)‐Hb], was synthesized by a covalent postmodification strategy. The crystalline structure was maintained after chemical and protein modification. The content of grafted Hb was tuned by the stoichiometric ratio and reached 50 wt % if the mass ratio of MIL‐125(Ti)/Hb was 1:1.25 in the feed. The oxygen‐transporting capacity of grafted Hb was kept, and the P50 (the half O2 pressure saturated with O2) and Hill coefficients of the MIL‐125(Ti)‐Hb conjugate were found to be 22.9 mm Hg and 2.35, respectively, which are close to the respective values of free Hb. All the results indicate that the MIL‐125(Ti)‐Hb conjugate could be potentially used as an oxygen carrier. 相似文献
17.
Aihui Liang Yafei Wang Yu Liu Hua Tan Yunbo Cao Liang Li Xiaoshuang Li Wenjie Ma Meixiang Zhu Prof. Dr. Weiguo Zhu 《中国化学》2010,28(12):2455-2462
Two heteroleptic iridium complexes with a general formulation of (piq)2Ir(G‐pic) were synthesized and characterized by 1H NMR, 13C NMR and element analysis, in which piq is 1‐phenylisoquinoline, G‐pic is picolinic acid derivative containing carrier‐transporting group by a non‐conjugated connection of 1,6‐dioxyhexane. Both (piq)2Ir(G‐pic) complexes exhibited an enhanced UV absorption band at 310–400 nm, an increased HOMO energy level and an identical red emission peaked at 612 nm with higher fluorescence quantum efficiency (øf), compared to (piq)2Ir(pic) in dichloromethane solution. Interestingly, this iridium complex containing both hole‐transporting triphenylamine and electron‐transporting oxadiazole moieties exhibited the best Фf of 0.58 using Ru(bpy)3(PF6)2 as the reference (øf=0.062 in acetonitrile). This work indicates that incorporating carrier‐transporting groups into ancillary ligand by a non‐conjugated connection is available for improving the optophysical properties of their iridium complexes. 相似文献
18.
The Synthesis,Spectral, and Electrochemical Characterization of Novel Alkoxybenzoquinone Derivatives
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The novel monosubstituted benzoquinone compounds 3e , 3g , 3h ; 2,5‐O‐ substituted benzoquinone compounds 4a , 4b , 4c , 4d , 4e 4g and known compound 4h and 2,6‐O‐ substituted benzoquinone compounds 5e , 5f , 5g , 5h were obtained by the reaction of p‐chloranil ( 1 ) and related alcohol compounds in potassium carbonate (K2CO3) solution of acetonitrile or chloroform with Et3N. The novel cyclic compounds 7 , 8 and 10 , 11 were obtained from the reaction of p‐chloranil ( 1 ) and diols in potassium carbonate (K2CO3) solution of acetonitrile at room temperature. The structures of novel compounds were characterized by using micro analysis, FT‐IR, 1H‐NMR, 13C‐NMR, MS and cyclic voltammetry. 相似文献
19.
Nanomagnetic bisethylferrocene‐containing ionic liquid supported on silica‐coated iron oxide (Fe3O4@SiO2@Im‐bisethylFc [HC2O4]) as a novel catalyst was designed and synthesized. The described catalyst was recycled and used without change in the time and efficiency of the condensation reaction. The Fourier transform‐infrared spectroscopy (FT‐IR), scanning electron microscopy images, X‐ray diffraction patterns, energy‐dispersive X‐ray spectroscopy, transmission electron microscope and vibrating‐sample magnetometer results confirmed the formation of Fe3O4@SiO2@Im‐bisethylFc [HC2O4] magnetic nanoparticle. The novel bis‐coumarin derivatives were identified by 1H‐NMR, 13C‐NMR, FT‐IR and CHNS analysis. 相似文献
20.
Relative rate techniques were used to study the kinetics of the reaction of OH radicals with acetylene at 296 K in 25–8000 Torr of air, N2/O2, or O2 diluent. Results obtained at total pressures of 25–750 Torr were in good agreement with the literature data. At pressures >3000 Torr, our results were substantially (~35%) lower than that reported previously. The kinetic data obtained over the pressure range 25–8000 Torr are well described (within 15%) by the Troe expression using ko = (2.92 ± 0.55) × 10?30 cm6 molecule?2 s?1, k∞ = (9.69 ± 0.30) × 10?13 cm3 molecule?1 s?1, and Fc = 0.60. At 760 Torr total pressure, this expression gives k = 8.49 × 10?13 cm molecule?1 s?1. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 191–197, 2003 相似文献