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1.
Dalton Trans ; 53(10): 4492-4500, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38348738

ABSTRACT

As important building blocks in natural products and organic synthesis, thioethers have a wide range of potential applications. Herein, polyoxometalate-based ionic liquids (POM-ILs-SO3H) derived from N-alkyl imidazole were synthesized and used for the first time for the thiolation of alcohols to construct C-S bonds in a series of benzyl thioethers. This type of POM-ILs-SO3H catalyst exhibited high catalytic activity, providing up to 98% yield of thioether within 1 h at 70 °C. The alkyl chain length of the imidazole had a certain effect on the solubility of the POM-ILs-SO3H catalysts in the reaction solvent, and then affected their catalytic activity. The catalytic system had a wide substrate scope and was suitable for the reaction of tertiary and secondary benzyl alcohols with thiophenols or cycloalkyl thiols. In particular, [PIMPS]3PW12O40 (PIM = 1-propylimidazole, PS = propane sulfonate) as a reversible phase transformation-type catalyst, combining the advantages of homogeneous and heterogeneous catalysts, exhibited high activity and good recyclability with only a slight decrease in the yield after five runs. Additionally, a carbocation mechanism was proposed for the thiolation reaction of alcohols.

4.
Med Sci Monit ; 27: e935766, 2021 Dec 14.
Article in English | MEDLINE | ID: mdl-34903709

ABSTRACT

This publication has been retracted by the Editor due to the identification of non-original figure images and manuscript content that raise concerns regarding the credibility and originality of the study and the manuscript. Reference: Bing Zhao, Zebao Zheng. Insulin Growth Factor 1 Protects Neural Stem Cells Against Apoptosis Induced by Hypoxia Through Akt/Mitogen-Activated Protein Kinase/Extracellular Signal-Regulated Kinase (Akt/MAPK/ERK) Pathway in Hypoxia-Ishchemic Encephalopathy. Med Sci Monit, 2017; 23: 1872-1879. DOI: 10.12659/MSM.901055.

5.
Spectrochim Acta A Mol Biomol Spectrosc ; 216: 328-334, 2019 Jun 05.
Article in English | MEDLINE | ID: mdl-30909089

ABSTRACT

Considering the excellent photochemical properties of ruthenium(II) complexes, two new ruthenium(II) complexes, RuL1-DNBS and RuL2-DNBS, have been developed as phosphorescence probes for detection of biothiols in 100:1 (v/v) Hepes buffer (20 mM, pH = 7.2)/CH3CN solution. The response rate was highly improved of these two probes toward biothiols because the steric interactions between 1H-imidazo [4, 5-f] [1,10] phenanthroline group and ortho-2, 4-dinitrobenzensulfonate resulted in a relatively rapid thiol-induced SNAr substitution reaction. RuL1-DNBS and RuL2-DNBS were weakly phosphorescent owing to the effectual photoinduced electron transfer from ruthenium(II) luminophore to the sensing group, 2,4-dinitrobenzenesulfonyl. After reacting with biothiols, the 2,4-dinitrobenzenesulfonyl group of RuL1-DNBS and RuL2-DNBS were cleavaged and the RuL1 and RuL2 were obtained. Meanwhile, the phosphorescence were "turn-on". Both of these two probes can detect biothiols sensitively and selectively under physiological conditions with submicromolar detection limits. Furthermore, application of RuL2-DNBS for detecting of intracellular biothiols has been successfully performed in living Glioma cells.


Subject(s)
Coordination Complexes/chemistry , Dinitrobenzenes/chemistry , Luminescent Agents/chemistry , Ruthenium/chemistry , Sulfhydryl Compounds/analysis , Cell Line, Tumor , Glioma/chemistry , Glioma/pathology , Humans , Luminescent Measurements/methods , Optical Imaging/methods , Phenanthrolines/chemistry
6.
Life Sci ; 216: 176-182, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30472296

ABSTRACT

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article "… the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated", the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.


Subject(s)
Apoptosis/drug effects , Cell Survival/drug effects , Hypoxia-Ischemia, Brain/prevention & control , Iridoids/pharmacology , RNA, Long Noncoding/genetics , Animals , Blotting, Western , Cell Proliferation/drug effects , Gene Knockdown Techniques , Glucose/metabolism , Hypoxia-Ischemia, Brain/genetics , Hypoxia-Ischemia, Brain/physiopathology , Oxygen/metabolism , PC12 Cells , Phosphatidylinositol 3-Kinase/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Rats , Signal Transduction/drug effects , Up-Regulation/drug effects , Wnt Signaling Pathway/drug effects
7.
Biomed Pharmacother ; 102: 295-301, 2018 06.
Article in English | MEDLINE | ID: mdl-29567543

ABSTRACT

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief. Given the comments of Dr Elisabeth Bik regarding this article "… the Western blot bands in all 400+ papers are all very regularly spaced and have a smooth appearance in the shape of a dumbbell or tadpole, without any of the usual smudges or stains. All bands are placed on similar looking backgrounds, suggesting they were copy/pasted from other sources, or computer generated", the journal requested the authors to provide the raw data. However, the authors were not able to fulfil this request and therefore the Editor-in-Chief decided to retract the article.


Subject(s)
Astragalus Plant/chemistry , MicroRNAs/genetics , Neural Stem Cells/drug effects , Neuroprotective Agents/pharmacology , Polysaccharides/pharmacology , Animals , Apoptosis/drug effects , Cell Hypoxia/drug effects , Cell Survival/drug effects , Cells, Cultured , Hippocampus/cytology , Hippocampus/embryology , Neural Stem Cells/metabolism , Neural Stem Cells/pathology , Neuroprotective Agents/isolation & purification , Polysaccharides/isolation & purification , Primary Cell Culture , Rats, Sprague-Dawley , Up-Regulation
8.
Inorg Chem ; 56(9): 4775-4779, 2017 May 01.
Article in English | MEDLINE | ID: mdl-28387505

ABSTRACT

The pH-switchable room-temperature near-infrared (NIR) phosphorescence emission based on ruthenium(II) polypyridyl complexes has been very rarely reported, even though it is very desirable for applications in sensing, switching, and logic molecular devices and bioimaging. Here we report a novel dinuclear ruthenium(II) complex in an aerated acetonitrile solution featuring a bright NIR emission centered at 760 nm with an absolute quantum yield of 1.03%, a large Stokes shift of 254 nm, and a long emission lifetime of 108.3 ± 0.4 ns. The complex in a Britton-Roberson buffer also exhibited pH-induced "off-on-off" NIR luminescent switches with a maximum intensity enhancement factor of 41 and one of the switching events occurring near the physiological pH range.

9.
Med Sci Monit ; 23: 1872-1879, 2017 04 19.
Article in English | MEDLINE | ID: mdl-28420864

ABSTRACT

BACKGROUND Insulin growth factor 1 (IGF-1) is reported to modulate cell growth and acts as potential therapy for traumatic brain injury. This study was designed to investigate the effect of IGF-1 on hypoxia-induced apoptosis in neural stem cells (NSCs). MATERIAL AND METHODS A hypoxia model was constructed using NSCs separated from the hippocampus of rat. NSCs were divided into four groups: cells under normoxic conditions that acted as controls (C group), cells under hypoxia (H group), cells under hypoxia with IGF-1 (HI group), and cells under hypoxia with IGF-1 as well as picropodophyllin (PPP), which acts as an inhibitor of the IGF-1 receptor (HIP group). The cell viability and apoptosis were respectively measured by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Finally, the phosphorylation levels of apoptosis-associated proteins and key kinases in the phosphatidylinositol-3-kinase (PI3K)/AKT and the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathways were detected by Western blot analysis. RESULTS In comparison with the H group, the cell viability was increased while the cell apoptosis was reduced by IGF-1 in the HI group. Besides, the expression levels of Bax, cytochrome c, and activated caspase-3 were all improved in the H group, and the remarkable differences were eliminated in the HI group compared with the C group. The expression level of Bcl-2 was the opposite. Additionally, down-regulations of phosphorylated AKT, MAPK, and ERK induced by hypoxia were all improved by IGF-1. All the influences of IGF-1 were weakened by addition of PPP. CONCLUSIONS IGF-1 increased cell viability while decreasing apoptosis in hypoxic NSCs through the PI3K/AKT and MAPK/ERK pathways.


Subject(s)
Hypoxia-Ischemia, Brain/metabolism , Insulin-Like Growth Factor I/metabolism , Neural Stem Cells/metabolism , Animals , Apoptosis/physiology , Cell Cycle/drug effects , Cell Hypoxia/drug effects , Cell Hypoxia/physiology , Cell Proliferation/drug effects , Cell Survival/drug effects , Disease Models, Animal , Extracellular Signal-Regulated MAP Kinases/metabolism , Hippocampus/metabolism , Hypoxia-Ischemia, Brain/prevention & control , MAP Kinase Signaling System/physiology , Neural Stem Cells/pathology , Phosphatidylinositol 3-Kinases/metabolism , Phosphorylation/drug effects , Podophyllotoxin/analogs & derivatives , Podophyllotoxin/pharmacology , Protective Agents/pharmacology , Proto-Oncogene Proteins c-akt/metabolism , Rats , Rats, Sprague-Dawley , Signal Transduction/drug effects
10.
J Inorg Biochem ; 141: 70-78, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25226435

ABSTRACT

A ruthenium(II) complex [Ru(bpy)2(HL(1))](ClO4)2·3H2O {bpy=2,2'-bipyridine and HL(1)=2-(2,6-di(pyridin-2-yl)pyridin-4-yl)-1H-imidazo[4,5-f][1,10]phenanthroline}, denoted as RuHL(1), was synthesized and characterized by elemental analysis, proton nuclear magnetic resonance spectroscopy, and mass spectrometry. The pH effects on the UV-visible (UV-vis) absorption and emission spectra and the luminescence lifetimes of RuHL(1) have been studied, and their ground- and excited-state acid ionization constants were derived. The complex was found to exhibit pH-induced "off-on-off" luminescence switching properties via protonation/deprotonation of the grafted imidazole and terpyridyl groups. A pH-induced emission on-off intensity ratio of 166 was observed as pH was increased from 2.00 to 5.44, which is one of the largest values observed among imidazole-containing Ru(II) complex-based acidic-pH-induced pH luminescence switches. RuHL(1) also strongly binds to calf thymus DNA in mixed binding modes involving classic intercalation and partial intercalation, as determined by UV-vis absorption and emission spectrophotometric DNA titration, ethidium bromide displacement, DNA denaturation and DNA viscosity measurements.


Subject(s)
Coordination Complexes/chemistry , DNA/chemistry , Intercalating Agents/chemistry , Protons , Pyridines/chemistry , Ruthenium/chemistry , Animals , Cattle , Coordination Complexes/chemical synthesis , Ethidium/chemistry , Hydrogen-Ion Concentration , Intercalating Agents/chemical synthesis , Luminescence , Nucleic Acid Denaturation , Phenanthrolines/chemistry , Structure-Activity Relationship , Viscosity
11.
Dalton Trans ; 43(8): 3273-84, 2014 Feb 28.
Article in English | MEDLINE | ID: mdl-24356444

ABSTRACT

A new heterobimetallic ruthenium(II)-rhenium(I) complex of [Ru(bpy)2(HL)Re(CO)3Cl](ClO4)2·6H2O (RuHLRe) {bpy = 2,2'-bipyridine and HL = 2-(4-(2,6-di(pyridin-2-yl)pyridin-4-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline} was synthesised and characterised by elemental analysis, proton nuclear magnetic resonance spectroscopy, and mass spectrometry. The ground- and excited-state acid-base properties of RuHLRe were studied using UV-Vis absorption spectrophotometric and spectrofluorimetric titrations in a 100 : 1 (v/v) Britton-Robinson buffer-CH3CN solution combined with luminescence lifetime measurements. The complex exhibited two-step separate protonation-deprotonation processes in both the ground and excited states. The complex acted as pH-induced "off-on-off" luminescence switches (I(on)/I(off) = 31.0 and 14.6), with one of the switching actions being driven by pH variations over the physiological pH range (5.3-8.0). Importantly, cellular imaging and cytotoxicity experiments demonstrated that RuHLRe rapidly and selectively illuminated the membrane of HeLa cells over fixed cells and exhibited reduced cytotoxicity at the imaging concentration compared to the Re(I)-free parent Ru(II) complex. In addition, RuHLRe acted as an efficient "turn on" emission sensor for H2PO4(-) and "turn off" emission sensor for F(-) and OAc(-).


Subject(s)
Coordination Complexes/metabolism , Phosphates/chemistry , Rhenium/chemistry , Ruthenium/chemistry , Acetic Acid/chemistry , Anions/chemistry , Cell Survival/drug effects , Coordination Complexes/chemistry , Coordination Complexes/toxicity , Fluorine/chemistry , HeLa Cells , Humans , Hydrogen-Ion Concentration , Kinetics , Microscopy, Confocal , Protons , Spectrometry, Fluorescence
12.
Langmuir ; 29(46): 14314-20, 2013 Nov 19.
Article in English | MEDLINE | ID: mdl-24206270

ABSTRACT

The multilayer films were fabricated by layer-by-layer electrostatically coassembling graphene oxide and a ruthenium complex of [Ru(bpy)2L](ClO4)2 {L = 2-(2,6-di(pyridin-2-yl)pyridine-4-yl)-1H-imidazo[4,5-f]-1,10-phenanthroline} and characterized using UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and cyclic voltammetry. The dependence of redox properties and cathodic photocurrents on the number of layers deposited and the photocurrent generation mechanism and polarity were studied in detail. The homogeneous growth and close packing of the two film-forming components, linear relationships of the dark cyclic voltometry peak currents and photocurrents vs number of layers deposited, and large cathodic photocurrent density of 4.1 µA/cm(2) for a four-layer film make this novel hybrid thin film promising applications ranging from molecular photovoltaic and photocatalytic molecular devices to photoelectrochemical sensing.

13.
J Colloid Interface Sci ; 402: 107-13, 2013 Jul 15.
Article in English | MEDLINE | ID: mdl-23639218

ABSTRACT

The multilayer films consisting of graphene oxide and a cobalt complex were fabricated though electrostatic layer-by-layer self-assembly technique and characterized by UV-Vis absorption spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and cyclic voltammetry. The results demonstrated that the hybrid films were successfully prepared and exhibited good electrochemical activity. The film was also subjected to photoelectrochemical studies and were found to exhibit large cathodic photocurrent density of 6.1 µA/cm(2) while irradiated with 100 mW/cm(2) polychromatic light (730 nm>λ>325 nm) at an applied potential of -0.4V versus saturated calomel electrode.

14.
Dalton Trans ; 42(16): 5764-77, 2013 Apr 28.
Article in English | MEDLINE | ID: mdl-23450276

ABSTRACT

The ground- and excited-state acid-base properties of [Ru2(bpy)4(H2bipt)]Cl4 1 {bpy = 2,2'-bipyridine, H2bipt = 2,5-bis[1,10]phenanthrolin[4,5-f]-imidazol-2-yl)thiophene} are investigated by emission and UV-visible absorption spectrophotometric pH titrations. The DNA binding properties of 1 are studied by means of DNA viscosity and optical spectroscopic techniques of UV-visible absorption and emission spectral titrations, steady-state emission quenching with ferrocyanide, ethidium bromide competitive binding, and DNA thermal denaturation as well as density functional theoretical calculations. The DNA photocleavage and singlet oxygen generation properties as well as in vitro anticancer activities against five cancer cell lines are studied as well. The results demonstrated that pH-induced luminescence switching, DNA binding, and anticancer properties of 1 are much improved with respect to those of the mononuclear analog [Ru(bpy)2(Htip)]Cl2 {Htip = 2-(thiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline}.


Subject(s)
Antineoplastic Agents/chemistry , Coordination Complexes/chemistry , DNA/metabolism , Ruthenium/chemistry , Antineoplastic Agents/metabolism , Antineoplastic Agents/toxicity , Apoptosis/drug effects , Cell Line, Tumor , Coordination Complexes/metabolism , Coordination Complexes/toxicity , DNA/chemistry , HeLa Cells , Hep G2 Cells , Humans , Hydrogen-Ion Concentration , MCF-7 Cells , Nucleic Acid Denaturation , Photolysis , Quantum Theory , Singlet Oxygen/metabolism , Spectrophotometry, Ultraviolet
15.
Inorg Chem ; 52(5): 2306-16, 2013 Mar 04.
Article in English | MEDLINE | ID: mdl-23410247

ABSTRACT

The anion-interaction properties of a Ru(II) complex of [Ru(bpy)2(Htppip)](ClO4)2·H2O·DMF (RuL) {bpy =2,2'-bipyridine and Htppip =2-(4-(2,6-di(pyridin-2-yl)pyridin-4-yl)phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline} were thoroughly investigated in CH3CN and CH3CN/H2O (50:1, v/v) solutions by UV-visible absorption, emission, and (1)H NMR spectra. These analyses revealed that RuL acts as an efficient "turn on" emission sensor for H2PO4(-), and a "turn off" sensor for F(-) and OAc(-); in addition, RuL exhibited slightly disturbed emission spectra in the presence of the other anions studied (Cl(-), Br(-), I(-), NO3(-), and ClO4(-)). The cation-sensing properties of RuL were also studied in both neat CH3CN and aqueous 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid buffer (pH = 7.2)/CH3CN (71/1, v/v) solutions. RuL was found to exhibit a colorimetric sensing ability that was highly selective for Fe(2+), as evidenced by an obvious color change from pale yellow to light red-purple to the naked eye over the other cations studied (Na(+), Mg(2+), Ba(2+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+), and Ag(+)). To obtain insights into the possible binding modes and the sensing mechanisms, (1)H NMR spectral analysis, luminescence lifetime measurements, and density functional theoretical calculations were also performed.


Subject(s)
Ferrous Compounds/chemistry , Fluorescent Dyes/chemistry , Organometallic Compounds/chemistry , Phosphates/chemistry , Ruthenium/chemistry , Anions/chemistry , Cations/chemistry , Colorimetry , Fluorescent Dyes/chemical synthesis , Luminescent Measurements , Molecular Structure , Organometallic Compounds/chemical synthesis , Quantum Theory
16.
Int J Mol Sci ; 10(7): 3186-3193, 2009 Jul 13.
Article in English | MEDLINE | ID: mdl-19742131

ABSTRACT

As a naturally occurring anthraquinone pigment, chrysophanol (MHAQ) has attracted considerable attention in recent years owing to its efficient photosensitivity under the solar spectrum. Considering the successful use of time-dependent density functional theory (TD-DFT) in investigating the photo-physicochemical behaviors of dyes and pigments, we performed a study by means of TD-DFT calculations, which provided us with various excited state properties of chrysophanol, including absorption spectrum, lowest triplet excited-state energy, vertical electron affinity and vertical ionization potential. On the basis of the calculated results, the photosensitive mechanisms of chrysophanol were discussed and some deeper insights were gained. First, we indicated that the experimentally observed chrysophanol's photo-damage to DNA in oxygen-free media is more likely to arise from MHAQ(*+) rather than from T(1) state chrysophanol. Second, we revealed that it is the MHAQ(*-) that is responsible for the O(2) (*-) generation in solvents. Based on the photosensitive activities, chrysophanol may be potentially used as the photodynamic medicine for clinical therapy of the diseases occurring on the shallow surface and vascular capillary diseases.


Subject(s)
Anthraquinones/chemistry , Photosensitizing Agents/chemistry , Rheum/chemistry , Models, Chemical
17.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 11): m1448, 2009 Oct 28.
Article in English | MEDLINE | ID: mdl-21578177

ABSTRACT

In the planar (r.m.s. deviation = 0.027 Å) title compound, [Hg(C(7)H(5)O(2))Cl], the Hg(II) atom shows a typical linear coordination by a C atom of the benzene ring and a Cl atom. Inter-molecular O-H⋯O hydrogen bonds are present in the crystal structure, resulting in chains propagating along the b axis. The crystal studied was a non-merohedral twin, with a twin ratio of 0.802 (2):0.198 (2).

18.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 12): o3084, 2009 Nov 14.
Article in English | MEDLINE | ID: mdl-21578814

ABSTRACT

In the title mol-ecule, C(15)H(12)O(3), the three five-membered rings are nearly coplanar: the dihedral angles between the cyclopentanone ring and the furan rings are 3.5 (2) and 9.7 (2)°, and the two furan rings form a dihedral angle of 7.2 (2)°. In the crystal structure, weak inter-molecular C-H⋯O hydrogen bonds help to consolidate the crystal packing.

19.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 12): o3085, 2009 Nov 14.
Article in English | MEDLINE | ID: mdl-21578815

ABSTRACT

The complete mol-ecule of the title compound, C(16)H(14)O(3), is generated by crystallographic mirror symmetry, with two C atoms and one O atom lying on the mirror plane. The mol-ecule adopts an E configuration about the C=C bond and the dihedral angle between the furan rings is 16.1 (2)°.

20.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 3): m500-1, 2008 Feb 29.
Article in English | MEDLINE | ID: mdl-21201881

ABSTRACT

The title compound, [Mn(C(5)H(2)N(2)O(4))(C(12)H(8)N(2))(H(2)O)(2)], was synthesized by the reaction of manganese(II) acetate and orotic acid in the presence of 1,10-phenanthroline. The crystal structure exhibits inter-molecular N-H⋯O and O-H⋯O hydrogen bonds . The Mn coordination environment consists of an N(3)O(3) donor set in an octa-hedral geometry.

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