2015 Volume 26 Issue 5

Strategies for synthesizing non-bioaccumulable alternatives to PFOA and PFOS
Min Sha , Ping Xing , Biao Jiang
2015, 26(5): 491-498  doi: 10.1016/j.cclet.2015.03.038
[Abstract](97) [FullText HTML] [PDF 973KB](0)
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This minireview describes the strategies for synthesis of fluorinated surfactants potentially nonbioaccumulable. Various strategies have been focused on (I) reducing the length of the perfluorocarbon chain, (II) introducing hetero atoms into the fluorocarbon chain, (III) introducing branch (herein and after branch means the fluoro-carbon chain section is not straight). In most cases, the surface tensions versus the surfactant concentrations have been assessed. These above strategies led to various highly fluorinated (perfluorinated or not perfluorinated) surfactants whose chemical changes enabled to obtain novel alternatives to perfluorooctanoic acid (PFOA) and perfluorooctane sulphonate (PFOS).
Syntheses, structures, luminescent and magnetic properties of two coordination polymers based on a fl exible multidentate carboxylate ligand
Dan Tian , Xiao-Jing Liu , Rong-Ying Chen , Ying-Hui Zhang
2015, 26(5): 499-503  doi: 10.1016/j.cclet.2015.01.019
[Abstract](90) [FullText HTML] [PDF 4292KB](0)
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Two coordination polymers, {[Cu3(tci)2(DMAc)3]·6DMAc·2H2O}n (1) and {[Cu3(tci)2(tpt)2(H2O)2]·2DMAc·2H2O}n (2) (H3tci = tris(2-carboxyethyl)isocyanurate, tpt = 2,4,6-tris(4-pyridyl)-1,3,5-triazine, DMAc = N,N-dimethylacetamide), have been constructed under solvothermal conditions. Both polymers were structurally characterized by single crystal X-ray diffraction, elemental analyses, IR spectra, thermogravimetric (TG) analyses and powder X-ray diffraction (RXPD). 1 shows a (3,4)-connected 2D layer structure comprising Cu2(CO2)4 paddle-wheel units, which are further bridged by C-H…O interactions to give a 3D supramolecular network. The introduction of tpt produces different framework for 2 that comprises a dinuclear and a mononuclear Cu(II) building units, which are further bridged together by tci3- and tpt ligands to give a 4-connected 2D topological net. Adjacent 2D layers are packed together via C-H…O interactions and π…π stacking interactions to form a 3D supramolecular structure. In addition, the luminescent properties and the solid-state UV-vis spectra of 1 and 2 were explored. Furthermore, antiferromagnetic exchange interactions were unveiled in the Cu2(COO)4 units of 1.
Gel-incorporated PbS and PbI2 single-crystals
Wei Liu , Yu-Jing Liu , Liao Chen , Tao Ye , Hong-Zheng Chen , Han-Ying Li
2015, 26(5): 504-508  doi: 10.1016/j.cclet.2015.01.020
[Abstract](89) [FullText HTML] [PDF 3752KB](0)
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Gel-incorporated single-crystals provide unique combinational properties of long-range order and composite structures, which is desired for semiconducting and conducting materials. However, the reported gel-incorporated single-crystals are limited to insulating crystals. Here, we examine crystals of two typical semiconductors, lead sulfide (PbS) and lead iodide (PbI2), grown from both silica gels and agarose gels. In all the four crystal-gel pairs, single-crystals of the cubic phase of PbS and the hexagonal phase of PbI2 were obtained according to the X-ray diffraction analysis. Dissolution of the gel-grown crystals exposed insoluble materials with the shape similar to the original crystals, indicative of gelincorporation inside the crystals. As such, this work creates a facile strategy to construct 3D heterostructures inside semiconducting single-crystals without destroying their long-range order.
Design, synthesis, and insecticidal bioactivities evaluation of pyrrole- and dihydropyrrole-fused neonicotinoid analogs containing chlorothiazole ring
Hong-Feng Shen , Xi Chen , Pin Liao , Xu-Shen Shao , Zhong Li , Xiao-Yong Xu
2015, 26(5): 509-512  doi: 10.1016/j.cclet.2015.03.017
[Abstract](120) [FullText HTML] [PDF 412KB](0)
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Chlorothiazole ring, as a substituted heterocycle, frequently occurred in structures of various insecticides, and brought positive effect on bioactivity. In purpose to find novel neonicotinoids, a series of pyrrole- and dihydropyrrole-fused neonicotinoid analogs containing chlorothiazole ring were synthesized for the first time. Results of the following biological assays showed that compounds 5a-c achieved good insecticidal activity against Aphis craccivora, and compound 5h exhibited good activity against Nilaparvata lugens.
A bestatin-based fl uorescent probe for aminopeptidase N cell imaging
Hui Chen , Hui Wang , Xiao-Jun Qin , Chen Chen , Lu Feng , Lai-Zhong Chen , Lu-Pei Du , Min-Yong Li
2015, 26(5): 513-516  doi: 10.1016/j.cclet.2015.01.023
[Abstract](89) [FullText HTML] [PDF 1074KB](0)
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Aminopeptidase N (APN) is an important drug target and biomarker for various tumors. The current work characterizes a novel APN-targeted fluorescent probe (Bes-Green, 2) that manifests comparable inhibitory activity with Bestatin. This probe has capacity of tightly binding to the APN for imaging endogenous APN in living human ovarian clear cell carcinoma cells (ES-2) and has potential application in biological study of cellular APN.
Two homosecoiridoids from the fl ower buds of Lonicera japonica
Wei-Xia Song , Qing-Lan Guo , Yong-Chun Yang , Jian-Gong Shi
2015, 26(5): 517-521  doi: 10.1016/j.cclet.2014.11.035
[Abstract](79) [FullText HTML] [PDF 939KB](0)
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Two new homosecoiridoids, named loniaceticiridoside (1) and lonimalondialiridoside (2), were isolated from an aqueous extract of the flower buds of Lonicera japonica. Their structures including the absolute configuration were determined by extensive spectroscopic studies, especially by 2D NMR and CD data analysis. A proposed biosynthetic pathway and preliminary investigations of the biological activity of compounds 1 and 2 are also discussed.
A facile preparation and electrochemical properties of nickel based compound-graphene sheet composites for supercapacitors
Li-Bin Zhang , Sheng-Rong Yang , Jin-Qing Wang , Ye Xu , Xiang-Zheng Kong
2015, 26(5): 522-528  doi: 10.1016/j.cclet.2015.01.025
[Abstract](90) [FullText HTML] [PDF 1641KB](0)
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Composites of a nickel based compound incorporated with graphene sheets (NiBC-GS) are prepared by a simple flocculation, using hydrazine hydrate as flocculant and reductant, from a homogeneous intermixture of nickel dichloride and graphene oxide dispersed in N,N-dimethylformamide. Morphology, microstructure and thermal stability of the obtained products were characterized by field-emission scanning electron microscopy, X-ray diffraction and thermal gravimetric analysis. Furthermore, the electrochemical properties of NiBC-GS, as electrodematerials for supercapacitors, were studied by cyclic voltammetry and galvanostatic charge/discharge in 2 mol L-1 KOH solution. It was determined that for NiBC-GS annealed at 250 8C, a high specific capacitance of 2394 F g-1 was achieved at a current density of 1 A g-1, with 78% of the value (i.e., 1864 F g-1) retained after 5000 times of repeated galvanostatic charge/discharge cycling. The high specific capacitance and available charge/discharge stability indicate the synthesized NiBC-GS250 composite is a good candidate as a novel electrode material for supercapacitors.
β-Octafl uorinated tetrakis(ethoxycarbonyl)porphyrin
Hua-Hua Wang , Yi-Yu Jiang , Mian HR Mahmood , Hai-Yang Liu , Herman H.Y. Sung , Ian D. Williams , Chi K. Chang
2015, 26(5): 529-533  doi: 10.1016/j.cclet.2015.01.026
[Abstract](96) [FullText HTML] [PDF 3132KB](0)
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Tetrakis(alkoxycarbonyl)porphyrin and its β-octafluoro-substituted derivatives were synthesized via Lindsey method and transformed to their zinc complexes. Single crystal X-ray structures of corresponding Zn(II) porphyrins revealed that β-octafluorination will give more compactness of porphyrin moieties in the crystal structure owing to the hydrogen bonding interactions involving bfluorine atoms. An unusual six-coordinated Zn(II) was found via intramolecular coordination of oxygen atom of meso-substituents with central Zn(II).
Novel pyrazole fused heterocyclic ligands: Synthesis, characterization, DNA binding/cleavage activity and anti-BVDV activity
Chao Han , Yan-Chun Guo , Dan-Dan Wang , Xing-Jie Dai , Feng-Juan Wu , Huan-Fei Liu , Gui-Fu Dai , Jing-Chao Tao
2015, 26(5): 534-538  doi: 10.1016/j.cclet.2015.01.006
[Abstract](94) [FullText HTML] [PDF 1822KB](0)
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A series of novel pyrazole fused heterocyclic derivatives were synthesized via a two-step procedure or a one-pot two step method, and their catalytic DNA cleavage abilities and anti-BVDV activities were also evaluated. The results obtained indicated that compounds 3b-3c could catalyze the cleavage of supercoiled DNA (pUC 19 plasmid DNA) to nicked DNA under physiological conditions with high yields via a hydrolytic mechanism. The studies on anti-viral activities against bovine viral diarrhea virus (BVDV) demonstrated that some of the pyrazole derivatives showed pronounced anti-BVDV activity with interesting EC50 values and no significant cytotoxicity. Among them, compound 3l showed the highest antiviral activity (EC50 = 0.12 μmol/L) and was 10 fold more than that of the positive control ribavirin (EC50 = 1.3 μmol/L), which provided a potential candidate for the development of anti-BVDV agents.
Fe(NO3)3·9H2O-catalyzed aerobic oxidation of sulfi des to sulfoxides under mild conditions with the aid of trifl uoroethanol
Xue-Dong Li , Ran Ma , Liang-Nian He
2015, 26(5): 539-542  doi: 10.1016/j.cclet.2014.12.010
[Abstract](80) [FullText HTML] [PDF 423KB](0)
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Selective oxidation of sulfides to sulfoxides was successfully performed by employing readily available Fe(NO3)3·9H2O as the active catalyst with oxygen as the oxidant in 2,2,2-trifluoroethanol (TFE) without the formation of sulfones. Nitrate anion could play a crucial role in promoting the reaction due to the oxidation capacity under acidic media. High yields of sulfoxides were exclusively obtained from the corresponding sulfides. Furthermore, both aromatic and aliphatic sulfides gave moderate to high yields of sulfoxides with this protocol.
Lipase-catalyzed synthesis of novel galactosylated cholesterol
Hua Nie , Yi Cheng , Pin-Jing Zheng , Li-Hua Luo , Sheng-Yuan Zhang
2015, 26(5): 543-546  doi: 10.1016/j.cclet.2015.01.005
[Abstract](80) [FullText HTML] [PDF 1884KB](0)
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In an organic phase system, an enzymes lipase was used as a catalyst to synthesize galactosylated cholesterol, (5-cholesten-3b-yl)[(4-O-β-D-galactopyranosyl)D-glucitol-6] sebacate (CHS-SE-LA), which contains galactose residues. Its chemical structure was characterized by ESI-MS, and NMR. For HepG2 cells, the cellular fluorescence intensities of liposomes modified with CHS-SE-LA (GAL-FL) were as much as 2.6-fold (p < 0.01) control liposomes (FL). Moreover, the presence of excess galactose significantly inhibited the uptake of GAL-FL suggesting ASGPR mediated uptake. In conclusion, the novel galactosylated ligand CHS-SE-LA was synthesized by lipase-catalyzation and revealed a great potential as drug carrier materials for hepatocyte-selective targeting.
Highly effi cient and regioselective thiocyanation of aromatic amines, anisols and activated phenols with H2O2/NH4SCN catalyzed by nanomagnetic Fe3O4
Dariush Khalili
2015, 26(5): 547-552  doi: 10.1016/j.cclet.2015.01.007
[Abstract](87) [FullText HTML] [PDF 1432KB](0)
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A new method employing magnetic nanoparticles Fe3O4 as a catalyst and H2O2 as a green oxidant is developed for the oxidative thiocyanation of aromatic amines, anisols and activated phenols with high yields under mild reaction conditions. The catalyst could be easily recovered from the reaction mixture using an external magnet and reused in several reaction cycles without loss of activity.
Rationalization of regioselectivity of electrophilic substitution reaction for cyclic compounds in terms of Dpb values
Yang Liu , Zhong-Zhi Yang , Dong-Xia Zhao
2015, 26(5): 553-556  doi: 10.1016/j.cclet.2014.12.013
[Abstract](87) [FullText HTML] [PDF 675KB](0)
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Accepted theories predict that substitution reactions are controlled by the electronic nature of the attacked site for electrophilic aromatic substitution. Here it is shown that in addition the bond strength of the broken bond may also influence the regioselectivity of the substitution reaction, and that the Dpb is a good indicator of the strength of a chemical bond. The Dpb denotes the depth of the potential acting on one electron in amolecule at the bond center (bc). In this letter, the values of Dpb along the C-H and N-H bonds have been investigated, and it is demonstrated that for aromatic compounds, the regioselectivity of the electrophilic substitution can well be rationalized in terms of Dpb values.
Microwave-assisted effi cient synthesis of azlactone derivatives using 2-aminopyridine-functionalized sphere SiO2 nanoparticles as a reusable heterogeneous catalyst
Akbar Mobinikhaledi , Hassan Moghanian , Samira Pakdel
2015, 26(5): 557-563  doi: 10.1016/j.cclet.2014.12.007
[Abstract](130) [FullText HTML] [PDF 1994KB](0)
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In the present work, the highly efficient Erlenmeyer synthesis of azlactones catalyzed by 2- aminopyridine, supported on nano-sphere SiO2 is reported. First, the silica nanoparticles were modified with triethoxysilylpropyl chloride and then 2-aminopyridine was attached to the support via covalent linkages. This new heterogenized catalyst was used for efficient microwave-assisted synthesis of azlactone derivatives with Ac2O as a condensing agent under solvent-free conditions. The present method offers advantages including high yields, short reaction times and simple work-up. Also, the catalyst can be easily recycled and reused several times, which makes this method attractive, economic and environmentally-benign.
Mechanism of trifl uoromethylation reactions with well-defi ned NHC copper trifl uoromethyl complexes and iodobenzene: A computational exploration
Dong-Hai Yu , Jing-Na Shao , Rong-Xing He , Ming Li
2015, 26(5): 564-566  doi: 10.1016/j.cclet.2014.12.017
[Abstract](84) [FullText HTML] [PDF 547KB](0)
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Computational calculation was performed to investigate the mechanism of trifluoromethylation reactions of iodobenzene with well-defined N-heterocyclic carbene (NHC)-supported CuI trifluoromethyl complexes. Four proposed reaction pathways, namely σ-bond metathesis (BM), concerted oxidative addition-reductive elimination (OARE), iodine atomtransfer (IAT) and single-electron transfer (SET), have been computed by density functional theory (DFT). The result indicated that the concerted OARE mechanism is favored among the four reaction pathways, suggesting the trifluoromethylation may occur via concerted OARE mechanism involving Ar-X oxidative addition to the Cu(I) center as the rate determining step.
Potential anti-tubercular agents: Hexahydro-3-phenyl indazol-2-yl(pyridin-4-yl)methanones from anti-tubercular drug isoniazid and bis(substituted-benzylidene)cycloalkanones
Ayyakannu Arumugam Napoleon , Fazlur-Rahman Nawaz Khan , Euh Duck Jeong , Eun Hyuk Chung
2015, 26(5): 567-571  doi: 10.1016/j.cclet.2015.01.008
[Abstract](92) [FullText HTML] [PDF 571KB](0)
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A series of indazol-2-yl(pyridin-4-yl)methanones, 4 were acquired from 2,6-bisbenzylidene cyclohexanones, 3 and anti-tubercular drug (isoniazid), and their anti-tubercular impacts were screened. Among the test compounds used against Mycobacterium tuberculosis H37 Ra cell line in the microplate alamar blue assay, the compounds 4g-j revealed moderate anti-tubercular activity with MIC 12.5 μg/mL, comparable to standard drugs (streptomycin, MIC, 6.25 μg/mL, pyrazinamide, isoniazid and ciprofloxacin with MICs of 3.125 μg/mL).
Synthesis and characterization of imide modified poly(dimethylsiloxane) with maleopimaric acid as raw material
Tao Xu , He Liu , Jie Song , Shi-Bin Shang , Zhan-Qian Song , Xiu-Jie Chen , Chong Yang
2015, 26(5): 572-574  doi: 10.1016/j.cclet.2015.01.011
[Abstract](112) [FullText HTML] [PDF 504KB](0)
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With the natural rosin derivative (maleopimaric acid, MPA) as the raw material, imide modified vinyl poly(dimethylsiloxane) (MP-VMS) was synthesized and characterized by 1H NMR and 13C NMR. The curing kinetic parameters of MP-VMS were determined by differential scanning calorimetry (DSC) at various heating rates (5, 8, 10, 15 ℃/min) from the Kissingner, Ozawa and Crane methods. The activation energy (Ea), pre-exponential factor (A) and reaction order (n) were respectively 18.6 kJ/mol, 71,108 and 0.902. The low-temperature and high-temperature resistance of its curing product were respectively investigated by DSC and thermogravimetric analysis. The results showed that incorporation of MPA could significantly improve the thermal stability of silicone while had no effect on the low-temperature resistance, and the Tmax (the temperature corresponding to themaximum weight loss rate) increased by 70.7 ℃.
Cesium carbonate supported on hydroxyapatite coated Ni0.5Zn0.5Fe2O4 magnetic nanoparticles as an effi cient and green catalyst for the synthesis of pyrano[2,3-c]pyrazoles
Farid Moeinpour , Amir Khojastehnezhad
2015, 26(5): 575-579  doi: 10.1016/j.cclet.2015.01.033
[Abstract](131) [FullText HTML] [PDF 1585KB](0)
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Cesium carbonate supported on hydroxyapatite coated Ni0.5Zn0.5Fe2O4 magnetic nanoparticles (Ni0.5Zn0.5Fe2O4@Hap-Cs2CO3) was found to be magnetically separable, highly efficient, green and recyclable heterogeneous catalyst. The synthesized nanocatalyst has been characterized with several methods (FT-IR, SEM, TEM, XRD and XRF) and these analyzes confirmed which the cesium carbonate is well supported to catalyst surface. After full characterization, its catalytic activity was investigated in the synthesis of pyranopyrazole derivatives and the reactions were carried out at room temperature in 50:50 water/ethanol with excellent yields (88-95%). More importantly, the Ni0.5Zn0.5Fe2O4@Hap-Cs2CO3 was easily separated from the reaction mixture by external magnetic field and efficiently reused at least six runs without any loss of its catalytic activity. Thus, the developed nanomagnetic base catalyst is potentially useful for the green and economic production of organic compounds.
A highly selective turn-on colorimetric and luminescence sensor based on a triphenylamine-appended ruthenium(II) dye for detecting mercury ion
Su-Hua Fan , Jie Shen , Hai Wu , Ke-Zhi Wangb , An-Guo Zhang
2015, 26(5): 580-584  doi: 10.1016/j.cclet.2014.11.031
[Abstract](76) [FullText HTML] [PDF 2220KB](0)
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A dual colorimetric and luminescent sensor based on a heteroleptic ruthenium dye [Ru(Hipdpa)(Hdcbpy)(NCS)2]-·0.5H+0.5[N(C4H9)4]+ Ru(Hipdpa) {where Hdcbpy = monodeprotonted-4,4'-dicarboxy-2,2'- bipyridine and Hipdpa = 4-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-N,N-diphenylaniline} for selective detection of Hg2+ is presented. The results of spectrophotometric titrations revealed an evident luminescence intensity enhancement (I/I0 = 11) and a considerable blue shift in visible absorption and luminescence maxima with the addition of Hg2+. The sensitive response of the optical sensor on Hg2+ was attributed to the binding of the electron-deficient Hg2+ to the electron-rich sulfur atom of the thiocyanate (NCS) ligand in the Ru(Hipdpa), which led to an increase in the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). Accordingly, the blue shift in the absorption spectrum of Ru(Hipdpa) due to the binding of Hg2+ was obtained. Ru(Hipdpa) was found to have decreased Hg2+ detection limit and improved linear region as compared to di(tetrabutylammonium) cis-bis(isothiocyanato)bis(2,2'-bipyridine-4-carboxylic acid-4'- carboxylate)ruthenium(II) N719. Moreover, a dramatic color change from pink to yellow was observed, which allowed simple monitoring of Hg2+ by either naked eyes or a simple colorimetric reader. Therefore, the proposed sensor can provide potential applications for Hg2+ detection.
New triterpenoid saponins from the leaves of Cyclocarya paliurus
Bao-Song Cui , Shuai Li
2015, 26(5): 585-589  doi: 10.1016/j.cclet.2014.11.033
[Abstract](78) [FullText HTML] [PDF 748KB](0)
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Two new secodammarane triterpenoid saponins, cyclocariosides I and J (1 and 2), and a new epoxydammarane triterpenoid saponin, cyclocarioside K (3) were isolated from the ethanol extracts of the leaves of Cyclocarya paliurus. The structures of these compounds were elucidated by spectroscopic techniques.
Studies of the intestinal absorption of the alkaloids in the Wu-tou decoction combined with different incompatible medicinal herbs in a Caco-2 cell culture system using UPLC-MS/MS
Hong Kan , Wen-Yue Jiang , Ru Ding , Zhong-Ying Liu , Zi-Feng Pi , Zhi-Qiang Liu
2015, 26(5): 590-594  doi: 10.1016/j.cclet.2014.12.008
[Abstract](197) [FullText HTML] [PDF 547KB](0)
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In this study, seven alkaloids were detected in Wu-tou decoction using ultra performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MSn). The aim of this study was to investigate the effect of Fritillariae Cirrhosae Bulbus, Fritillariae Thunbergii Bulbus, Pinelliae Rhizoma in different ratios with Wu-tou decoction (2:1, 1:1, 1:2) by measuring the therapeutic effects in Wu-tou decoction of main seven alkaloids including benzoylaconitine (BA), benzoylmesaconitine (BM), benzoylhypaconitine (BH), hypaconitine (HA), fuziline (FU), niaolin (NE) and deoxyaconitine (DA). The permeability of aconitum alkaloids extract through a Caco-2 cell monolayer was analyzed in the absence and presence of Fritillariae Cirrhosae Bulbus, Fritillariae Thunbergii Bulbus, and Pinelliae Rhizoma, respectively. The results showed that Pinelliae Rhizoma could reduce the absorption of the alkaloids and increase the excretion of the alkaloids, which would attenuate the therapeutic effects of Wu-tou decoction. Therefore, Pinelliae Rhizoma is an incompatible herb of Wu-tou decoction because of the inhibition of the absorption of alkaloids in the intestine. And that Fritillariae Cirrhosae Bulbus and Fritillariae Thunbergii Bulbus showed the effects to improve the permeability of the alkaloids in Wu-tou decoction. These effects of these two herbs were similar, but the former was stronger than the latter, which most likely is due to the fact that the compositions of these two traditional Chinese medicines are similar. The in vitro data suggests that the compounds such as fritillary presented in alkaloids in the formula maybe improve the therapeutic function caused by the increased bioavailability of alkaloids in intestine.
Quantum-chemical study on the catalytic activity of TinRumO2(1 1 0) surfaces on chlorine evolution
Xiao-Hua Hu , Jia-Chuan Pan , Dan Wang , Wen Zhong , Hao-Yuan Wang , Lin-Yi Wang
2015, 26(5): 595-598  doi: 10.1016/j.cclet.2014.12.011
[Abstract](174) [FullText HTML] [PDF 3310KB](0)
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Based on the generalized gradient approximation (GGA), Perdew-Wang-91 (PW91) combined with a periodic slab model has been applied to study the catalytic activity of chlorine evolution on TinRumO2(1 1 0) surface. Metal oxide model TinRumO2 has been established with pure TiO2 and RuO2 on the basis set of Double Numerical plus polarization (DNP), in which the proportion of n:m was 3:1, 1:1, or 1:3. Analysis on the reaction activity in the electrochemical reaction and the electrochemical desorption reaction was based on Frontiermolecular orbital theory. The results show that the TinRumO2 with a ratio of Ti:Ru at 3:1 is best facilitates the electrochemical reaction and electrochemical desorption reaction to produce M-Clads intermediate and precipitate Cl2. In addition, the adsorption energy of Cl on the surface of Ti3Ru1O2 possesses the minimum value of 2.514 eV, and thus electrochemical desorption reaction could occur most easily.
Alumina-supported heteropoly acid: An effi cient catalyst for the synthesis of azaarene substituted 3-hydroxy-2-oxindole derivatives via C(sp3)H bond functionalization
Shuang-Hong Hao , Xue-Yan Zhang , Dao-Qing Dong , Zu-Li Wang
2015, 26(5): 599-602  doi: 10.1016/j.cclet.2014.12.018
[Abstract](84) [FullText HTML] [PDF 1672KB](0)
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A method of C(sp3)-H bond functionalization of methyl azaarenes catalyzed by alumina-supported heteropoly acid and addition to isatins was developed. This transformation could be used for the synthesis of biologically important 3-hydroxy-2-oxindole derivatives in good to excellent yields and the catalyst could be reused for six times without significant decrease in activity.
Preparation of aromatic nitriles via direct oxidative conversion of benzyl alcohols, aldehydes and amines with pentylpyridinium tribromide in aqueous NH4OAc
Ghodsieh Bagherzade , Abbas Zali , Arash Shokrolahi
2015, 26(5): 603-606  doi: 10.1016/j.cclet.2015.01.009
[Abstract](95) [FullText HTML] [PDF 527KB](0)
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Pentylpyridinium tribromide and aqueous ammonium acetate was used for the rapid oxidative conversion of benzyl alcohols, benzaldehydes and benzyl amines to the corresponding benzonitriles in good to excellent yields. This simple, mild and one-pot system provides easy workup and separation of the products.
Synthesis and biological evaluation of 5,6,7-trimethoxy- 1- benzylidene-3,4-dihydro-naphthalen-2-one as tubulinpolymerization inhibitors
Jun-Hang Jiang , Can-Hui Zheng , Chong-Qing Wang , Juan Wang , Wei Tian , Chao Yang , Yun-Long Song , Yong Hu , Ju Zhu , You-Yun Zhou
2015, 26(5): 607-609  doi: 10.1016/j.cclet.2015.03.022
[Abstract](89) [FullText HTML] [PDF 2108KB](0)
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A series of new combretastatin-A4 analogs were synthesized, in which a six-membered ring connects the linking bridge and A ring, and their tumor cell growth and tubulin-polymerization inhibitory activity were evaluated. These compounds appear to be potential tubulin-polymerization inhibitors. Compounds 1b with amino substituted on position 3 of B ring conferred optimal bioactivity, higher than that of the lead compound 22b and equivalent to that of CA-4. The binding modes of these compounds to tubulin were obtained by molecular docking, which can explain the structure-activity relationship. The studies presented here provide a new structural type for the development of novel antitumor agents.
Polyoxygenated dihydropyrano[2,3-c]pyrrole-4,5-dione derivatives from the marine mangrove-derived endophytic fungus Penicillium brocae MA-231 and their antimicrobial activity
Ling-Hong Meng , Xiao-Ming Li , Yang Liu , Bin-Gui Wang
2015, 26(5): 610-612  doi: 10.1016/j.cclet.2015.01.024
[Abstract](124) [FullText HTML] [PDF 744KB](0)
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A new polyoxygenated dihydropyrano[2,3-c]pyrrole-4,5-dione derivative, pyranonigrin F (1), together with a related known compound, pyranonigrin A (2), were isolated and identified from Penicillium brocae MA-231, an endophytic fungus obtained from the fresh tissue of the marine mangrove plant Avicennia marina. The structures of these metabolites were determined based on comprehensive spectral interpretation and the absolute configuration of compound 1 was established by X-ray crystallographic analysis. Compounds 1, and 2 showed potent activity against a broad spectrum of human-, aqua-, and plant-pathogens.
Electroanalytical method for determination of shikonin based on the enhancement effect of cyclodextrin functionalized carbon nanotubes
Yan-Sha Gao , Li-Ping Wu , Kai-Xin Zhang , Jing-Kun Xu , Li-Min Lu , Xiao-Fei Zhu , Yao Wu
2015, 26(5): 613-618  doi: 10.1016/j.cclet.2014.11.032
[Abstract](53) [FullText HTML] [PDF 3049KB](0)
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A simple and sensitive electroanalytical method for determination of shikonin, a widely used antitumoral agent, using β-cyclodextrin-functionalized multiwalled carbon nanotubes composite modified glassy carbon electrodes (MWCNTs/β-CD/GCE) was presented. CDs are water-soluble and environmentally friendly and can improve the dispersibility of MWCNTs/β-CD functional materials, which was confirmed by SEM. The electrochemical behaviors of shikonin on different electrodes were investigated by cyclic voltammetry (CV) and differential pulse voltammograms (DPVs). The results demonstrated that the redox peak currents of shikonin obtained at MWCNTs/β-CD/GCE were much higher than those at the β-CD/GCE and MWCNTs/GCE, which can be attributed to the combination of the excellent electrocatalytic properties of MWCNTs and the molecular recognition ability of β-CD. At MWCNTs/β-CD/GCE, the response current exhibits a linear range from 5.0 nmol/L to 10.0 μmol/L with a detection limit of 1.0 nmol/L (S/N = 3). As a practical application, the proposed method was applied to quantitatively determine shikoninin urine samples with satisfying results.
Synthesis of 2-[2H]-2-(1-methylalkyl)succinic acids
Xin-Yu Bian , Serge Maurice Mbadinga , Shi-Zhong Yang , Ru-Qiang Ye , Ji-Dong Gu , Bo-Zhong Mua
2015, 26(5): 619-622  doi: 10.1016/j.cclet.2015.01.010
[Abstract](58) [FullText HTML] [PDF 2021KB](0)
Abstract:
We describe a specific procedure for the synthesis of deuterium-labelled 2-(1-methylalkyl)succinate established via alkylation of diethyl malonate, Krapcho decarboxylation reaction with D2O and hydrolysis reaction. Two novel compounds, 2-[2H]-2-ethylsuccinic acid and 2-[2H]-2-(1-methylheptyl) succinic acid were prepared via this synthetic route and characterized by mass spectrometry and 1H NMR. The results showed that the 2-(1-methylalkyl)succinic acids were deuterated at the β-position, which is considered as an important reaction centre in the anaerobic degradation of n-alkanes.
Effi cient synthesis of fused pyrazoles via simple cyclization of o-alkynylchalcones with hydrazine
Ying Li , Chun-E. Dong
2015, 26(5): 623-626  doi: 10.1016/j.cclet.2015.01.002
[Abstract](80) [FullText HTML] [PDF 552KB](0)
Abstract:
The synthesis of pyrazole derivatives from o-alkynylchalcones and hydrazine via simple cyclization is described. This greener syntheticmethodology provides a straightforward approach to the synthesis of a variety of pyrazole derivatives under mild reaction condition.
Synthesis and biological evaluation of novel phenothiazine derivatives as non-peptide arginine vasopressin V2 receptor antagonists
Shuang Zhi , Shuai Mu , Ying Liu , Min Gong , Ping-Bao Wang , Deng-Ke Liu
2015, 26(5): 627-630  doi: 10.1016/j.cclet.2015.01.022
[Abstract](52) [FullText HTML] [PDF 444KB](0)
Abstract:
A series of novel phenothiazine derivatives was synthesized and tested for arginine vasopressin receptor antagonist activity. They were synthesized as novel arginine vasopressin receptor antagonists from phenothiazine as a scaffold via successive acylation, reduction and acylation reactions. Their structures were characterized by 1HNMR, 13CNMRandHRMS, and biological activitywas evaluated by in vitro and in vivo studies. The in vitro binding assay indicated that several compounds are potent selective V2 receptor antagonists. Compounds with promising binding affinity to V2 receptors were selected to conduct the in vivo diuretic studies on Sprague-Dawley rats. Among them, 1n, 1r, 1t and 1v exhibited excellent diuretic activity, especially 1r and 1v. Therefore, 1r and 1v are potent novelAVP V2receptor antagonist candidates.
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