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2013 Volume 24 Issue 6
2013, 24(6): 437-441
Abstract:
Chiral photochemistry appears to be a highly challenging topic and still very much in its infancy, especially if comparing to its well-developed thermochemical counterpart. Significant efforts have been devoted in order to improve stereoselectivity of chiral photoreactions, among which, the supramolecular strategy proven the most promising. The present review, motivated by the rapid progress in the supramolecular chiral photochemistry, concentrates on advancements achieved mainly in the last decade. The features and advantages of supramolecular chiral photochemistry are exemplified by representative photoreactions in terms of the chiral hosts/assemblies.
Chiral photochemistry appears to be a highly challenging topic and still very much in its infancy, especially if comparing to its well-developed thermochemical counterpart. Significant efforts have been devoted in order to improve stereoselectivity of chiral photoreactions, among which, the supramolecular strategy proven the most promising. The present review, motivated by the rapid progress in the supramolecular chiral photochemistry, concentrates on advancements achieved mainly in the last decade. The features and advantages of supramolecular chiral photochemistry are exemplified by representative photoreactions in terms of the chiral hosts/assemblies.
2013, 24(6): 442-446
Abstract:
Two β-cyclodextrin derivatives bearing appended quinolyl and isoquinolyl arms, i.e. mono-(6-quinolyl-6-deoxy)-β-cyclodextrin (1) and mono-(6-isoquinolyl-6-deoxy)-β-cyclodextrin (2) were synthesized in satisfactory yields and fully characterized. Their original conformations and binding behaviors toward four bile salt guests, that is, sodium cholate (CA), sodium deoxycholate (DCA), sodium glycocholate (GCA), and sodium taurocholate (TCA), were investigated by means of fluorescence, circular dichroism and 2D NMR spectroscopy. The study of solution structures revealed that both quinolyl and isoquinolyl arms were located outside the cyclodextrin cavity. The results obtained from the fluorescence titrations showed that the binding abilities of hosts 1 and 2 with selected bile salts varied in an order of DCA > CA > GCA. The selective binding of hosts toward bile salt guests was discussed from the viewpoints of induced-fit and multiple binding.
Two β-cyclodextrin derivatives bearing appended quinolyl and isoquinolyl arms, i.e. mono-(6-quinolyl-6-deoxy)-β-cyclodextrin (1) and mono-(6-isoquinolyl-6-deoxy)-β-cyclodextrin (2) were synthesized in satisfactory yields and fully characterized. Their original conformations and binding behaviors toward four bile salt guests, that is, sodium cholate (CA), sodium deoxycholate (DCA), sodium glycocholate (GCA), and sodium taurocholate (TCA), were investigated by means of fluorescence, circular dichroism and 2D NMR spectroscopy. The study of solution structures revealed that both quinolyl and isoquinolyl arms were located outside the cyclodextrin cavity. The results obtained from the fluorescence titrations showed that the binding abilities of hosts 1 and 2 with selected bile salts varied in an order of DCA > CA > GCA. The selective binding of hosts toward bile salt guests was discussed from the viewpoints of induced-fit and multiple binding.
2013, 24(6): 447-449
Abstract:
-first order reaction rate constants of 5,10,15-tris(pentafluorophenyl)corrole Mn(V)-oxo (F5CMn(V)-oxo), 5,15-bis(pentafluorophenyl)-10-(phenyl)corrole Mn(V)-oxo (F10CMn(V)-oxo), 5,15-bis(phenyl)-10-(pentafluorophenyl)corrole Mn(V)-oxo (F5CMn(V)-oxo) and 5,10,15-tris(phenyl)corrole Mn(V)-oxo (F0CMn(V)-oxo) with a series of alkene substrates in different solvents were determined by UV-vis spectroscopy. The results indicated that the oxygen atom transfer pathway between Mn(V)-oxo corrole and alkene is solvent-dependent.
2013, 24(6): 450-452
Abstract:
Using a click reaction between alkynylthiacalix[4]arene and ethyl 2-azidoacetate followed by an ammonolysis with ethanolamine, leucinol and hydrazine hydrate, respectively, three novel thiacalix[4]arene derivatives 4, 5 and 6 with triazolyl and hydrogen bonding groups (NH and OH) were synthesized in high yields. They exhibited excellent extraction capability for six anionic and cationic dyes. The flexible cavity, π-triazole rings and hydrogen bonding groups all play crucial roles in dye complexation.
Using a click reaction between alkynylthiacalix[4]arene and ethyl 2-azidoacetate followed by an ammonolysis with ethanolamine, leucinol and hydrazine hydrate, respectively, three novel thiacalix[4]arene derivatives 4, 5 and 6 with triazolyl and hydrogen bonding groups (NH and OH) were synthesized in high yields. They exhibited excellent extraction capability for six anionic and cationic dyes. The flexible cavity, π-triazole rings and hydrogen bonding groups all play crucial roles in dye complexation.
2013, 24(6): 453-456
Abstract:
A hexaazatriphenylene (HAT) derivative that bears two n-octyl chains was designed and synthesized. Its photophysical and electrochemical properties have been investigated. SEM study revealed that it could self-assemble into well-ordered 1D nanoribbons or 2D microsheets, which depends on the polarity of the solvents used.
A hexaazatriphenylene (HAT) derivative that bears two n-octyl chains was designed and synthesized. Its photophysical and electrochemical properties have been investigated. SEM study revealed that it could self-assemble into well-ordered 1D nanoribbons or 2D microsheets, which depends on the polarity of the solvents used.
2013, 24(6): 457-462
Abstract:
A remarkable solvent effect in a single-phase synthesis of monodisperse amine-capped Au nanoparticles is demonstrated. Oleylamine-capped Au nanoparticles were prepared via the reduction of HAuCl4 by an amine-borane complex in the presence of oleylamine in an organic solvent. When linear or planar hydrocarbon (e.g., n-hexane, n-octane, 1-octadecylene, benzene, and toluene) was used as the solvent, high-quality monodisperse Au nanoparticles with tunable sizes were obtained. However, Au nanoparticles with poor size dispersity were obtained when tetralin, chloroform or cyclohexane was used as the solvent. The revealed solvent effect allows the controlled synthesis of monodisperse Au nanoparticles with tunable size of 3-10 nm.
A remarkable solvent effect in a single-phase synthesis of monodisperse amine-capped Au nanoparticles is demonstrated. Oleylamine-capped Au nanoparticles were prepared via the reduction of HAuCl4 by an amine-borane complex in the presence of oleylamine in an organic solvent. When linear or planar hydrocarbon (e.g., n-hexane, n-octane, 1-octadecylene, benzene, and toluene) was used as the solvent, high-quality monodisperse Au nanoparticles with tunable sizes were obtained. However, Au nanoparticles with poor size dispersity were obtained when tetralin, chloroform or cyclohexane was used as the solvent. The revealed solvent effect allows the controlled synthesis of monodisperse Au nanoparticles with tunable size of 3-10 nm.
2013, 24(6): 463-466
Abstract:
Three novel Zn(Ⅱ) complexes, [Zn4L1Cl4]·3H2O (1), [Zn4L2Cl4]·2DMF (2) and [Zn4L3Cl4]·H2O (3), have been synthesized and structurally characterized. In these complexes, interesting 32-membered dodecadentate macrocyclic ligands were generated in situ by ‘2 + 2’ type condensation reactions between a tetraamine and various dialdehydes. All the complexes are isostructurally tetranuclear Zn(Ⅱ) complexes, containing endogenous alkoxo and phenoxo bridges. Applications of themacrocyclic ligands as Zn2+ sensors have been investigated. Take H4L1 for example, it exhibits a 4-fold fluorescence enhancement upon the addition of 2 equiv. of Zn2+ in MeOH.
Three novel Zn(Ⅱ) complexes, [Zn4L1Cl4]·3H2O (1), [Zn4L2Cl4]·2DMF (2) and [Zn4L3Cl4]·H2O (3), have been synthesized and structurally characterized. In these complexes, interesting 32-membered dodecadentate macrocyclic ligands were generated in situ by ‘2 + 2’ type condensation reactions between a tetraamine and various dialdehydes. All the complexes are isostructurally tetranuclear Zn(Ⅱ) complexes, containing endogenous alkoxo and phenoxo bridges. Applications of themacrocyclic ligands as Zn2+ sensors have been investigated. Take H4L1 for example, it exhibits a 4-fold fluorescence enhancement upon the addition of 2 equiv. of Zn2+ in MeOH.
2013, 24(6): 467-470
Abstract:
A novel triazatruxene-based fluorescent glycocluster was synthesized and its selective binding interactions with PNA lectin were investigated by fluorescence spectroscopy, CD spectroscopy, and a turbidity assay. The glycocluster exhibited a strong binding affinity for PNA lectin with a Stern-Volmer quenching constant of 5.8×105 mol-1 L.
A novel triazatruxene-based fluorescent glycocluster was synthesized and its selective binding interactions with PNA lectin were investigated by fluorescence spectroscopy, CD spectroscopy, and a turbidity assay. The glycocluster exhibited a strong binding affinity for PNA lectin with a Stern-Volmer quenching constant of 5.8×105 mol-1 L.
2013, 24(6): 471-474
Abstract:
Two novel, supramolecular,multiferrocenyl rhomboids 5 and 6 have been successfully constructed from newly designed 60° ferrocenyl donor precursor 1 via coordination-driven self-assembly. The structures of all multiferrocenyl rhomboids were characterized by multinuclear NMR (1H and 31P), CSI-TOF-MS, and PM6 semi-empirical molecular simulation, and their electrochemical behaviors have been investigated.
Two novel, supramolecular,multiferrocenyl rhomboids 5 and 6 have been successfully constructed from newly designed 60° ferrocenyl donor precursor 1 via coordination-driven self-assembly. The structures of all multiferrocenyl rhomboids were characterized by multinuclear NMR (1H and 31P), CSI-TOF-MS, and PM6 semi-empirical molecular simulation, and their electrochemical behaviors have been investigated.
2013, 24(6): 475-478
Abstract:
Single crystals of two triptycene-based catechol derivatives 1 and 2 were obtained, and their X-ray crystal structural studies showed that the two tecton molecules had different conformations in the solid state, and they could self-assemble into interesting 3D networks with solventmolecules included inside, in which multiple O-H...O hydrogen bonds played important roles.
Single crystals of two triptycene-based catechol derivatives 1 and 2 were obtained, and their X-ray crystal structural studies showed that the two tecton molecules had different conformations in the solid state, and they could self-assemble into interesting 3D networks with solventmolecules included inside, in which multiple O-H...O hydrogen bonds played important roles.
2013, 24(6): 479-482
Abstract:
A new fluorescent probe, DQCd2, based on 4-piperidinoquinoline has been synthesized as a fluorescent probe for Cd2+. It can ratiometrically respond to Cd2+ in PBS buffer by a remarkable emission intensity enhancement (88-fold) and wavelength shift (70 nm).
A new fluorescent probe, DQCd2, based on 4-piperidinoquinoline has been synthesized as a fluorescent probe for Cd2+. It can ratiometrically respond to Cd2+ in PBS buffer by a remarkable emission intensity enhancement (88-fold) and wavelength shift (70 nm).
2013, 24(6): 483-486
Abstract:
To study the diverse coordination modes of the H2btib, three new coordination architectures, namely, [Ag(Hbtib)CH3CN]n (1), [Ag(Hbtib)]n (2) and [Pb(btib)(CH3OH)2]n (3) (where H2btib = 4-((2-butyl-5-(2-carboxy-3-(thiophen-2-yl)prop-1-enyl)-1H-imidazol-1-yl)methyl)benzoic acid) have been synthesized and characterized by elemental analysis, IR spectrum and single-crystal X-ray diffraction. Complex 1 exhibits 1D single chain structure, while 2 shows 1D double metal chainmotif, and 3 features a 2D layer topology. Also, 1, 2 and 3 display strong emission band in the solid state at room temperature.
To study the diverse coordination modes of the H2btib, three new coordination architectures, namely, [Ag(Hbtib)CH3CN]n (1), [Ag(Hbtib)]n (2) and [Pb(btib)(CH3OH)2]n (3) (where H2btib = 4-((2-butyl-5-(2-carboxy-3-(thiophen-2-yl)prop-1-enyl)-1H-imidazol-1-yl)methyl)benzoic acid) have been synthesized and characterized by elemental analysis, IR spectrum and single-crystal X-ray diffraction. Complex 1 exhibits 1D single chain structure, while 2 shows 1D double metal chainmotif, and 3 features a 2D layer topology. Also, 1, 2 and 3 display strong emission band in the solid state at room temperature.
2013, 24(6): 487-490
Abstract:
The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction, 2D NMR spectroscopy and semi-empirical methods AM1. The crystallographic study shows that two β-cyclodextrins are held together by hydrogen bonds to form head-to-head dimers. The disordered guest molecule adjusts itself to attain the most stable accommodation into the cavity in which the nitro group is located at the dimer interface while the carboxyl group is buried in the primary hydroxyl groups of β-cyclodextrin. The guest inside the cavity is disordered over two sites and exhibits mobility. Moreover, 2D NMR spectroscopy and theoretical study show the same inclusion behavior. In comparison to the inclusion complex of β-cyclodextrin with p-nitrophenoxyacetic acid, the host-guest stoichiometries are different, i.e., 2:1 for m-nitrophenoxyacetic acid and 1:1 for p-nitrophenoxyacetic acid, while the inclusion orientation and the packing pattern of the host are similar in both complexes.
The inclusion complex of β-cyclodextrin with m-nitrophenoxyacetic acid was studied by single crystal X-ray diffraction, 2D NMR spectroscopy and semi-empirical methods AM1. The crystallographic study shows that two β-cyclodextrins are held together by hydrogen bonds to form head-to-head dimers. The disordered guest molecule adjusts itself to attain the most stable accommodation into the cavity in which the nitro group is located at the dimer interface while the carboxyl group is buried in the primary hydroxyl groups of β-cyclodextrin. The guest inside the cavity is disordered over two sites and exhibits mobility. Moreover, 2D NMR spectroscopy and theoretical study show the same inclusion behavior. In comparison to the inclusion complex of β-cyclodextrin with p-nitrophenoxyacetic acid, the host-guest stoichiometries are different, i.e., 2:1 for m-nitrophenoxyacetic acid and 1:1 for p-nitrophenoxyacetic acid, while the inclusion orientation and the packing pattern of the host are similar in both complexes.
2013, 24(6): 491-493
Abstract:
A freezing technique protocol was proposed for coupling microchip electrophoresis withmatrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The microfluidic flow was frozen immediately after electrophoresis on microfluidic chip and the separated analyte molecules were kept in their zone pattern in the electrophoresis. Then, the frozen-chip was lyophilized and sent into TOF-MS instrument as a MALDI target, and the analyte molecules in the microfluidic channels were subjected to analysis by mass spectrometry. This approach could eliminate sample cross-contamination, providing a new interface for microchip electrophoresis and MALDI-MS.
A freezing technique protocol was proposed for coupling microchip electrophoresis withmatrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The microfluidic flow was frozen immediately after electrophoresis on microfluidic chip and the separated analyte molecules were kept in their zone pattern in the electrophoresis. Then, the frozen-chip was lyophilized and sent into TOF-MS instrument as a MALDI target, and the analyte molecules in the microfluidic channels were subjected to analysis by mass spectrometry. This approach could eliminate sample cross-contamination, providing a new interface for microchip electrophoresis and MALDI-MS.
2013, 24(6): 494-496
Abstract:
A series of long-chain quaternary ammonium hydroxides were synthesized from tertiary amines and confirmed by 1H NMR and FTIR. Surface properties and pH of these surfactants were investigated. The critical micelle concentrations (CMC) of the synthesized quaternary ammonium hydroxides are lower than the conventional quaternary ammonium surfactants. The micelles shapes of these long-chain quaternary ammonium hydroxides in aqueous solution are spherical at a concentration of 0.1 mol/L. The pH values of the synthesized quaternary ammonium hydroxides are 12.25-12.51.
A series of long-chain quaternary ammonium hydroxides were synthesized from tertiary amines and confirmed by 1H NMR and FTIR. Surface properties and pH of these surfactants were investigated. The critical micelle concentrations (CMC) of the synthesized quaternary ammonium hydroxides are lower than the conventional quaternary ammonium surfactants. The micelles shapes of these long-chain quaternary ammonium hydroxides in aqueous solution are spherical at a concentration of 0.1 mol/L. The pH values of the synthesized quaternary ammonium hydroxides are 12.25-12.51.
2013, 24(6): 497-499
Abstract:
An efficient triethylamine-catalyzed synthesis of 4-amino-3,5-dicyano-6-arylphthalates is described. A one-pot, simple pseudo four-component reaction between arylaldehydes, dialkyl acetylenedicarboxylates, and twice as muchmalononitrile gave 4-amino-3,5-dicyano-6-arylphthalates in good to excellent yields.
An efficient triethylamine-catalyzed synthesis of 4-amino-3,5-dicyano-6-arylphthalates is described. A one-pot, simple pseudo four-component reaction between arylaldehydes, dialkyl acetylenedicarboxylates, and twice as muchmalononitrile gave 4-amino-3,5-dicyano-6-arylphthalates in good to excellent yields.
2013, 24(6): 500-502
Abstract:
Buagafuran is a novel drug candidate derived from natural product. Its absolute configuration has been confirmed by electronic circular dichroism combined with modern quantum-chemical calculation using time-dependent density functional theory. The predicted UV absorbance peak is underestimated by several nanometers compared with the experimental data. The applicability of empirical rule for the C=C-C-O system in Buagafuran has also been discussed. Our results show that electronic circular dichroism could be a useful tool for the absolute configuration assignment of chiral drugs, especially for the oily or semisolid substances, whose crystal structures are impossible to obtain.
Buagafuran is a novel drug candidate derived from natural product. Its absolute configuration has been confirmed by electronic circular dichroism combined with modern quantum-chemical calculation using time-dependent density functional theory. The predicted UV absorbance peak is underestimated by several nanometers compared with the experimental data. The applicability of empirical rule for the C=C-C-O system in Buagafuran has also been discussed. Our results show that electronic circular dichroism could be a useful tool for the absolute configuration assignment of chiral drugs, especially for the oily or semisolid substances, whose crystal structures are impossible to obtain.
2013, 24(6): 503-505
Abstract:
A method for rapid and simultaneous determination of multiple pyrrolidinium ionic liquid cations by ion chromatography with direct conductivity detection was developed. Chromatographic separations were performed on a cation exchange column using ethylenediamine-acetonitrile as the mobile phase. The effects of chromatographic column and the mobile phase, as well as the column temperature on the retention of the cations were investigated. The retention rules of the cations under different chromatographic conditions were formulated. The retention of the cations followed the carbon number rule. Themethod has been successfully applied to the determination of three ionic liquids synthesized by a chemical laboratory.
A method for rapid and simultaneous determination of multiple pyrrolidinium ionic liquid cations by ion chromatography with direct conductivity detection was developed. Chromatographic separations were performed on a cation exchange column using ethylenediamine-acetonitrile as the mobile phase. The effects of chromatographic column and the mobile phase, as well as the column temperature on the retention of the cations were investigated. The retention rules of the cations under different chromatographic conditions were formulated. The retention of the cations followed the carbon number rule. Themethod has been successfully applied to the determination of three ionic liquids synthesized by a chemical laboratory.
2013, 24(6): 506-508
Abstract:
A new method for the analysis of copper and its speciation in Rhizoma coptidis was proposed using chelatometric dispersive liquid-liquid microextraction (cDLLME) followed by capillary electrophoresis. Dithizone was used as a chelating agent for extraction and carbon tetrachloride and ethanol were used as extraction and dispersive solvent, respectively. The calibration curve was linear in the range of 0.5-20.0 μg/mL with a correlation coefficient of 0.9990 (n = 6) and the average recovery was in the range of 88.26%-94.44%. The method was successfully used to determine the total and water soluble copper in Rhizoma coptidis herbal medicine. The results suggested that it would be reasonable to setting the criterion of heavy metals in an herbal medicine according to the dosage forms.
A new method for the analysis of copper and its speciation in Rhizoma coptidis was proposed using chelatometric dispersive liquid-liquid microextraction (cDLLME) followed by capillary electrophoresis. Dithizone was used as a chelating agent for extraction and carbon tetrachloride and ethanol were used as extraction and dispersive solvent, respectively. The calibration curve was linear in the range of 0.5-20.0 μg/mL with a correlation coefficient of 0.9990 (n = 6) and the average recovery was in the range of 88.26%-94.44%. The method was successfully used to determine the total and water soluble copper in Rhizoma coptidis herbal medicine. The results suggested that it would be reasonable to setting the criterion of heavy metals in an herbal medicine according to the dosage forms.
2013, 24(6): 509-511
Abstract:
In this paper, we developed and validated a simple, sensitive, and selective high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method to identify and measure the following prohibited substances that may be found in cosmetic products: minoxidil, hydrocortisone, spironolactone, estrone, canrenone, triamcinolone acetonide and progesterone. Chromatographic separation was performed on a Waters Symmetry C18 (100 m×2.1 mm, 3.5 μm particle size) with a gradient elution system composed of 0.2% (v/v) formic acid aqueous solution and methanol containing 0.2% (v/v) formic acid at a flow rate of 0.3 mL/min. The substances were detected using a triple quadrupole mass spectrometer in the multiple reaction monitoring mode with an electrospray ionization source. All of the calibration curves showed good linearity (r > 0.999) within the tested concentration ranges. The limit of detection was <25 pg. The relative standard deviations for intraday precision for each of the prohibited substances were <3.5% at two concentration levels (2 μg/g, 10 μg/g). The relative recovery rate for each of the prohibited substances ranged from 91.8% to 111% at three concentration levels (0.1 μg/g, 2 μg/g, 10 μg/g), including the limit of quantification. In conclusion, we have developed and validated a method that can identify seven prohibited substances in cosmetic products.
In this paper, we developed and validated a simple, sensitive, and selective high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method to identify and measure the following prohibited substances that may be found in cosmetic products: minoxidil, hydrocortisone, spironolactone, estrone, canrenone, triamcinolone acetonide and progesterone. Chromatographic separation was performed on a Waters Symmetry C18 (100 m×2.1 mm, 3.5 μm particle size) with a gradient elution system composed of 0.2% (v/v) formic acid aqueous solution and methanol containing 0.2% (v/v) formic acid at a flow rate of 0.3 mL/min. The substances were detected using a triple quadrupole mass spectrometer in the multiple reaction monitoring mode with an electrospray ionization source. All of the calibration curves showed good linearity (r > 0.999) within the tested concentration ranges. The limit of detection was <25 pg. The relative standard deviations for intraday precision for each of the prohibited substances were <3.5% at two concentration levels (2 μg/g, 10 μg/g). The relative recovery rate for each of the prohibited substances ranged from 91.8% to 111% at three concentration levels (0.1 μg/g, 2 μg/g, 10 μg/g), including the limit of quantification. In conclusion, we have developed and validated a method that can identify seven prohibited substances in cosmetic products.
2013, 24(6): 512-514
Abstract:
Two new cyclic diarylheptanoids named ostryopsitrienol (1) and ostryopsitriol (2), together with six known compounds, were isolated from the stems of endemic medicinal plant of Ostryopsis nobilis (Betulaceae). The structures of the new compounds were elucidated by means of HRMS, 1D NMR, 2DNMR and X-ray crystallography analysis.
Two new cyclic diarylheptanoids named ostryopsitrienol (1) and ostryopsitriol (2), together with six known compounds, were isolated from the stems of endemic medicinal plant of Ostryopsis nobilis (Betulaceae). The structures of the new compounds were elucidated by means of HRMS, 1D NMR, 2DNMR and X-ray crystallography analysis.
2013, 24(6): 515-517
Abstract:
The natural product, 1,7-dimethoxy-2-hydroxyxanthone (1), isolated from Securidaca inappendiculate Hassk, has a potential in the treatment of erectile dysfunction due to its significant relaxation activity on rabbit Corpus cavernosum. However, the isolation of compound 1 is problematic because of its high similarity in structure to its analogs. In this paper, the first synthesis of 1 was reported featuring two key reactions: a copper-catalyzed coupling reaction and an intramolecular cyclization.
The natural product, 1,7-dimethoxy-2-hydroxyxanthone (1), isolated from Securidaca inappendiculate Hassk, has a potential in the treatment of erectile dysfunction due to its significant relaxation activity on rabbit Corpus cavernosum. However, the isolation of compound 1 is problematic because of its high similarity in structure to its analogs. In this paper, the first synthesis of 1 was reported featuring two key reactions: a copper-catalyzed coupling reaction and an intramolecular cyclization.
2013, 24(6): 518-520
Abstract:
ZnO/graphene oxide (ZnO/GO) composite material, in which ZnO nanoparticles were densely coated on the GO nanosheets, was successfully prepared by an improved two-step method and characterized by IR, XRD, TEM, and UV-vis techniques. The improved photocatalytic property of the ZnO/GO composite material, evaluated by the photocatalytic degradation of methyl orange (MO) under UV irradiation, is ascribed to the intimate contact between ZnO and GO, the enhanced adsorption ofMO, the quick electron transfer from excited ZnO particles to GO sheets and the activation of MO molecules via π-π interaction between MO and GO.
ZnO/graphene oxide (ZnO/GO) composite material, in which ZnO nanoparticles were densely coated on the GO nanosheets, was successfully prepared by an improved two-step method and characterized by IR, XRD, TEM, and UV-vis techniques. The improved photocatalytic property of the ZnO/GO composite material, evaluated by the photocatalytic degradation of methyl orange (MO) under UV irradiation, is ascribed to the intimate contact between ZnO and GO, the enhanced adsorption ofMO, the quick electron transfer from excited ZnO particles to GO sheets and the activation of MO molecules via π-π interaction between MO and GO.
2013, 24(6): 521-523
Abstract:
A new diarylheptanoid glucoside, (8R,9R)-17-methoxy-2-oxatricyclo[13.2.2.13,7]icosa-1(17),3(20),4,6, 15,18-hexaene-4,9,10-triol-9-O-β-D-glucopyranoside (1), namely jugcathayenoside, together with two known diarylheptanoids, (+)-galeon (2) and 4-hydroxy-17-methoxy-2-oxatricyclo[13.2.2.13,7 ]icosa-1(17),3(20),4,6,15,18-hexaene-9-one (3), were isolated from the root bark of Juglans cathayensis. Their structures were elucidated on the basis of extensive spectroscopic data analysis.
A new diarylheptanoid glucoside, (8R,9R)-17-methoxy-2-oxatricyclo[13.2.2.13,7]icosa-1(17),3(20),4,6, 15,18-hexaene-4,9,10-triol-9-O-β-D-glucopyranoside (1), namely jugcathayenoside, together with two known diarylheptanoids, (+)-galeon (2) and 4-hydroxy-17-methoxy-2-oxatricyclo[13.2.2.13,7 ]icosa-1(17),3(20),4,6,15,18-hexaene-9-one (3), were isolated from the root bark of Juglans cathayensis. Their structures were elucidated on the basis of extensive spectroscopic data analysis.
2013, 24(6): 524-526
Abstract:
Bioassay-guided fractionation of the acid hydrolysate of total ginsenosides of Panax ginseng C.A. Meyer (Araliaceae) led to the isolation of a novel ginsengenin (1). The structure of 1 was determined as (20S,22S)-dammar-22,25-epoxy-3β,,12β,20-triol by extensive spectroscopy and single-crystal X-ray diffraction analyses. The cytotoxicity of 1 was further tested against SW1116, HCT116, and A549 cells by the MTT method, with IC50 values in the range of 2.96-30.9 μmol/L.
Bioassay-guided fractionation of the acid hydrolysate of total ginsenosides of Panax ginseng C.A. Meyer (Araliaceae) led to the isolation of a novel ginsengenin (1). The structure of 1 was determined as (20S,22S)-dammar-22,25-epoxy-3β,,12β,20-triol by extensive spectroscopy and single-crystal X-ray diffraction analyses. The cytotoxicity of 1 was further tested against SW1116, HCT116, and A549 cells by the MTT method, with IC50 values in the range of 2.96-30.9 μmol/L.
2013, 24(6): 527-530
Abstract:
A series of novel chiral C2-symmetric multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis(o-formylphenyl)phenylphosphane and easily available monoprotected (1R,2R)-diaminocyclohexane. The catalytic properties of these ligands were investigated in Ir-catalyzed asymmetric transfer hydrogenation of various aromatic ketones, giving the corresponding optical active alcohols with up to 98% conversion and good ee under mild reaction conditions.
A series of novel chiral C2-symmetric multidentate aminophosphine ligands have been successfully synthesized by Schiff-base condensation of bis(o-formylphenyl)phenylphosphane and easily available monoprotected (1R,2R)-diaminocyclohexane. The catalytic properties of these ligands were investigated in Ir-catalyzed asymmetric transfer hydrogenation of various aromatic ketones, giving the corresponding optical active alcohols with up to 98% conversion and good ee under mild reaction conditions.
2013, 24(6): 531-534
Abstract:
Series of novel derivatives of desloratadine designed as arginine vasopressin receptor antagonists were synthesized and structurally characterized by melting points, 1H NMR and HRMS. Their in vivo diuretic activities were evaluated on rats, and several target compounds showed promising diuretic results, especially compounds 8, 18, 27 and 31. Further in vitro bonding assay and cAMP assay showed that these compounds had a higher affinity to vasopressin V2 receptor than V1a receptor. Our studies indicated that desloratadine may be an active substructure for novel arginine vasopressin receptor antagonist development.
Series of novel derivatives of desloratadine designed as arginine vasopressin receptor antagonists were synthesized and structurally characterized by melting points, 1H NMR and HRMS. Their in vivo diuretic activities were evaluated on rats, and several target compounds showed promising diuretic results, especially compounds 8, 18, 27 and 31. Further in vitro bonding assay and cAMP assay showed that these compounds had a higher affinity to vasopressin V2 receptor than V1a receptor. Our studies indicated that desloratadine may be an active substructure for novel arginine vasopressin receptor antagonist development.
2013, 24(6): 535-538
Abstract:
An efficient method was developed for chlorination of aromatic compounds with electron-donating groups using iodobenzene as the catalyst and m-chloroperbenzoic acid as the terminal oxidant in the presence of 4-methylbenzenesulfonic acid in THF at room temperature for 24 h, and a series of the monochlorinated compounds was obtained in good yields. In this protocol, the catalyst iodobenzene was first oxidized into the hypervalent iodine intermediate, which then treated with lithium chloride and finally reacted with aromatic compounds to form the chlorinated compounds.
An efficient method was developed for chlorination of aromatic compounds with electron-donating groups using iodobenzene as the catalyst and m-chloroperbenzoic acid as the terminal oxidant in the presence of 4-methylbenzenesulfonic acid in THF at room temperature for 24 h, and a series of the monochlorinated compounds was obtained in good yields. In this protocol, the catalyst iodobenzene was first oxidized into the hypervalent iodine intermediate, which then treated with lithium chloride and finally reacted with aromatic compounds to form the chlorinated compounds.
2013, 24(6): 539-541
Abstract:
Graphene-Fe3O4 nanocomposite (G-Fe3O4) was synthesized by a chemical co-precipitation method which was used as an efficient catalyst for the reduction of nitroarenes with hydrazine hydrate. The method has been applied to a broad range of compounds with different properties and the yields were in the range of 75%-92%. The G-Fe3O4 catalyst can be readily recovered and reused 5 times without significant loss of the catalytic activity.
Graphene-Fe3O4 nanocomposite (G-Fe3O4) was synthesized by a chemical co-precipitation method which was used as an efficient catalyst for the reduction of nitroarenes with hydrazine hydrate. The method has been applied to a broad range of compounds with different properties and the yields were in the range of 75%-92%. The G-Fe3O4 catalyst can be readily recovered and reused 5 times without significant loss of the catalytic activity.
2013, 24(6): 542-544
Abstract:
A rapid headspace single-drop micro-extraction (mix) gas chromatography mass spectrometry (SDME-GC-MS) for the analysis of the volatile compounds in Herba Asari was developed in this study. A mixed solvent of n-tridecane and butyl acetate (1:1) was finally used for the extraction at 70 ℃ for 15 min with sample amount of 0.750 g and 100 mesh particle size. Under the determined conditions, the pound samples of Herba Asari were directly applied for the analysis. SDME-GC-MS, SPME-GC-MS and SD-GC-MS methods were compared and the results showed that SDME-GC-MS method was a simple, inexpensive and effective way to measure the volatile compounds in Herba Asari and could be used for the analysis of volatile compounds in complex samples.
A rapid headspace single-drop micro-extraction (mix) gas chromatography mass spectrometry (SDME-GC-MS) for the analysis of the volatile compounds in Herba Asari was developed in this study. A mixed solvent of n-tridecane and butyl acetate (1:1) was finally used for the extraction at 70 ℃ for 15 min with sample amount of 0.750 g and 100 mesh particle size. Under the determined conditions, the pound samples of Herba Asari were directly applied for the analysis. SDME-GC-MS, SPME-GC-MS and SD-GC-MS methods were compared and the results showed that SDME-GC-MS method was a simple, inexpensive and effective way to measure the volatile compounds in Herba Asari and could be used for the analysis of volatile compounds in complex samples.
