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2008 Volume 19 Issue 6
2008, 19(6): 631-633
doi: 10.1016/j.cclet.2008.04.006
Abstract:
One novel carbon-carbon bond insertion reaction of arynes has been developed. By this reaction β-keto sulfones can insert the triple bond of arynes to prepare polysubstituted ortho-keto benzyl sulfones.
One novel carbon-carbon bond insertion reaction of arynes has been developed. By this reaction β-keto sulfones can insert the triple bond of arynes to prepare polysubstituted ortho-keto benzyl sulfones.
2008, 19(6): 634-638
doi: 10.1016/j.cclet.2008.04.016
Abstract:
A novel POSS-based organic/inorganic hybrid covalently attached at molecular level, 2-(4-(allyloxy)phenyl)-5-(4-(octyloxy)phenyl)-1,3,4-oxadiazole-POSS (6) (abbreviated as oxadiazole-POSS) was synthesized by Pt (dcp) catalyst. The hybrid was soluble in common organic solvents such as CHCl3, toluene, C2H4Cl2, and THF. Its structures and properties were characterized and evaluated with FTIR, 1H NMR, 13C NMR, 29Si NMR, EA, TGA, DSC, GPC, and CV, respectively. The results show that the novel hybrid possesses high thermal stability and good electron injection ability.
A novel POSS-based organic/inorganic hybrid covalently attached at molecular level, 2-(4-(allyloxy)phenyl)-5-(4-(octyloxy)phenyl)-1,3,4-oxadiazole-POSS (6) (abbreviated as oxadiazole-POSS) was synthesized by Pt (dcp) catalyst. The hybrid was soluble in common organic solvents such as CHCl3, toluene, C2H4Cl2, and THF. Its structures and properties were characterized and evaluated with FTIR, 1H NMR, 13C NMR, 29Si NMR, EA, TGA, DSC, GPC, and CV, respectively. The results show that the novel hybrid possesses high thermal stability and good electron injection ability.
2008, 19(6): 639-642
doi: 10.1016/j.cclet.2008.03.027
Abstract:
2,5-Di-substituted 1,3,4-oxadiazoles 3a-n have been synthesized as a one pot procedure from the reaction of acid hydrazide 1, acyl halides 2 and phosphorus pentoxide in acetonitrile at room temperature. High yield, short reaction time (10-15 min), mild condition, and easy work-up are advantages of this methodology.
2,5-Di-substituted 1,3,4-oxadiazoles 3a-n have been synthesized as a one pot procedure from the reaction of acid hydrazide 1, acyl halides 2 and phosphorus pentoxide in acetonitrile at room temperature. High yield, short reaction time (10-15 min), mild condition, and easy work-up are advantages of this methodology.
2008, 19(6): 643-646
doi: 10.1016/j.cclet.2008.03.005
Abstract:
An unexpected multi-component reaction of cyanothioacetamide with aldehyde and aminopyrazole under MWI was reported. Through this reaction, a series of pyrazolo[3,4-b]-pyridine derivatives was prepared in high yields via simple operational procedure.
An unexpected multi-component reaction of cyanothioacetamide with aldehyde and aminopyrazole under MWI was reported. Through this reaction, a series of pyrazolo[3,4-b]-pyridine derivatives was prepared in high yields via simple operational procedure.
2008, 19(6): 647-650
doi: 10.1016/j.cclet.2008.04.008
Abstract:
Amorphous 2,4,6-trissubstituted pyridines containing three peripheral carbazole or two triphenylamine and one carbazole moieties, respectively, have been synthesized and characterized. The properties of the compounds are investigated by UV-visabsorption, photoluminescence spectroscopy, thermal analysis as well as cyclic voltammetry. The results show that the compounds have high thermal stability, emit blue light. Also, the compounds possess the HOMO and LUMO energy levels comparable to those of NPB. The effects of different substituents on the electronic properties of the materials have been discussed.
Amorphous 2,4,6-trissubstituted pyridines containing three peripheral carbazole or two triphenylamine and one carbazole moieties, respectively, have been synthesized and characterized. The properties of the compounds are investigated by UV-visabsorption, photoluminescence spectroscopy, thermal analysis as well as cyclic voltammetry. The results show that the compounds have high thermal stability, emit blue light. Also, the compounds possess the HOMO and LUMO energy levels comparable to those of NPB. The effects of different substituents on the electronic properties of the materials have been discussed.
2008, 19(6): 651-654
doi: 10.1016/j.cclet.2008.04.009
Abstract:
Diamidine (A) was identified in our in vitro bio-assay as a possible inhibitor of ketol-acid reductoisomerase (KARI) from the ACD database search based on the known three-dimensional crystal structure of KARI. An investigation on interaction of A on KARI active sites, led to the design and synthesis of 15 novel monoamidines. Some of those showed better biological activity than A on rice KARI (in vitro) and in greenhouse herbicidal tests (in vivo). The structure-biological activity relationship was investigated, which provides valuable information to further study of potential KARI inhibitors.
Diamidine (A) was identified in our in vitro bio-assay as a possible inhibitor of ketol-acid reductoisomerase (KARI) from the ACD database search based on the known three-dimensional crystal structure of KARI. An investigation on interaction of A on KARI active sites, led to the design and synthesis of 15 novel monoamidines. Some of those showed better biological activity than A on rice KARI (in vitro) and in greenhouse herbicidal tests (in vivo). The structure-biological activity relationship was investigated, which provides valuable information to further study of potential KARI inhibitors.
2008, 19(6): 655-657
doi: 10.1016/j.cclet.2008.04.015
Abstract:
In this work, the preparation of α, ω-dichloride-terminated multi-vinyl branched siloxane 1 (yield:57.1%) used for self-healing polymer composites were synthesized via ring-opening of 1,3,5,7-tetravinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane (D4Vi) in the presence of vinylmethydichlorosilane (VM-32). 1 was hydrogenated by aluminum lithium hydride (LiAlH4) to get self-healing monomer 2 (yield:79.8%) which contained both Si-H bonds and Si-vinyl bonds. Then hydrosilation occurred between these two bands and finally silicone 3 was obtained, showing the potential of self-healing.
In this work, the preparation of α, ω-dichloride-terminated multi-vinyl branched siloxane 1 (yield:57.1%) used for self-healing polymer composites were synthesized via ring-opening of 1,3,5,7-tetravinyl-1,3,5,7-tetramethyl-cyclotetrasiloxane (D4Vi) in the presence of vinylmethydichlorosilane (VM-32). 1 was hydrogenated by aluminum lithium hydride (LiAlH4) to get self-healing monomer 2 (yield:79.8%) which contained both Si-H bonds and Si-vinyl bonds. Then hydrosilation occurred between these two bands and finally silicone 3 was obtained, showing the potential of self-healing.
2008, 19(6): 658-660
doi: 10.1016/j.cclet.2008.04.019
Abstract:
The total synthesis of (±)-abyssinoflavanone V was first achieved through C-prenylation, selective protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap 4-hydroxybenzaldehyde and 2,4,6-trihydroxyacetophenone, with total yield 24%. All structures of new compounds were confirmed by IR,1H NMR and MS.
The total synthesis of (±)-abyssinoflavanone V was first achieved through C-prenylation, selective protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap 4-hydroxybenzaldehyde and 2,4,6-trihydroxyacetophenone, with total yield 24%. All structures of new compounds were confirmed by IR,1H NMR and MS.
2008, 19(6): 661-664
doi: 10.1016/j.cclet.2008.04.003
Abstract:
Substituted 2-halomethy1-2,3-dihydrobenzofurans were synthesized in one pot and in mild yield from substituted o-allylphenols with diacetoxyiodobenzene in the presence of I2 or Br2 in dry CH2Cl2 under reflux.
Substituted 2-halomethy1-2,3-dihydrobenzofurans were synthesized in one pot and in mild yield from substituted o-allylphenols with diacetoxyiodobenzene in the presence of I2 or Br2 in dry CH2Cl2 under reflux.
2008, 19(6): 665-668
doi: 10.1016/j.cclet.2008.04.004
Abstract:
Silica sulfuric acid was developed as a stable and efficient heterogeneous catalyst in organic synthesis. This solid acid catalyzed the regioselective ring opening of epoxides by thiocyanate anion to give thiocyanohydrins as key intermediates in agricultural and pharmaceutical chemistry in high yields under solvent-free conditions.
Silica sulfuric acid was developed as a stable and efficient heterogeneous catalyst in organic synthesis. This solid acid catalyzed the regioselective ring opening of epoxides by thiocyanate anion to give thiocyanohydrins as key intermediates in agricultural and pharmaceutical chemistry in high yields under solvent-free conditions.
2008, 19(6): 669-672
doi: 10.1016/j.cclet.2008.04.020
Abstract:
A series of imidazo [1,2-a] pyrimidine derivatives substituted adjacently with two aryls at positions 2 and 3 were designed and synthesized in order to improve their anti-inflammatory activities. Biological tests suggested that these compounds have antiinflammatory activities with COX-2 selectivity to some extent.
A series of imidazo [1,2-a] pyrimidine derivatives substituted adjacently with two aryls at positions 2 and 3 were designed and synthesized in order to improve their anti-inflammatory activities. Biological tests suggested that these compounds have antiinflammatory activities with COX-2 selectivity to some extent.
2008, 19(6): 673-675
doi: 10.1016/j.cclet.2008.04.010
Abstract:
Histone deacetylases (HDACs) play an important role in tumorigenesis. Inhibition of HDACs is considered as a potent strategy for cancer therapy. Two lead compounds (ja and jb) were found to have activities against HDACs with IC50 at about 15 μmol/L. Then a new series of hydroximic acid derivatives were designed and synthesized based on them. The HDACs activity assay in vitro found that compounds J04 and J09 are nearly as potent as the positive control drug Zolinza.
Histone deacetylases (HDACs) play an important role in tumorigenesis. Inhibition of HDACs is considered as a potent strategy for cancer therapy. Two lead compounds (ja and jb) were found to have activities against HDACs with IC50 at about 15 μmol/L. Then a new series of hydroximic acid derivatives were designed and synthesized based on them. The HDACs activity assay in vitro found that compounds J04 and J09 are nearly as potent as the positive control drug Zolinza.
2008, 19(6): 676-680
doi: 10.1016/j.cclet.2008.04.005
Abstract:
A mild, efficient and fast method for direct oxidation of trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds using trinitratocerium (IV) bromate (TNCB) supported on NaHSO4·H2O under solvent-flee conditions is reported.
A mild, efficient and fast method for direct oxidation of trimethylsilyl, tetrahydropyranyl and methoxymethyl ethers to their corresponding carbonyl compounds using trinitratocerium (IV) bromate (TNCB) supported on NaHSO4·H2O under solvent-flee conditions is reported.
2008, 19(6): 681-684
doi: 10.1016/j.cclet.2008.04.021
Abstract:
Tetrahydrosalen ligand was employed in the synthesis of gadolinium complex. The ligand was deprotoned by LiBu, and the afforded lithium salt was reacted with anhydrous GdCl3 to produce the gadolinium complex through salt metathesis. This complex was successfully used to initiate the ring-opening polymerization of ε-caprolactone. The initiation conditions in different temperature, monomer-to-initiator ratio and time were investigated. Under the condition:[ε-caprolactone]:[catalyst]=600,56℃, toluene:2ml, poly(ε-caprolactone) (PCL) with Mw=11,2782 and PDI=1.96 was achieved.
Tetrahydrosalen ligand was employed in the synthesis of gadolinium complex. The ligand was deprotoned by LiBu, and the afforded lithium salt was reacted with anhydrous GdCl3 to produce the gadolinium complex through salt metathesis. This complex was successfully used to initiate the ring-opening polymerization of ε-caprolactone. The initiation conditions in different temperature, monomer-to-initiator ratio and time were investigated. Under the condition:[ε-caprolactone]:[catalyst]=600,56℃, toluene:2ml, poly(ε-caprolactone) (PCL) with Mw=11,2782 and PDI=1.96 was achieved.
2008, 19(6): 685-688
doi: 10.1016/j.cclet.2008.04.022
Abstract:
A new one-pot neat synthesis of some 5-aryl-2,4-dihydro-3H-1,2,4-triazol-3-ones through cyclocondensation of ethyl carbazate with aryl nitriles catalyzed by DMAP as an efficient and basic nucleophilic catalyst is described.
A new one-pot neat synthesis of some 5-aryl-2,4-dihydro-3H-1,2,4-triazol-3-ones through cyclocondensation of ethyl carbazate with aryl nitriles catalyzed by DMAP as an efficient and basic nucleophilic catalyst is described.
2008, 19(6): 689-692
doi: 10.1016/j.cclet.2008.03.035
Abstract:
Two series of novel derivatives of 4,5,6,7-tetrahydromieno [3,2-c] pyridine were synthesized and structurally characterized by 1H NMR and MS. Their in vivo antiplatelet aggregation activities were evaluated.
Two series of novel derivatives of 4,5,6,7-tetrahydromieno [3,2-c] pyridine were synthesized and structurally characterized by 1H NMR and MS. Their in vivo antiplatelet aggregation activities were evaluated.
2008, 19(6): 693-695
doi: 10.1016/j.cclet.2008.04.002
Abstract:
Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as (+)-5-(1,2-dihydroxypentyl)-benzene-1,3-diol and (-)-5-(1,2-dihydroxypentyl) benzene-1,3-diol.
Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as (+)-5-(1,2-dihydroxypentyl)-benzene-1,3-diol and (-)-5-(1,2-dihydroxypentyl) benzene-1,3-diol.
2008, 19(6): 696-698
doi: 10.1016/j.cclet.2007.12.038
Abstract:
The chemical constituents of the stems of Schisandra sphenanthera are described for the first time. This investigation has resulted in the isolation of a new phenolic glycoside (1), along with seven known compounds. The structure of 1 was assigned by using spectroscopic techniques, including 2D NMR spectra.
The chemical constituents of the stems of Schisandra sphenanthera are described for the first time. This investigation has resulted in the isolation of a new phenolic glycoside (1), along with seven known compounds. The structure of 1 was assigned by using spectroscopic techniques, including 2D NMR spectra.
2008, 19(6): 699-702
doi: 10.1016/j.cclet.2008.04.017
Abstract:
A highly sensitive telomerase detection method that combines telomeric repeat amplification protocol (TRAP) and magnetic beads based electrochemiluminescence (ECL) assay has been developed. Briefly, telomerase recognizes biotinylated telomerase synthesis primer (B-TS) and synthesizes extension products, which then serve as the templates for PCR amplification using B-TS as the forward primer and Iris-(2´2´-bipyridyl) ruthenium (TBR) labeled ACX (TBR-ACX) as the reversed primer. The amplified product is captured on streptavidin-coated paramagnetic beads and detected by ECL. Telomerase positive HeLa cells were used to validate the feasibility of the method. The experimental results showed down to 10 cancer cells can be detected easily. The method is a useful tool for telomerase activity analysis due to its sensitivity, rapidity, safety, high throughput, and low cost. It can be used for screening a large amount of clinical samples.
A highly sensitive telomerase detection method that combines telomeric repeat amplification protocol (TRAP) and magnetic beads based electrochemiluminescence (ECL) assay has been developed. Briefly, telomerase recognizes biotinylated telomerase synthesis primer (B-TS) and synthesizes extension products, which then serve as the templates for PCR amplification using B-TS as the forward primer and Iris-(2´2´-bipyridyl) ruthenium (TBR) labeled ACX (TBR-ACX) as the reversed primer. The amplified product is captured on streptavidin-coated paramagnetic beads and detected by ECL. Telomerase positive HeLa cells were used to validate the feasibility of the method. The experimental results showed down to 10 cancer cells can be detected easily. The method is a useful tool for telomerase activity analysis due to its sensitivity, rapidity, safety, high throughput, and low cost. It can be used for screening a large amount of clinical samples.
2008, 19(6): 703-706
doi: 10.1016/j.cclet.2008.04.001
Abstract:
Based on the electrocatalytic oxidation of levodopa at gold electrode and the reduction of permanganate at platinum electrode, a novel flow injection irreversible biamperometric method is developed for the determination of levodopa under the potential difference of 0 V imposed between two electrodes. In H2SO4 solution, the linear relationships between currents and the concentrations of levodopa are obtained in the range from 0.04mg/L to 20mg/L with the detection limit of 0.012mg/L. The proposed method is applied to the determination of levodopa in pharmaceutical preparations.
Based on the electrocatalytic oxidation of levodopa at gold electrode and the reduction of permanganate at platinum electrode, a novel flow injection irreversible biamperometric method is developed for the determination of levodopa under the potential difference of 0 V imposed between two electrodes. In H2SO4 solution, the linear relationships between currents and the concentrations of levodopa are obtained in the range from 0.04mg/L to 20mg/L with the detection limit of 0.012mg/L. The proposed method is applied to the determination of levodopa in pharmaceutical preparations.
2008, 19(6): 707-710
doi: 10.1016/j.cclet.2008.04.012
Abstract:
In this work, the capillary electrophoresis mobility shift assay (CEMSA) was first adopted to study the interaction of protein with quantum dots (QDs). In this study, bovine serum albumin (BSA) and CdTe QDs were used as model samples. We observed that BSA was facilely adsorbed to CdTe QDs surface, and the QD-BSA complex was formed by a 1:1 stoichiometric ratio. A value of 2.17±0.27×106mol-1 L--1 (at 25℃) for the association constant was obtained by CEMSA.
In this work, the capillary electrophoresis mobility shift assay (CEMSA) was first adopted to study the interaction of protein with quantum dots (QDs). In this study, bovine serum albumin (BSA) and CdTe QDs were used as model samples. We observed that BSA was facilely adsorbed to CdTe QDs surface, and the QD-BSA complex was formed by a 1:1 stoichiometric ratio. A value of 2.17±0.27×106mol-1 L--1 (at 25℃) for the association constant was obtained by CEMSA.
2008, 19(6): 711-715
doi: 10.1016/j.cclet.2008.04.025
Abstract:
A new tetrastilbene named carasinol D (1) was isolated from the roots of Caragana sinica. Its structure was elucidated by spectroscopic analysis. Compound 1 was obtained from carasinol B (2) by an acid-catalyzed conversion.
A new tetrastilbene named carasinol D (1) was isolated from the roots of Caragana sinica. Its structure was elucidated by spectroscopic analysis. Compound 1 was obtained from carasinol B (2) by an acid-catalyzed conversion.
2008, 19(6): 716-719
doi: 10.1016/j.cclet.2008.04.026
Abstract:
A highly sensitive indirect spectrophotometric red-ox method for the determination of osmium is reported. The method is based on the oxidation of iodide by osmium (VI) and the spectrophotometric detection of the liberated iodine in the form of complex anion and ion associate with 2-(4-diethylaminostyryl)-1,3,3-trimethyl-6-nitro-3H-indolium chloride reagent. The appropriate reaction conditions have been established. The molar absorptivity is (1.6-5.6)×104 L mol-1cm-1. Beer's law holds for the concentration range of 0.5-11.4μgmL-1 of Os(Ⅵ).
A highly sensitive indirect spectrophotometric red-ox method for the determination of osmium is reported. The method is based on the oxidation of iodide by osmium (VI) and the spectrophotometric detection of the liberated iodine in the form of complex anion and ion associate with 2-(4-diethylaminostyryl)-1,3,3-trimethyl-6-nitro-3H-indolium chloride reagent. The appropriate reaction conditions have been established. The molar absorptivity is (1.6-5.6)×104 L mol-1cm-1. Beer's law holds for the concentration range of 0.5-11.4μgmL-1 of Os(Ⅵ).
2008, 19(6): 720-724
doi: 10.1016/j.cclet.2008.04.018
Abstract:
The deaggregating ability of β-CD and α-CD against the aggregated n-hexadecyl β-naphthoate (A16) and n-dodecyl β-naphthoate (A12) depended not only on the aggregating tendency of A16 and A12 but also on the initial concentration of the aggregated A16 or A12. The inclusive ability of β-CD with the substrates is greater than that of α-CD under hydrophobic lipophilie interaction.
The deaggregating ability of β-CD and α-CD against the aggregated n-hexadecyl β-naphthoate (A16) and n-dodecyl β-naphthoate (A12) depended not only on the aggregating tendency of A16 and A12 but also on the initial concentration of the aggregated A16 or A12. The inclusive ability of β-CD with the substrates is greater than that of α-CD under hydrophobic lipophilie interaction.
2008, 19(6): 725-729
doi: 10.1016/j.cclet.2008.03.003
Abstract:
The effect of dopant valence on oxygen desorption and oxygen permeability of SrCo0.4Fe0.5M0.1O3-δ(M=Ni, Al and Zr) mixed-conducting oxides were investigated in detail by O2-TPD and oxygen permeation measurement. The SrCo0.4Fe0.5M0.1O3-δ for M=Fe, Ni, AI and Zr were denoted as SCF, SCFN, SCFA and SCFZ, respectively. O2-TPD analysis revealed that the amount of α oxygen desorption decreased with increasing the valance of doped metal elements (SCFN > SCFA≈SCF > SCFZ). The oxygen permeation flux at the temperature higher than 1148 K decreased in the order of SCFN > SCF > SCFZ > SCFA. Single activation for oxygen permeation was observed for SCFZ oxide and the activation energies of SCF and SCFA change at around 1073K, while the change temperature of SCFN was about 1173K.
The effect of dopant valence on oxygen desorption and oxygen permeability of SrCo0.4Fe0.5M0.1O3-δ(M=Ni, Al and Zr) mixed-conducting oxides were investigated in detail by O2-TPD and oxygen permeation measurement. The SrCo0.4Fe0.5M0.1O3-δ for M=Fe, Ni, AI and Zr were denoted as SCF, SCFN, SCFA and SCFZ, respectively. O2-TPD analysis revealed that the amount of α oxygen desorption decreased with increasing the valance of doped metal elements (SCFN > SCFA≈SCF > SCFZ). The oxygen permeation flux at the temperature higher than 1148 K decreased in the order of SCFN > SCF > SCFZ > SCFA. Single activation for oxygen permeation was observed for SCFZ oxide and the activation energies of SCF and SCFA change at around 1073K, while the change temperature of SCFN was about 1173K.
2008, 19(6): 730-733
doi: 10.1016/j.cclet.2008.03.021
Abstract:
Peroxidase-like catalytic properties of Fe3O4 nanoparticles (NPs) with three different sizes, synthesized by chemical coprecipitation and sol-gel methods, were investigated by UV-vis spectrum analysis. By comparing Fe3O4 NPs with average diameters of 11,20, and 150 nm, we found that the catalytic activity increases with the reduced nanoparticle size. The electrochemical method to characterize the catalytic activity of Fe3O4 NPs using the response currents of the reaction product and substrate was also developed.
Peroxidase-like catalytic properties of Fe3O4 nanoparticles (NPs) with three different sizes, synthesized by chemical coprecipitation and sol-gel methods, were investigated by UV-vis spectrum analysis. By comparing Fe3O4 NPs with average diameters of 11,20, and 150 nm, we found that the catalytic activity increases with the reduced nanoparticle size. The electrochemical method to characterize the catalytic activity of Fe3O4 NPs using the response currents of the reaction product and substrate was also developed.
2008, 19(6): 734-738
doi: 10.1016/j.cclet.2008.03.007
Abstract:
Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity (ca. 95%) and high molecular weight (ca. 105) in the presence of the triisobutyl aluminium (AliBu3) as cocatalyst. The microstructure of obtained polyisoprene was investigated by FTIR, 1H NMR. Two different kinds of active centers in the catalyst system were examined by GPC method.
Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity (ca. 95%) and high molecular weight (ca. 105) in the presence of the triisobutyl aluminium (AliBu3) as cocatalyst. The microstructure of obtained polyisoprene was investigated by FTIR, 1H NMR. Two different kinds of active centers in the catalyst system were examined by GPC method.
2008, 19(6): 739-741
doi: 10.1016/j.cclet.2008.04.014
Abstract:
Three fluorescent indocyanines containing p-carboxybenzyl groups on N atoms in the heterocyclic rings were synthesized under supersonic. The maxima wavelength of the absorption and emission of the dyes were 550-800 nm in water. Compared with those in aqueous solutions, the fluorescence intensity of the dyes in the α/β-cyclodextrin, Al3+, Zn2+, Sn2+ or the α/β-cyclodextrin in the aqueous solutions of the cations became stronger. The crystal shapes of the dyes and their cyclodextrin inclusions were mostly acicular or polygon. The NHS-carboxyl squarylium indocyanine was prepared and used to conjugate with taurine or benzylamine, the results indicated that the dyes could couple covalently to biomass containing free NH2 group. Structure and some thermal parameters of the molecule of the trimethine cyanine were obtained by DFT method of Gaussian 03.
Three fluorescent indocyanines containing p-carboxybenzyl groups on N atoms in the heterocyclic rings were synthesized under supersonic. The maxima wavelength of the absorption and emission of the dyes were 550-800 nm in water. Compared with those in aqueous solutions, the fluorescence intensity of the dyes in the α/β-cyclodextrin, Al3+, Zn2+, Sn2+ or the α/β-cyclodextrin in the aqueous solutions of the cations became stronger. The crystal shapes of the dyes and their cyclodextrin inclusions were mostly acicular or polygon. The NHS-carboxyl squarylium indocyanine was prepared and used to conjugate with taurine or benzylamine, the results indicated that the dyes could couple covalently to biomass containing free NH2 group. Structure and some thermal parameters of the molecule of the trimethine cyanine were obtained by DFT method of Gaussian 03.
2008, 19(6): 742-746
doi: 10.1016/j.cclet.2008.03.016
Abstract:
A photocatalyst of nanometer TiO2/conjugated polymer complex was successfully synthesized and characterized by spectroscopic methods and photocatalytic experiments. The complex photocatalyst could be activated by absorbing both ultraviolet and visible light (λ=190-800nm). Methylene blue (MB) could be degraded more efficiently on the complex photocatalyst than on the TiO2 under natural light. The conjugated polymer played a promoting role in the photocatalytic degradation of MB. The calcination temperature had an important effect in degradation of dye and could be summarized as 260℃ > 300℃ > 340℃ > 220℃ > 180℃.
A photocatalyst of nanometer TiO2/conjugated polymer complex was successfully synthesized and characterized by spectroscopic methods and photocatalytic experiments. The complex photocatalyst could be activated by absorbing both ultraviolet and visible light (λ=190-800nm). Methylene blue (MB) could be degraded more efficiently on the complex photocatalyst than on the TiO2 under natural light. The conjugated polymer played a promoting role in the photocatalytic degradation of MB. The calcination temperature had an important effect in degradation of dye and could be summarized as 260℃ > 300℃ > 340℃ > 220℃ > 180℃.
2008, 19(6): 747-751
doi: 10.1016/j.cclet.2008.04.013
Abstract:
In order to understand whether the ameliorating effect on old ages memory disorder by the root of Salvia miltiorhiza is related to the acetylcholinesterase (AChE) inhibition, two main ingredients, salvianolic acid B (1) and rosmarinic acid (2), which were isolated from S. miltiorhiza water extract, were investigated in vitro byNMR relaxation rate in this work. The results showed that the proton selective relaxation rates and the molecular rotational correlation time of proton pairs for compounds 1 and 2 increased significantly by adding of AChE in mixing solution. The study reveals that the two compounds might bind to the enzyme and have AChE inhibitory effect, which could contribute to the ameliorating effect at some extent on old ages memory disorder.
In order to understand whether the ameliorating effect on old ages memory disorder by the root of Salvia miltiorhiza is related to the acetylcholinesterase (AChE) inhibition, two main ingredients, salvianolic acid B (1) and rosmarinic acid (2), which were isolated from S. miltiorhiza water extract, were investigated in vitro byNMR relaxation rate in this work. The results showed that the proton selective relaxation rates and the molecular rotational correlation time of proton pairs for compounds 1 and 2 increased significantly by adding of AChE in mixing solution. The study reveals that the two compounds might bind to the enzyme and have AChE inhibitory effect, which could contribute to the ameliorating effect at some extent on old ages memory disorder.
2008, 19(6): 752-755
doi: 10.1016/j.cclet.2008.04.007
Abstract:
The 2-methylpyrazine was synthesized by catalytic reaction of ethylene diamine and propylene glycol at 380℃. The alumina supported copper catalysts with promoter were prepared by impregnation method, characterized by ICP-AES, BET and TPR. The results demonstrated that the dehydrogenation was improved by addition of chromium promoter. The selectivity of 2-methylpyrazine reached 84.75%, while the conversions of reactants were also enhanced.
The 2-methylpyrazine was synthesized by catalytic reaction of ethylene diamine and propylene glycol at 380℃. The alumina supported copper catalysts with promoter were prepared by impregnation method, characterized by ICP-AES, BET and TPR. The results demonstrated that the dehydrogenation was improved by addition of chromium promoter. The selectivity of 2-methylpyrazine reached 84.75%, while the conversions of reactants were also enhanced.
2008, 19(6): 756-757
doi: 10.1016/j.cclet.2007.12.023
Abstract:
The role of acrylamide on the human peripheral lymphocytes was studied by laser scanning confocal microscopy technique and fluo-3. The calibration value of the apparent dissociation constant (Kd) of the fluo-3-Ca2+ complex was obtained as 4.83×10-7mol/L. Acrylamide ( < 54μg/mL) evoked a rise in free intracellular calcium concentration [Ca2+]i, in a dose dependent manner. Acrylamide induced the increase of [Ca2+]i was discussed in detail.
The role of acrylamide on the human peripheral lymphocytes was studied by laser scanning confocal microscopy technique and fluo-3. The calibration value of the apparent dissociation constant (Kd) of the fluo-3-Ca2+ complex was obtained as 4.83×10-7mol/L. Acrylamide ( < 54μg/mL) evoked a rise in free intracellular calcium concentration [Ca2+]i, in a dose dependent manner. Acrylamide induced the increase of [Ca2+]i was discussed in detail.
