Login In
2003 Volume 14 Issue 7
2003, 14(7): 661-662
Abstract:
3-Carboxycoumsrins were synthesized via the solid phase synthesis conviently. The resin bound cyclic malonic ester reacted with o-methoxy or o-hydroxybenzaldehydes. Then cyclization was processed under H2SO4 to afford the products in excellent purities and yields.
3-Carboxycoumsrins were synthesized via the solid phase synthesis conviently. The resin bound cyclic malonic ester reacted with o-methoxy or o-hydroxybenzaldehydes. Then cyclization was processed under H2SO4 to afford the products in excellent purities and yields.
2003, 14(7): 663-666
Abstract:
Aldol condensation of acetylferrocene with aromatic aldehydes afforded ferroceny-lenones in 76%-92% yields under ultrasound at room temperature
Aldol condensation of acetylferrocene with aromatic aldehydes afforded ferroceny-lenones in 76%-92% yields under ultrasound at room temperature
2003, 14(7): 667-669
Abstract:
A series of novel cyclic derivatives have been synthesized by utilizing a nickel powder mediated radical cyclization as the key step. The structures of the new compounds were confirmed by 1H-NMR and MS.
A series of novel cyclic derivatives have been synthesized by utilizing a nickel powder mediated radical cyclization as the key step. The structures of the new compounds were confirmed by 1H-NMR and MS.
2003, 14(7): 670-672
Abstract:
AF-5 was synthesized through a convergent method. The key step was the Robinson annulation using a key intermediate pentyl vinyl ketone.
AF-5 was synthesized through a convergent method. The key step was the Robinson annulation using a key intermediate pentyl vinyl ketone.
2003, 14(7): 673-676
Abstract:
The cyclomercurated ferrocenylimines containing heterocyclic ring were prepared by the condensation of cyclomercuration of acylferrocene with the appropriate heterocyclic amine. This procedure provides an efficient method for the synthesis of cyclomerucurated ferroceny-limines containing heterocyclic ring which are difficultly synthesized by the conventional method. The reaction mechanism is proposed.
The cyclomercurated ferrocenylimines containing heterocyclic ring were prepared by the condensation of cyclomercuration of acylferrocene with the appropriate heterocyclic amine. This procedure provides an efficient method for the synthesis of cyclomerucurated ferroceny-limines containing heterocyclic ring which are difficultly synthesized by the conventional method. The reaction mechanism is proposed.
2003, 14(7): 677-680
Abstract:
An efficient and convenient method for the synthesis of acyl-diazenes is reported. Ten acyl-diazenes have been synthesized from acylhydrazines in excellent yields under mild conditions. There are eight new substances among these compounds.
An efficient and convenient method for the synthesis of acyl-diazenes is reported. Ten acyl-diazenes have been synthesized from acylhydrazines in excellent yields under mild conditions. There are eight new substances among these compounds.
2003, 14(7): 681-684
Abstract:
A series of novel bis-squaramidoacid ligands were prepared. Prochiral ketone and diketones were direct reduced by borane in the presence of these ligands giving secondary alcohol products with enantiomeric excesses up to 64.2% for ω-bromoacetophenone and 90.0% for 1, 6-diphenyl-1, 6-hexanedione.
A series of novel bis-squaramidoacid ligands were prepared. Prochiral ketone and diketones were direct reduced by borane in the presence of these ligands giving secondary alcohol products with enantiomeric excesses up to 64.2% for ω-bromoacetophenone and 90.0% for 1, 6-diphenyl-1, 6-hexanedione.
2003, 14(7): 685-688
Abstract:
The α-L-rhamnopyranosyl phosphomonoesters conjugated with L-amino acid methyl esters were stereoselectively synthesized in a convenient route by utilizing H-phosphonate intermediate.
The α-L-rhamnopyranosyl phosphomonoesters conjugated with L-amino acid methyl esters were stereoselectively synthesized in a convenient route by utilizing H-phosphonate intermediate.
Dienone-phenol Rearrangement of C-9 Oxygenated Decalinic Dienone and Analogs through B-Ring Cleavage
2003, 14(7): 689-692
Abstract:
Dehydrogenation of 9-hydroxy decalinic enones and analogs with DDQ resulted in a formal dienone-phenol type rearrangement via B-ring cleavage, while the corresponding dienone acetates underwent base-catalyzed formal dienone-phenol type rearrangement analogously.
Dehydrogenation of 9-hydroxy decalinic enones and analogs with DDQ resulted in a formal dienone-phenol type rearrangement via B-ring cleavage, while the corresponding dienone acetates underwent base-catalyzed formal dienone-phenol type rearrangement analogously.
2003, 14(7): 693-696
Abstract:
Myasthenia Gravis (MG) is an organ specific autoimmune disease mediated by autoantibodies (AChR Ab) against the acetylcholine receptor (AChR). Literature reported that the AChR Ab can be removed by absorbent linked with tryptophan. It was studied in detail in our lab. With the aid of computer, we docked some ligands into AChR Ab, and the results from scores of docking under different generations showed that there was no specific binding between tryptophan and scFv fragment just as the binding between antigen-antibody. The interaction between Trp and immunoglobulin was a broad-spectrum binding.
Myasthenia Gravis (MG) is an organ specific autoimmune disease mediated by autoantibodies (AChR Ab) against the acetylcholine receptor (AChR). Literature reported that the AChR Ab can be removed by absorbent linked with tryptophan. It was studied in detail in our lab. With the aid of computer, we docked some ligands into AChR Ab, and the results from scores of docking under different generations showed that there was no specific binding between tryptophan and scFv fragment just as the binding between antigen-antibody. The interaction between Trp and immunoglobulin was a broad-spectrum binding.
2003, 14(7): 697-699
Abstract:
A new rhodium catalyzed ring opening reaction of oxabenzonorbornadienes and its derivatives was described. This reaction forms a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead oxygen with a piperazine's derivatives, which proceeds with very high regioselectivity.
A new rhodium catalyzed ring opening reaction of oxabenzonorbornadienes and its derivatives was described. This reaction forms a new carbon-nitrogen bond via an intermolecular allylic displacement of the bridgehead oxygen with a piperazine's derivatives, which proceeds with very high regioselectivity.
2003, 14(7): 700-703
Abstract:
Chlorobenzene was dechlorinated by Pd/Fe bimetallic system in water through catalytic reduction. The dechlorination rate increases with increase of bulk loading of Pd due to the increase of both the surface loading of the Pd and the total surface area. For conditions with 0.005% Pd/Fe, 45% dechlorination efficiency was achieved within 5 h. The dechlorinated reaction is believed to take place on the bimetal surface in a pseudo-first-order reaction, with the rate constant being 0.0043 min-1.
Chlorobenzene was dechlorinated by Pd/Fe bimetallic system in water through catalytic reduction. The dechlorination rate increases with increase of bulk loading of Pd due to the increase of both the surface loading of the Pd and the total surface area. For conditions with 0.005% Pd/Fe, 45% dechlorination efficiency was achieved within 5 h. The dechlorinated reaction is believed to take place on the bimetal surface in a pseudo-first-order reaction, with the rate constant being 0.0043 min-1.
2003, 14(7): 704-706
Abstract:
Two new pyrone derivatives phelligridins A 1 and B 2 were isolated from the fruit body of Phellinus igniarius. Their structrues were elucidated as 8, 9-dihydroxy-3-methyl-1H,6H-pyrano[4,3-c] [2]benzopyran-1,6-dione and 4-hydroxy-6-(3',4'-dihydroxystyryl)-3-methoxycarbon-yl-2-pyrone, respectively, by means of spectral methods, including IR, MS, 1D and 2DNMR spectra.
Two new pyrone derivatives phelligridins A 1 and B 2 were isolated from the fruit body of Phellinus igniarius. Their structrues were elucidated as 8, 9-dihydroxy-3-methyl-1H,6H-pyrano[4,3-c] [2]benzopyran-1,6-dione and 4-hydroxy-6-(3',4'-dihydroxystyryl)-3-methoxycarbon-yl-2-pyrone, respectively, by means of spectral methods, including IR, MS, 1D and 2DNMR spectra.
2003, 14(7): 707-710
Abstract:
Antifungal assay-guided isolation of the ethanol extract of the aerial parts of Clematis tangutica yielded two novel triterpene saponins. Their structures were determined to be 3-O-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl ester (1) and 3-O-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl ester (2) on the basis of spectral data and chemical reactions.
Antifungal assay-guided isolation of the ethanol extract of the aerial parts of Clematis tangutica yielded two novel triterpene saponins. Their structures were determined to be 3-O-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl ester (1) and 3-O-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl hederagenin 28-O-α-L-rhamnopyranosyl ester (2) on the basis of spectral data and chemical reactions.
2003, 14(7): 711-712
Abstract:
Neo-przewaquinone A was isolated from the root of Salvia przewalskii Maxim. The structure elucidation and 1H, 13C NMR assignments were achieved by spectroscopic method.
Neo-przewaquinone A was isolated from the root of Salvia przewalskii Maxim. The structure elucidation and 1H, 13C NMR assignments were achieved by spectroscopic method.
2003, 14(7): 713-716
Abstract:
Flammulin, an anti-tumor protein, was purified from the aqueous extract of basidiomes of Flammulina Velutipes to electrophoretic homogeneity and crystallized by microdialysis against a polyethylene glycol-sodium phosphate buffer. The purified product was found to have marked antitumor effects and be able to affect the tumor cells directly.
Flammulin, an anti-tumor protein, was purified from the aqueous extract of basidiomes of Flammulina Velutipes to electrophoretic homogeneity and crystallized by microdialysis against a polyethylene glycol-sodium phosphate buffer. The purified product was found to have marked antitumor effects and be able to affect the tumor cells directly.
2003, 14(7): 717-719
Abstract:
A new furost-20(22)-ene oligoglycoside named as aspacochioside C was isolated from the roots of Asparagus cochinchinensis (Lour.) Merr.. Its structure was elucidated to be 26-O-β-D-glucopyranosyl-(25S)-5β-furost-20(22)-en-3β,26-diol-3-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside on the basis of spectroscopic techniques including 1D and 2D NMR experiments.
A new furost-20(22)-ene oligoglycoside named as aspacochioside C was isolated from the roots of Asparagus cochinchinensis (Lour.) Merr.. Its structure was elucidated to be 26-O-β-D-glucopyranosyl-(25S)-5β-furost-20(22)-en-3β,26-diol-3-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranoside on the basis of spectroscopic techniques including 1D and 2D NMR experiments.
2003, 14(7): 720-723
Abstract:
The absolute configuration of rohitukine, isolated from the stem-bark of Dysoxylum binectariferum, was determined to be 5,7-dihydroxy-2-methyl-8-[4-(3S, 4R-3-hydroxy-1-methyl)-piperidinyl]-4H-1-benzopyran-4-one by X-ray crystallographic analysis on the crystal of 4-bromobenzoyl derivatives of rohitukine. At the same time, the modified Mosher'method was proved to be unsuitable for determining the absolute configuration of C-3'position in rohitukine.
The absolute configuration of rohitukine, isolated from the stem-bark of Dysoxylum binectariferum, was determined to be 5,7-dihydroxy-2-methyl-8-[4-(3S, 4R-3-hydroxy-1-methyl)-piperidinyl]-4H-1-benzopyran-4-one by X-ray crystallographic analysis on the crystal of 4-bromobenzoyl derivatives of rohitukine. At the same time, the modified Mosher'method was proved to be unsuitable for determining the absolute configuration of C-3'position in rohitukine.
2003, 14(7): 724-727
Abstract:
A simple, rapid and low-cost method of determination for cordycepin in Cordyceps kyushuensis by capillary zone electrophoresis (CZE) was developed. Based on the finding that there is a high concentration of cordycepin in both natural and cultured Cordyceps kyushuensis, the in vitro antitumor activity of cordycepin and the water extracts of Cordyceps kyushuensis has been investigated. This is the first report about the antitumor effect of Cordyceps kyushuensis.
A simple, rapid and low-cost method of determination for cordycepin in Cordyceps kyushuensis by capillary zone electrophoresis (CZE) was developed. Based on the finding that there is a high concentration of cordycepin in both natural and cultured Cordyceps kyushuensis, the in vitro antitumor activity of cordycepin and the water extracts of Cordyceps kyushuensis has been investigated. This is the first report about the antitumor effect of Cordyceps kyushuensis.
2003, 14(7): 728-729
Abstract:
A facile method has been developed for the fabrication of Au nanoelecrodes (Au NEs). The tip of Au NEs can be controlled within the range from dozens to hundreds of nanometer.
A facile method has been developed for the fabrication of Au nanoelecrodes (Au NEs). The tip of Au NEs can be controlled within the range from dozens to hundreds of nanometer.
2003, 14(7): 730-733
Abstract:
The stability of three forms of nateglinide, especially S-form and H-form, was determined. S-form was a new crystal structure1 of nateglinide. Three forms of nateglinide were treated in different conditions, such as in various temperatures, humidity, light and so on. Analysis of their crystal structures was performed by X-ray powder diffraction (XRD) and their particle shapes were observed with scanning electron microscope (SEM). The results indicated that the stability of S-form of nateglinide is the best among the three forms and their particle shapes are quite difference. S-form is the sheet structure of layer upon layer, H-form looks like a hank of silk lines and B-form is the clubbed shape.
The stability of three forms of nateglinide, especially S-form and H-form, was determined. S-form was a new crystal structure1 of nateglinide. Three forms of nateglinide were treated in different conditions, such as in various temperatures, humidity, light and so on. Analysis of their crystal structures was performed by X-ray powder diffraction (XRD) and their particle shapes were observed with scanning electron microscope (SEM). The results indicated that the stability of S-form of nateglinide is the best among the three forms and their particle shapes are quite difference. S-form is the sheet structure of layer upon layer, H-form looks like a hank of silk lines and B-form is the clubbed shape.
2003, 14(7): 734-736
Abstract:
Effect of Ti(iso-C3H7O)4 treatment on the photoinduced charge carrier kinetics of nanocrystalline porous TiO2 films is studied by time-resolved microwave conductivity measurements. Analysis of the transient photoconductivity decays indicates that Ti(iso-C3H7O)4 treatment leads to an increased concentration of photogenerated charge carriers and a fast interfacial transfer rate of holes via the surface modification of the freshly growing TiO2 nanocrystallites.
Effect of Ti(iso-C3H7O)4 treatment on the photoinduced charge carrier kinetics of nanocrystalline porous TiO2 films is studied by time-resolved microwave conductivity measurements. Analysis of the transient photoconductivity decays indicates that Ti(iso-C3H7O)4 treatment leads to an increased concentration of photogenerated charge carriers and a fast interfacial transfer rate of holes via the surface modification of the freshly growing TiO2 nanocrystallites.
2003, 14(7): 737-739
Abstract:
The electrochemical behaviors (cyclic voltammetry, CV and different pulse voltammetry, DPV) of dopamine (DA) were studied in this paper. The result indicated that the oxidation of dopamine was controlled by diffusion and adsorption simultaneously at nano-gold (NG) modified carbon fiber electrode (CFE). This modified electrode can separate the peak potentials of dopamine and ascorbic acid (AA). The peak current of DA in DPV curve was found to be linearly proportional to the concentration of DA at range of 2.0×10-6~1.5×10-5mol/L and 1.0×10-5~5.0×10-4mol/L, respectively.
The electrochemical behaviors (cyclic voltammetry, CV and different pulse voltammetry, DPV) of dopamine (DA) were studied in this paper. The result indicated that the oxidation of dopamine was controlled by diffusion and adsorption simultaneously at nano-gold (NG) modified carbon fiber electrode (CFE). This modified electrode can separate the peak potentials of dopamine and ascorbic acid (AA). The peak current of DA in DPV curve was found to be linearly proportional to the concentration of DA at range of 2.0×10-6~1.5×10-5mol/L and 1.0×10-5~5.0×10-4mol/L, respectively.
2003, 14(7): 740-743
Abstract:
A new heteronuclear complex, dimer[(μ2-OH2)2Ba2(H2O)4] [VO2(tpa)]2·4H2O(tpa:2,4,6-tripicolinate trianion), was synthesized and structurally determined by X-ray diffraction technique where all hydrogen atoms have been located directly. The coordination geometry of V(V) ion is a distorted trigonal bipyrimid and that of Ba(Ⅱ) ion is a capped square antiprism. One μ2-O bridging bond and two hydrogen bonds act between the coordination geometries. A 1-D extended porous construction containing 20-member cavities is observed in the crystal.
A new heteronuclear complex, dimer[(μ2-OH2)2Ba2(H2O)4] [VO2(tpa)]2·4H2O(tpa:2,4,6-tripicolinate trianion), was synthesized and structurally determined by X-ray diffraction technique where all hydrogen atoms have been located directly. The coordination geometry of V(V) ion is a distorted trigonal bipyrimid and that of Ba(Ⅱ) ion is a capped square antiprism. One μ2-O bridging bond and two hydrogen bonds act between the coordination geometries. A 1-D extended porous construction containing 20-member cavities is observed in the crystal.
2003, 14(7): 744-747
Abstract:
An open-framework ammonium ferricborophosphate compound was synthesized by mild hydrothermal condition at 110℃. The crystal structure has been determined by single-crystal X-ray diffraction analysis:hexagonal, P6522, a=9.452(2)A, c=15.698(5)A,α=90°,γ=120°,Z=6, Mr=310.58, V=1214.0(5)A3, Dc=2.549 g/cm3, μ=2.311mm-1, F(000)=930. The chiral tetrahedral-tetrahedral helical ribbons are linked by the mixed valance FeⅡ/FeⅢO6 coordinated octahedra. The ammonium ions are located inside the free loop of helical ribbons close to the inner wall of the helical channels ∞{[BP2O8]3-}, effecting on balancing charge and stabilizing helical ribbons.
An open-framework ammonium ferricborophosphate compound was synthesized by mild hydrothermal condition at 110℃. The crystal structure has been determined by single-crystal X-ray diffraction analysis:hexagonal, P6522, a=9.452(2)A, c=15.698(5)A,α=90°,γ=120°,Z=6, Mr=310.58, V=1214.0(5)A3, Dc=2.549 g/cm3, μ=2.311mm-1, F(000)=930. The chiral tetrahedral-tetrahedral helical ribbons are linked by the mixed valance FeⅡ/FeⅢO6 coordinated octahedra. The ammonium ions are located inside the free loop of helical ribbons close to the inner wall of the helical channels ∞{[BP2O8]3-}, effecting on balancing charge and stabilizing helical ribbons.
2003, 14(7): 748-751
Abstract:
The SiO2 and γ-Al2O3 supported MoOx catalyst and a MoOx-SiO2 catalyst have been studied in a conventional fixed-bed flow reactor for n-alkanes isomerization. It is shown that the MoOx-SiO2catalyst with SiO2 framework, in which the bulk MoOx phase is large enough to form typical mesoporous structure, is promising in terms of its advantages of both improved mechanical strength and high catalytic properties over the supported MoOx and bulk MoOx catalyst.
The SiO2 and γ-Al2O3 supported MoOx catalyst and a MoOx-SiO2 catalyst have been studied in a conventional fixed-bed flow reactor for n-alkanes isomerization. It is shown that the MoOx-SiO2catalyst with SiO2 framework, in which the bulk MoOx phase is large enough to form typical mesoporous structure, is promising in terms of its advantages of both improved mechanical strength and high catalytic properties over the supported MoOx and bulk MoOx catalyst.
2003, 14(7): 752-754
Abstract:
CO2-copolymer based polyurethane foams were synthesized and characterized in this paper. The foams were found to have higher strength and lower heat of combustion than the conventional polyether polyurethane foams. They may find wide applications in many fields.
CO2-copolymer based polyurethane foams were synthesized and characterized in this paper. The foams were found to have higher strength and lower heat of combustion than the conventional polyether polyurethane foams. They may find wide applications in many fields.
2003, 14(7): 755-758
Abstract:
A novel gel-like process has been developed for synthesizing LiaNi0.8Co0.2O2 powders, using citric acid as a chelating agent. This process improves the homogeneity of constituent cation and enhances their reactivity in the obtained precursor. The results of electrochemical test demonstrated that these materials exhibited excellent electrochemical properties. Its initial capacity reached 181.6 mAh/g and reversible efficiency at the first cycle is about 88.6%.
A novel gel-like process has been developed for synthesizing LiaNi0.8Co0.2O2 powders, using citric acid as a chelating agent. This process improves the homogeneity of constituent cation and enhances their reactivity in the obtained precursor. The results of electrochemical test demonstrated that these materials exhibited excellent electrochemical properties. Its initial capacity reached 181.6 mAh/g and reversible efficiency at the first cycle is about 88.6%.
2003, 14(7): 759-762
Abstract:
Nanocrystalline MoS2with hollow spherical morphology has been prepared by the hydrothermal method. The products are characterized by means of X-ray powder diffraction, transmission electron microscopy and high-resolution transmission electron microscopy. The experimental results give the evidence that the sample is consists of hollow spheres 400~600 nm in diameter, and there is much whisker on the surface of MoS2 hollow sphere.
Nanocrystalline MoS2with hollow spherical morphology has been prepared by the hydrothermal method. The products are characterized by means of X-ray powder diffraction, transmission electron microscopy and high-resolution transmission electron microscopy. The experimental results give the evidence that the sample is consists of hollow spheres 400~600 nm in diameter, and there is much whisker on the surface of MoS2 hollow sphere.
2003, 14(7): 763-766
Abstract:
The highly ordered macroporous Au and Pd with regular arrays of spherical pores have been synthesized by poly (styrene-co-acrylic) (PSA) colloidal crystal template. The pore size is tuneable in the range of 100-400 nm according to the size of PSA latex. The mechanism is based on the in-situ impregnating and reducing of metal ions in the interspaces of the PSA spheres then removing the template.
The highly ordered macroporous Au and Pd with regular arrays of spherical pores have been synthesized by poly (styrene-co-acrylic) (PSA) colloidal crystal template. The pore size is tuneable in the range of 100-400 nm according to the size of PSA latex. The mechanism is based on the in-situ impregnating and reducing of metal ions in the interspaces of the PSA spheres then removing the template.
2003, 14(7): 767-770
Abstract:
A cyclomaltoheptaose-β-cyclodextrin (β-CD) crosslinked chitosan derivative via glyoxal or glutaraldehyde was prepared. The structures of β-CD crosslined chitosan with glyoxal or glutaraldehyde were characterized by IR spectra. The surface morphology of the β-CD crosslinked chitosan particles was examined using a scanning electron microscope. The immobilization capacity of β-CD on chitosan was affected on the weight ratio of β-CD/chitosan, the utilization amount of crosslinking agent, the acidity of the reaction system and the temperature. The adsorption for nicotine indicated that the chitosan-β-CD was a good adsorbent.
A cyclomaltoheptaose-β-cyclodextrin (β-CD) crosslinked chitosan derivative via glyoxal or glutaraldehyde was prepared. The structures of β-CD crosslined chitosan with glyoxal or glutaraldehyde were characterized by IR spectra. The surface morphology of the β-CD crosslinked chitosan particles was examined using a scanning electron microscope. The immobilization capacity of β-CD on chitosan was affected on the weight ratio of β-CD/chitosan, the utilization amount of crosslinking agent, the acidity of the reaction system and the temperature. The adsorption for nicotine indicated that the chitosan-β-CD was a good adsorbent.
