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2006 Volume 17 Issue 12
2006, 17(12): 1531-1533
Abstract:
Functional crown-ether ionic liquids were used as catalytic green solvents of Finkelstein reaction of 1-bromooctane and iodide. The rate and yield of the reaction were obvious improved compared with that using crown ether in water. No free crown ether loss was observed after reaction.
Functional crown-ether ionic liquids were used as catalytic green solvents of Finkelstein reaction of 1-bromooctane and iodide. The rate and yield of the reaction were obvious improved compared with that using crown ether in water. No free crown ether loss was observed after reaction.
2006, 17(12): 1534-1536
Abstract:
Synthesis of 3-naphthylcyclohexene by the Heck reactions of bromonaphthalene and naphthyl triflates with cyclohexene catalyzed by palladiun and nickel complex (promoted by ultrasonic and microwave in ionic liquid of [bmim][BF4]) were performed with high yield and good regioselectivity. This method has advantages of environmentally benign, generality, simplicity and potential for recycling of ionic liquid and catalyat.
Synthesis of 3-naphthylcyclohexene by the Heck reactions of bromonaphthalene and naphthyl triflates with cyclohexene catalyzed by palladiun and nickel complex (promoted by ultrasonic and microwave in ionic liquid of [bmim][BF4]) were performed with high yield and good regioselectivity. This method has advantages of environmentally benign, generality, simplicity and potential for recycling of ionic liquid and catalyat.
2006, 17(12): 1537-1539
Abstract:
The tetrazole analogues have been synthesized from fluorenylmethoxycarbonyl (Fmoc)protected amino acids by three steps. The structures of the analogues were characterized by HPLC-MS, 1H NMR and 13C NMR.
The tetrazole analogues have been synthesized from fluorenylmethoxycarbonyl (Fmoc)protected amino acids by three steps. The structures of the analogues were characterized by HPLC-MS, 1H NMR and 13C NMR.
2006, 17(12): 1540-1542
Abstract:
N-Phenylpyrrolidine was efficiently synthesized over the mesoporous Al2O3 catalyst by the reaction of the aniline and 1, 4-butylene-glycol at atmospheric pressure. The catalyst exhibited very high activity and selectivity. At the reaction temperature of 300℃, 1, 4-butylene glycol conversion attained 100% and the selectivity of N-phenylpyrrolidine could exceed 98%.
N-Phenylpyrrolidine was efficiently synthesized over the mesoporous Al2O3 catalyst by the reaction of the aniline and 1, 4-butylene-glycol at atmospheric pressure. The catalyst exhibited very high activity and selectivity. At the reaction temperature of 300℃, 1, 4-butylene glycol conversion attained 100% and the selectivity of N-phenylpyrrolidine could exceed 98%.
2006, 17(12): 1543-1546
Abstract:
A novel bridged bis(β-cyclodextrin), 4, 4'-diaminodiphenyl ether-briged-bis (6-aimino-6-deoxy-β-cyclodextrin) 3, has been synthesized and its inclusion complexation behavior with three linear guest dyes (AR, NR and MB) has been investigated by means of fluorescence spectrometry. The result obtained demonstrated that the novel bridged bis(β-cyclodextrin)showed much higher affinities towards guest dyes than native β-cyclodextrin.
A novel bridged bis(β-cyclodextrin), 4, 4'-diaminodiphenyl ether-briged-bis (6-aimino-6-deoxy-β-cyclodextrin) 3, has been synthesized and its inclusion complexation behavior with three linear guest dyes (AR, NR and MB) has been investigated by means of fluorescence spectrometry. The result obtained demonstrated that the novel bridged bis(β-cyclodextrin)showed much higher affinities towards guest dyes than native β-cyclodextrin.
2006, 17(12): 1547-1550
Abstract:
In order to set up a simple and effective method for resolution of optical isomers, hydroxypropyl-β-cyclodextrin was bonded to silica-gel, which can be used for preparation of thin-layer chromatography plates. Resolution of clenbuterol and propranolol were investigated on these thin-layer chromatography plates using different combinations of solvent systems at ambient temperature. The best simultaneous resolution was achieved in solvent system of acetonitrile-n-butanol (50:50, v/v). Rst values of resolution of clenbuterol hydrochloride and propranolol hydrochloride are 3.6 and 4.3, respectively. The spots of different enantiomers are separated clearly. The results showed that hydroxypropyl-β-cyclodextrin bonded silica-gel could be successful in resolution of chiral adrenergic drugs. The study offers a direct, rapid and reliable method for separation of this kind of optically active compounds.
In order to set up a simple and effective method for resolution of optical isomers, hydroxypropyl-β-cyclodextrin was bonded to silica-gel, which can be used for preparation of thin-layer chromatography plates. Resolution of clenbuterol and propranolol were investigated on these thin-layer chromatography plates using different combinations of solvent systems at ambient temperature. The best simultaneous resolution was achieved in solvent system of acetonitrile-n-butanol (50:50, v/v). Rst values of resolution of clenbuterol hydrochloride and propranolol hydrochloride are 3.6 and 4.3, respectively. The spots of different enantiomers are separated clearly. The results showed that hydroxypropyl-β-cyclodextrin bonded silica-gel could be successful in resolution of chiral adrenergic drugs. The study offers a direct, rapid and reliable method for separation of this kind of optically active compounds.
2006, 17(12): 1551-1554
Abstract:
(S)-4-Phenyl-2-oxazolidinone imprinted polymers were prepared by using methacrylic acid (MAA) as the functional monomer, and divinylbenzene (DVB) as crosslinker. The factors, which influence the selectivity of the polymers were explored. Effective separation was observed for racemic 4-phenyl-2-oxazolidinone in mobile phase of acetonitrile. The investigation of mobile phase suggested that the hydrogen bonds between template and functional monomer was a primary factor in chiral recognition, while the preparation of polymers implied that the π-π stacking interaction between template and crosslinker played a role in imprinting procedure.
(S)-4-Phenyl-2-oxazolidinone imprinted polymers were prepared by using methacrylic acid (MAA) as the functional monomer, and divinylbenzene (DVB) as crosslinker. The factors, which influence the selectivity of the polymers were explored. Effective separation was observed for racemic 4-phenyl-2-oxazolidinone in mobile phase of acetonitrile. The investigation of mobile phase suggested that the hydrogen bonds between template and functional monomer was a primary factor in chiral recognition, while the preparation of polymers implied that the π-π stacking interaction between template and crosslinker played a role in imprinting procedure.
2006, 17(12): 1555-1558
Abstract:
Based on the crystal structure of AHAS/sulfonylurea complex, we obtained 296 compounds with low binding energy towards AHAS via virtual screening. One series of them have been synthesized. Preliminary bioassay indicated that some compounds displayed good herbicidal activity on rape and barnygrass and inhibited AHAS to some extent. This study indicated the rationality of our molecular design based on the crystal structure of target enzyme.
Based on the crystal structure of AHAS/sulfonylurea complex, we obtained 296 compounds with low binding energy towards AHAS via virtual screening. One series of them have been synthesized. Preliminary bioassay indicated that some compounds displayed good herbicidal activity on rape and barnygrass and inhibited AHAS to some extent. This study indicated the rationality of our molecular design based on the crystal structure of target enzyme.
2006, 17(12): 1559-1562
Abstract:
Oximes of ketones and aldehydes are efficiently converted to the corresponding carbonyl compounds, using a combination of NaHSO4·H2O and paraformaldehyde in good to excellent yields under solid state conditions at room temperature for 10 minutes.
Oximes of ketones and aldehydes are efficiently converted to the corresponding carbonyl compounds, using a combination of NaHSO4·H2O and paraformaldehyde in good to excellent yields under solid state conditions at room temperature for 10 minutes.
2006, 17(12): 1563-1565
Abstract:
1, 2-O-Isopropylidene-5-O-p-toluenesulfonyl-α-D-erythro-pentofuranos-3-ulose 1 was treated with thiourea and aminothiourea to give a D-ribose derivative 2 bearing a 2-amino 1, 3-thiazine ring and a thiosemicarbazone derivative 5, respectively. 2 was acylated with Ac2O and propandioic acid to afford two acylation derivatives 3 and 4, respectively. Reduction of 5 with NaBH4 in methanol produced a hydrothiosemicarbazone derivative 6. The absolute configuration of 2 was confirmed by X-ray crystallographic analysis. The structures of all products were elucidated by IR, NMR and HRMS spectra.
1, 2-O-Isopropylidene-5-O-p-toluenesulfonyl-α-D-erythro-pentofuranos-3-ulose 1 was treated with thiourea and aminothiourea to give a D-ribose derivative 2 bearing a 2-amino 1, 3-thiazine ring and a thiosemicarbazone derivative 5, respectively. 2 was acylated with Ac2O and propandioic acid to afford two acylation derivatives 3 and 4, respectively. Reduction of 5 with NaBH4 in methanol produced a hydrothiosemicarbazone derivative 6. The absolute configuration of 2 was confirmed by X-ray crystallographic analysis. The structures of all products were elucidated by IR, NMR and HRMS spectra.
2006, 17(12): 1566-1568
Abstract:
A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium(Ⅳ) ammonium nitrate(CAN) under ultrasonic irradiation.
A variety of β-enamino ketones were synthesized in high to excellent yields by reacting acetylacetone with amines in the presence of a catalytic amount of cerium(Ⅳ) ammonium nitrate(CAN) under ultrasonic irradiation.
2006, 17(12): 1569-1572
Abstract:
A new triterpene, named cynanotriterpene A, with a ring-A-fission (3, 4-seco) and 13, 27-cyclours-3-oic acid methyl ester skeleton was isolated from the roots of Cynanchum forrestii Schlechter. The structure of the new compound was elucidated on the basis of spectroscopic method and X-ray diffraction.
A new triterpene, named cynanotriterpene A, with a ring-A-fission (3, 4-seco) and 13, 27-cyclours-3-oic acid methyl ester skeleton was isolated from the roots of Cynanchum forrestii Schlechter. The structure of the new compound was elucidated on the basis of spectroscopic method and X-ray diffraction.
2006, 17(12): 1573-1575
Abstract:
A new taraxastane-20β, 28β-epoxy-28-hydroxy-3β, 11α-diol- 11-p-hydroxylbenzoate was isolated from the roots of Potentilla multicaulis. Its structure was elucidated by spectroscopic methods, especially 2D NMR techniques.
A new taraxastane-20β, 28β-epoxy-28-hydroxy-3β, 11α-diol- 11-p-hydroxylbenzoate was isolated from the roots of Potentilla multicaulis. Its structure was elucidated by spectroscopic methods, especially 2D NMR techniques.
2006, 17(12): 1576-1578
Abstract:
A new flavonoid 1 rhamnocitrin-3-O-(6"-feruloyl)-β-D-galactopyranoside-4'-O-β-D-glucospyranoside called kansuensisoside A together with a known flavonoid 2 (rhamnocitrin-3-O-β-D-galactopyranoside-4'-O-β-D-glucospyranoside) were isolated from the extract of the whole plant of Oxytropis kansuensis Bunge. The structure of 1 was elucidated by spectroscopic methods including 2D-NMR techniques (COSY, HMQC, HMBC) and HR-ESIMS.
A new flavonoid 1 rhamnocitrin-3-O-(6"-feruloyl)-β-D-galactopyranoside-4'-O-β-D-glucospyranoside called kansuensisoside A together with a known flavonoid 2 (rhamnocitrin-3-O-β-D-galactopyranoside-4'-O-β-D-glucospyranoside) were isolated from the extract of the whole plant of Oxytropis kansuensis Bunge. The structure of 1 was elucidated by spectroscopic methods including 2D-NMR techniques (COSY, HMQC, HMBC) and HR-ESIMS.
2006, 17(12): 1579-1581
Abstract:
A new dimeric phthalide named Z, Z'-3.3'a, 7.7'a-diligustilide was isolated from the roots of Angelica sinensis. Its structure was determined using spectroscopic methods and X-ray crystallographic diffraction analysis.
A new dimeric phthalide named Z, Z'-3.3'a, 7.7'a-diligustilide was isolated from the roots of Angelica sinensis. Its structure was determined using spectroscopic methods and X-ray crystallographic diffraction analysis.
2006, 17(12): 1582-1584
Abstract:
A new highly sensitive method (detection limit: 4.1 ag spot-1, sample volume: 0.4 μL spot-1) for the determination of trace Hg2+ by catalytic solid substrate-room temperature phosphorimetry has been established in this paper. This method has been successfully applied to determine trace Hg2+ in water.
A new highly sensitive method (detection limit: 4.1 ag spot-1, sample volume: 0.4 μL spot-1) for the determination of trace Hg2+ by catalytic solid substrate-room temperature phosphorimetry has been established in this paper. This method has been successfully applied to determine trace Hg2+ in water.
2006, 17(12): 1585-1588
Abstract:
Platinum nanowire (PtNW) can be grown by electrodeposition in polycarbonate membrane, with the average diameter of the nanowires about 250 nm. The PtNW and multiwalled carbon nanotubes (CNT) are then dispersed into chitosan (CHIT) solution. The resulting PtNW-CNT-CHIT material brings new capabilities for electrochemical devices by using the synergistic action of the electrocatalytic activity of PtNW and CNT. By dropping the PtNW-CNT-CHIT film onto the glassy carbon (GC) electrode surface, and after evaporationan amperometric sensor for the determination of indole-3-acetic acid (IAA) was developed. The oxidation current of IAA increased significantly at the PtNW-CNT-CHIT film coated GC electrode, in contrast to that at the CNT-CHIT modified GC. The linear response of the sensor is from 50ng/ml to 50 μg/ml with a detection limit of 25 ng/mL.
Platinum nanowire (PtNW) can be grown by electrodeposition in polycarbonate membrane, with the average diameter of the nanowires about 250 nm. The PtNW and multiwalled carbon nanotubes (CNT) are then dispersed into chitosan (CHIT) solution. The resulting PtNW-CNT-CHIT material brings new capabilities for electrochemical devices by using the synergistic action of the electrocatalytic activity of PtNW and CNT. By dropping the PtNW-CNT-CHIT film onto the glassy carbon (GC) electrode surface, and after evaporationan amperometric sensor for the determination of indole-3-acetic acid (IAA) was developed. The oxidation current of IAA increased significantly at the PtNW-CNT-CHIT film coated GC electrode, in contrast to that at the CNT-CHIT modified GC. The linear response of the sensor is from 50ng/ml to 50 μg/ml with a detection limit of 25 ng/mL.
2006, 17(12): 1589-1591
Abstract:
Room temperature ionic liquid (RTILs) [BMIM]PF6 was used as a new kind of binder to construct a chemical modified carbon paste electrode (CPE) and the direct electrochemistry of hemoglobin (Hb), which was immobilized on the surface of RTIL/CPE with the film of sodium alginate hydrogel, was studied by cyclic voltammetry. The presence of RTILs improved the direct electron transfer of Hb and a pair of well-defined quasi-revesible redox peaks appeared in pH 7.0 B-R buffer solution. The cathodic and anodic peak potentials were located at -0.383 V and -0.305 V with the formal potential (E0') at -0.344 V (vs. SCE). In addition the immobilized Hb showed good electrocatalytic activity to the reduction of H2O2.
Room temperature ionic liquid (RTILs) [BMIM]PF6 was used as a new kind of binder to construct a chemical modified carbon paste electrode (CPE) and the direct electrochemistry of hemoglobin (Hb), which was immobilized on the surface of RTIL/CPE with the film of sodium alginate hydrogel, was studied by cyclic voltammetry. The presence of RTILs improved the direct electron transfer of Hb and a pair of well-defined quasi-revesible redox peaks appeared in pH 7.0 B-R buffer solution. The cathodic and anodic peak potentials were located at -0.383 V and -0.305 V with the formal potential (E0') at -0.344 V (vs. SCE). In addition the immobilized Hb showed good electrocatalytic activity to the reduction of H2O2.
2006, 17(12): 1592-1594
Abstract:
The interactions between L-tryptophan(L-Trp) and water-soluble p-sulfonatocalix[4]-arene (SCX4) were investigated by spectrofluorometry. The effect of pH was discussed. The interaction process was estimated from the thermodynamic viewpoint. The SCX4 was found to be able to adjust its conformation to fit the size of L-Trp, and the benzene of L-Trp penetrated into the hydrophobic cavity of SCX4. Meanwhile, the binding mechanism was further elucidated by 1HNMR and molecular mechanics calculations.
The interactions between L-tryptophan(L-Trp) and water-soluble p-sulfonatocalix[4]-arene (SCX4) were investigated by spectrofluorometry. The effect of pH was discussed. The interaction process was estimated from the thermodynamic viewpoint. The SCX4 was found to be able to adjust its conformation to fit the size of L-Trp, and the benzene of L-Trp penetrated into the hydrophobic cavity of SCX4. Meanwhile, the binding mechanism was further elucidated by 1HNMR and molecular mechanics calculations.
2006, 17(12): 1595-1598
Abstract:
In this work, a sensitive, rapid and simple method for the determination of trace amounts of potassium ferrocyanide in salinized foods and table salt using EV as a RRS probe is established. The detection limit (3σ) of the EV system is 7.8 ng/mL. This new method is more suitable for the determination of the trace amounts of potassium ferrocyanide in colour salinized foods and it can not be disturbed by the color of salinized foods.
In this work, a sensitive, rapid and simple method for the determination of trace amounts of potassium ferrocyanide in salinized foods and table salt using EV as a RRS probe is established. The detection limit (3σ) of the EV system is 7.8 ng/mL. This new method is more suitable for the determination of the trace amounts of potassium ferrocyanide in colour salinized foods and it can not be disturbed by the color of salinized foods.
2006, 17(12): 1599-1602
Abstract:
In this work, a novel method was constructed to determine the enantiomeric composition of tryptophan (Trp) by bovine serum albumin (BSA) based on the fluorescence spectra of the receptor-ligand mixtures coupled with partial least squares (PLS-1) analysis. As a result the enantiomeric composition of Trp was accurately determined.
In this work, a novel method was constructed to determine the enantiomeric composition of tryptophan (Trp) by bovine serum albumin (BSA) based on the fluorescence spectra of the receptor-ligand mixtures coupled with partial least squares (PLS-1) analysis. As a result the enantiomeric composition of Trp was accurately determined.
2006, 17(12): 1603-1606
Abstract:
A simple sensitive and quick assay for simultaneously determining magnolol (MOL)and honokiol (HOL) has been described based on their natural fluorescence. This method is based on the fact that synchronous fluorometry could resolve the overlapping of fluorescence spectra, which was aroused by their similar molecular structures. In this work, the synchronous spectrum, maintaining a constant difference of Δλ=10 nm between the emission and excitation wavelengths, has been selected for the determination of HOL and MOL. Under the optimum conditions, the fluorescence intensity is proportional to the concentration of MOL and HOL in solution over the range 0.075-0.7 μg/mL and 0.05-0.9 μg/mL with the detection limit of 0.029 μg/mL and 0.019 μg/mL, respectively. The method was applied to the simultaneous determination of MOL and HOL in pharmaceutical dosage with satisfactory results.
A simple sensitive and quick assay for simultaneously determining magnolol (MOL)and honokiol (HOL) has been described based on their natural fluorescence. This method is based on the fact that synchronous fluorometry could resolve the overlapping of fluorescence spectra, which was aroused by their similar molecular structures. In this work, the synchronous spectrum, maintaining a constant difference of Δλ=10 nm between the emission and excitation wavelengths, has been selected for the determination of HOL and MOL. Under the optimum conditions, the fluorescence intensity is proportional to the concentration of MOL and HOL in solution over the range 0.075-0.7 μg/mL and 0.05-0.9 μg/mL with the detection limit of 0.029 μg/mL and 0.019 μg/mL, respectively. The method was applied to the simultaneous determination of MOL and HOL in pharmaceutical dosage with satisfactory results.
2006, 17(12): 1607-1610
Abstract:
A novel direct method for preparation of dimethyl carbonate and poly(ethylene terephthalate) from ethylene carbonate and dimethyl terephthalate has been demonstrated in the presence of metal acetate catalysts, lithium acetate dihydrate showed highest catalytic activity with 47.9% yield of dimethyl carbonate. This method was a green chemical process.
A novel direct method for preparation of dimethyl carbonate and poly(ethylene terephthalate) from ethylene carbonate and dimethyl terephthalate has been demonstrated in the presence of metal acetate catalysts, lithium acetate dihydrate showed highest catalytic activity with 47.9% yield of dimethyl carbonate. This method was a green chemical process.
2006, 17(12): 1611-1614
Abstract:
Terpolymer of 1, 8-octanediol, adipic acid, and L-malic acid was synthesized via a lipase-catalyzed direct polycondensation. The products were characterized by GPC and 1H NMR.The results indicated that the molecular weight of the prepared polymers decreased with increasing L-malic acid content in the monomer feed ratio, and that change in the L-malic acid content from 0to 20 mol% did not remarkably influenced on the molecular weight distribution Mw/Mn of the prepared samples. The 1H NMR spectra of the obtained copolymer samples showed that hydroxyl groups of L-malic acid did not take part in the polymerization reaction.
Terpolymer of 1, 8-octanediol, adipic acid, and L-malic acid was synthesized via a lipase-catalyzed direct polycondensation. The products were characterized by GPC and 1H NMR.The results indicated that the molecular weight of the prepared polymers decreased with increasing L-malic acid content in the monomer feed ratio, and that change in the L-malic acid content from 0to 20 mol% did not remarkably influenced on the molecular weight distribution Mw/Mn of the prepared samples. The 1H NMR spectra of the obtained copolymer samples showed that hydroxyl groups of L-malic acid did not take part in the polymerization reaction.
2006, 17(12): 1615-1618
Abstract:
The self-assembled monolayers (SAMs) of imidazoline (IM) on the iron surface were characterized by scanning electron microscope (SEM) and scanning electrochemical microscopy(SECM). The results showed that SAMs were an effective inhibition film for iron.
The self-assembled monolayers (SAMs) of imidazoline (IM) on the iron surface were characterized by scanning electron microscope (SEM) and scanning electrochemical microscopy(SECM). The results showed that SAMs were an effective inhibition film for iron.
2006, 17(12): 1619-1622
Abstract:
A chip was modified with bovine serum albumin (BSA), then interaction between glutathione (GSH) immobilized on the top of BSA and glutathione-S-transferase (GST) was examined, using surface plasmon resonance (SPR). The SPR results showed that BSA-modified chip was effective not only in binding the target proteins but also in suppressing the nonspecific binding (NSB) of proteins.
A chip was modified with bovine serum albumin (BSA), then interaction between glutathione (GSH) immobilized on the top of BSA and glutathione-S-transferase (GST) was examined, using surface plasmon resonance (SPR). The SPR results showed that BSA-modified chip was effective not only in binding the target proteins but also in suppressing the nonspecific binding (NSB) of proteins.
2006, 17(12): 1623-1627
Abstract:
The PdCo bimetallic hollow nanospheres with 80 nm average diameter and around 9.0 nm thickness of the shell were prepared with a special reduction method and characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The electrochemical measurements illustrated that the electrocatalytic activity of the PdCo bimetallic hollow nanospheres for the oxidation of formic acid is much higher than that of the Pd solid nanospheres.
The PdCo bimetallic hollow nanospheres with 80 nm average diameter and around 9.0 nm thickness of the shell were prepared with a special reduction method and characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). The electrochemical measurements illustrated that the electrocatalytic activity of the PdCo bimetallic hollow nanospheres for the oxidation of formic acid is much higher than that of the Pd solid nanospheres.
