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2010 Volume 21 Issue 12
2010, 21(12): 1391-1394
doi: 10.1016/j.cclet.2010.06.035
Abstract:
Eight new 13-O-aminocarbonylivermectin aglycones and 4'-O-aminocarbonylivermectin monosaccharide were synthesized from ivermectin aglycone and ivermectin monosaccharide by the selective protection of C5-OH group. Their bioactivities were evaluated against spicier mites (Tetranychus cinnabarinus), aphid (Aphis fabae) and orlental armyworm (Mythimma sepatara). Their structures were confirmed by 1H NMR. MS.
Eight new 13-O-aminocarbonylivermectin aglycones and 4'-O-aminocarbonylivermectin monosaccharide were synthesized from ivermectin aglycone and ivermectin monosaccharide by the selective protection of C5-OH group. Their bioactivities were evaluated against spicier mites (Tetranychus cinnabarinus), aphid (Aphis fabae) and orlental armyworm (Mythimma sepatara). Their structures were confirmed by 1H NMR. MS.
2010, 21(12): 1395-1398
doi: 10.1016/j.cclet.2010.07.024
Abstract:
Silica gel supported alumirtium trichloride (SiO2-AlCl3) has been shown to be a mild, efficient, and chemoselective heterogeneous Lewis acid catalyst for the acylation of aromatic compounds with acid chlorides. The catalyst can be reused up to five times after simple washing with ether and is stable (as a bench top catalyst).
Silica gel supported alumirtium trichloride (SiO2-AlCl3) has been shown to be a mild, efficient, and chemoselective heterogeneous Lewis acid catalyst for the acylation of aromatic compounds with acid chlorides. The catalyst can be reused up to five times after simple washing with ether and is stable (as a bench top catalyst).
2010, 21(12): 1399-1402
doi: 10.1016/j.cclet.2010.06.030
Abstract:
The fluorination reaction involving a β-ketosulfones by SelectfluorTM was efficiently promoted by the ionic liquid,[Hbim]BF4 (IL) as a reaction medium with methanol as co-solvent at room temperature under ultrasonic irradiation to afford the corresponding mono and difluoro-β-ketosulfones in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under room temperature without the requirement of any added catalyst under ultrasonic irradiation.
The fluorination reaction involving a β-ketosulfones by SelectfluorTM was efficiently promoted by the ionic liquid,[Hbim]BF4 (IL) as a reaction medium with methanol as co-solvent at room temperature under ultrasonic irradiation to afford the corresponding mono and difluoro-β-ketosulfones in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under room temperature without the requirement of any added catalyst under ultrasonic irradiation.
2010, 21(12): 1403-1406
doi: 10.1016/j.cclet.2010.05.027
Abstract:
A series of chiral secondary alcohols were easily prepared by means of asymmetric hydrogenation of prochiral aromatic ketones using a new ((Rax)-BuP)/(R, R)-DPEN-Ru (Ⅱ) complex catalyst system. The hydrogenation of 2-methylacetophenone in n-butanol (t-BuOK/Ru=45.6/1, S/C=500, 20 atm. Of H2, 20℃, 48h) afforded (S)-1-(2'-methylphenyl) ethanol in 92% ee and>99% conversion.
A series of chiral secondary alcohols were easily prepared by means of asymmetric hydrogenation of prochiral aromatic ketones using a new ((Rax)-BuP)/(R, R)-DPEN-Ru (Ⅱ) complex catalyst system. The hydrogenation of 2-methylacetophenone in n-butanol (t-BuOK/Ru=45.6/1, S/C=500, 20 atm. Of H2, 20℃, 48h) afforded (S)-1-(2'-methylphenyl) ethanol in 92% ee and>99% conversion.
2010, 21(12): 1407-1410
doi: 10.1016/j.cclet.2010.05.026
Abstract:
A series of novel derivatives of indirubin were synthesized and evaluated for their anti-proliferative activity against human cancer cell lines of SGC7901, A549, HL-60, SK-BR-3 and HCT116. Most of the compounds displayed more potent activity than Sunitinib. In addition, the derivatives showed improved water solubility, which may be favorable to their pharmacokinetic performances.
A series of novel derivatives of indirubin were synthesized and evaluated for their anti-proliferative activity against human cancer cell lines of SGC7901, A549, HL-60, SK-BR-3 and HCT116. Most of the compounds displayed more potent activity than Sunitinib. In addition, the derivatives showed improved water solubility, which may be favorable to their pharmacokinetic performances.
2010, 21(12): 1411-1414
doi: 10.1016/j.cclet.2010.06.019
Abstract:
A ligand-free Heck reaction catalyzed by in situ-generated palladium nanoparticles in PEG-400 has been developed. This catalytic system is a simple and active protocol for the Heck reaction of aryl halides under mild conditions. Comparative experiments demonstrated that the Heck reaction catalyzed by the palladium nanoparticles in situ-generated under the Heck reaction conditions was carried out much quicker than that by the in ex situ-generated ones.
A ligand-free Heck reaction catalyzed by in situ-generated palladium nanoparticles in PEG-400 has been developed. This catalytic system is a simple and active protocol for the Heck reaction of aryl halides under mild conditions. Comparative experiments demonstrated that the Heck reaction catalyzed by the palladium nanoparticles in situ-generated under the Heck reaction conditions was carried out much quicker than that by the in ex situ-generated ones.
2010, 21(12): 1415-1418
doi: 10.1016/j.cclet.2010.07.005
Abstract:
Based on the fact that petroselinic acid showed good inhibitory activity (IC50=6.99 μmol/L) against protein tyrosine phophatase 1B (PTP1B) in vitro, a series of novel N-(alkoxyphenyl)-aminocarbonylbenzoic acid derivatives were designed and synthesized. The results indicated that most of the derivatives showed more potent activities against PTP1B. Especially, compound 13 had obvious activity with an IC50 of 106 nmol/L in vitro.
Based on the fact that petroselinic acid showed good inhibitory activity (IC50=6.99 μmol/L) against protein tyrosine phophatase 1B (PTP1B) in vitro, a series of novel N-(alkoxyphenyl)-aminocarbonylbenzoic acid derivatives were designed and synthesized. The results indicated that most of the derivatives showed more potent activities against PTP1B. Especially, compound 13 had obvious activity with an IC50 of 106 nmol/L in vitro.
2010, 21(12): 1419-1422
doi: 10.1016/j.cclet.2010.07.006
Abstract:
4-Amino-3-mercapto-6-methyl-1, 2, 4-triazin-5 (4H)-one 1 converted to 4-amino-6-methy-3-(methylthio)-l, 2, 4-triazin-5 (4H)-one by methylation with methyl iodide. Controlled hydrazination of the resulting compound afforded 4-amino-3-hydrazinyl-6-methyl-l, 2, 4-triazin-5 (4H)-one 2 as a building block, to the synthesis of some novel derivatives of[1, 2, 4]triazino-[4, 3, b] [1, 2, 4, 5]tetrazepine 3-6, by the reaction with 3-chloropentane-2, 4-dione, chloro acetonitrile, 1, 3-dichloroacetone, and methyl bromoacetate. This general synthetic procedure can be extended to the preparation of wide variety of tetrazepines using 1, 2-bielectrophiles derivatives.
4-Amino-3-mercapto-6-methyl-1, 2, 4-triazin-5 (4H)-one 1 converted to 4-amino-6-methy-3-(methylthio)-l, 2, 4-triazin-5 (4H)-one by methylation with methyl iodide. Controlled hydrazination of the resulting compound afforded 4-amino-3-hydrazinyl-6-methyl-l, 2, 4-triazin-5 (4H)-one 2 as a building block, to the synthesis of some novel derivatives of[1, 2, 4]triazino-[4, 3, b] [1, 2, 4, 5]tetrazepine 3-6, by the reaction with 3-chloropentane-2, 4-dione, chloro acetonitrile, 1, 3-dichloroacetone, and methyl bromoacetate. This general synthetic procedure can be extended to the preparation of wide variety of tetrazepines using 1, 2-bielectrophiles derivatives.
2010, 21(12): 1423-1426
doi: 10.1016/j.cclet.2010.07.007
Abstract:
An efficient and easy method for one-pot three-component synthesis of l, 3-disubstituted-3H-benzo[f]chromenes by the condensation of naphtol, aromatic aldehyde derivatives and phenylacetylene in the presence of ferric hydrogensulfate[Fe (HSO4)3], has been described. The catalyst displayed high activity which afforded the corresponding l, 3-disubstituted-3H-benzo[f]chromenes in satisfying yields. Alkyl-substituted phenols were examined and the corresponding benzopyran derivatives were synthesized in moderate yields. Heterogeneous nature of the using catalyst made it reusable for further chemical reactions.
An efficient and easy method for one-pot three-component synthesis of l, 3-disubstituted-3H-benzo[f]chromenes by the condensation of naphtol, aromatic aldehyde derivatives and phenylacetylene in the presence of ferric hydrogensulfate[Fe (HSO4)3], has been described. The catalyst displayed high activity which afforded the corresponding l, 3-disubstituted-3H-benzo[f]chromenes in satisfying yields. Alkyl-substituted phenols were examined and the corresponding benzopyran derivatives were synthesized in moderate yields. Heterogeneous nature of the using catalyst made it reusable for further chemical reactions.
2010, 21(12): 1427-1429
doi: 10.1016/j.cclet.2010.07.014
Abstract:
16 ADT carboxylate esters were prepared by means of esterification and these compounds were expected to increase the bioavailability of 4-hydroxyanehole trithione. In vivo studies showed that ADT concentration of 3a in plasma was much higher than that of ATT during 120 min. Compound 3a could reach blood peak values of ADT at 660.6 ng/mL which was about 14 times of that by ATT. Additionally, the acute toxicity assay indicated high safety of compound 3a that the maximum tolerated dose was no less than 3.25 g/kg.
16 ADT carboxylate esters were prepared by means of esterification and these compounds were expected to increase the bioavailability of 4-hydroxyanehole trithione. In vivo studies showed that ADT concentration of 3a in plasma was much higher than that of ATT during 120 min. Compound 3a could reach blood peak values of ADT at 660.6 ng/mL which was about 14 times of that by ATT. Additionally, the acute toxicity assay indicated high safety of compound 3a that the maximum tolerated dose was no less than 3.25 g/kg.
2010, 21(12): 1430-1434
doi: 10.1016/j.cclet.2010.05.025
Abstract:
The catalytic application of p-toluenesulfonyl chloride for efficient acetylation of various types of alcohols and phenols with acetic anhydride in solvent-free conditions is reported. Also structurally diverse alcohols were formylated using formic acid based on the use of catalytic amount of p-toluenesulfonyl chloride under solvent-free condition. The reactions were carried out in short reaction time and in good to excellent yields at room temperature.
The catalytic application of p-toluenesulfonyl chloride for efficient acetylation of various types of alcohols and phenols with acetic anhydride in solvent-free conditions is reported. Also structurally diverse alcohols were formylated using formic acid based on the use of catalytic amount of p-toluenesulfonyl chloride under solvent-free condition. The reactions were carried out in short reaction time and in good to excellent yields at room temperature.
2010, 21(12): 1435-1438
doi: 10.1016/j.cclet.2010.07.017
Abstract:
A series of new 7-aryl-11, 12-dihydrobenzo[h]pyrimido-[4, 5-b]quinoline-8, 10(7H, 9H)-diones were synthesized via three-component reaction of aldehydes, 1-naphthylamine and barbituric acid in ionic liquid. The method provided several advantages such as easy work-up, high yields and environmentally benign procedure.
A series of new 7-aryl-11, 12-dihydrobenzo[h]pyrimido-[4, 5-b]quinoline-8, 10(7H, 9H)-diones were synthesized via three-component reaction of aldehydes, 1-naphthylamine and barbituric acid in ionic liquid. The method provided several advantages such as easy work-up, high yields and environmentally benign procedure.
2010, 21(12): 1439-1442
doi: 10.1016/j.cclet.2010.06.038
Abstract:
1-Methyl-3-ethyl imidazolium bromide[meim]Br/basic alumina (AI2O3) has been found to promote the cyclocondensation of chloroacetone/chloroethyl acetate with salicylaldehydes under conventional as well as microwave irradiation to yield benzofuran derivatives.
1-Methyl-3-ethyl imidazolium bromide[meim]Br/basic alumina (AI2O3) has been found to promote the cyclocondensation of chloroacetone/chloroethyl acetate with salicylaldehydes under conventional as well as microwave irradiation to yield benzofuran derivatives.
2010, 21(12): 1443-1445
doi: 10.1016/j.cclet.2010.06.024
Abstract:
A new C-glycosyl flavone 7, 4'-dihydroxy-5-methoxyflavone-6-C-β-D-glucopyranoside 1 has been isolated and characterized form ethanolic extract of leaves part of Glycosmis arborea. The structure of compound was verified by means of high field ID and 2D NMR (DEPT, COSY, DQF-HSQC, HMBC) and HRMS spectral analysis, respectively.
A new C-glycosyl flavone 7, 4'-dihydroxy-5-methoxyflavone-6-C-β-D-glucopyranoside 1 has been isolated and characterized form ethanolic extract of leaves part of Glycosmis arborea. The structure of compound was verified by means of high field ID and 2D NMR (DEPT, COSY, DQF-HSQC, HMBC) and HRMS spectral analysis, respectively.
2010, 21(12): 1446-1448
doi: 10.1016/j.cclet.2010.07.018
Abstract:
Magnoline (1), a new isoquinoline derivative, was isolated from the leaves of Magnolia sieboldii K. Koch (Magnoliaceae). Its structure was elucidated on the basis of spectral analysis including ID, 2D NMR and HR-TOF-MS.
Magnoline (1), a new isoquinoline derivative, was isolated from the leaves of Magnolia sieboldii K. Koch (Magnoliaceae). Its structure was elucidated on the basis of spectral analysis including ID, 2D NMR and HR-TOF-MS.
2010, 21(12): 1449-1452
doi: 10.1016/j.cclet.2010.07.008
Abstract:
The ability of Cocos nucifera L. water (CW) as non-toxic corrosion inhibitor for acid corrosion of aluminium in 0.5 mol/L HCl has been studied using chemical technique. CW shows significant inhibition as corrosion inhibitor, with 93% efficiency at the highest concentration of the inhibitor. The inhibitive action is attributed to the adsorption of the inhibitor molecules on metal surface following Langmuir adsorption isotherm.
The ability of Cocos nucifera L. water (CW) as non-toxic corrosion inhibitor for acid corrosion of aluminium in 0.5 mol/L HCl has been studied using chemical technique. CW shows significant inhibition as corrosion inhibitor, with 93% efficiency at the highest concentration of the inhibitor. The inhibitive action is attributed to the adsorption of the inhibitor molecules on metal surface following Langmuir adsorption isotherm.
2010, 21(12): 1453-1456
doi: 10.1016/j.cclet.2010.07.002
Abstract:
The separation of enzymatic hydrolysis products of yeast RNA by ion-pair HPLC was studied. A modified chromatographic response function (MCRF) was proposed to appraise the effectiveness of chromatographic separation. This function takes the number of peaks, resolution and the retention time of the last peak into consideration. It shows advantages for optimization of HPLC separation of complex mixtures. An orthogonal array design was used to separate the hydrolysate of yeast RNA and the optimal chromatographic conditions were obtained.
The separation of enzymatic hydrolysis products of yeast RNA by ion-pair HPLC was studied. A modified chromatographic response function (MCRF) was proposed to appraise the effectiveness of chromatographic separation. This function takes the number of peaks, resolution and the retention time of the last peak into consideration. It shows advantages for optimization of HPLC separation of complex mixtures. An orthogonal array design was used to separate the hydrolysate of yeast RNA and the optimal chromatographic conditions were obtained.
2010, 21(12): 1457-1461
doi: 10.1016/j.cclet.2010.06.029
Abstract:
A fast, sensitive, and reliable method for the determination of sulfite (SO32-) in fresh water and seawater samples was developed. The proposed method was based on the reaction of o-phthalaldehyde (OPA)-sulfite-NH3 in alkaline solution, with flow injection analysis and fluorescence detection. The experimental parameters were investigated in pure water and seawater matrixes. The detection limits (S/N=3) were 0.006 μmol/L in pure water and 0.018 μmol/L in seawater for SO32-. The method was successfully applied to analyze SO32-in the samples of rain water and flue gas desulfurization seawater.
A fast, sensitive, and reliable method for the determination of sulfite (SO32-) in fresh water and seawater samples was developed. The proposed method was based on the reaction of o-phthalaldehyde (OPA)-sulfite-NH3 in alkaline solution, with flow injection analysis and fluorescence detection. The experimental parameters were investigated in pure water and seawater matrixes. The detection limits (S/N=3) were 0.006 μmol/L in pure water and 0.018 μmol/L in seawater for SO32-. The method was successfully applied to analyze SO32-in the samples of rain water and flue gas desulfurization seawater.
2010, 21(12): 1462-1466
doi: 10.1016/j.cclet.2010.06.004
Abstract:
Electrocatalytic oxidation of thiosulfate at the 2, 7-BFEFMCPE occurs at a potential about 460 mV less positive than that unmodified carbon paste electrode. The diffusion coefficient (=5.6×10-5 cm2 s-1), the kinetic parameters such as electron transfer coefficient, (=0.5) and kh (=1.21×10-3 cm s-1) of thiosulfate oxidation at the surface of, 2, 7-BFEFMCPE were determined. The electrocatalytic oxidation peak current of thiosulfate showed two linear dynamic ranges (0.00 (0-0.009 mmol/L and 0.009-0.900 mmol/L) and a detection limit of 0.00015 mmol/L. This method was also examined as a new electrochemical sensor for the determination of thiosulfate in real sample.
Electrocatalytic oxidation of thiosulfate at the 2, 7-BFEFMCPE occurs at a potential about 460 mV less positive than that unmodified carbon paste electrode. The diffusion coefficient (=5.6×10-5 cm2 s-1), the kinetic parameters such as electron transfer coefficient, (=0.5) and kh (=1.21×10-3 cm s-1) of thiosulfate oxidation at the surface of, 2, 7-BFEFMCPE were determined. The electrocatalytic oxidation peak current of thiosulfate showed two linear dynamic ranges (0.00 (0-0.009 mmol/L and 0.009-0.900 mmol/L) and a detection limit of 0.00015 mmol/L. This method was also examined as a new electrochemical sensor for the determination of thiosulfate in real sample.
2010, 21(12): 1467-1470
doi: 10.1016/j.cclet.2010.06.020
Abstract:
In this work. we describe a new strategy for the electrochemical determination of captopril (CA) using ferrocenemonocarboxylic acid as a mediator and muhiwall carbon nanotubes as sensors in aqueous solution at pH 7.0. The diffusion coefficient (D), and the kinetic parameters such as electron transfer coefficient (α), and heterogeneous rate constant (kh), for CA were also determined using electrochemical approaches. Under the optimized conditions, the electrocatalytic oxidation peak current of captopril showed. two linear dynamic ranges with a detection limit of 0.3×10-6 mol L-1 captopril. The linear calibration range was 0.8×10-6 to 65×10-6 mol L-1 using cyclic voltammetry. Finally, this modified electrode was also examined as a selective, simple and precise new electrochemical sensor for the determination of captopril in real samples such as drug and patient human urine.
In this work. we describe a new strategy for the electrochemical determination of captopril (CA) using ferrocenemonocarboxylic acid as a mediator and muhiwall carbon nanotubes as sensors in aqueous solution at pH 7.0. The diffusion coefficient (D), and the kinetic parameters such as electron transfer coefficient (α), and heterogeneous rate constant (kh), for CA were also determined using electrochemical approaches. Under the optimized conditions, the electrocatalytic oxidation peak current of captopril showed. two linear dynamic ranges with a detection limit of 0.3×10-6 mol L-1 captopril. The linear calibration range was 0.8×10-6 to 65×10-6 mol L-1 using cyclic voltammetry. Finally, this modified electrode was also examined as a selective, simple and precise new electrochemical sensor for the determination of captopril in real samples such as drug and patient human urine.
2010, 21(12): 1471-1474
doi: 10.1016/j.cclet.2010.07.026
Abstract:
The electrochemical behavior of vitamin C (ascorbic acid or AA) is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2, 2'-(1, 2 butanediylbis (nitriloethylidyne))-bis-hydroquinone (BBNBH). The prepared modified electrode showed an efficient catalytic role in the electrochemical oxidation of AA, leading to remarkable decrease in oxidation overpotential and enhancement of the kinetics of the electrode reaction. This modified electrode exhibits well-separated oxidation peaks for AA and uric acid (UA). The modified electrode is successfully applied for the accurate determination of AA in pharmaceutical preparations.
The electrochemical behavior of vitamin C (ascorbic acid or AA) is investigated on the surface of a carbon-paste electrode modified with TiO2 nanoparticles and 2, 2'-(1, 2 butanediylbis (nitriloethylidyne))-bis-hydroquinone (BBNBH). The prepared modified electrode showed an efficient catalytic role in the electrochemical oxidation of AA, leading to remarkable decrease in oxidation overpotential and enhancement of the kinetics of the electrode reaction. This modified electrode exhibits well-separated oxidation peaks for AA and uric acid (UA). The modified electrode is successfully applied for the accurate determination of AA in pharmaceutical preparations.
2010, 21(12): 1475-1478
doi: 10.1016/j.cclet.2010.06.039
Abstract:
One chloride-terminated ionic liquid (CTIL) and two hydroxyl-terminated ionic liquids (HTILs) were synthesized and used as stationary phases for capillary gas chromatography (CGC). Molecular interactions of these stationary phases were evaluated by Abraham solvation parameter model, indicating that the CTIL exhibits remarkably strong H-bond basicity and the HTILs possess both H-bond basicity and acidity. The molecular interactions were further confirmed by separation of a complex mixture consisting of ketones, aldehydes, esters, alcohols and aromatic compounds. It was found that the obtained solvation parameters correlate well with the chromatographic performances of the analytes in terms of elution order and resolution. The well correlated relationship between the solvation parameters and the selectivity of the CTIL and HTILs stationary phases is quite helpful in predicting and understanding the retention behaviors of different types of analytes on these stationary phases.
One chloride-terminated ionic liquid (CTIL) and two hydroxyl-terminated ionic liquids (HTILs) were synthesized and used as stationary phases for capillary gas chromatography (CGC). Molecular interactions of these stationary phases were evaluated by Abraham solvation parameter model, indicating that the CTIL exhibits remarkably strong H-bond basicity and the HTILs possess both H-bond basicity and acidity. The molecular interactions were further confirmed by separation of a complex mixture consisting of ketones, aldehydes, esters, alcohols and aromatic compounds. It was found that the obtained solvation parameters correlate well with the chromatographic performances of the analytes in terms of elution order and resolution. The well correlated relationship between the solvation parameters and the selectivity of the CTIL and HTILs stationary phases is quite helpful in predicting and understanding the retention behaviors of different types of analytes on these stationary phases.
2010, 21(12): 1479-1481
doi: 10.1016/j.cclet.2010.06.032
Abstract:
Lignosulfonate with low polydispersity index of 1.178-1.210 was isolated by gel column chromatography of Sephacryl S-100eluted with 0.2 mol/L of NaNO3 aqueous solution, whereas nearly monodisperse ligosulfonate fraction with polydispersity of 1.067can be obtained after chromatographic separation twice. This method provides an available approach to investigate the structure and characteristics of lignosulfonate.
Lignosulfonate with low polydispersity index of 1.178-1.210 was isolated by gel column chromatography of Sephacryl S-100eluted with 0.2 mol/L of NaNO3 aqueous solution, whereas nearly monodisperse ligosulfonate fraction with polydispersity of 1.067can be obtained after chromatographic separation twice. This method provides an available approach to investigate the structure and characteristics of lignosulfonate.
2010, 21(12): 1482-1486
doi: 10.1016/j.cclet.2010.06.040
Abstract:
A rapid, green and highly sensitive excitation-emission matrix (EEM) fluorescence method was proposed for analysis of irinotecan (CPT-11) in biological fluids including human plasma and urine samples of uncalibrated interferences with the aid of second-order advantage. Due to the serious spectral overlapping from biological matrices, the parallel factor analysis (PARAFAC) and the alternating normalization-weighted error (ANWE) have been recommended to perform directly calibration and overcome the problem which makes the traditional fluorospectrophotometer in trouble. Satisfactory results can be achieved. Furthermore, performance of the proposed method was evaluated based on figures of merit and some statistical parameters. The accuracy of both algorithms was validated by the elliptical joint confidence region (EJCR) test. The precision and repeatability were also investigated by the relative standard deviations (RSDs) of intra-day and inter-day.
A rapid, green and highly sensitive excitation-emission matrix (EEM) fluorescence method was proposed for analysis of irinotecan (CPT-11) in biological fluids including human plasma and urine samples of uncalibrated interferences with the aid of second-order advantage. Due to the serious spectral overlapping from biological matrices, the parallel factor analysis (PARAFAC) and the alternating normalization-weighted error (ANWE) have been recommended to perform directly calibration and overcome the problem which makes the traditional fluorospectrophotometer in trouble. Satisfactory results can be achieved. Furthermore, performance of the proposed method was evaluated based on figures of merit and some statistical parameters. The accuracy of both algorithms was validated by the elliptical joint confidence region (EJCR) test. The precision and repeatability were also investigated by the relative standard deviations (RSDs) of intra-day and inter-day.
2010, 21(12): 1487-1489
doi: 10.1016/j.cclet.2010.06.005
Abstract:
In this letter, N-acryloyl-3-aminophenylboronic acid (AAPBA) was synthesized and then examined as a new functional monomer for protein imprinting. It was allowed to be copolymerized with acrylamide to produce hemoglobin-or lysozyme-imprinted hydrogels. In template rebinding tests, the imprinted gels showed significant increase in the specific binding with the increase of the AAPBA amounts in the prepolymerization recipes. These results indicate that AAPBA may be a useful functional monomer for its moderate interactions with protein molecules.
In this letter, N-acryloyl-3-aminophenylboronic acid (AAPBA) was synthesized and then examined as a new functional monomer for protein imprinting. It was allowed to be copolymerized with acrylamide to produce hemoglobin-or lysozyme-imprinted hydrogels. In template rebinding tests, the imprinted gels showed significant increase in the specific binding with the increase of the AAPBA amounts in the prepolymerization recipes. These results indicate that AAPBA may be a useful functional monomer for its moderate interactions with protein molecules.
2010, 21(12): 1490-1492
doi: 10.1016/j.cclet.2010.07.016
Abstract:
The electropolymerized film of amaranth was prepared on the surface of graphite pencil electrode (GPE) using cyclic voltammetric technique. This poly (amaranth) film coated electrode exhibited an excellent electrocatalytic activity towards the detection of dopamine (DA) in the presence of uric acid (UA) in 0.2 mol/L phosphate buffer solution at pH 7.0. The effect of interference study was carried out using differential pulse voltammetric technique. The poly (amaranth) modified GPE was applied for the detection of DA in dopamine injection with satisfactory results.
The electropolymerized film of amaranth was prepared on the surface of graphite pencil electrode (GPE) using cyclic voltammetric technique. This poly (amaranth) film coated electrode exhibited an excellent electrocatalytic activity towards the detection of dopamine (DA) in the presence of uric acid (UA) in 0.2 mol/L phosphate buffer solution at pH 7.0. The effect of interference study was carried out using differential pulse voltammetric technique. The poly (amaranth) modified GPE was applied for the detection of DA in dopamine injection with satisfactory results.
2010, 21(12): 1493-1496
doi: 10.1016/j.cclet.2010.07.015
Abstract:
A versatile and effective method for incorporating functional groups on the pore wall of three-dimensionally ordered macroporous cross-linked polystyrene (3DOM CLPS) by hydrophilic spacer arm has been investigated. The 3DOM CLPS with pore size 865 nm was prepared by sacrifice template method. The hydrophilic spacer arm (polyethylene glycol, molecular weight is 600) was grafted to the 3DOM CLPS via nucleophilic substitution reaction. The other side of active hydroxyl can be further converted into a lot of other functional groups. In this report, the chelating ligand 2-mercaptobenzothiazole (MBZ) group was introduced on the end of the PGE chain to evidence the versatile functionalization approach. The functionalized ordered macroporous materials were characterized by FT-IR, element analyzer, SEM. The results reveal that the pores were successfully bonded with 2-mercaptobenzothiazole groups via hydrophilic spacer arms and the original morphology of ordered macroporous materials were remained after functionalization. The MBZ group density is 0.052 mmol/m2. The functionalized 3DOM CLPS are expected to application as heavy metal ions adsorbent.
A versatile and effective method for incorporating functional groups on the pore wall of three-dimensionally ordered macroporous cross-linked polystyrene (3DOM CLPS) by hydrophilic spacer arm has been investigated. The 3DOM CLPS with pore size 865 nm was prepared by sacrifice template method. The hydrophilic spacer arm (polyethylene glycol, molecular weight is 600) was grafted to the 3DOM CLPS via nucleophilic substitution reaction. The other side of active hydroxyl can be further converted into a lot of other functional groups. In this report, the chelating ligand 2-mercaptobenzothiazole (MBZ) group was introduced on the end of the PGE chain to evidence the versatile functionalization approach. The functionalized ordered macroporous materials were characterized by FT-IR, element analyzer, SEM. The results reveal that the pores were successfully bonded with 2-mercaptobenzothiazole groups via hydrophilic spacer arms and the original morphology of ordered macroporous materials were remained after functionalization. The MBZ group density is 0.052 mmol/m2. The functionalized 3DOM CLPS are expected to application as heavy metal ions adsorbent.
2010, 21(12): 1497-1500
doi: 10.1016/j.cclet.2010.06.001
Abstract:
Polystyrene-styrene/butadiene diblock copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization. During the polymerization process, the molecular weight distribution was narrow and the numerical molecular weight of the copolymers increased with increasing conversion of monomers, which was close to the theoretical. FT-IR and 1H NMR results indicated that the microstructure of the polymer was mainly 1, 4-trans-butadiene with small amount of 1, 2-units, and composition in the copolymers was obtained.
Polystyrene-styrene/butadiene diblock copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization. During the polymerization process, the molecular weight distribution was narrow and the numerical molecular weight of the copolymers increased with increasing conversion of monomers, which was close to the theoretical. FT-IR and 1H NMR results indicated that the microstructure of the polymer was mainly 1, 4-trans-butadiene with small amount of 1, 2-units, and composition in the copolymers was obtained.
Methyl and methane elimination in the gas phase reaction of zirconium atom with 2-butyne:A DFT study
2010, 21(12): 1501-1504
doi: 10.1016/j.cclet.2010.07.025
Abstract:
The mechanisms for CH3-and CH4-elimination in the gas phase reaction of ground-state Zr with 2-butyne has been investigated in detail using B3LYP method. For the elimination of CH3, two mechanisms which are similar to those previously found for the reactions of Y and Zr with propyne are identified. The mechanism for the elimination of CH4 was revealed as:Zr+CH3C≡CCH3→π-complex→TS (H-migration)→HZr-(H2CCC)-CH3→TS (C-C insertion)→ (H2CCC)-HZr-CH3→TS (H-migration)→CH4+ZrC3H2.
The mechanisms for CH3-and CH4-elimination in the gas phase reaction of ground-state Zr with 2-butyne has been investigated in detail using B3LYP method. For the elimination of CH3, two mechanisms which are similar to those previously found for the reactions of Y and Zr with propyne are identified. The mechanism for the elimination of CH4 was revealed as:Zr+CH3C≡CCH3→π-complex→TS (H-migration)→HZr-(H2CCC)-CH3→TS (C-C insertion)→ (H2CCC)-HZr-CH3→TS (H-migration)→CH4+ZrC3H2.
2010, 21(12): 1505-1508
doi: 10.1016/j.cclet.2010.07.004
Abstract:
Porous SnO2 nanocrystalline thin films were successfully electrodeposited from an oxygen-saturated acid aqueous solution of SnCl2 containing different concentrations of butyl-rhodamine B (BRhB) at 70℃. BRhB with substitute of amidocyanogen can be dissolved in the acid deposition solution, where HCl was added to suppress hydrolysis of SnCl2. So it was used as a structure-directing agent to promote the crystal growth of SnO2. The formed porous morphology and tetragonal rutile crystalline structure of the electrodeposited thin films were controlled by the addition of BRhB with different amounts.
Porous SnO2 nanocrystalline thin films were successfully electrodeposited from an oxygen-saturated acid aqueous solution of SnCl2 containing different concentrations of butyl-rhodamine B (BRhB) at 70℃. BRhB with substitute of amidocyanogen can be dissolved in the acid deposition solution, where HCl was added to suppress hydrolysis of SnCl2. So it was used as a structure-directing agent to promote the crystal growth of SnO2. The formed porous morphology and tetragonal rutile crystalline structure of the electrodeposited thin films were controlled by the addition of BRhB with different amounts.
2010, 21(12): 1509-1512
doi: 10.1016/j.cclet.2010.07.003
Abstract:
A novel nano-composite of polyaniline/mesoporous carbon (PANI/CMK-3) was prepared with mesoporous carbon (CMK-3) serving as the support. Electrochemical asymmetric capacitors have been successfully designed by using PANI/CMK-3 composite and CMK-3 as positive and negative electrode, respectively. The results showed that the discharge capacity of the asymmetric capacitor could reach 87.4 Fig under the current density of 5 mA/cm2 and cell voltage of 1.4 V. The energy density of the asymmetric capacitor was up to 23.8 Wh/kg with a power density of 206 W/kg. Furthermore, PANI/CMK-3-CMK-3 asymmetric capacitor using this PANI/CMK-3 nano-composite could be activated quickly and possess high charge-discharge efficiency.
A novel nano-composite of polyaniline/mesoporous carbon (PANI/CMK-3) was prepared with mesoporous carbon (CMK-3) serving as the support. Electrochemical asymmetric capacitors have been successfully designed by using PANI/CMK-3 composite and CMK-3 as positive and negative electrode, respectively. The results showed that the discharge capacity of the asymmetric capacitor could reach 87.4 Fig under the current density of 5 mA/cm2 and cell voltage of 1.4 V. The energy density of the asymmetric capacitor was up to 23.8 Wh/kg with a power density of 206 W/kg. Furthermore, PANI/CMK-3-CMK-3 asymmetric capacitor using this PANI/CMK-3 nano-composite could be activated quickly and possess high charge-discharge efficiency.
2010, 21(12): 1513-1516
doi: 10.1016/j.cclet.2010.06.006
Abstract:
Mesoporous carbon (MC) with surface area of 380 m2/g was prepared and employed as the carbon support of Pt catalyst for counter electrode of dye-sensitized solar cells. Pt/MC samples containing 1 wt% Pt were prepared by reducing chloroplatinic acid on MC using wet impregnation. It was found that Pt nanoparticles were uniform in size and highly dispersed on MC supports. The average size of Pt nanoparticles is about 3.4 rim. Pt/MC electrodes were fabricated by coating Pt/MC samples on fluorine-doped tin oxide glass. The overall conversion efficiency of dye-sensitized solar cells with Pt/MC counter electrode is 6.62%, which is higher than that of the cells with conventional Pt counter electrode in the same conditions.
Mesoporous carbon (MC) with surface area of 380 m2/g was prepared and employed as the carbon support of Pt catalyst for counter electrode of dye-sensitized solar cells. Pt/MC samples containing 1 wt% Pt were prepared by reducing chloroplatinic acid on MC using wet impregnation. It was found that Pt nanoparticles were uniform in size and highly dispersed on MC supports. The average size of Pt nanoparticles is about 3.4 rim. Pt/MC electrodes were fabricated by coating Pt/MC samples on fluorine-doped tin oxide glass. The overall conversion efficiency of dye-sensitized solar cells with Pt/MC counter electrode is 6.62%, which is higher than that of the cells with conventional Pt counter electrode in the same conditions.
