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2006 Volume 17 Issue 7
2006, 17(7): 853-856
Abstract:
Two functionalized pentacyclic compounds 12a, 12b were constructed via a highly efficient synthetic route, employing a tricyclic amino aldehyde as the key intermediate. The crucial steps involved coupling of two segments via amide bond, Swern oxidation and intramolecular Pictet-Spengler cyclization.
Two functionalized pentacyclic compounds 12a, 12b were constructed via a highly efficient synthetic route, employing a tricyclic amino aldehyde as the key intermediate. The crucial steps involved coupling of two segments via amide bond, Swern oxidation and intramolecular Pictet-Spengler cyclization.
2006, 17(7): 857-858
Abstract:
The Lewis acid mediated polystyrene supported selenium induced intramolecular cyclization of chalcones and oxidative cleavage of selenium resins gave the corresponding flavonoids in good yields and purities have been reported.
The Lewis acid mediated polystyrene supported selenium induced intramolecular cyclization of chalcones and oxidative cleavage of selenium resins gave the corresponding flavonoids in good yields and purities have been reported.
2006, 17(7): 859-862
Abstract:
N-Alkylhydroxylamines have been shown to undergo a stereospecific cis addition to 1-phenyl-2 -nitropropene compounds, whereas the corresponding O-alkylhydroxylamines give no diastereoselectivity. The concerted addition mechanism was provided to explain the difference.
N-Alkylhydroxylamines have been shown to undergo a stereospecific cis addition to 1-phenyl-2 -nitropropene compounds, whereas the corresponding O-alkylhydroxylamines give no diastereoselectivity. The concerted addition mechanism was provided to explain the difference.
2006, 17(7): 863-866
Abstract:
A series of isopentenyl-derived unsaturated alkyl ethers 19-31 of racemic deoxyisopodophyllotoxin were designed and synthesized. For comparison, compound 32 with a benzyl group at the same position was also prepared. The cytotoxicities of the synthetic compounds have been screened for six human tumor cell lines such as KB, BEL-7404, A549, Hela, PC-3 and CNE.The results showed that two of them exhibited significant cytotoxicities with their IC50 values on selected cell lines at μmol/L scale.
A series of isopentenyl-derived unsaturated alkyl ethers 19-31 of racemic deoxyisopodophyllotoxin were designed and synthesized. For comparison, compound 32 with a benzyl group at the same position was also prepared. The cytotoxicities of the synthetic compounds have been screened for six human tumor cell lines such as KB, BEL-7404, A549, Hela, PC-3 and CNE.The results showed that two of them exhibited significant cytotoxicities with their IC50 values on selected cell lines at μmol/L scale.
2006, 17(7): 867-870
Abstract:
In the system of ammonium acetate and acetic acid and under microwave irradiation,N-phenacylpyridinium chloride 1 reacted with chalcone 2 to give 2,4,6-triarylpyrididnes 3a-g in high yields. 3a-g can also be prepared from one-pot reaction of 1 with aromatic aldehydes 4 and substituted acetophenones 5. Under the same conditions 1 can also react with pyridinecar boxaldehyde 6a-c and acetophenone to yield bipyridine derivatives 7a-c. 1 reacted with aromatic aldehyde and cyclohexanone 6 to yield 2,4-diaryltetrahydroquinolines 8a-d. At last 1 reacted with aromatic aldehydes to give 2,4,6-triarylpyrimidine 9a-i. The structure of the products was characterized with 1H NMR and IR and mass spectroscopy.
In the system of ammonium acetate and acetic acid and under microwave irradiation,N-phenacylpyridinium chloride 1 reacted with chalcone 2 to give 2,4,6-triarylpyrididnes 3a-g in high yields. 3a-g can also be prepared from one-pot reaction of 1 with aromatic aldehydes 4 and substituted acetophenones 5. Under the same conditions 1 can also react with pyridinecar boxaldehyde 6a-c and acetophenone to yield bipyridine derivatives 7a-c. 1 reacted with aromatic aldehyde and cyclohexanone 6 to yield 2,4-diaryltetrahydroquinolines 8a-d. At last 1 reacted with aromatic aldehydes to give 2,4,6-triarylpyrimidine 9a-i. The structure of the products was characterized with 1H NMR and IR and mass spectroscopy.
2006, 17(7): 871-873
Abstract:
A novel total synthesis of (±)shikonin 1 was presented. The key intermediate 6 was achieved by the formylation of 1,8:4,5-bis(methylenedioxy)naphthalene 5 with N-methylforma-nilide in good yield. It was first reported that the addition of prenyllithium to 2-formyl-1,8:4,5-bismethylenedioxy naphthalene 6 gave 2-(1-hydroxy-4-methylpentyl) 1,8:4,5-bis(methylenedioxy)naphthalene 8 in 45% yield and 2-(1-hydroxy-2,2-dimethyl-3-butenyl)-1,8:4,5-bis(methylene-dioxy)naphthalene 9 in 48% yield. After the electrooxide deprotection of 8, (±)shikonin 1 was prepared in high yield.
A novel total synthesis of (±)shikonin 1 was presented. The key intermediate 6 was achieved by the formylation of 1,8:4,5-bis(methylenedioxy)naphthalene 5 with N-methylforma-nilide in good yield. It was first reported that the addition of prenyllithium to 2-formyl-1,8:4,5-bismethylenedioxy naphthalene 6 gave 2-(1-hydroxy-4-methylpentyl) 1,8:4,5-bis(methylenedioxy)naphthalene 8 in 45% yield and 2-(1-hydroxy-2,2-dimethyl-3-butenyl)-1,8:4,5-bis(methylene-dioxy)naphthalene 9 in 48% yield. After the electrooxide deprotection of 8, (±)shikonin 1 was prepared in high yield.
2006, 17(7): 874-876
Abstract:
The condensation reactions of aromatic aldehydes, 5,5-dimethyl-1,3-cyclohexanedione and ammonium acetate efficiently promoted by several ionic liquids under solvent-free condition to afford corresponding 3, 3, 6, 6-tetramethyl-1, 8-dioxo-9-aryl-1, 2, 3, 4, 5, 6, 7, 8, 9, 10-deca-hydroacridines in good yields.
The condensation reactions of aromatic aldehydes, 5,5-dimethyl-1,3-cyclohexanedione and ammonium acetate efficiently promoted by several ionic liquids under solvent-free condition to afford corresponding 3, 3, 6, 6-tetramethyl-1, 8-dioxo-9-aryl-1, 2, 3, 4, 5, 6, 7, 8, 9, 10-deca-hydroacridines in good yields.
2006, 17(7): 877-879
Abstract:
A convenient method has been developed toward the stereoselective synthesis of N-substituted benzotriazole derivatives under mild conditions. The good stereolectivity, high yields and the simple procedure make the present protocol attractive.
A convenient method has been developed toward the stereoselective synthesis of N-substituted benzotriazole derivatives under mild conditions. The good stereolectivity, high yields and the simple procedure make the present protocol attractive.
2006, 17(7): 880-882
Abstract:
Ferrocenecarboxyaldehyde reacted with iodine in commercial available ammonia water gave ferrocenylcyanide with high yield.
Ferrocenecarboxyaldehyde reacted with iodine in commercial available ammonia water gave ferrocenylcyanide with high yield.
2006, 17(7): 883-886
Abstract:
Combined with an effective copper-catalyzed triazole-forming reaction, a series of novel camptothecin derivatives were synthesized. Incorporating oligo(ethylene glycol) chains into the derivatives enhanced their water-solubility when compared to the parent compound (up to 55-fold).
Combined with an effective copper-catalyzed triazole-forming reaction, a series of novel camptothecin derivatives were synthesized. Incorporating oligo(ethylene glycol) chains into the derivatives enhanced their water-solubility when compared to the parent compound (up to 55-fold).
2006, 17(7): 887-890
Abstract:
Asymmetric pinacol coupling of aromatic aldehydes with TiCl4-Zn in the presence of enantiopure squaric acid amidoalcohols afforded 1, 2-diols in excellent yields with high dl-diastereoselectivities and enantioselectivities in the range of 46-89% ee. Some factors influencing dl-diastereoselectivity and enantioselectivity were discussed.
Asymmetric pinacol coupling of aromatic aldehydes with TiCl4-Zn in the presence of enantiopure squaric acid amidoalcohols afforded 1, 2-diols in excellent yields with high dl-diastereoselectivities and enantioselectivities in the range of 46-89% ee. Some factors influencing dl-diastereoselectivity and enantioselectivity were discussed.
2006, 17(7): 891-894
Abstract:
Two novel N-dichloroacetyl oxazolidines were synthesized with a simple, mild and convenient method in good yields. The compounds were characterized by IR, 1H NMR and elemental analysis. The preliminary biological test show that the compounds protected maize against injure by chlorsulfuron to some extent.
Two novel N-dichloroacetyl oxazolidines were synthesized with a simple, mild and convenient method in good yields. The compounds were characterized by IR, 1H NMR and elemental analysis. The preliminary biological test show that the compounds protected maize against injure by chlorsulfuron to some extent.
2006, 17(7): 895-898
Abstract:
The synthesis of four analogs of philanthotoxin is described. The preliminary bioassay showed that these compounds all had good insecticidal activities, and the compound 6a had the best killing effect.
The synthesis of four analogs of philanthotoxin is described. The preliminary bioassay showed that these compounds all had good insecticidal activities, and the compound 6a had the best killing effect.
2006, 17(7): 899-902
Abstract:
4-Amino-5-pyridin-4-yl-s-triazole-3-thiol (1) was sequentally reacted with 3-chloro-1-phenylpropan-1-one to afford 3-(4-amino-5-pyridin-4-yl-s-triazole-3-sulfanyl)-1-phenylpropan-1-one (2) followed by oximation with hydroxylamine hydrochloride and etherification with 5-aryl-[13,4]oxadiazole-2-chloromethanes to the corresponding oxime (3) and oxime-ethers (4a-e),respectively. The condensation of compounds 4 with salicylaldehyde gave the title compounds (5a-e). The antibacterial activity in vitro against Gram-postive (G+) and Gram negative (G-)bacteria was primarily evaluated.
4-Amino-5-pyridin-4-yl-s-triazole-3-thiol (1) was sequentally reacted with 3-chloro-1-phenylpropan-1-one to afford 3-(4-amino-5-pyridin-4-yl-s-triazole-3-sulfanyl)-1-phenylpropan-1-one (2) followed by oximation with hydroxylamine hydrochloride and etherification with 5-aryl-[13,4]oxadiazole-2-chloromethanes to the corresponding oxime (3) and oxime-ethers (4a-e),respectively. The condensation of compounds 4 with salicylaldehyde gave the title compounds (5a-e). The antibacterial activity in vitro against Gram-postive (G+) and Gram negative (G-)bacteria was primarily evaluated.
2006, 17(7): 903-906
Abstract:
The ITO/5T/PCH/Al device has a short circuit current of 3.4 mA/cm2, an open circuit voltage of 2.1 V, fill fact of 27.5% and photoelectric conversion efficiency of 2.5%.
The ITO/5T/PCH/Al device has a short circuit current of 3.4 mA/cm2, an open circuit voltage of 2.1 V, fill fact of 27.5% and photoelectric conversion efficiency of 2.5%.
2006, 17(7): 907-910
Abstract:
A new economical synthetic route of entecavir was presented, involving the preparation of the key intermediate 6. The synthesis of 6 was conveniently achieved in good overall yield by a modified Mitsunobu reaction.
A new economical synthetic route of entecavir was presented, involving the preparation of the key intermediate 6. The synthesis of 6 was conveniently achieved in good overall yield by a modified Mitsunobu reaction.
2006, 17(7): 911-912
Abstract:
Immobilizing chiral 1,1'-bi-2-naphthol (BINOL) in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic asymmetric oxidation of sulfide to sulfoxide exhibited good activity (up to 60% yield) and high enantioselectivity (up to 89% ee). The immobilized chiral catalyst was very stable and could be readily reused for over 5 times without significant loss of catalytic activity and enantioselectivity.
Immobilizing chiral 1,1'-bi-2-naphthol (BINOL) in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic asymmetric oxidation of sulfide to sulfoxide exhibited good activity (up to 60% yield) and high enantioselectivity (up to 89% ee). The immobilized chiral catalyst was very stable and could be readily reused for over 5 times without significant loss of catalytic activity and enantioselectivity.
2006, 17(7): 913-915
Abstract:
The chemical investigation of Ixeris polycephala afforded two new norsesquiterpenes,named as ixerols A and B (1-2). Their structures were established based on spectroscopic methods including 2D NMR experiments. The absolute structure of ixerol B was determined by its CD spectrum.
The chemical investigation of Ixeris polycephala afforded two new norsesquiterpenes,named as ixerols A and B (1-2). Their structures were established based on spectroscopic methods including 2D NMR experiments. The absolute structure of ixerol B was determined by its CD spectrum.
2006, 17(7): 916-918
Abstract:
A new monoterpene glycoside, together with nine known ones, 3-O-methylpaeoniflorin,mudanpioside J, paeoniflorin, benzoylpaeoniflorin, oxypaeoniflorin, benzoyloxypaeoniflorin,oxybenzoylpaeoniflorin, albiflorin and lactiflorin, was isolated from the roots of Paeonia lactiflora Pall.. The structure of the new compound was elucidated as galloylalbiflorin by the spectroscopic evidence including ESI-MS, 1D- and 2D-NMR spectra.
A new monoterpene glycoside, together with nine known ones, 3-O-methylpaeoniflorin,mudanpioside J, paeoniflorin, benzoylpaeoniflorin, oxypaeoniflorin, benzoyloxypaeoniflorin,oxybenzoylpaeoniflorin, albiflorin and lactiflorin, was isolated from the roots of Paeonia lactiflora Pall.. The structure of the new compound was elucidated as galloylalbiflorin by the spectroscopic evidence including ESI-MS, 1D- and 2D-NMR spectra.
2006, 17(7): 919-921
Abstract:
A new C21 steroidal glycoside, named cynanversicoside F (1), was isolated from the root of Cynanchum versicolor Bunge. Its structure was established as glaucogenin-A 3-O-β-D-digitoxopyranosyl-(1→4)-β-D-cymaropyranoside by spectroscopic and chemical methods.
A new C21 steroidal glycoside, named cynanversicoside F (1), was isolated from the root of Cynanchum versicolor Bunge. Its structure was established as glaucogenin-A 3-O-β-D-digitoxopyranosyl-(1→4)-β-D-cymaropyranoside by spectroscopic and chemical methods.
2006, 17(7): 922-924
Abstract:
Glioclatine, a novel epidithiodioxopiperazine was isolated from wheat solid-substrate fermentation of Gliocladium roseum YMF1.00133. Its structure was elucidated by HRESI-MS and NMR spectra.
Glioclatine, a novel epidithiodioxopiperazine was isolated from wheat solid-substrate fermentation of Gliocladium roseum YMF1.00133. Its structure was elucidated by HRESI-MS and NMR spectra.
2006, 17(7): 925-928
Abstract:
A capillary electrophoresis(CE) with on-line inhibited chemiluminescence (CL) detection was firstly used for the simultaneous analysis of benzenediol isomers and phenol. It is based on the quenching effect of benzenediol isomers and phenol on the chemiluminescence reaction of luminol with potassium ferricyanide in sodium hydroxide medium. Under the optimum conditions, the four phenols were baseline separated and detected in less than 10 min.The detection limits (S/N=3) for hydroquinone, resorcinol, catechol and phenol were 2.9×10-8 mol/L, 3.7×10-7 mol/L, 8.4×10-8 mol/L and 4.4×10-6 mol/L, respectively. Finally, the presented method has been successfully applied to real sample.
A capillary electrophoresis(CE) with on-line inhibited chemiluminescence (CL) detection was firstly used for the simultaneous analysis of benzenediol isomers and phenol. It is based on the quenching effect of benzenediol isomers and phenol on the chemiluminescence reaction of luminol with potassium ferricyanide in sodium hydroxide medium. Under the optimum conditions, the four phenols were baseline separated and detected in less than 10 min.The detection limits (S/N=3) for hydroquinone, resorcinol, catechol and phenol were 2.9×10-8 mol/L, 3.7×10-7 mol/L, 8.4×10-8 mol/L and 4.4×10-6 mol/L, respectively. Finally, the presented method has been successfully applied to real sample.
2006, 17(7): 929-932
Abstract:
This paper studies various classifiers to identify primary, secondary or tertiary alcohols by using segmental spectra and their combinations to support vector machines (SVMs). The results showed that the O-H in-plane bending absorption contributed most to identification their substitute. This conclusion disagrees with related known research results.
This paper studies various classifiers to identify primary, secondary or tertiary alcohols by using segmental spectra and their combinations to support vector machines (SVMs). The results showed that the O-H in-plane bending absorption contributed most to identification their substitute. This conclusion disagrees with related known research results.
2006, 17(7): 933-936
Abstract:
A novel method of ultra-trace Cd(Ⅱ) preconcentration with nanometer-size TiO2 colloid and determination by graphite furnace atomic adsorption spectrometry(GFAAS) with slurry sampling was first advanced in this paper. The adsorption efficiency of nanometer-size TiO2 colloid for ultra-trace Cd(Ⅱ) could reach above 96% in a short time when the pH value was between 5 and 6. Other problems were also studied, such as adsorption capacity, nanometer-size TiO2 colloid dosage, effect of coexistent ions. The detection limit(3σ) and the relative standard deviation (R.S.D) of this method were 4.46·10-3 μg/L and 1.30%(n=7), respectively. The method was successfully applied to the analysis of environmental samples with recoveries between 93.8%and 96.4%.
A novel method of ultra-trace Cd(Ⅱ) preconcentration with nanometer-size TiO2 colloid and determination by graphite furnace atomic adsorption spectrometry(GFAAS) with slurry sampling was first advanced in this paper. The adsorption efficiency of nanometer-size TiO2 colloid for ultra-trace Cd(Ⅱ) could reach above 96% in a short time when the pH value was between 5 and 6. Other problems were also studied, such as adsorption capacity, nanometer-size TiO2 colloid dosage, effect of coexistent ions. The detection limit(3σ) and the relative standard deviation (R.S.D) of this method were 4.46·10-3 μg/L and 1.30%(n=7), respectively. The method was successfully applied to the analysis of environmental samples with recoveries between 93.8%and 96.4%.
2006, 17(7): 937-940
Abstract:
Complex formation between aluminium and quercetin(Q) in methanol was investigated by means of 27Al solid-state, 13C and 1H NMR and MS(ESI), UV and IR spectra. Formation of the 1:2 complex was favored in methanol relative to all other solvent and the predominant species observed of Al(Ⅲ) has a 1:2 stoichiometry. The fine structure of 1:2 aluminum complex of quercetin was that the aluminum central atom chelated with two quercetin molecules and two methoxyl groups between two five membered rings, its coordination is six, the chelated site was 3-hydroxy-4-carbonyl.
Complex formation between aluminium and quercetin(Q) in methanol was investigated by means of 27Al solid-state, 13C and 1H NMR and MS(ESI), UV and IR spectra. Formation of the 1:2 complex was favored in methanol relative to all other solvent and the predominant species observed of Al(Ⅲ) has a 1:2 stoichiometry. The fine structure of 1:2 aluminum complex of quercetin was that the aluminum central atom chelated with two quercetin molecules and two methoxyl groups between two five membered rings, its coordination is six, the chelated site was 3-hydroxy-4-carbonyl.
2006, 17(7): 941-944
Abstract:
A novel tetraiodocadmate(Ⅱ)-selective membrane electrode consisting of tetraiodo-cadmate(Ⅱ)-rhodamin B ion pair (TICRhB) dispersed in a PVC matrix plasticized with 2-nitrophenyl octyl ether (o-NPOE) was prepared. The sensor demonstrated a near-Nernstian response for 1×10-2 to 2×10-6 mol/L cadmium (Ⅱ) at 25℃ with an anionic slope of 29.0. Itrevealed very good selectivity for Cd2+ with negligible interference from many cations and anions,and could be used in a pH range of 3 to 6.
A novel tetraiodocadmate(Ⅱ)-selective membrane electrode consisting of tetraiodo-cadmate(Ⅱ)-rhodamin B ion pair (TICRhB) dispersed in a PVC matrix plasticized with 2-nitrophenyl octyl ether (o-NPOE) was prepared. The sensor demonstrated a near-Nernstian response for 1×10-2 to 2×10-6 mol/L cadmium (Ⅱ) at 25℃ with an anionic slope of 29.0. Itrevealed very good selectivity for Cd2+ with negligible interference from many cations and anions,and could be used in a pH range of 3 to 6.
2006, 17(7): 945-948
Abstract:
The influence of different concentration of oxalic acid matrix on elemental inductively coupled plasma mass spectrometry (ICP-MS) has been investigated. It has been proved that the sensitivity of analytes can be significantly enhanced by adding small amounts of oxalic acid medium with adjusted nebulizer flow-rate gas, especially for the elements with ionization potential between 9 and 11 eV. Oxalic acid, as an enhancement agent, can be used to compensate the signal depression caused by inorganic matrix and to improve the detection limits about two to eight times,for the hard-to-ionize elements in ICP-MS determination.
The influence of different concentration of oxalic acid matrix on elemental inductively coupled plasma mass spectrometry (ICP-MS) has been investigated. It has been proved that the sensitivity of analytes can be significantly enhanced by adding small amounts of oxalic acid medium with adjusted nebulizer flow-rate gas, especially for the elements with ionization potential between 9 and 11 eV. Oxalic acid, as an enhancement agent, can be used to compensate the signal depression caused by inorganic matrix and to improve the detection limits about two to eight times,for the hard-to-ionize elements in ICP-MS determination.
2006, 17(7): 949-952
Abstract:
A highly sensitive stopped-flow spectrophotometry kinetic method was proposed forquantification phenoxyl radicals based on their accelerating effect on the oxidation of nicotinamide adenine dinucleotide (NADH). Phenoxyl radicals generated from as low as 1×10-8 mol/L 2,4-DCP can be readily detected with the proposed method and the detecting limit was 2.5×10-9mol/L.
A highly sensitive stopped-flow spectrophotometry kinetic method was proposed forquantification phenoxyl radicals based on their accelerating effect on the oxidation of nicotinamide adenine dinucleotide (NADH). Phenoxyl radicals generated from as low as 1×10-8 mol/L 2,4-DCP can be readily detected with the proposed method and the detecting limit was 2.5×10-9mol/L.
2006, 17(7): 953-956
Abstract:
A sensitive and simple micellar electrokinetic chromatography (MEKC) method was developed for the determination of antiepileptic drug, carbamazepine (CBZ), using sweeping on-line concentration method with photodiode array detection. Under the optimal conditions, the calbration curve was linear oevr a range of 1.5-40μg·mL-1for CBZ with a correlation clefficient of 0.998.The detection limt(S/N=3:1)of CBZ was 0.10μg·mL-1.The sweeping-MEKC method has been successfully applied to the analysis of CBZ in human serum.
A sensitive and simple micellar electrokinetic chromatography (MEKC) method was developed for the determination of antiepileptic drug, carbamazepine (CBZ), using sweeping on-line concentration method with photodiode array detection. Under the optimal conditions, the calbration curve was linear oevr a range of 1.5-40μg·mL-1for CBZ with a correlation clefficient of 0.998.The detection limt(S/N=3:1)of CBZ was 0.10μg·mL-1.The sweeping-MEKC method has been successfully applied to the analysis of CBZ in human serum.
2006, 17(7): 957-960
Abstract:
A new method is proposed to determine the amplification factor for 2-hydroxy ethylperoxy radicals (HOC2H4O2·) in chemical amplifier.The radical source comes from the reaction of excess ethene with HO·radicals generated in the photolysis of water vapor at the wave length of 185 nm in air in a flow tube.This produces a radical source which contains equal amount of HO2· and HOC2H4O2·.The amplification factor is derived from the slopes of the lines between produced NO2 in chemical amplifier and total initial radical concentrations measured for the source of HO2·and that of the same amount of HO2·and HOC2H4O2·respectively.The amplification factor of HOC2H4O2·was similar to that of HO2·, indicating that HOC2H4O2·can be measured with the same sensitivity as HO2· by chemical amplifier.
A new method is proposed to determine the amplification factor for 2-hydroxy ethylperoxy radicals (HOC2H4O2·) in chemical amplifier.The radical source comes from the reaction of excess ethene with HO·radicals generated in the photolysis of water vapor at the wave length of 185 nm in air in a flow tube.This produces a radical source which contains equal amount of HO2· and HOC2H4O2·.The amplification factor is derived from the slopes of the lines between produced NO2 in chemical amplifier and total initial radical concentrations measured for the source of HO2·and that of the same amount of HO2·and HOC2H4O2·respectively.The amplification factor of HOC2H4O2·was similar to that of HO2·, indicating that HOC2H4O2·can be measured with the same sensitivity as HO2· by chemical amplifier.
2006, 17(7): 961-964
Abstract:
The interaction of CdSe quantum dots (QDs) with bovine serum albumin (BSA) has been investigated with ultraviolet visible absorption spectroscopy (UVAS). It was found that the absorption intensity of CdSe QDs significantly decreased after adding BSA solution, showing that CdSe QDs were bonded to BSA. The binding molar ratio was 1:1 and the binding constant was 9.7×106 L mol-1.
The interaction of CdSe quantum dots (QDs) with bovine serum albumin (BSA) has been investigated with ultraviolet visible absorption spectroscopy (UVAS). It was found that the absorption intensity of CdSe QDs significantly decreased after adding BSA solution, showing that CdSe QDs were bonded to BSA. The binding molar ratio was 1:1 and the binding constant was 9.7×106 L mol-1.
2006, 17(7): 965-968
Abstract:
Novel SPPESK/PAA composite proton exchange membranes with semi-interpenetrating polymer network (sIPN) structure have been synthesized through the in-situ polymerization of acrylic acid (AA) in the presence of sulfonated poly (phthalazinone ether sulfone ketone) (SPPESK). The composite membranes were identified by FT-IR analysis. Water uptake of the composite membranes was as high as 89.7% at 90℃, nearly one time higher than that of the corresponding SPPESK membrane.
Novel SPPESK/PAA composite proton exchange membranes with semi-interpenetrating polymer network (sIPN) structure have been synthesized through the in-situ polymerization of acrylic acid (AA) in the presence of sulfonated poly (phthalazinone ether sulfone ketone) (SPPESK). The composite membranes were identified by FT-IR analysis. Water uptake of the composite membranes was as high as 89.7% at 90℃, nearly one time higher than that of the corresponding SPPESK membrane.
2006, 17(7): 969-972
Abstract:
A novel mimic was synthesized by modifying hyaluronic acid (HA) with tellurium,whose function is similar to that of glutathione peroxidase (GPX). The structure of TeHA was characterized by means of IR and NMR, the target-Te was located at -CH2OH of the N-acetyl-D-glucosamine of HA. The H2O2 reducing activity of TeHA, by glutathione (GSH), was 163.6 U/μmol according to Wilson's method. In contrast to other mimics, TeHA displayed the highest activity. Moreover, TeHA accepted many hydroperoxides as its substrates, such as H2O2, cumenyl hydroperoxide (CuOOH) and tert-butyl hydroperoxide (t-BuOOH), and CuOOH was the optimal substrate of TeHA. A ping-pong mechanism was observed in the steady-state kinetic studies of the reactions catalyzed by TeHA.
A novel mimic was synthesized by modifying hyaluronic acid (HA) with tellurium,whose function is similar to that of glutathione peroxidase (GPX). The structure of TeHA was characterized by means of IR and NMR, the target-Te was located at -CH2OH of the N-acetyl-D-glucosamine of HA. The H2O2 reducing activity of TeHA, by glutathione (GSH), was 163.6 U/μmol according to Wilson's method. In contrast to other mimics, TeHA displayed the highest activity. Moreover, TeHA accepted many hydroperoxides as its substrates, such as H2O2, cumenyl hydroperoxide (CuOOH) and tert-butyl hydroperoxide (t-BuOOH), and CuOOH was the optimal substrate of TeHA. A ping-pong mechanism was observed in the steady-state kinetic studies of the reactions catalyzed by TeHA.
2006, 17(7): 973-976
Abstract:
The photocatalytic hydrogen evolution and electrochemical behaviors of Kiggen-type XW12O40n- (X=P, Ge and Si) are investigated. It is found that the two-electron reduced species are active for H+ reduction and the more negative the potential of XW12O40(n+2)-/(n+1)- is, the higher the activity for hydrogen evolution is.
The photocatalytic hydrogen evolution and electrochemical behaviors of Kiggen-type XW12O40n- (X=P, Ge and Si) are investigated. It is found that the two-electron reduced species are active for H+ reduction and the more negative the potential of XW12O40(n+2)-/(n+1)- is, the higher the activity for hydrogen evolution is.
2006, 17(7): 977-980
Abstract:
Ferrierite zeolite membranes were prepared for the first time in the absence of organic structure-directing agents (SDA) on the surface of a porous α-alumina support. These membranes were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and pervaporation tests.
Ferrierite zeolite membranes were prepared for the first time in the absence of organic structure-directing agents (SDA) on the surface of a porous α-alumina support. These membranes were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and pervaporation tests.
2006, 17(7): 981-984
Abstract:
Three quaternized chitosan derivatives were synthesized and their adsorption performance of bile acid from aqueous solution was studied. The adsorption capacities and rates of bile acid onto quaternized chitosan derivatives were evaluated. The kinetic experimental data properly correlated with the second-order kinetic model, which indicated that the chemical sorption is the rate-limiting step. The results showed that the quaternized chitosan derivatives are favorable adsorbents for bile acid.
Three quaternized chitosan derivatives were synthesized and their adsorption performance of bile acid from aqueous solution was studied. The adsorption capacities and rates of bile acid onto quaternized chitosan derivatives were evaluated. The kinetic experimental data properly correlated with the second-order kinetic model, which indicated that the chemical sorption is the rate-limiting step. The results showed that the quaternized chitosan derivatives are favorable adsorbents for bile acid.
2006, 17(7): 985-987
Abstract:
Layered double hydroxide was investigated as cordycepin delivery nanocarrier for the first time in this study. Negatively charged biomolecule-cordycepin was intercalated in the gallery spaces of [Mg-Al-NO3], which was confirmed by the results of X-ray diffraction and electrophoretic mobility. Cell experiment suggested that the new bio-LDH nanohybrid could prevent cordycepin decomposition by adenosine deaminase. This new formulation could possibly be used as a novel form cordycepin intravenous injection.
Layered double hydroxide was investigated as cordycepin delivery nanocarrier for the first time in this study. Negatively charged biomolecule-cordycepin was intercalated in the gallery spaces of [Mg-Al-NO3], which was confirmed by the results of X-ray diffraction and electrophoretic mobility. Cell experiment suggested that the new bio-LDH nanohybrid could prevent cordycepin decomposition by adenosine deaminase. This new formulation could possibly be used as a novel form cordycepin intravenous injection.
2006, 17(7): 988-990
Abstract:
A kinetic study of two ruthenium carbene catalysts, (PCy3)2Cl2Ru=CHPh 1 (Grubbs catalyst) and a new catalyst [1,3-bis(2,6-dimethylphenyl)4,5-dihydroimidazol-2-ylidene](PPh3)(Cl)2Ru=CHPh 3, were conducted in metathesis of 1-hexene. The kinetic behavior of these catalysts at 40, 50, 60 and 70℃ was compared. Complex 3 has the more active catalytic effect at temperatures 40-70℃.
A kinetic study of two ruthenium carbene catalysts, (PCy3)2Cl2Ru=CHPh 1 (Grubbs catalyst) and a new catalyst [1,3-bis(2,6-dimethylphenyl)4,5-dihydroimidazol-2-ylidene](PPh3)(Cl)2Ru=CHPh 3, were conducted in metathesis of 1-hexene. The kinetic behavior of these catalysts at 40, 50, 60 and 70℃ was compared. Complex 3 has the more active catalytic effect at temperatures 40-70℃.
2006, 17(7): 991-994
Abstract:
A series of catalysts of Mn/USY and Mn-Fe/USY prepared by impregnation were studied for low-temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of excess of oxygen. It was found that the addition of Fe enhanced the catalytic performance at low-temperature. Mn-Fe/USY catalyst yielded nearly 100% NO conversion in a range of temperature from 423 to 573 K at a space velocity of 36 000 cm3·g-1·h-1,Coexistemce of manganese and iron oxides enhanced the dispersion of the supported oxides, no visible phase of the oxides can be observed on catalyst. The addition of Fe enhanced the number and strength of the Brönsted and Lewis acid sites on the surface of the catalyst, which might promote the absorption of NH3 to form active intermediate and enhance the catalytic performance at low-temperature.
A series of catalysts of Mn/USY and Mn-Fe/USY prepared by impregnation were studied for low-temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of excess of oxygen. It was found that the addition of Fe enhanced the catalytic performance at low-temperature. Mn-Fe/USY catalyst yielded nearly 100% NO conversion in a range of temperature from 423 to 573 K at a space velocity of 36 000 cm3·g-1·h-1,Coexistemce of manganese and iron oxides enhanced the dispersion of the supported oxides, no visible phase of the oxides can be observed on catalyst. The addition of Fe enhanced the number and strength of the Brönsted and Lewis acid sites on the surface of the catalyst, which might promote the absorption of NH3 to form active intermediate and enhance the catalytic performance at low-temperature.
