Login In
2008 Volume 19 Issue 5
2008, 19(5): 505-508
doi: 10.1016/j.cclet.2008.03.013
Abstract:
4(3H)-Quinazolinones have been synthesized from poly (ethylene glycol) (PEG) supported aza-Wittig reaction. 2-Dialkylamino-4(3H)-quinazolinones 6 were synthesized efficiently by reaction of secondary amine with PEG-supported carbodiimides 4, whichwere obtained from aza-Wittig reaction of PEG-supported iminophosphoranes 3 with isocyanates.
4(3H)-Quinazolinones have been synthesized from poly (ethylene glycol) (PEG) supported aza-Wittig reaction. 2-Dialkylamino-4(3H)-quinazolinones 6 were synthesized efficiently by reaction of secondary amine with PEG-supported carbodiimides 4, whichwere obtained from aza-Wittig reaction of PEG-supported iminophosphoranes 3 with isocyanates.
2008, 19(5): 509-512
doi: 10.1016/j.cclet.2008.03.006
Abstract:
Two novel mononaphthalimide homospermidine derivatives (2a, 2b) with three or four methylene unit as linkages weresynthesized and evaluated for cytotoxicity against human leukemia K562, murine melanoma B 16 and Chinese hamster ovary CHOcell lines. The presence of homospermidine motif could greatly elevate the potency of 1,8-naphthalimide. Conjugate 2b with longerspacer exhibited higher in vitro cytotoxicity than 2a. The DNA binding experiments indicated that conjugates 2b could bind toherring sperm DNA. The topoisomerase Ⅱ poison trials revealed that 2b could inhibit the activity of top. Ⅱ.
Two novel mononaphthalimide homospermidine derivatives (2a, 2b) with three or four methylene unit as linkages weresynthesized and evaluated for cytotoxicity against human leukemia K562, murine melanoma B 16 and Chinese hamster ovary CHOcell lines. The presence of homospermidine motif could greatly elevate the potency of 1,8-naphthalimide. Conjugate 2b with longerspacer exhibited higher in vitro cytotoxicity than 2a. The DNA binding experiments indicated that conjugates 2b could bind toherring sperm DNA. The topoisomerase Ⅱ poison trials revealed that 2b could inhibit the activity of top. Ⅱ.
2008, 19(5): 513-517
doi: 10.1016/j.cclet.2008.03.002
Abstract:
Two novel biscrown ethers with rigid cisltrans ethylene linker were synthesized v/a Wittig reaction in high yield (about 80%).Their pure cis/trans-isomers were obtained by column chromatography separation. And their structure/configuration was confirmedby 1H NMR, 13C NMR, ESI mass spectrum, elemental analysis and UV-vis spectra.
Two novel biscrown ethers with rigid cisltrans ethylene linker were synthesized v/a Wittig reaction in high yield (about 80%).Their pure cis/trans-isomers were obtained by column chromatography separation. And their structure/configuration was confirmedby 1H NMR, 13C NMR, ESI mass spectrum, elemental analysis and UV-vis spectra.
2008, 19(5): 518-520
doi: 10.1016/j.cclet.2008.03.028
Abstract:
A rapid and efficient method was established for the synthesis of indoloquinolinone and its analogues using acid-promotedcyclization in the present of PPA. All the reactions were completed in good yields in 10min under microwave irradiation.
A rapid and efficient method was established for the synthesis of indoloquinolinone and its analogues using acid-promotedcyclization in the present of PPA. All the reactions were completed in good yields in 10min under microwave irradiation.
2008, 19(5): 521-524
doi: 10.1016/j.cclet.2008.01.043
Abstract:
A liquid crystalline gelator containing the azobenzene chromophore was synthesized for the first time; it was used to form self-assembled network in nematic liquid crystals resulting in liquid crystal gels with distinct features.
A liquid crystalline gelator containing the azobenzene chromophore was synthesized for the first time; it was used to form self-assembled network in nematic liquid crystals resulting in liquid crystal gels with distinct features.
2008, 19(5): 525-528
doi: 10.1016/j.cclet.2008.01.037
Abstract:
A rapid and efficient method for the synthesis of isoxazolo[5,4-d]pyrimidin-4(5H)-ones has been developed throughcyclocondensation of 5-aminoisoxazole-4-carboxamides with orthoesters under conventional heating and solvent-free microwaveirradiation with solid acid catalysis. In comparison, the reactions are faster and the yields are higher under microwave irradiation.
A rapid and efficient method for the synthesis of isoxazolo[5,4-d]pyrimidin-4(5H)-ones has been developed throughcyclocondensation of 5-aminoisoxazole-4-carboxamides with orthoesters under conventional heating and solvent-free microwaveirradiation with solid acid catalysis. In comparison, the reactions are faster and the yields are higher under microwave irradiation.
2008, 19(5): 529-532
doi: 10.1016/j.cclet.2008.03.020
Abstract:
Photopromoted carbonylation of 1-bromo-6-chlorohexane with CO catalyzed by CuBr2 and CdI2 has been carried out underambient conditions. The results indicate that the carbonylation proceeds with the major product of chlorocsterCICH2(CH2)5COOCH3 under catalysis of CuBr2. Furthermore, the activity of the carbonylation can be improved by additionof basic additives (NaOAc, Na3PO4 or (n-C4H9)3N). Among these additives, (n-C4H9)3N is the most efficient in terms of the yield ofClCH2(CH2)5COOCH3. However, the methoxycarbonyl substituting chlorine product of BrCH2(CH2)5COOCH3 is not obtained inthe presence of CdI2. This is quite different from the carbonylation of monochloroalkane.
Photopromoted carbonylation of 1-bromo-6-chlorohexane with CO catalyzed by CuBr2 and CdI2 has been carried out underambient conditions. The results indicate that the carbonylation proceeds with the major product of chlorocsterCICH2(CH2)5COOCH3 under catalysis of CuBr2. Furthermore, the activity of the carbonylation can be improved by additionof basic additives (NaOAc, Na3PO4 or (n-C4H9)3N). Among these additives, (n-C4H9)3N is the most efficient in terms of the yield ofClCH2(CH2)5COOCH3. However, the methoxycarbonyl substituting chlorine product of BrCH2(CH2)5COOCH3 is not obtained inthe presence of CdI2. This is quite different from the carbonylation of monochloroalkane.
2008, 19(5): 533-536
doi: 10.1016/j.cclet.2008.03.034
Abstract:
A series of aza-naphthindolizinedione derivatives, such as indolizinoquinolinedione derivatives, indolizinophthalazinedionederivatives and indolizinoquinoxalinedione derivatives were designed and synthesized. The synthetic pathway was also proposed.
A series of aza-naphthindolizinedione derivatives, such as indolizinoquinolinedione derivatives, indolizinophthalazinedionederivatives and indolizinoquinoxalinedione derivatives were designed and synthesized. The synthetic pathway was also proposed.
2008, 19(5): 537-540
doi: 10.1016/j.cclet.2008.03.022
Abstract:
A facile, efficient and novel approach to access 2-substituted-N1-carbethoxy-2,3-dihydro-4(1H)-quinazolinones was developedby condensation of substituted N-carbethoxyanthranilamide with alkyl, aromatic or heteroaromatic aldehydes in the refluxing 2,2,2-trifluoroethanol or hexafluoroisopropanol using p-toluenesulfonic acid as catalyst.
A facile, efficient and novel approach to access 2-substituted-N1-carbethoxy-2,3-dihydro-4(1H)-quinazolinones was developedby condensation of substituted N-carbethoxyanthranilamide with alkyl, aromatic or heteroaromatic aldehydes in the refluxing 2,2,2-trifluoroethanol or hexafluoroisopropanol using p-toluenesulfonic acid as catalyst.
2008, 19(5): 541-543
doi: 10.1016/j.cclet.2008.03.025
Abstract:
As an important intermediate to study cyclin-dependent kinase (CDK) inhibitors, 2-aryl-8-(piperidin-4-yl)-5,7-dimethoxy-4H-chromen-4-one derivatives were prepared using β-diketone route with low yield. In our study, chalcone route has been investigatedand the result suggested that the benzaldehydes substituted with electron-donating group give much better yield than β-diketoneroute. This new method will be an efficient way to start further research on new anticancer flavonoids.
As an important intermediate to study cyclin-dependent kinase (CDK) inhibitors, 2-aryl-8-(piperidin-4-yl)-5,7-dimethoxy-4H-chromen-4-one derivatives were prepared using β-diketone route with low yield. In our study, chalcone route has been investigatedand the result suggested that the benzaldehydes substituted with electron-donating group give much better yield than β-diketoneroute. This new method will be an efficient way to start further research on new anticancer flavonoids.
2008, 19(5): 544-546
doi: 10.1016/j.cclet.2008.03.008
Abstract:
Two new Steroidal alkaloids, named pengbeisine A and pengbeisine B, were isolated from the fresh bulbs of Fritillaria monatha Migo. along with a known alkaloid. The structures were characterized as 22,26-imino-17, 23-oxido-5α-jerv-6-oxo-2α,3β-diol and22, 26-imino-17, 23-oxido-5α-jerv-6-oxo-2β,3α-diol on the basis of spectroscopic methods.
Two new Steroidal alkaloids, named pengbeisine A and pengbeisine B, were isolated from the fresh bulbs of Fritillaria monatha Migo. along with a known alkaloid. The structures were characterized as 22,26-imino-17, 23-oxido-5α-jerv-6-oxo-2α,3β-diol and22, 26-imino-17, 23-oxido-5α-jerv-6-oxo-2β,3α-diol on the basis of spectroscopic methods.
2008, 19(5): 547-549
doi: 10.1016/j.cclet.2008.03.004
Abstract:
A new diarylheptanoid, 3,5-dimethoxyl-17-hydroxyl-4,11,19-triketo-[7,0]meta-cyclophane, named as rubanone 1, was isolatedfrom the bark of Myrica rubra along with four known compounds 2-5. Their structures were elucidated by various spectroscopicmethods including 2D-NMR techniques or comparison with authentic samples.
A new diarylheptanoid, 3,5-dimethoxyl-17-hydroxyl-4,11,19-triketo-[7,0]meta-cyclophane, named as rubanone 1, was isolatedfrom the bark of Myrica rubra along with four known compounds 2-5. Their structures were elucidated by various spectroscopicmethods including 2D-NMR techniques or comparison with authentic samples.
2008, 19(5): 550-552
doi: 10.1016/j.cclet.2008.03.017
Abstract:
One new compound, ilexlignan A (1), was isolated from the root of llex pubescens. Its structure was elucidated by thecombination of one-and two-dimensional NMR analysis, mass spectrometry, CD spectrum measurement and chemical evidence.
One new compound, ilexlignan A (1), was isolated from the root of llex pubescens. Its structure was elucidated by thecombination of one-and two-dimensional NMR analysis, mass spectrometry, CD spectrum measurement and chemical evidence.
2008, 19(5): 553-555
doi: 10.1016/j.cclet.2008.03.031
Abstract:
Novel phosphorus-containing polyoxamacrocycles with one to two reactive thiophosphoryl chloride groups 5, 6, 7, 8 weresynthesized from bishydroxyl compounds 1, 2, 3, 4 and thiophosphoryl chloride respectively. Their structures were confirmed by 1HNMR, 13C NMR, 31p NMR and elemental analysis.
Novel phosphorus-containing polyoxamacrocycles with one to two reactive thiophosphoryl chloride groups 5, 6, 7, 8 weresynthesized from bishydroxyl compounds 1, 2, 3, 4 and thiophosphoryl chloride respectively. Their structures were confirmed by 1HNMR, 13C NMR, 31p NMR and elemental analysis.
2008, 19(5): 556-558
doi: 10.1016/j.cclet.2008.03.026
Abstract:
Three new anthranilic acid derivatives, N-heneicosanoylanthranilic acid (1b), N-tricosanoylanthranilic acid (1d), N-tetra-cosanoylanthranilic acid (1e), and two known N-arachidylanthranilic acid (1a) and N-docosanoylanthranilic acid (1c) were isolatedfrom the aerial parts of Inula japonica Thunb. Their structures were established by spectroscopic and chemical methods.
Three new anthranilic acid derivatives, N-heneicosanoylanthranilic acid (1b), N-tricosanoylanthranilic acid (1d), N-tetra-cosanoylanthranilic acid (1e), and two known N-arachidylanthranilic acid (1a) and N-docosanoylanthranilic acid (1c) were isolatedfrom the aerial parts of Inula japonica Thunb. Their structures were established by spectroscopic and chemical methods.
2008, 19(5): 559-561
doi: 10.1016/j.cclet.2008.03.023
Abstract:
A new bibenzyl derivative 1, named 2-(4"-hydrixybenzyl)-3-(3'-hydroxyphenethyl)-5-methoxy-cyclohexa-2,5-diene-1,4-dione, and two known stilbenoids (2,3) were isolated from the tubers of Pleione bulbocodioides (Franch.) Rolfe. Their structureswere elucidated by spectroscopic methods.
A new bibenzyl derivative 1, named 2-(4"-hydrixybenzyl)-3-(3'-hydroxyphenethyl)-5-methoxy-cyclohexa-2,5-diene-1,4-dione, and two known stilbenoids (2,3) were isolated from the tubers of Pleione bulbocodioides (Franch.) Rolfe. Their structureswere elucidated by spectroscopic methods.
2008, 19(5): 562-564
doi: 10.1016/j.cclet.2008.03.018
Abstract:
Six eremophilane sesquiterpenes were obtained from a marine fungus Penicillium sp. BL27-2. Their structures were elucidatedas 3-acetyl-9, 7 (11)-dien-7ot-hydroxy-8-oxoeremophilane (1), 3-acetyl-13-deoxyphomenone (2), Sporogen-AO 1 (3), 7-hydro-xypetasol (4), 8α-hydroxy-13-deo-xyphomenone (5) and 6-dehydropetasol (6) based on detailed NMR analysis. 1 was a newcompound and 2 was obtained as a new natural compound. These compounds were assayed for their cytotoxic activity on P388,A549, HL60, BEL7402 and K562 cell lines by the MTT method. The assay results suggested the epoxide tings in eremophilanemolecules were essential for their activity, and acetylation could enhance their activity.
Six eremophilane sesquiterpenes were obtained from a marine fungus Penicillium sp. BL27-2. Their structures were elucidatedas 3-acetyl-9, 7 (11)-dien-7ot-hydroxy-8-oxoeremophilane (1), 3-acetyl-13-deoxyphomenone (2), Sporogen-AO 1 (3), 7-hydro-xypetasol (4), 8α-hydroxy-13-deo-xyphomenone (5) and 6-dehydropetasol (6) based on detailed NMR analysis. 1 was a newcompound and 2 was obtained as a new natural compound. These compounds were assayed for their cytotoxic activity on P388,A549, HL60, BEL7402 and K562 cell lines by the MTT method. The assay results suggested the epoxide tings in eremophilanemolecules were essential for their activity, and acetylation could enhance their activity.
2008, 19(5): 565-568
doi: 10.1016/j.cclet.2008.03.033
Abstract:
A new method was developed for the determination of cefradine by extraction-flotation of CuSCN. The experiment indicatedthat in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at 100℃. The thiol group (-SH) ofthe degradation product could reduce Cu(Ⅱ) to Cu(Ⅰ) for the formation of the emulsion CuSCN in the presence of NH4SCN at pH4.0. By determining the residual amount of Cu(Ⅱ) in the solution and calculating the flotation yield of Cu(Ⅱ), the indirectdetermination of cefradine can be obtained. This method has been applied to determine cefradine in capsules, human serum andurine samples, respectively.
A new method was developed for the determination of cefradine by extraction-flotation of CuSCN. The experiment indicatedthat in the presence of 0.20 mol/L NaOH the degradation of cefradine took place in water bath at 100℃. The thiol group (-SH) ofthe degradation product could reduce Cu(Ⅱ) to Cu(Ⅰ) for the formation of the emulsion CuSCN in the presence of NH4SCN at pH4.0. By determining the residual amount of Cu(Ⅱ) in the solution and calculating the flotation yield of Cu(Ⅱ), the indirectdetermination of cefradine can be obtained. This method has been applied to determine cefradine in capsules, human serum andurine samples, respectively.
2008, 19(5): 569-572
doi: 10.1016/j.cclet.2008.02.004
Abstract:
The adsorptive precipitation between eosin Y (EY) and AgCl colloids at pH 3.73 caused the sensitive color change of thesolution. The reaction mechanism between EY and AgCl was analyzed and this reaction was used for determination of Cl-in tracelevel by the light-absorption radio variation approach.
The adsorptive precipitation between eosin Y (EY) and AgCl colloids at pH 3.73 caused the sensitive color change of thesolution. The reaction mechanism between EY and AgCl was analyzed and this reaction was used for determination of Cl-in tracelevel by the light-absorption radio variation approach.
2008, 19(5): 573-576
doi: 10.1016/j.cclet.2008.03.029
Abstract:
Ambient volatile organic compounds (VOCs) were sampled at six sites in Beijing in the summer of 2004 and analyzed byGCMS. The chemical reactivities of 73 quantified VOCs species were evaluated by OH loss rates (LOH) and ozone formationpotentials (OFPs). Top 15 reactive species, mainly alkenes and aromatics, were identified by these two methods, and accounted formore than 70% of total reactivity of VOCs. In urban areas, isoprene was the most reactive species in term of OH loss rate,contributing 11.4% to the LOH of VOCs. While toluene, accounting for 9.4% of OFPs, appeared to have a long-time role in thephotochemical processes. Tongzhou site is obviously influenced by local chemical industry, but the other five sites showed typicalurban features influenced mainly by vehicular emissions.
Ambient volatile organic compounds (VOCs) were sampled at six sites in Beijing in the summer of 2004 and analyzed byGCMS. The chemical reactivities of 73 quantified VOCs species were evaluated by OH loss rates (LOH) and ozone formationpotentials (OFPs). Top 15 reactive species, mainly alkenes and aromatics, were identified by these two methods, and accounted formore than 70% of total reactivity of VOCs. In urban areas, isoprene was the most reactive species in term of OH loss rate,contributing 11.4% to the LOH of VOCs. While toluene, accounting for 9.4% of OFPs, appeared to have a long-time role in thephotochemical processes. Tongzhou site is obviously influenced by local chemical industry, but the other five sites showed typicalurban features influenced mainly by vehicular emissions.
2008, 19(5): 577-580
doi: 10.1016/j.cclet.2008.01.038
Abstract:
In this study, we have fabricated the functionalized nickel nanoparticles and investigated their effects on cellular uptake ofquercetin in leukemia K562 cancer cells by using electrochemical assay. The results indicate that nickel nanoparticles couldefficiently enhance the quercetin uptake and increase the intracellular accumulation in cancer cells, implying the great potential offunctionalized nickel nanoparticles in target cancer therapy.
In this study, we have fabricated the functionalized nickel nanoparticles and investigated their effects on cellular uptake ofquercetin in leukemia K562 cancer cells by using electrochemical assay. The results indicate that nickel nanoparticles couldefficiently enhance the quercetin uptake and increase the intracellular accumulation in cancer cells, implying the great potential offunctionalized nickel nanoparticles in target cancer therapy.
2008, 19(5): 581-584
doi: 10.1016/j.cclet.2008.03.024
Abstract:
In pH 5.5 phosphate buffer solution, N-n-undecyl-N'-(sodium-p-amino-benzenesulfonate) thiourea (UPT) produced a pair ofredox peaks on the bare glassy carbon electrode. At the multi-walled carbon nanotube (MWNT) modified electrode, theelectrochemical behavior of UPT enhanced greatly. In the presence of bovine serum albumin (BSA), the peak currents ofUPT decreased linearly due to the formation of a super-molecular complex. This method was successfully applied to thedetermination of BSA in a bovine serum sample.
In pH 5.5 phosphate buffer solution, N-n-undecyl-N'-(sodium-p-amino-benzenesulfonate) thiourea (UPT) produced a pair ofredox peaks on the bare glassy carbon electrode. At the multi-walled carbon nanotube (MWNT) modified electrode, theelectrochemical behavior of UPT enhanced greatly. In the presence of bovine serum albumin (BSA), the peak currents ofUPT decreased linearly due to the formation of a super-molecular complex. This method was successfully applied to thedetermination of BSA in a bovine serum sample.
2008, 19(5): 585-588
doi: 10.1016/j.cclet.2008.03.001
Abstract:
A solvothermal process was developed for the preparation of cauliflower-like Bi2S3 from N,N-dimethylformamide (DMF)solution of bismuth nitrate [Bi(NO3)3·5H2O] and thioacetamide (TAA) with 2-undecyl-1-dithioureido-ethyl-imidazoline (SUDEI)as the morphology-controlling agent· The obtained Bi2S3 products were characterized by transmission electron microscopy (TEM),scanning electron microscopy (SEM), and X-ray diffraction (XRD), etc· The sensing properties of Bi2S3 with differentmorphologies were evaluated by the electrochemical analysis of dopamine (DA) and ascorbic acid (AA) coexisting solution·The results showed that cauliflower-like Bi2S3 showed a better resolving ability than rod-like Bi2S3 for the simultaneousdetermination of DA and AA·
A solvothermal process was developed for the preparation of cauliflower-like Bi2S3 from N,N-dimethylformamide (DMF)solution of bismuth nitrate [Bi(NO3)3·5H2O] and thioacetamide (TAA) with 2-undecyl-1-dithioureido-ethyl-imidazoline (SUDEI)as the morphology-controlling agent· The obtained Bi2S3 products were characterized by transmission electron microscopy (TEM),scanning electron microscopy (SEM), and X-ray diffraction (XRD), etc· The sensing properties of Bi2S3 with differentmorphologies were evaluated by the electrochemical analysis of dopamine (DA) and ascorbic acid (AA) coexisting solution·The results showed that cauliflower-like Bi2S3 showed a better resolving ability than rod-like Bi2S3 for the simultaneousdetermination of DA and AA·
2008, 19(5): 589-591
doi: 10.1016/j.cclet.2008.03.012
Abstract:
A novel electrochemical DNA biosensor based on zinc oxide (ZnO) nanoparticles and multi-walled carbon nanotubes (MWNTs)for DNA immobilization and enhanced hybridization detection is presented. The MWNTs/nano ZnO/chitosan composite filmmodified glassy carbon electrode (MWNTs/ZnO/CHIT/GCE) was fabricated and DNA probes were immobilized on the electrodesurface. The hybridization events were monitored by differential pulse voltammetry (DPV) using methylene blue (MB) as anindicator. The sensor can effectively discriminate different DNA sequences related to PAT gene in the.transgenic corn, with adetection limit of 2.8×10-12 mol/L of target sequence.
A novel electrochemical DNA biosensor based on zinc oxide (ZnO) nanoparticles and multi-walled carbon nanotubes (MWNTs)for DNA immobilization and enhanced hybridization detection is presented. The MWNTs/nano ZnO/chitosan composite filmmodified glassy carbon electrode (MWNTs/ZnO/CHIT/GCE) was fabricated and DNA probes were immobilized on the electrodesurface. The hybridization events were monitored by differential pulse voltammetry (DPV) using methylene blue (MB) as anindicator. The sensor can effectively discriminate different DNA sequences related to PAT gene in the.transgenic corn, with adetection limit of 2.8×10-12 mol/L of target sequence.
2008, 19(5): 592-594
doi: 10.1016/j.cclet.2008.03.014
Abstract:
he paper describes a controllable layer-by-layer (LBL) self-assembly modification technique of multi-walled carbon nanotubes(MWNTs) and poly(diallyldimethylammonium chloride) (PDDA) towards glassy carbon electrode (GCE), Acetylcholinesterase(ACHE) was immobilized directly to the modified GCE by LBL self-assembly method, the activity value of AChE was detected by using i-t technique based on the modified Ellman method. Then the composition of carbaryl were detected by the enzyme electrode with 0.01U activity value and the detection limit of carbaryl is 10-12 g L-1 so the enzyme biosensor showed good properties for pesticides residue detection.
he paper describes a controllable layer-by-layer (LBL) self-assembly modification technique of multi-walled carbon nanotubes(MWNTs) and poly(diallyldimethylammonium chloride) (PDDA) towards glassy carbon electrode (GCE), Acetylcholinesterase(ACHE) was immobilized directly to the modified GCE by LBL self-assembly method, the activity value of AChE was detected by using i-t technique based on the modified Ellman method. Then the composition of carbaryl were detected by the enzyme electrode with 0.01U activity value and the detection limit of carbaryl is 10-12 g L-1 so the enzyme biosensor showed good properties for pesticides residue detection.
2008, 19(5): 595-598
doi: 10.1016/j.cclet.2008.03.030
Abstract:
Artificial molecular chaperone (AMC) and ion exchange chromatography (IEC) were integrated, thus a new refolding method,artificial molecular chaperone-ion exchange chromatography (AMC-IEC) was developed. Compared with AMC and IEC, theactivity recovery of lysozyme obtained by AMC-IEC was much higher in the investigated range of initial protein concentrations,and the results show that AMC-IEC is very efficient for protein refolding at high concentrations. When the initial concentration oflysozyme is 180 mg/mL, its activity recovery obtained by AMC-IEC is still as high as 76.6%, while the activity recoveries obtainedby AMC and IEC are 45.6% and 42.4%, respectively.
Artificial molecular chaperone (AMC) and ion exchange chromatography (IEC) were integrated, thus a new refolding method,artificial molecular chaperone-ion exchange chromatography (AMC-IEC) was developed. Compared with AMC and IEC, theactivity recovery of lysozyme obtained by AMC-IEC was much higher in the investigated range of initial protein concentrations,and the results show that AMC-IEC is very efficient for protein refolding at high concentrations. When the initial concentration oflysozyme is 180 mg/mL, its activity recovery obtained by AMC-IEC is still as high as 76.6%, while the activity recoveries obtainedby AMC and IEC are 45.6% and 42.4%, respectively.
2008, 19(5): 599-603
doi: 10.1016/j.cclet.2008.03.032
Abstract:
We report the structural characterization and proposed formation mechanism of honeycomb-like ZnO conglomerationsfabricated by direct precipitation method. X-ray diffraction (XRD), energy-disperse X-ray spectrometry (EDS), scanning electronmicroscopy (SEM) showed that the as-prepared ZnO calcined at 700℃ were micron sphere particles with honeycomb-likestructure. In the UV-vis absorbing spectrum, it was observed that there is a new additional absorption band at 260 nm, and it wasspeculated that the absorption may be caused by defects on the surface and interface of honeycomb-like ZnO. The as-productsshowed high sensitivity and short response time to sulfured hydrogen gas. These results demonstrate that honeycomb-like ZnOconglomerations are very promising materials for fabricating H2S gas sensors.
We report the structural characterization and proposed formation mechanism of honeycomb-like ZnO conglomerationsfabricated by direct precipitation method. X-ray diffraction (XRD), energy-disperse X-ray spectrometry (EDS), scanning electronmicroscopy (SEM) showed that the as-prepared ZnO calcined at 700℃ were micron sphere particles with honeycomb-likestructure. In the UV-vis absorbing spectrum, it was observed that there is a new additional absorption band at 260 nm, and it wasspeculated that the absorption may be caused by defects on the surface and interface of honeycomb-like ZnO. The as-productsshowed high sensitivity and short response time to sulfured hydrogen gas. These results demonstrate that honeycomb-like ZnOconglomerations are very promising materials for fabricating H2S gas sensors.
2008, 19(5): 604-606
doi: 10.1016/j.cclet.2008.01.020
Abstract:
A novel co-ordination polymer based on IB metal thiocyanates, [Ag2(NCS)2(4,4'-bipy)]n (1)(4,4'-bipy=4,4'-bispyridine), hasbeen synthesized by the pre-assembly method and characterized by X-ray crystallography. The complex exists as a three-dimensional network consisting of (AgSCN)n undulating layers linked by 4,4'-bipy bridges.
A novel co-ordination polymer based on IB metal thiocyanates, [Ag2(NCS)2(4,4'-bipy)]n (1)(4,4'-bipy=4,4'-bispyridine), hasbeen synthesized by the pre-assembly method and characterized by X-ray crystallography. The complex exists as a three-dimensional network consisting of (AgSCN)n undulating layers linked by 4,4'-bipy bridges.
2008, 19(5): 607-610
doi: 10.1016/j.cclet.2008.03.015
Abstract:
Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem Ⅰ, catalyst ofhydrogenase, methyl viologen and electron donor under radiation. Absorption spectral features confirmed that electron transferfrom electron donors to proton was via a photoinduced reductive process of methyl viologen.
Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem Ⅰ, catalyst ofhydrogenase, methyl viologen and electron donor under radiation. Absorption spectral features confirmed that electron transferfrom electron donors to proton was via a photoinduced reductive process of methyl viologen.
2008, 19(5): 611-614
doi: 10.1016/j.cclet.2008.02.003
Abstract:
A kind of pseudo-hypercrosslinked polymer resin was firstly synthesized via a continuous Friedel--Crafts alkylation poly-merization of benzene, diphenyl and their dichloromethyl derivatives. And the micromorphology and adsorption properties of theseresins were investigated. The results demonstrated that the novel resins have high-specific surface area (581.26-974.88 m2/g), high-pore volume (0.56-1.65 mL/g), small average porous radius (1.93-3.67 nm) and excellent adsorption properties for small non-polarorganic molecules.
A kind of pseudo-hypercrosslinked polymer resin was firstly synthesized via a continuous Friedel--Crafts alkylation poly-merization of benzene, diphenyl and their dichloromethyl derivatives. And the micromorphology and adsorption properties of theseresins were investigated. The results demonstrated that the novel resins have high-specific surface area (581.26-974.88 m2/g), high-pore volume (0.56-1.65 mL/g), small average porous radius (1.93-3.67 nm) and excellent adsorption properties for small non-polarorganic molecules.
2008, 19(5): 615-618
doi: 10.1016/j.cclet.2008.03.009
Abstract:
A new way to prepare PMMA contain lead salt was presented. This work firstly prepares the material by microemulsionpolymerization. The ability of anti-radiation, transmittance ratio and glass transition temperature (Tg) of the material wascharacterized. The anti-radiation ability is enhanced with the increasing of lead salt content and the thickness of the material. Thetransmittance ratio decreased with the content of the lead salt. The glass transition temperature of the material is increased with thelead salt content of the organic glass.
A new way to prepare PMMA contain lead salt was presented. This work firstly prepares the material by microemulsionpolymerization. The ability of anti-radiation, transmittance ratio and glass transition temperature (Tg) of the material wascharacterized. The anti-radiation ability is enhanced with the increasing of lead salt content and the thickness of the material. Thetransmittance ratio decreased with the content of the lead salt. The glass transition temperature of the material is increased with thelead salt content of the organic glass.
2008, 19(5): 619-622
doi: 10.1016/j.cclet.2008.03.011
Abstract:
An effective prediction pharmacophore model (RMS=0.634, Correl=0.893, Weight=1.463, Config=11.940) was success-fully obtained by 3D-QSAR based on a series of nAChR (nicotinic acetylcholine receptors) agonists, which consists of a hydrogen-bonding acceptor, a hydrogen-bond donor, a hydrophobic aliphatic and a hydrophobic aromatic centre. This pharmacophore modelmay provide theoretical basis for designation and development of higher active insectici
An effective prediction pharmacophore model (RMS=0.634, Correl=0.893, Weight=1.463, Config=11.940) was success-fully obtained by 3D-QSAR based on a series of nAChR (nicotinic acetylcholine receptors) agonists, which consists of a hydrogen-bonding acceptor, a hydrogen-bond donor, a hydrophobic aliphatic and a hydrophobic aromatic centre. This pharmacophore modelmay provide theoretical basis for designation and development of higher active insectici
2008, 19(5): 623-626
doi: 10.1016/j.cclet.2008.03.010
Abstract:
Aqueous phase layer around bubble and water droplet are two additional processes in solvent sublation. In the dynamic processof mass transfer, they are always neglected, but they are very important in the investigation of thermodynamic equilibrium. In thispaper, the effect of water droplet in solvent sublation was discussed in detail, and the previous mathematical model of solventsubaltion was improved. Matlab 6.5 was used to simulate the process of water droplets, and the comparison between the previoushypothesis and the improvement in this paper showed the superiority, especially in the investigation of thermodynamic equilibrium.Moreover, the separation and concentration of the complex compound dithizone-Co(Ⅱ) from aqueous phase to n-octanol by solventsublation also proved the improved mathematical model was reasonable.
Aqueous phase layer around bubble and water droplet are two additional processes in solvent sublation. In the dynamic processof mass transfer, they are always neglected, but they are very important in the investigation of thermodynamic equilibrium. In thispaper, the effect of water droplet in solvent sublation was discussed in detail, and the previous mathematical model of solventsubaltion was improved. Matlab 6.5 was used to simulate the process of water droplets, and the comparison between the previoushypothesis and the improvement in this paper showed the superiority, especially in the investigation of thermodynamic equilibrium.Moreover, the separation and concentration of the complex compound dithizone-Co(Ⅱ) from aqueous phase to n-octanol by solventsublation also proved the improved mathematical model was reasonable.
2008, 19(5): 627-630
doi: 10.1016/j.cclet.2008.03.019
Abstract:
A three-dimensional global potential energy surface for the electronic ground state of HXeBr molecule is constructed from morethan 4200 ab initio points. These points are generated using an internally contracted multi-reference configuration interactionmethod with the Davidson correction (icMRCI+Q) and large basis sets. The stabilities and dissociation barriers are identified fromthe potential energy surfaces. The three-body dissociation channel is found to be the dominate dissociation channel for HXeBr.Based on the obtained potentials, low-lying vibrational energy levels of HXeBr calculated using the Lanczos algorithm is found tobe in good agreement with the available experimental band origins.
A three-dimensional global potential energy surface for the electronic ground state of HXeBr molecule is constructed from morethan 4200 ab initio points. These points are generated using an internally contracted multi-reference configuration interactionmethod with the Davidson correction (icMRCI+Q) and large basis sets. The stabilities and dissociation barriers are identified fromthe potential energy surfaces. The three-body dissociation channel is found to be the dominate dissociation channel for HXeBr.Based on the obtained potentials, low-lying vibrational energy levels of HXeBr calculated using the Lanczos algorithm is found tobe in good agreement with the available experimental band origins.
