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2009 Volume 20 Issue 5
2009, 20(5): 507-510
doi: 10.1016/j.cclet.2008.12.057
Abstract:
A series of novel bis(trifluoroethyl) phosphonomethyl ether derivatives of acyclovir was synthesized and their in vitro anti-HBV activity was evaluated in HepG2 2.2.15 cells. In contrast to acyclovir, most of the described phosphonates emerged as potent inhibitors of HBV replication. Especially, the most active compound 11 with IC50 value of 2.92 mmol/L was 33 times more potent than acyclovir with IC50 value of 100 mmol/L.
A series of novel bis(trifluoroethyl) phosphonomethyl ether derivatives of acyclovir was synthesized and their in vitro anti-HBV activity was evaluated in HepG2 2.2.15 cells. In contrast to acyclovir, most of the described phosphonates emerged as potent inhibitors of HBV replication. Especially, the most active compound 11 with IC50 value of 2.92 mmol/L was 33 times more potent than acyclovir with IC50 value of 100 mmol/L.
2009, 20(5): 511-513
doi: 10.1016/j.cclet.2009.01.033
Abstract:
Under mild condition, using FeCl3 as catalyst, a series of functionalized diarylmethanes were prepared efficiently from the reactions of arenes with paraformaldehyde. This catalytic system is not sensitive to air and moisture.
Under mild condition, using FeCl3 as catalyst, a series of functionalized diarylmethanes were prepared efficiently from the reactions of arenes with paraformaldehyde. This catalytic system is not sensitive to air and moisture.
2009, 20(5): 514-518
doi: 10.1016/j.cclet.2009.01.039
Abstract:
Semicarbazones, 1,1-diacetates and acetals are efficiently converted to their corresponding carbonyl compounds using synergistic effect between KBrO3 and MoO3 in refluxing CH3CN-H2O in good to high yields.
Semicarbazones, 1,1-diacetates and acetals are efficiently converted to their corresponding carbonyl compounds using synergistic effect between KBrO3 and MoO3 in refluxing CH3CN-H2O in good to high yields.
2009, 20(5): 519-522
doi: 10.1016/j.cclet.2009.01.025
Abstract:
Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane (WPU) and 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (BMImTFSI) have been prepared and characterized. The addition of BMImTFSI results in an increase of the ionic conductivity. At high BMImTFSI concentration (BMImTFSI/WPU=3 in weight ratio), the ionic conductivity reaches 4.27×10-3 S/cm at 30℃. These composite polymer electrolytes exhibit good thermal and electrochemical stability, which are high enough to be applied in lithium batteries.
Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane (WPU) and 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (BMImTFSI) have been prepared and characterized. The addition of BMImTFSI results in an increase of the ionic conductivity. At high BMImTFSI concentration (BMImTFSI/WPU=3 in weight ratio), the ionic conductivity reaches 4.27×10-3 S/cm at 30℃. These composite polymer electrolytes exhibit good thermal and electrochemical stability, which are high enough to be applied in lithium batteries.
2009, 20(5): 523-526
doi: 10.1016/j.cclet.2009.01.001
Abstract:
The activities of the catalytic hydrolysis of phosphate diester (BNPP)[bis (p-nitrophenyl)phosphate diester] and plasmid DNA (pUC18) by mononuclear macrocyclic polyamine metal complexes have been investigated in this paper. The results showed that the highest activity in hydrolysis of BNPP was obtained with 1e-Zn(II) complex (composed of lipophilic group) as catalyst. The hydrolysis rate enhancement is up to 3.64×104 fold. These metal complexes could effectively promote the cleavage of plasmid DNA (pUC18) at physiological conditions.
The activities of the catalytic hydrolysis of phosphate diester (BNPP)[bis (p-nitrophenyl)phosphate diester] and plasmid DNA (pUC18) by mononuclear macrocyclic polyamine metal complexes have been investigated in this paper. The results showed that the highest activity in hydrolysis of BNPP was obtained with 1e-Zn(II) complex (composed of lipophilic group) as catalyst. The hydrolysis rate enhancement is up to 3.64×104 fold. These metal complexes could effectively promote the cleavage of plasmid DNA (pUC18) at physiological conditions.
2009, 20(5): 527-530
doi: 10.1016/j.cclet.2009.01.032
Abstract:
The first total synthesis of paecilodepsipeptide A is reported. A convergent, flexible strategy employing peptide chemistry and culminating in macrolactamisation is described. The previously reported structure of compound is confirmed.
The first total synthesis of paecilodepsipeptide A is reported. A convergent, flexible strategy employing peptide chemistry and culminating in macrolactamisation is described. The previously reported structure of compound is confirmed.
2009, 20(5): 531-534
doi: 10.1016/j.cclet.2009.01.008
Abstract:
The photopromoted carbonylation of bromobenzene with carbon monoxide catalyzed by inexpensive commercially available cobalt salts[Co(OAc)2, CoCl2] was carried out under ambient conditions. The results revealed that methyl benzoate was produced in the presence of basic additives (CH3ONa, NaOAc or (n-C4H9)3N). The catalytic activity of Co(OAc)2 was higher than that of CoCl2. Furthermore, the activity of the carbonylation was greatly improved by addition of acetophenone, e.g. both the yield and selectivity of the ester were increased from 47% to 91% with Co(OAc)2 as catalyst and CH3ONa as additive, while the yield of byproduct benzene from hydrodehalogenation of bromobenzene decreased from 32% to 8%.
The photopromoted carbonylation of bromobenzene with carbon monoxide catalyzed by inexpensive commercially available cobalt salts[Co(OAc)2, CoCl2] was carried out under ambient conditions. The results revealed that methyl benzoate was produced in the presence of basic additives (CH3ONa, NaOAc or (n-C4H9)3N). The catalytic activity of Co(OAc)2 was higher than that of CoCl2. Furthermore, the activity of the carbonylation was greatly improved by addition of acetophenone, e.g. both the yield and selectivity of the ester were increased from 47% to 91% with Co(OAc)2 as catalyst and CH3ONa as additive, while the yield of byproduct benzene from hydrodehalogenation of bromobenzene decreased from 32% to 8%.
2009, 20(5): 535-538
doi: 10.1016/j.cclet.2008.12.004
Abstract:
Synthesis of 2-aryl-1-arylmethyl-1H-1,3-benzo[d]imidazoles by the reaction of o-phenylenediamine with substituted aromatic aldehydes in the presence of 1-heptanesulfonic acid sodium salt (10 mol%) at room temperature. The reactions were performed in acetonitrile:water (8:2). The method was proved to be eco-friendly, convenient and the products were isolated with good yields (82-90%).
Synthesis of 2-aryl-1-arylmethyl-1H-1,3-benzo[d]imidazoles by the reaction of o-phenylenediamine with substituted aromatic aldehydes in the presence of 1-heptanesulfonic acid sodium salt (10 mol%) at room temperature. The reactions were performed in acetonitrile:water (8:2). The method was proved to be eco-friendly, convenient and the products were isolated with good yields (82-90%).
2009, 20(5): 539-541
doi: 10.1016/j.cclet.2008.12.026
Abstract:
A highly efficient one-pot synthesis of 1,8-dioxooctahydroxanthenes under solvent-free conditions catalyzed by sulfonic acid covalently anchored onto the surface of silica gel is reported. All types of aldehydes, including aromatic, unsaturated, and heterocyclic, are used. The silica gel/sulfonic acid catalyst (SiO2-R-SO3H) is completely heterogeneous and can be recycled.
A highly efficient one-pot synthesis of 1,8-dioxooctahydroxanthenes under solvent-free conditions catalyzed by sulfonic acid covalently anchored onto the surface of silica gel is reported. All types of aldehydes, including aromatic, unsaturated, and heterocyclic, are used. The silica gel/sulfonic acid catalyst (SiO2-R-SO3H) is completely heterogeneous and can be recycled.
2009, 20(5): 542-544
doi: 10.1016/j.cclet.2008.12.011
Abstract:
Twenty 7-azaindirubin derivatives were designed and synthesized. Their antitumor activities were evaluated in vitro against DU145 cell line. The pharmacological results showed that most of the prepared compounds displayed the excellent activity.Compound 18 exhibited the most potent antitumor activity among the tested compounds.
Twenty 7-azaindirubin derivatives were designed and synthesized. Their antitumor activities were evaluated in vitro against DU145 cell line. The pharmacological results showed that most of the prepared compounds displayed the excellent activity.Compound 18 exhibited the most potent antitumor activity among the tested compounds.
2009, 20(5): 545-548
doi: 10.1016/j.cclet.2009.01.020
Abstract:
A convenient one-pot synthesis of functionalized (E)-2-arylvinyl bromides was achieved by microwave-induced deacetylation and subsequent acylation using dicyclohexyl carbodiimide (DCC) and dimethylamino-pyridine (DMAP) at room temperature from (E)-4-(2-bromovinyl)phenyl acetate.
A convenient one-pot synthesis of functionalized (E)-2-arylvinyl bromides was achieved by microwave-induced deacetylation and subsequent acylation using dicyclohexyl carbodiimide (DCC) and dimethylamino-pyridine (DMAP) at room temperature from (E)-4-(2-bromovinyl)phenyl acetate.
2009, 20(5): 549-553
doi: 10.1016/j.cclet.2008.12.058
Abstract:
Six novel rod-like magnetic liquid crystals have been prepared, in which trans-bicyclohexyl or trans-cyclohexylphenyl and biphenylcarboxylic acid phenyl ester mesogenic cores with n-propyl and n-pentyl substituents were terminated by 4-hydroxyl-TEMPO (TEMPO=2,2,6,6-tetramethylpiperidine-1-oxy). Their structures were confirmed by elemental analysis, IR and MS.Determined by SQUID, EPR, DSC and HS-POM (heat stage polarizing optical microscope), the six compounds all have both magnetic and liquid crystalline properties; their temperature ranges of mesophase were from 16.0 to 24.8℃, and the magnetic liquid crystal molecules could obviously improve the response sensitivity of liquid crystal materials.
Six novel rod-like magnetic liquid crystals have been prepared, in which trans-bicyclohexyl or trans-cyclohexylphenyl and biphenylcarboxylic acid phenyl ester mesogenic cores with n-propyl and n-pentyl substituents were terminated by 4-hydroxyl-TEMPO (TEMPO=2,2,6,6-tetramethylpiperidine-1-oxy). Their structures were confirmed by elemental analysis, IR and MS.Determined by SQUID, EPR, DSC and HS-POM (heat stage polarizing optical microscope), the six compounds all have both magnetic and liquid crystalline properties; their temperature ranges of mesophase were from 16.0 to 24.8℃, and the magnetic liquid crystal molecules could obviously improve the response sensitivity of liquid crystal materials.
2009, 20(5): 554-556
doi: 10.1016/j.cclet.2009.01.029
Abstract:
The new synthesis of 10-bromo-α-chamigrene was achieved as follows; 6-methyl-5-heptene-2-one was transformed into corresponding thioacetals, and then successively treated with Cp2Ti(P(OEt)3)2. The intermediate reacted with mono-ketal of cyclohexane-1,4-dione, and gave the carbonyl coupling product. It was then transformed into the key intermediate γ-bisabolene via deketalization, Grignard reaction, dehydration and then furnished the target molecule by polyene cyclization, with total yield 2%.All structures were confirmed by 1H NMR and 13C NMR. The final compound was confirmed by 1H NMR, 13C NMR and MS.
The new synthesis of 10-bromo-α-chamigrene was achieved as follows; 6-methyl-5-heptene-2-one was transformed into corresponding thioacetals, and then successively treated with Cp2Ti(P(OEt)3)2. The intermediate reacted with mono-ketal of cyclohexane-1,4-dione, and gave the carbonyl coupling product. It was then transformed into the key intermediate γ-bisabolene via deketalization, Grignard reaction, dehydration and then furnished the target molecule by polyene cyclization, with total yield 2%.All structures were confirmed by 1H NMR and 13C NMR. The final compound was confirmed by 1H NMR, 13C NMR and MS.
2009, 20(5): 557-561
doi: 10.1016/j.cclet.2009.01.031
Abstract:
A convenient synthesis of quino[2,3-b] [1,5]benzoxazepines from substituted 2-chloroquinoline-3-carbaldehyde and 2-hydroxy aniline by using stable, non-toxic and inexpensive catalyst 1,8-diazabicyclo-undecan-7-ene (DBU)/silica gel is described. This method affords the quino[2,3-b][1,5]benzoxazepines under the influence of microwave irradiation (360 W) in solvent-free conditions within short reaction times (2-3 min), giving high yields of products (93-96%).
A convenient synthesis of quino[2,3-b] [1,5]benzoxazepines from substituted 2-chloroquinoline-3-carbaldehyde and 2-hydroxy aniline by using stable, non-toxic and inexpensive catalyst 1,8-diazabicyclo-undecan-7-ene (DBU)/silica gel is described. This method affords the quino[2,3-b][1,5]benzoxazepines under the influence of microwave irradiation (360 W) in solvent-free conditions within short reaction times (2-3 min), giving high yields of products (93-96%).
2009, 20(5): 562-565
doi: 10.1016/j.cclet.2009.01.012
Abstract:
In this paper, a series of chiral non-symmetrical liquid crystals (nBA-chol) consisting of a cholesteryl ester moiety as chiral entity and a biphenyl aromatic core with different terminal alkyl chain has been synthesized and investigated for their liquid crystalline properties. Effects of numbers of methylene units in the terminal alkyl chain on the phase transition temperatures and on the temperature-dependent pitch lengths of the chiral liquid crystals have been studied. The long terminal alkyl chain tends to exhibit smectic A mesophases. The pitch lengths of the cholesteric mesophases of the chiral liquid crystals decrease with increasing temperature and with increasing numbers of methylene units in the terminal alkyl chain, respectively.
In this paper, a series of chiral non-symmetrical liquid crystals (nBA-chol) consisting of a cholesteryl ester moiety as chiral entity and a biphenyl aromatic core with different terminal alkyl chain has been synthesized and investigated for their liquid crystalline properties. Effects of numbers of methylene units in the terminal alkyl chain on the phase transition temperatures and on the temperature-dependent pitch lengths of the chiral liquid crystals have been studied. The long terminal alkyl chain tends to exhibit smectic A mesophases. The pitch lengths of the cholesteric mesophases of the chiral liquid crystals decrease with increasing temperature and with increasing numbers of methylene units in the terminal alkyl chain, respectively.
2009, 20(5): 566-568
doi: 10.1016/j.cclet.2008.12.019
Abstract:
Several 7-alkynyl camptothecin derivatives were prepared via Sonogashira coupling. And anti-tumor activities of these compounds were evaluated against human esophageal cancer cell line (Eca-109), human chronic myeloid leukaemia cell line (K562), bladder cancer cell line (5637) and gastric cell line (SGC7901). Compounds 9a-d and 10a exhibited remarkable in vitro cytotoxic activity, compared with topotecan.
Several 7-alkynyl camptothecin derivatives were prepared via Sonogashira coupling. And anti-tumor activities of these compounds were evaluated against human esophageal cancer cell line (Eca-109), human chronic myeloid leukaemia cell line (K562), bladder cancer cell line (5637) and gastric cell line (SGC7901). Compounds 9a-d and 10a exhibited remarkable in vitro cytotoxic activity, compared with topotecan.
2009, 20(5): 569-571
doi: 10.1016/j.cclet.2009.01.004
Abstract:
A new triterpenoid saponin, bacopaside IX, was isolated from the whole plant of Bacopa monniera (L.) Wettst. and its structure was elucidated as 3-O-{β-d-glucopyranosyl(1→4)[α-l-arabinofuranosyl-(1→2)]-b-d-glucop-yranosyl}-20-O-α-l-arabinopyranosyljujubogenin by spectroscopic methods and some chemical transformations.
A new triterpenoid saponin, bacopaside IX, was isolated from the whole plant of Bacopa monniera (L.) Wettst. and its structure was elucidated as 3-O-{β-d-glucopyranosyl(1→4)[α-l-arabinofuranosyl-(1→2)]-b-d-glucop-yranosyl}-20-O-α-l-arabinopyranosyljujubogenin by spectroscopic methods and some chemical transformations.
2009, 20(5): 572-575
doi: 10.1016/j.cclet.2008.12.052
Abstract:
Two new triterpenes, 2α,3β-dihydroxy-urs-12-en-18,19-epoxy-28-oic acid (1) and 18,19-seco,2α,3α-dihydroxyl-19-oxo-urs-11,13(18)-dien-28-oic acid (2) were isolated from the herbaceous part of Duchesnea indica. Their structures were elucidated by spectroscopic analysis, including 2D NMR technique. The isolated compounds exhibited moderate cytotoxic activities against HeLa and L929 cell lines.
Two new triterpenes, 2α,3β-dihydroxy-urs-12-en-18,19-epoxy-28-oic acid (1) and 18,19-seco,2α,3α-dihydroxyl-19-oxo-urs-11,13(18)-dien-28-oic acid (2) were isolated from the herbaceous part of Duchesnea indica. Their structures were elucidated by spectroscopic analysis, including 2D NMR technique. The isolated compounds exhibited moderate cytotoxic activities against HeLa and L929 cell lines.
2009, 20(5): 576-578
doi: 10.1016/j.cclet.2009.01.013
Abstract:
A new flavonoid with chalcone skeleton was isolated from the dried aerial roots of Ficus microcarpa. The structure of the compound was elucidated on the basis of spectral methods including 1D and 2D NMR. The new compound showed weak inhibitory effect on nitric oxide production and cytotoxicity against K562 and PC3 cells.
A new flavonoid with chalcone skeleton was isolated from the dried aerial roots of Ficus microcarpa. The structure of the compound was elucidated on the basis of spectral methods including 1D and 2D NMR. The new compound showed weak inhibitory effect on nitric oxide production and cytotoxicity against K562 and PC3 cells.
2009, 20(5): 579-581
doi: 10.1016/j.cclet.2008.12.025
Abstract:
Two new flavanone glycosides 1 and 2 were isolated from the aerial parts of Macrothelypteris torresiana (Gaud.) Ching. The structures of two products were identified as (2S)-5,7,2',5'-tetrahydroxyflavanone-20-O-β-D-6"-O-acetylglucopyranoside and (2S)-5,7,2',5'-tetrahydroxyflavanone-2'-O-β-D-glucopyranoside on the basis of their chemical and spectral analysis, respectively.
Two new flavanone glycosides 1 and 2 were isolated from the aerial parts of Macrothelypteris torresiana (Gaud.) Ching. The structures of two products were identified as (2S)-5,7,2',5'-tetrahydroxyflavanone-20-O-β-D-6"-O-acetylglucopyranoside and (2S)-5,7,2',5'-tetrahydroxyflavanone-2'-O-β-D-glucopyranoside on the basis of their chemical and spectral analysis, respectively.
2009, 20(5): 582-585
doi: 10.1016/j.cclet.2009.01.007
Abstract:
Synthesis of the disaccharide β-D-Glup-(1→3)-6-deoxy-α-L-Talp II, and its dimer III from the O-antigenic polysaccharide of Burkholderia pseudomallei strain 304b, were achieved through assembly of suitably synthesized building blocks, 4-methoxylphenyl 6-deoxy-2,4-di-O-benzoyl-α-L-talopyranoside (7), 3-O-allyl-2,4,6-tri-O-benzoyl-α,β-D-glucopyranosyl trichloroacetimidate (8) and 2,3,4,6-tetra-O-benzoyl-α,β-D-glucopyranosyl trichloroacetimidate (11). The total yield of III from 4-methoxylphenyl 2,3-O-isopropylidene-α-L-rhamnopyranoside (1) was 18%.
Synthesis of the disaccharide β-D-Glup-(1→3)-6-deoxy-α-L-Talp II, and its dimer III from the O-antigenic polysaccharide of Burkholderia pseudomallei strain 304b, were achieved through assembly of suitably synthesized building blocks, 4-methoxylphenyl 6-deoxy-2,4-di-O-benzoyl-α-L-talopyranoside (7), 3-O-allyl-2,4,6-tri-O-benzoyl-α,β-D-glucopyranosyl trichloroacetimidate (8) and 2,3,4,6-tetra-O-benzoyl-α,β-D-glucopyranosyl trichloroacetimidate (11). The total yield of III from 4-methoxylphenyl 2,3-O-isopropylidene-α-L-rhamnopyranoside (1) was 18%.
2009, 20(5): 586-588
doi: 10.1016/j.cclet.2009.01.016
Abstract:
A new nor-sesquiterpene lactone ainsliatone A (1) was isolated from the aerial parts of Ainsliaea fulvioides. Its structure was established by the basis of spectroscopic methods and single-crystal X-ray diffraction analysis.
A new nor-sesquiterpene lactone ainsliatone A (1) was isolated from the aerial parts of Ainsliaea fulvioides. Its structure was established by the basis of spectroscopic methods and single-crystal X-ray diffraction analysis.
2009, 20(5): 589-591
doi: 10.1016/j.cclet.2009.01.034
Abstract:
A new lignan ligballinone 1 with the know ligballinol 2 were isolated from plant Gynostemma pentaphyllum. Their structures were determined through spectroscopic methods including ESI-MS, 1D and 2D NMR (1H, 13C, DEPT, 1H-1H COSY, HMQC,HMBC) and X-ray diffraction experiment for 2.
A new lignan ligballinone 1 with the know ligballinol 2 were isolated from plant Gynostemma pentaphyllum. Their structures were determined through spectroscopic methods including ESI-MS, 1D and 2D NMR (1H, 13C, DEPT, 1H-1H COSY, HMQC,HMBC) and X-ray diffraction experiment for 2.
2009, 20(5): 592-594
doi: 10.1016/j.cclet.2009.01.002
Abstract:
A new coumarin was obtained from the stems and roots of Wikstroemia indica (L.) C. A. Mey. Its structure was elucidated as methyl 3-(2-hydroxy-4-(7-hydroxy-6-methoxy-2-oxo-2H-chromen-3-yloxy) phenyl) propanoate by spectroscopic methods.
A new coumarin was obtained from the stems and roots of Wikstroemia indica (L.) C. A. Mey. Its structure was elucidated as methyl 3-(2-hydroxy-4-(7-hydroxy-6-methoxy-2-oxo-2H-chromen-3-yloxy) phenyl) propanoate by spectroscopic methods.
2009, 20(5): 595-597
doi: 10.1016/j.cclet.2009.01.005
Abstract:
6-(2-Hydroxy-5-acetylphenyl)-apigenin (1), a new flavonoid with a phenyl substituent, was first isolated from Selaginella tamariscina. Its structure was elucidated on the basis of 1D and 2D NMR as well as ESI-HR-MS spectroscopic analysis.
6-(2-Hydroxy-5-acetylphenyl)-apigenin (1), a new flavonoid with a phenyl substituent, was first isolated from Selaginella tamariscina. Its structure was elucidated on the basis of 1D and 2D NMR as well as ESI-HR-MS spectroscopic analysis.
2009, 20(5): 598-600
doi: 10.1016/j.cclet.2009.01.017
Abstract:
Two new compounds, senarguines A and B, were isolated from Senecio argunensis. They were respectively identified as (Z)-3-ethylidene-9-hydroxyl-9-methyl-6,7-dioxaspiro[4.4] nonane-5,8-dione (1) and 3,6,6-trimethyl 6,7,8-tetrahydronaphtha-[1,2b] furan (2) on the basis of spectral data.
Two new compounds, senarguines A and B, were isolated from Senecio argunensis. They were respectively identified as (Z)-3-ethylidene-9-hydroxyl-9-methyl-6,7-dioxaspiro[4.4] nonane-5,8-dione (1) and 3,6,6-trimethyl 6,7,8-tetrahydronaphtha-[1,2b] furan (2) on the basis of spectral data.
2009, 20(5): 601-603
doi: 10.1016/j.cclet.2008.12.053
Abstract:
A new 3,4-seco-lanostane triterpenoid, schisanlactone G (1), was isolated from the fruits of Schisandra sphenanthera. Its structure was established on the basis of extensive spectroscopic analysis.
A new 3,4-seco-lanostane triterpenoid, schisanlactone G (1), was isolated from the fruits of Schisandra sphenanthera. Its structure was established on the basis of extensive spectroscopic analysis.
2009, 20(5): 604-607
doi: 10.1016/j.cclet.2008.12.029
Abstract:
Poly(vinylpyridine) WH-225 resin was prepared and characterized. Compared with the commercial hypercrosslinked adsorbent NDA-100 and macroporous adsorbent XAD-4 resins, the newly synthesized poly(vinylpyridine) WH-225 resin exhibited the highest adsorption capacity toward SIPA from aqueous solution.
Poly(vinylpyridine) WH-225 resin was prepared and characterized. Compared with the commercial hypercrosslinked adsorbent NDA-100 and macroporous adsorbent XAD-4 resins, the newly synthesized poly(vinylpyridine) WH-225 resin exhibited the highest adsorption capacity toward SIPA from aqueous solution.
2009, 20(5): 608-610
doi: 10.1016/j.cclet.2008.12.031
Abstract:
Methane gas sensor was fabricated based on electrocatalytic properties of the Pd/MWNT nanocomposites on indium tin oxide (ITO) glass substrates. A linear response for methane was obtained in the range of 0-16% (v/v) with a detection limit of 0.167% (v/v) and R.S.D. of 4.1%. After 100 times sensing or stable stored more than 12 months in atmosphere, unconspicuous measurable decrease was observed. The response time was less than 60 s at room temperature and ambient pressure. Some common potential interferents in samples such as N2, CO, CO2, ethane, propane, pentane, methanol, ethanol, H2 and NH3 were investigated and all the effects were less than 5% on the response for 3.0% (v/v) methane. The sensor was applied to methane determinations in man-made gas samples, the results are satisfied.
Methane gas sensor was fabricated based on electrocatalytic properties of the Pd/MWNT nanocomposites on indium tin oxide (ITO) glass substrates. A linear response for methane was obtained in the range of 0-16% (v/v) with a detection limit of 0.167% (v/v) and R.S.D. of 4.1%. After 100 times sensing or stable stored more than 12 months in atmosphere, unconspicuous measurable decrease was observed. The response time was less than 60 s at room temperature and ambient pressure. Some common potential interferents in samples such as N2, CO, CO2, ethane, propane, pentane, methanol, ethanol, H2 and NH3 were investigated and all the effects were less than 5% on the response for 3.0% (v/v) methane. The sensor was applied to methane determinations in man-made gas samples, the results are satisfied.
2009, 20(5): 611-614
doi: 10.1016/j.cclet.2009.01.024
Abstract:
Triangular silver nanoprisms were prepared and applied to make colorimetric detection of cysteine based on our findings that cysteine could lead to the blue shift of the dipole plasmon resonance absorption, but other 19 kinds of natural amino acids could not.Cysteine with a concentration 160 nmol/L can result in a color change that can be discerned with naked eyes.
Triangular silver nanoprisms were prepared and applied to make colorimetric detection of cysteine based on our findings that cysteine could lead to the blue shift of the dipole plasmon resonance absorption, but other 19 kinds of natural amino acids could not.Cysteine with a concentration 160 nmol/L can result in a color change that can be discerned with naked eyes.
2009, 20(5): 615-619
doi: 10.1016/j.cclet.2009.01.006
Abstract:
Benzoic acid (BA), methylparaben (MP), propylparaben (PP) and sorbic acid (SA) are food preservatives, and they have well defined UV spectra. However, their spectra overlap seriously, and it is difficult to determine them individually from their mixtures without preseparation. In this paper, seven different chemometric approaches were applied to resolve the overlapping spectra and to determine these compounds simultaneously. With respect to the criteria of% relative prediction error (RPE) and% recovery,principal component regression (PCR) and radial basis function-artificial neural network (RBF-ANN) were the preferred methods.These two methods were successfully applied to the analysis of some commercial samples.
Benzoic acid (BA), methylparaben (MP), propylparaben (PP) and sorbic acid (SA) are food preservatives, and they have well defined UV spectra. However, their spectra overlap seriously, and it is difficult to determine them individually from their mixtures without preseparation. In this paper, seven different chemometric approaches were applied to resolve the overlapping spectra and to determine these compounds simultaneously. With respect to the criteria of% relative prediction error (RPE) and% recovery,principal component regression (PCR) and radial basis function-artificial neural network (RBF-ANN) were the preferred methods.These two methods were successfully applied to the analysis of some commercial samples.
2009, 20(5): 620-622
doi: 10.1016/j.cclet.2009.01.030
Abstract:
Novel and effective H-shaped chromophores were doped into polymethyl methacrylate (PMMA) to form guest-host polymer thin films. The measurement results of Maker fringe method show that the polymer thin films containing the H-shaped chromophores as a guest exhibit high second harmonic coefficients (d33) compared with other two-dimensional chromophores.
Novel and effective H-shaped chromophores were doped into polymethyl methacrylate (PMMA) to form guest-host polymer thin films. The measurement results of Maker fringe method show that the polymer thin films containing the H-shaped chromophores as a guest exhibit high second harmonic coefficients (d33) compared with other two-dimensional chromophores.
2009, 20(5): 623-626
doi: 10.1016/j.cclet.2009.01.022
Abstract:
Influence of non-gelling methylcellulose (MC) on gelation behavior of wheat gliadins in 13 wt% alkaline propanol/water (50:50,v/v) solution was investigated using dynamic rheological time sweep test. Increasing MC concentration (CMC) up to CMC=1 wt% caused a significant reduction in gelation time (tgel) of the solution and an increase in loss tangent (tan δ) value of the resultant gel at T < 30℃.
Influence of non-gelling methylcellulose (MC) on gelation behavior of wheat gliadins in 13 wt% alkaline propanol/water (50:50,v/v) solution was investigated using dynamic rheological time sweep test. Increasing MC concentration (CMC) up to CMC=1 wt% caused a significant reduction in gelation time (tgel) of the solution and an increase in loss tangent (tan δ) value of the resultant gel at T < 30℃.
2009, 20(5): 627-630
doi: 10.1016/j.cclet.2009.01.026
Abstract:
A novel axially substituted silicon(IV) phthalocyanine, namely di-pyridyloxy axially substituted silicon(IV) phthalocyanine 2 was synthesized and characterized by UV/vis, IR, elemental analysis, MS as well as 1H NMR spectroscopy. Hydrophobic 2 was encapsulated by amphiphilic triblock copolymer poly[Nε-(benzyloxycarbonyl-lysine]-poly(ethylene glycol)-poly[Nε-(benzyl oxycarbonyl) (PLL(Z)-b-PEG-b-PLL(Z)) to form hydrophobic 2-loaded polymeric complex micelle (PIC) (2-loaded PIC). Atom force microscopy (AFM) image showed that 2-loaded PIC formed a spherical nanocarrier with approximately 35-50 nm in diameter. The fluorescence intensity and lifetime of 2-loaded PIC was significantly enhanced by the incorporation 2 into PIC nanocarrier.
A novel axially substituted silicon(IV) phthalocyanine, namely di-pyridyloxy axially substituted silicon(IV) phthalocyanine 2 was synthesized and characterized by UV/vis, IR, elemental analysis, MS as well as 1H NMR spectroscopy. Hydrophobic 2 was encapsulated by amphiphilic triblock copolymer poly[Nε-(benzyloxycarbonyl-lysine]-poly(ethylene glycol)-poly[Nε-(benzyl oxycarbonyl) (PLL(Z)-b-PEG-b-PLL(Z)) to form hydrophobic 2-loaded polymeric complex micelle (PIC) (2-loaded PIC). Atom force microscopy (AFM) image showed that 2-loaded PIC formed a spherical nanocarrier with approximately 35-50 nm in diameter. The fluorescence intensity and lifetime of 2-loaded PIC was significantly enhanced by the incorporation 2 into PIC nanocarrier.
2009, 20(5): 631-634
doi: 10.1016/j.cclet.2009.01.037
Abstract:
Apocytochrome b5 with a typical heme-binding motif of HPGG, and its variants with mutated motifs, GPGG, GPGH, HVGG,and HPGP, have been subjected to molecular dynamics simulation. Comparison of the dynamic consequences has revealed the crucial role of HPGG in assembling the heme group of cytochrome b5 and in modulating protein structure, property and function.
Apocytochrome b5 with a typical heme-binding motif of HPGG, and its variants with mutated motifs, GPGG, GPGH, HVGG,and HPGP, have been subjected to molecular dynamics simulation. Comparison of the dynamic consequences has revealed the crucial role of HPGG in assembling the heme group of cytochrome b5 and in modulating protein structure, property and function.
