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2006 Volume 17 Issue 3
2006, 17(3): 285-288
Abstract:
The synthesis of a marine cytotoxic cyclic depsipeptide obyanamide has been accomplished. The key steps include assembling liner pentapeptide via Yamaguchi esterification and HATU-promoted ring closing. The structure of the synthetic sample was identified by 1H and 13C NMR, H-H COSY, HMQC, HMBC, and HRESIMS, but appears to be different from that of the marine natural product.
The synthesis of a marine cytotoxic cyclic depsipeptide obyanamide has been accomplished. The key steps include assembling liner pentapeptide via Yamaguchi esterification and HATU-promoted ring closing. The structure of the synthetic sample was identified by 1H and 13C NMR, H-H COSY, HMQC, HMBC, and HRESIMS, but appears to be different from that of the marine natural product.
2006, 17(3): 289-292
Abstract:
Some novel peptide dendrimers bearing four amino acids, GD and RGD peptides on their surface were synthesized from tetrakis[(carboxyethoxy)methyl]-methane using DCC method.
Some novel peptide dendrimers bearing four amino acids, GD and RGD peptides on their surface were synthesized from tetrakis[(carboxyethoxy)methyl]-methane using DCC method.
2006, 17(3): 293-295
Abstract:
Carbosilane dendrimers with p-bromophenyl core were synthesized by alternating Grignard and hydrosilylation reaction. And the α-naphthalenyl was connected to the core by the Suzuki coupling reaction. A new carbosilane dendrimer with big π-conjugated structure[4-(naphthalen-1-yl)phenyl core] was given. It shows Suzuki coupling reaction is an effective and powerful core-functionalization method and the satisfactory result can be obtained through prolonging the reaction time with the increase of the generation of dendrimer.
Carbosilane dendrimers with p-bromophenyl core were synthesized by alternating Grignard and hydrosilylation reaction. And the α-naphthalenyl was connected to the core by the Suzuki coupling reaction. A new carbosilane dendrimer with big π-conjugated structure[4-(naphthalen-1-yl)phenyl core] was given. It shows Suzuki coupling reaction is an effective and powerful core-functionalization method and the satisfactory result can be obtained through prolonging the reaction time with the increase of the generation of dendrimer.
2006, 17(3): 296-298
Abstract:
We have developed an asymmetric ring opening reaction of oxabenzonorbornadienes with substituted phenolic nucleophiles. Under the reaction conditions ([Rh(COD)Cl]2 (1 mol%), (S)-(R)-PPF-ptBu2 (2 mol%), THF, reflux), the reaction products were obtained with high yield and enantiomeric excesses (up to 99% ee).
We have developed an asymmetric ring opening reaction of oxabenzonorbornadienes with substituted phenolic nucleophiles. Under the reaction conditions ([Rh(COD)Cl]2 (1 mol%), (S)-(R)-PPF-ptBu2 (2 mol%), THF, reflux), the reaction products were obtained with high yield and enantiomeric excesses (up to 99% ee).
2006, 17(3): 299-301
Abstract:
An efficient and environmental benign method is reported for the condensation of 3-methyl-1-phenyl-5-pyrazolone with carbonyl compounds in ionic liquids [Bmim]BF4 and [Bmim]PF6 catalyzed by ethylenediammonium diacetate.
An efficient and environmental benign method is reported for the condensation of 3-methyl-1-phenyl-5-pyrazolone with carbonyl compounds in ionic liquids [Bmim]BF4 and [Bmim]PF6 catalyzed by ethylenediammonium diacetate.
2006, 17(3): 302-304
Abstract:
A convenient synthesis of oxazolidinone antibacterial linezolid from readily available L-ascorbic acid is described. The key steps include reductive amination of arylamine and (S)-glyceraldehyde acetonide in the presence of NaBH4 and 4Ǻ sieve, followed by hydrolysis and regioselective cyclization.
A convenient synthesis of oxazolidinone antibacterial linezolid from readily available L-ascorbic acid is described. The key steps include reductive amination of arylamine and (S)-glyceraldehyde acetonide in the presence of NaBH4 and 4Ǻ sieve, followed by hydrolysis and regioselective cyclization.
2006, 17(3): 305-306
Abstract:
A new aromatic dianhydride monomer containing pyridine moiety, 2, 6-bis[4'-(3", 4"dicarboxyphenoxy)benzoyl]-pyridine dianhydride (Md), was synthesized in four steps, starting from 2, 6-pyridinedicarboxyl chloride. A novel pyridine-containing polyimide was prepared via polycondensation of Md with ODA by two-step method. The resulting polyimide exhibits excellent solubility, film-forming capability and high thermal resistance.
A new aromatic dianhydride monomer containing pyridine moiety, 2, 6-bis[4'-(3", 4"dicarboxyphenoxy)benzoyl]-pyridine dianhydride (Md), was synthesized in four steps, starting from 2, 6-pyridinedicarboxyl chloride. A novel pyridine-containing polyimide was prepared via polycondensation of Md with ODA by two-step method. The resulting polyimide exhibits excellent solubility, film-forming capability and high thermal resistance.
2006, 17(3): 307-309
Abstract:
A total synthesis of three new dihydrostilbenes, 1, 2 and 3, which were isolated from Bulbophyllum odoratissimum Lindl. with significant cytotoxicity toward human cancer cell lines, was developed via Horner reaction etc. The natural products 1, 2 and 3 were obtained in 5.8%, 6.6% and 5.9%, respectively.
A total synthesis of three new dihydrostilbenes, 1, 2 and 3, which were isolated from Bulbophyllum odoratissimum Lindl. with significant cytotoxicity toward human cancer cell lines, was developed via Horner reaction etc. The natural products 1, 2 and 3 were obtained in 5.8%, 6.6% and 5.9%, respectively.
2006, 17(3): 310-312
Abstract:
A new series of bone affinity compounds were synthesized by linking chrysophanol with 5-fluorouracil derivatives. Their bone affinity was established by hydroxyapafive (HA)affinity experiment in vitro, and their cytostatic effects were shown by the MTT assay.
A new series of bone affinity compounds were synthesized by linking chrysophanol with 5-fluorouracil derivatives. Their bone affinity was established by hydroxyapafive (HA)affinity experiment in vitro, and their cytostatic effects were shown by the MTT assay.
2006, 17(3): 313-316
Abstract:
Ma's CuI/proline procedure for the catalytic cross coupling between nitrogen heterocycles and aryl halides was markedly improved. The key finding was that K3PO4 was a much better base than K2CO3 for the reaction. With this new reaction condition the cross coupling with aryl iodides could be accomplished in 1, 4-dioxane instead of DMSO. This reactin also could be carried out in DMF. Furthermore, the coupling yields under the new conditions are usually higher than in Ma's original methods.
Ma's CuI/proline procedure for the catalytic cross coupling between nitrogen heterocycles and aryl halides was markedly improved. The key finding was that K3PO4 was a much better base than K2CO3 for the reaction. With this new reaction condition the cross coupling with aryl iodides could be accomplished in 1, 4-dioxane instead of DMSO. This reactin also could be carried out in DMF. Furthermore, the coupling yields under the new conditions are usually higher than in Ma's original methods.
2006, 17(3): 317-320
Abstract:
The new complexes, [PdCl{C5H4FeC5H4CHRN=CHC4H3O}(Ph3P)] (R=H, CH3) were synthesized via two novel Schiff bases (C5H5FeC5H4CHRN=CHC4H3O, R=H, CH3) with lithium tetrachloropalladate (Ⅱ), and characterized by IR, elemental analysis, 1H NMR. Complex 5a was further determined by X-ray single crystal diffraction. We found that it contained an intramolecular N→Pd coordination in the compound Sa, and the palladium atom was bound to the unsubstituted Cp ring. The Pd-N, Pd-C (1) and Pd-O bond lengths were 2.121(3), 2.008(4) and 2.990(A), respectively.
The new complexes, [PdCl{C5H4FeC5H4CHRN=CHC4H3O}(Ph3P)] (R=H, CH3) were synthesized via two novel Schiff bases (C5H5FeC5H4CHRN=CHC4H3O, R=H, CH3) with lithium tetrachloropalladate (Ⅱ), and characterized by IR, elemental analysis, 1H NMR. Complex 5a was further determined by X-ray single crystal diffraction. We found that it contained an intramolecular N→Pd coordination in the compound Sa, and the palladium atom was bound to the unsubstituted Cp ring. The Pd-N, Pd-C (1) and Pd-O bond lengths were 2.121(3), 2.008(4) and 2.990(A), respectively.
2006, 17(3): 321-324
Abstract:
Novel Lewis acidic ionic liquids containing thionyl cations and chloroaluminate anions were obtained by one-pot synthesis for the first time. Their acidities were determined by acetonitrile probe on IR spectrography. The ionic liquids were used as catalyst for Friedel-Crafts alkylation of benzene and 1-dodecene. The turnovers of 1-dodecene were higher than 99%. Monoalkylbenzene selectivity was 98%, while the 2-substituent product selectivity was 45%.
Novel Lewis acidic ionic liquids containing thionyl cations and chloroaluminate anions were obtained by one-pot synthesis for the first time. Their acidities were determined by acetonitrile probe on IR spectrography. The ionic liquids were used as catalyst for Friedel-Crafts alkylation of benzene and 1-dodecene. The turnovers of 1-dodecene were higher than 99%. Monoalkylbenzene selectivity was 98%, while the 2-substituent product selectivity was 45%.
2006, 17(3): 325-328
Abstract:
A series of thiazole derivatives of ibuprofen, as cyclooxygenase-2 Inhibitors, were designed, synthesized and in vitro evaluated.
A series of thiazole derivatives of ibuprofen, as cyclooxygenase-2 Inhibitors, were designed, synthesized and in vitro evaluated.
2006, 17(3): 329-332
Abstract:
The sequential oxidation-Horner-Wadsworth-Emmons reaction of alcohols to prepare α-halo-α, β-unsaturated esters (halo=F, Cl) with middle to excellent (Z)-selectivity was developed.
The sequential oxidation-Horner-Wadsworth-Emmons reaction of alcohols to prepare α-halo-α, β-unsaturated esters (halo=F, Cl) with middle to excellent (Z)-selectivity was developed.
2006, 17(3): 333-336
Abstract:
A number of naphthalene derivatives containing adamantanamine binding moiety and an (CH2)n (n=2, 3, 4, 5, 6) spacer were prepared as electron donor. A supramolecular assembly was fabricated by the inclusion complexation of the donor substrates with the host molecules, mono-6-O-p-nitrobenzoyl-β-cyclodextrin (p-NBCD) and mono-6-O-m-nitrobenzoyl-β-cyclodextrin (m-NBCD), in water. The fluorescence quenching in these systems was studied and detailed Stern-Volmer constants were measured. It revealed that an efficient photoinduced electron transfers (PET) between the naphthalene donors and the cyclodextrin acceptors occurred.
A number of naphthalene derivatives containing adamantanamine binding moiety and an (CH2)n (n=2, 3, 4, 5, 6) spacer were prepared as electron donor. A supramolecular assembly was fabricated by the inclusion complexation of the donor substrates with the host molecules, mono-6-O-p-nitrobenzoyl-β-cyclodextrin (p-NBCD) and mono-6-O-m-nitrobenzoyl-β-cyclodextrin (m-NBCD), in water. The fluorescence quenching in these systems was studied and detailed Stern-Volmer constants were measured. It revealed that an efficient photoinduced electron transfers (PET) between the naphthalene donors and the cyclodextrin acceptors occurred.
2006, 17(3): 337-340
Abstract:
Two new iridoids (1 and 2) were isolated from the roots of Patrinia rupestris (Pall.) Juss.Their structures were elucidated by spectroscopic methods. Compounds 1 and 2 exhibited strong antibacterial activities against Eschecichia coli and Staphylococcus aureus, respectively.
Two new iridoids (1 and 2) were isolated from the roots of Patrinia rupestris (Pall.) Juss.Their structures were elucidated by spectroscopic methods. Compounds 1 and 2 exhibited strong antibacterial activities against Eschecichia coli and Staphylococcus aureus, respectively.
2006, 17(3): 341-343
Abstract:
Tow new oplopanol esters were isolated from the roots of Ligularia narynensis. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.
Tow new oplopanol esters were isolated from the roots of Ligularia narynensis. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.
2006, 17(3): 344-346
Abstract:
A novel pyrone derivative was isolated from the ethyl acetate extract of a culture broth of a strain of the fungus Cephalosporium sp. AL031. Its structure was characterized as 7-hydroxy-9-methoxyl-10-methyl-2H, 4aH, 6H, 10bH-pyrano[5, 6-c][2]benzopyran-2, 6-dione by spectroscopic analysis including IR, MS, 1D and 2D NMR spectra.
A novel pyrone derivative was isolated from the ethyl acetate extract of a culture broth of a strain of the fungus Cephalosporium sp. AL031. Its structure was characterized as 7-hydroxy-9-methoxyl-10-methyl-2H, 4aH, 6H, 10bH-pyrano[5, 6-c][2]benzopyran-2, 6-dione by spectroscopic analysis including IR, MS, 1D and 2D NMR spectra.
2006, 17(3): 347-350
Abstract:
Two new acetyl cimicifugosides were isolated from the rhizomes of Cimicifuga racemosa. Their structures were elucidated as 2'-O-acetyl cimicifugoside H-1 1 and 3'-O-acetyl cimicifugoside H-1 2 by the spectroscopic evidence and chemical methods.
Two new acetyl cimicifugosides were isolated from the rhizomes of Cimicifuga racemosa. Their structures were elucidated as 2'-O-acetyl cimicifugoside H-1 1 and 3'-O-acetyl cimicifugoside H-1 2 by the spectroscopic evidence and chemical methods.
2006, 17(3): 351-354
Abstract:
Four new aminooligosaccharides, isovalertatins M33 1, D13 2, D33 3, and D43 4, were isolated from the culture filtrate of Streptomyces luteogriseus. Their structures were established by chemical and spectroscopic evidences including ESI multistage mass spectrometry and 2-dimensional NMR techniques, and were found in full consistencies with the previous profiling results proposed by LC/ESI/MS analysis.
Four new aminooligosaccharides, isovalertatins M33 1, D13 2, D33 3, and D43 4, were isolated from the culture filtrate of Streptomyces luteogriseus. Their structures were established by chemical and spectroscopic evidences including ESI multistage mass spectrometry and 2-dimensional NMR techniques, and were found in full consistencies with the previous profiling results proposed by LC/ESI/MS analysis.
2006, 17(3): 355-357
Abstract:
A novel sesquiterpenoid was isolated from the whole plant of Glechoma longituba. Its structure was elucidated as 1, 8-epoxy-7(11)-germacren-5-one-12, 8-olide 1 on the basis of spectral evidences.
A novel sesquiterpenoid was isolated from the whole plant of Glechoma longituba. Its structure was elucidated as 1, 8-epoxy-7(11)-germacren-5-one-12, 8-olide 1 on the basis of spectral evidences.
2006, 17(3): 358-360
Abstract:
Two novel diphoshinoamine ligands have been synthesized. Combination of Cr(Ⅲ) and methylaluminoxane(MAO) generated active catalytic system which can catalyze tetramerization of ethylene with high catalytic activity up to 2.5×10-6g/mol Cr.h and high selectivity to produce 1-octene (C8 in products is being 89.80 wt%).
Two novel diphoshinoamine ligands have been synthesized. Combination of Cr(Ⅲ) and methylaluminoxane(MAO) generated active catalytic system which can catalyze tetramerization of ethylene with high catalytic activity up to 2.5×10-6g/mol Cr.h and high selectivity to produce 1-octene (C8 in products is being 89.80 wt%).
2006, 17(3): 361-364
Abstract:
Poly(N-isopropylacrylamide)-based hydrogel was prepared under microwave irradiation.The hydrogel thus prepared, comparing with that prepared by thermal heating method, exhibits faster swelling and shrinking kinetics. The improved responsive properties are due to the more heterogeneous and porous networks formed under microwave irradiation.
Poly(N-isopropylacrylamide)-based hydrogel was prepared under microwave irradiation.The hydrogel thus prepared, comparing with that prepared by thermal heating method, exhibits faster swelling and shrinking kinetics. The improved responsive properties are due to the more heterogeneous and porous networks formed under microwave irradiation.
2006, 17(3): 365-368
Abstract:
Polyacrylonitrile-block-poly(methyl acrylate)(P(AN-b-MA)) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization employing macro-RAFT agent (PAN-RAFT) as the chain transfer agent and azobis(isobutyronitrile) (AIBN) as the initiator.A linear relationship between ln([M]0/[M]t) and reaction time was observed. The molecular structure of P(AN-b-MA) was characterized by 1H-NMR, element analysis, FTIR and SEC. The molecular weight distribution (MWD) was less than 1.40, the Mn could be controled from 0.733 to 4.834×104, and the molar content of MA in P(AN-b-MA) were from 15.6 to 75.0 percentage, respectively.
Polyacrylonitrile-block-poly(methyl acrylate)(P(AN-b-MA)) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization employing macro-RAFT agent (PAN-RAFT) as the chain transfer agent and azobis(isobutyronitrile) (AIBN) as the initiator.A linear relationship between ln([M]0/[M]t) and reaction time was observed. The molecular structure of P(AN-b-MA) was characterized by 1H-NMR, element analysis, FTIR and SEC. The molecular weight distribution (MWD) was less than 1.40, the Mn could be controled from 0.733 to 4.834×104, and the molar content of MA in P(AN-b-MA) were from 15.6 to 75.0 percentage, respectively.
2006, 17(3): 369-372
Abstract:
A novel ultraviolet (UV) curable aqueous dispersion polyurethane PDHA-PEDA-PU was synthesized based on isophorone diisocyanate (IPDI), polyester dihydric alcohol (PDHA), dimethylol propionic acid (DMPA), pentaerythritol diacrylate (PEDA), 2-hydroxyethyl acrylate (HEA) and triethylamine (TEA). Acrylate groups were incorporated in the side and end of PDHA-PEDA-PU chain. The C=C content in the chain can be controlled easily through the change of IPDI/PDHA/PEDA ratio. Fourier transform infrared spectroscopy (FTIR) was used to identify the structure of prepolymer, aqueous dispersion and cured polyurethane. The curing rule of the polyurethane for different C=C content has been investigated depending on the change of C=C content during the curing process. The hardness, thermal stability and scrub resistance to MEK of UV cured PDHA-PEDA-PU were also discussed for the samples with different C=C content.
A novel ultraviolet (UV) curable aqueous dispersion polyurethane PDHA-PEDA-PU was synthesized based on isophorone diisocyanate (IPDI), polyester dihydric alcohol (PDHA), dimethylol propionic acid (DMPA), pentaerythritol diacrylate (PEDA), 2-hydroxyethyl acrylate (HEA) and triethylamine (TEA). Acrylate groups were incorporated in the side and end of PDHA-PEDA-PU chain. The C=C content in the chain can be controlled easily through the change of IPDI/PDHA/PEDA ratio. Fourier transform infrared spectroscopy (FTIR) was used to identify the structure of prepolymer, aqueous dispersion and cured polyurethane. The curing rule of the polyurethane for different C=C content has been investigated depending on the change of C=C content during the curing process. The hardness, thermal stability and scrub resistance to MEK of UV cured PDHA-PEDA-PU were also discussed for the samples with different C=C content.
2006, 17(3): 373-376
Abstract:
Branched poly(ε-caprolactone) was synthesized by self-condensing atom transfer radical polymerization of macroinimer, α-acryloyoxy-ω-2-bromopropionyloxy poly(ε-caprolactone), which was prepared by enzyme-catalyzed ring-opening polymerization of ε-caprolactone with 2-hydroxylethyl acrylate as initiator and esterification of the ω-hydroxyl group of the obtained poly(ε-caprolactone) by 2-bromopropionyl bromide.
Branched poly(ε-caprolactone) was synthesized by self-condensing atom transfer radical polymerization of macroinimer, α-acryloyoxy-ω-2-bromopropionyloxy poly(ε-caprolactone), which was prepared by enzyme-catalyzed ring-opening polymerization of ε-caprolactone with 2-hydroxylethyl acrylate as initiator and esterification of the ω-hydroxyl group of the obtained poly(ε-caprolactone) by 2-bromopropionyl bromide.
2006, 17(3): 377-379
Abstract:
The blue color system of supramolecular assembly formed by di(hydroxymethyl)di-(2-pyrrolyl)methane and tetracyanoquinodimethane (TCNQ) may be used for effective and selective detection of aniline through the visual color change in CH3CN/H2O mixed solvent. The excellent properties of the system make the supramolecular assembly to be a highly selective colorimetric probe for aniline.
The blue color system of supramolecular assembly formed by di(hydroxymethyl)di-(2-pyrrolyl)methane and tetracyanoquinodimethane (TCNQ) may be used for effective and selective detection of aniline through the visual color change in CH3CN/H2O mixed solvent. The excellent properties of the system make the supramolecular assembly to be a highly selective colorimetric probe for aniline.
2006, 17(3): 380-382
Abstract:
A new method of resolving overlapped peak, Fourier self-deconvolution (FSD) using approximation CN obtained from frequency domain wavelet transform of F(ω) yielded by Fourier transform of overlapped peak signals f(t) as the linear function, was presented in this paper.Compared with classical FSD, the new method exhibits excellent resolution for different overlapped peak signals such as HPLC signals, and have some characteristics such as an extensive applicability for any overlapped peak shape signals and a simple operation because of no selection procedure of the linear function. Its excellent resolution for those different overlapped peak signals is mainly because F(ω) obtained from Fourier transform of f(t) and CN obtained from wavelet transform of F(ω) have the similar linearity and peak width. The effect of those fake peaks can be eliminated by the algorithm proposed by authors. This method has good potential in the process of different overlapped peak signals.
A new method of resolving overlapped peak, Fourier self-deconvolution (FSD) using approximation CN obtained from frequency domain wavelet transform of F(ω) yielded by Fourier transform of overlapped peak signals f(t) as the linear function, was presented in this paper.Compared with classical FSD, the new method exhibits excellent resolution for different overlapped peak signals such as HPLC signals, and have some characteristics such as an extensive applicability for any overlapped peak shape signals and a simple operation because of no selection procedure of the linear function. Its excellent resolution for those different overlapped peak signals is mainly because F(ω) obtained from Fourier transform of f(t) and CN obtained from wavelet transform of F(ω) have the similar linearity and peak width. The effect of those fake peaks can be eliminated by the algorithm proposed by authors. This method has good potential in the process of different overlapped peak signals.
2006, 17(3): 383-386
Abstract:
Two 17-mer dsDNA with different sequence characteristics were designed to investigate the binding characteristics of berberine, an anticancer drug with uncertain binding mode, and Hoechst 33258, a model DNA minor groove binder, with dsDNA, respectively by the capillary zone electrophoresis (CZE). Kenndler model analysis revealed that Hoechst 33258 exhibited intermediate affinity with dsDNA, while there was only low affinity and some weak binding preference for AATT-containing to GGCC-containing dsDNA for berberine.
Two 17-mer dsDNA with different sequence characteristics were designed to investigate the binding characteristics of berberine, an anticancer drug with uncertain binding mode, and Hoechst 33258, a model DNA minor groove binder, with dsDNA, respectively by the capillary zone electrophoresis (CZE). Kenndler model analysis revealed that Hoechst 33258 exhibited intermediate affinity with dsDNA, while there was only low affinity and some weak binding preference for AATT-containing to GGCC-containing dsDNA for berberine.
2006, 17(3): 387-390
Abstract:
The solution binding properties of calix[4]pyrroles with anion (as tetraalkylammonium salts) were investigated using UV-Vis spectroscopic techniques. The obvious red-shift of absorption maximum band of calix[4]pyrrole in EtOH in the presence of the tetramethylammonium (TMA+) salts or tetraethylammonium (TEA+) salts were observed, due to the charge-transfer interactions between the electron-rich pyrrole rings of calix[4]pyrroles and TMA+ or TEA+ cation subunit. The results indicated that calix[4]pyrrole receptors, which link the anionic species through multiple hydrogen bonding interactions, can use the periphery cavity for selectively binding cation subunits by cation-π charge-transfer interaction. The subsidiary interaction mode helps to further stabilize the calix[4]pyrrole-anion complex.
The solution binding properties of calix[4]pyrroles with anion (as tetraalkylammonium salts) were investigated using UV-Vis spectroscopic techniques. The obvious red-shift of absorption maximum band of calix[4]pyrrole in EtOH in the presence of the tetramethylammonium (TMA+) salts or tetraethylammonium (TEA+) salts were observed, due to the charge-transfer interactions between the electron-rich pyrrole rings of calix[4]pyrroles and TMA+ or TEA+ cation subunit. The results indicated that calix[4]pyrrole receptors, which link the anionic species through multiple hydrogen bonding interactions, can use the periphery cavity for selectively binding cation subunits by cation-π charge-transfer interaction. The subsidiary interaction mode helps to further stabilize the calix[4]pyrrole-anion complex.
2006, 17(3): 391-394
Abstract:
The silver ionic complexes of xanthone glycosides were studied by ESI-MS/MS in the positive ion mode. The fragmentation pathways of silver ionic complexes under collisioninduced dissociation (CID) were investigated and the differences in MS/MS spectra of different silver ionic complexes of xanthones were correlated to the characterization of saccharide and the coordination pattern of silver ion with xanthones, including the glycosilation position and linkage type of disaccharide (1-2 and 1-6 linkages).
The silver ionic complexes of xanthone glycosides were studied by ESI-MS/MS in the positive ion mode. The fragmentation pathways of silver ionic complexes under collisioninduced dissociation (CID) were investigated and the differences in MS/MS spectra of different silver ionic complexes of xanthones were correlated to the characterization of saccharide and the coordination pattern of silver ion with xanthones, including the glycosilation position and linkage type of disaccharide (1-2 and 1-6 linkages).
2006, 17(3): 395-398
Abstract:
The addition of packing material for high performance hydrophobic interaction chrornatograghy (HPHIC) into the denaturant solution to prevent, or depress protein aggregation in the denatuaration process is presented. The renaturation of α-chymotrypsin (α-Chy)denatured with guanidine hydrochloride (GuHCl) solution indicated that renaturation efficiency can be enhanced from 36.1% to 59.0% by this new method. The structure of the ligand linking of HPHIC packings is also important for the protein renaturation.
The addition of packing material for high performance hydrophobic interaction chrornatograghy (HPHIC) into the denaturant solution to prevent, or depress protein aggregation in the denatuaration process is presented. The renaturation of α-chymotrypsin (α-Chy)denatured with guanidine hydrochloride (GuHCl) solution indicated that renaturation efficiency can be enhanced from 36.1% to 59.0% by this new method. The structure of the ligand linking of HPHIC packings is also important for the protein renaturation.
2006, 17(3): 399-402
Abstract:
A pH-sensitive modified polyacrylamide hydrogel was prepared by two steps and the modified polyacrylamide was characterized by 1HNMR spectrum. The surface morphology and swelling behavior of the hydrogels were investigated.
A pH-sensitive modified polyacrylamide hydrogel was prepared by two steps and the modified polyacrylamide was characterized by 1HNMR spectrum. The surface morphology and swelling behavior of the hydrogels were investigated.
2006, 17(3): 403-406
Abstract:
Interpenetrating polymer network (IPN) composed of silk sericin (SS) and poly(N-isopropylacrylamide) (PNIPAAm) was prepared. The morphology of the IPNs, in which the SS phase was stained with ammonium cuprate, was examined with TEM and a relative homogeneous distribution of the two polymers was exhibited. The swelling behavior of the IPN hydrogels showed both temperature and pH dependences.
Interpenetrating polymer network (IPN) composed of silk sericin (SS) and poly(N-isopropylacrylamide) (PNIPAAm) was prepared. The morphology of the IPNs, in which the SS phase was stained with ammonium cuprate, was examined with TEM and a relative homogeneous distribution of the two polymers was exhibited. The swelling behavior of the IPN hydrogels showed both temperature and pH dependences.
2006, 17(3): 407-410
Abstract:
A cationic cyclodextrin derivative 6-O-(hydroxypropyltrimethylammonia)-β-cyclodextrin (GTA-β-CD) with low degree of substitution was prepared through a convenient method in solid phase. The product could be used as a valuable chiral selector in the capillary electrophoresis (CE) separation of some acidic drug enantiomers such as naproxen, ofloxacin, ibuprofen and warfarin.
A cationic cyclodextrin derivative 6-O-(hydroxypropyltrimethylammonia)-β-cyclodextrin (GTA-β-CD) with low degree of substitution was prepared through a convenient method in solid phase. The product could be used as a valuable chiral selector in the capillary electrophoresis (CE) separation of some acidic drug enantiomers such as naproxen, ofloxacin, ibuprofen and warfarin.
2006, 17(3): 411-414
Abstract:
Three new cyclometalated iridium(Ⅲ) complexes based on ligands of diphenylquinoline with fluorinated substituents were prepared, and characterized by elemental analysis (EA), 1H NMR, and mass spectroscopy (MS). The photophysical and electrophosphorescent properties of the complexes were briefly discussed.
Three new cyclometalated iridium(Ⅲ) complexes based on ligands of diphenylquinoline with fluorinated substituents were prepared, and characterized by elemental analysis (EA), 1H NMR, and mass spectroscopy (MS). The photophysical and electrophosphorescent properties of the complexes were briefly discussed.
2006, 17(3): 415-418
Abstract:
The effects of oligodeoxynucleotide (ODN) on the conformation of basic fibroblast growth factor (bFGF) were studied by spectral method. The results showed that ODN destabilized the protein.
The effects of oligodeoxynucleotide (ODN) on the conformation of basic fibroblast growth factor (bFGF) were studied by spectral method. The results showed that ODN destabilized the protein.
2006, 17(3): 419-422
Abstract:
A new heterogeneous catalyst, copper tetrahydrosalen complex encapsulated in zeolite Y (denoted as Cu[H4]salen/Y) has been developed with flexible ligand method, and characterized by FTIR, DR UV-Vis spectroscopy, N2 adsorption/desorption at -196℃. This catalyst behaved like a bio-mimic enzyme, and exhibited much higher activity for the oxidation of cycloalkanes than Cusalen/Y prepared with the same method. The effects of the reaction conditions on the catalytic performance were investigated.
A new heterogeneous catalyst, copper tetrahydrosalen complex encapsulated in zeolite Y (denoted as Cu[H4]salen/Y) has been developed with flexible ligand method, and characterized by FTIR, DR UV-Vis spectroscopy, N2 adsorption/desorption at -196℃. This catalyst behaved like a bio-mimic enzyme, and exhibited much higher activity for the oxidation of cycloalkanes than Cusalen/Y prepared with the same method. The effects of the reaction conditions on the catalytic performance were investigated.
2006, 17(3): 423-426
Abstract:
The Michael addition reactions of Z and E benzaldoximes with propene were investigated theoretically by DFT method at B3LYP/6-31G* level. The calculation results show that both addition reactions are concerted processes accompanied by the migration of hydrogen from the atom oxygen to carbon. Both products Z and E nitrones have dipolar charge distributions and activities. Z isomer is more favorable in the reaction due to the barrier is lower.
The Michael addition reactions of Z and E benzaldoximes with propene were investigated theoretically by DFT method at B3LYP/6-31G* level. The calculation results show that both addition reactions are concerted processes accompanied by the migration of hydrogen from the atom oxygen to carbon. Both products Z and E nitrones have dipolar charge distributions and activities. Z isomer is more favorable in the reaction due to the barrier is lower.
