Login In
1995 Volume 6 Issue 5
1995, 6(5): 361-362
Abstract:
Seven title compounds were synthesized by condensation of 4'-demethylepipodophyllotoxin with 5-alkyl-4-amino-3-mercapto-l,2,4-trizoles in the presence of CF3COOH (TFA).
Seven title compounds were synthesized by condensation of 4'-demethylepipodophyllotoxin with 5-alkyl-4-amino-3-mercapto-l,2,4-trizoles in the presence of CF3COOH (TFA).
1995, 6(5): 365-367
Abstract:
Synthesis of l,3,4,6-tetrathiapentalene-2,5-dione(thiapendione) has been studied in detail and a convenient synthetic procedure is reported.
Synthesis of l,3,4,6-tetrathiapentalene-2,5-dione(thiapendione) has been studied in detail and a convenient synthetic procedure is reported.
1995, 6(5): 367-368
Abstract:
3'-Methoxy-5'-prenylnaringenin was first synthesized via the condensation of 2-hydroxy-4,6-dirnethoxymethoxyacetophenone with 3-methoxy-4-methoxymethoxy-5-prenylbenzaldehyde followed by cyclization and demethoxymethylation.
3'-Methoxy-5'-prenylnaringenin was first synthesized via the condensation of 2-hydroxy-4,6-dirnethoxymethoxyacetophenone with 3-methoxy-4-methoxymethoxy-5-prenylbenzaldehyde followed by cyclization and demethoxymethylation.
1995, 6(5): 369-372
Abstract:
Two new dipeptide sweeteners 3a,3b have been prepared from the commercial starting material in three steps with the sweetness over 100 and 200 times of that of sucrose,respectively.The two compounds appear to have sucrose-like taste and high stability.
Two new dipeptide sweeteners 3a,3b have been prepared from the commercial starting material in three steps with the sweetness over 100 and 200 times of that of sucrose,respectively.The two compounds appear to have sucrose-like taste and high stability.
1995, 6(5): 373-376
Abstract:
Twelve new nitrogen-oxygen donor macrocycles have been synthesized by condensation of N,N-bis [2-(2-formylphenoxy) ethyl]-4-methylphenylsulfonamide with diamines followed by a one pot reduction of the corresponding Schiff-base derivatives.The 4-methylphenylsulfonyl group can be removed by Na-Hg (6%) in methanol.All of the new aza-crowns were identified by EA,NMR,IR and MS.
Twelve new nitrogen-oxygen donor macrocycles have been synthesized by condensation of N,N-bis [2-(2-formylphenoxy) ethyl]-4-methylphenylsulfonamide with diamines followed by a one pot reduction of the corresponding Schiff-base derivatives.The 4-methylphenylsulfonyl group can be removed by Na-Hg (6%) in methanol.All of the new aza-crowns were identified by EA,NMR,IR and MS.
1995, 6(5): 377-378
Abstract:
A series of amino acids and oligopeptidyl derivatives of Gd-DTPA were synthesized.The structure of these chelates were confirmed by IR and elementary analysis.Toxicity of chelates was almost the same as Gd-DTPA.The spin-lattice relaxivity (R1) of these chelates were a little bit larger than that of Gd-DTPA.
A series of amino acids and oligopeptidyl derivatives of Gd-DTPA were synthesized.The structure of these chelates were confirmed by IR and elementary analysis.Toxicity of chelates was almost the same as Gd-DTPA.The spin-lattice relaxivity (R1) of these chelates were a little bit larger than that of Gd-DTPA.
1995, 6(5): 379-382
Abstract:
A series of para-substituted meso-tetraphenylporphinatomanganese (Ⅱ) complexes,Mn■ (T(p-X)PP) (L),where X=H,CH3,Cl,OCH3,containing a new kind of axial ligand L=t-RuNH2 have been synthesized by the NaRH4 reduction method.These compounds were characterized by electronic and infrared spectra.
A series of para-substituted meso-tetraphenylporphinatomanganese (Ⅱ) complexes,Mn■ (T(p-X)PP) (L),where X=H,CH3,Cl,OCH3,containing a new kind of axial ligand L=t-RuNH2 have been synthesized by the NaRH4 reduction method.These compounds were characterized by electronic and infrared spectra.
RESOLUTION OF DL-α-AMINO ACIDS ON A L-HYDROXY PROLINE CHIRAL PHASE BY LIGAND-EXCHANGE CHROMATOGRAPHY
1995, 6(5): 383-384
Abstract:
A HPLC bonded phase with L-hydroxy proline was prepared by coupling L-hydroxy proline as a chiral selector to silica gel via 3-glycidyloxypropyltrimethoxysilane.The chiral separations of 12 DL-amino acids on the chiral phase were performed and the effects of the chromatographic conditions,the pH of the mobile phase and the column temperature,on the resolution of DL-α-amino acids were studied.
A HPLC bonded phase with L-hydroxy proline was prepared by coupling L-hydroxy proline as a chiral selector to silica gel via 3-glycidyloxypropyltrimethoxysilane.The chiral separations of 12 DL-amino acids on the chiral phase were performed and the effects of the chromatographic conditions,the pH of the mobile phase and the column temperature,on the resolution of DL-α-amino acids were studied.
1995, 6(5): 385-386
Abstract:
From the BtOAc extract of the underground parts of Pleurospermum rivulorum (Diels),a new bicoumarin,rivulobirin was isolated along with eight known furocoumarins.
From the BtOAc extract of the underground parts of Pleurospermum rivulorum (Diels),a new bicoumarin,rivulobirin was isolated along with eight known furocoumarins.
1995, 6(5): 385-398
Abstract:
The evidence for the sp2 C-H…O=C intramolecular interaction like hydrogen bond observed from the 1H NMR signal shifted extremely to down field (δ=10.23 ppm) at the bay area of phenaleno[2,3-f] quinolin-13-one has been confirmed by EIMS and MS/MS(CAD) spectroscopy and IR spectroscopy,as well as MNDO-PM3 calculations.
The evidence for the sp2 C-H…O=C intramolecular interaction like hydrogen bond observed from the 1H NMR signal shifted extremely to down field (δ=10.23 ppm) at the bay area of phenaleno[2,3-f] quinolin-13-one has been confirmed by EIMS and MS/MS(CAD) spectroscopy and IR spectroscopy,as well as MNDO-PM3 calculations.
1995, 6(5): 387-390
Abstract:
Further phytochemical investigation of the roots of Ligularia nelumbifolia afforded six new sinapyl alcohol derivatives.Their structures were elucidated by high field NMR spectroscopy.
Further phytochemical investigation of the roots of Ligularia nelumbifolia afforded six new sinapyl alcohol derivatives.Their structures were elucidated by high field NMR spectroscopy.
1995, 6(5): 391-394
Abstract:
A new sesquiterpenoid compound named ligustilone was isolated from the roots of Ligusticum sinense Oliv.Based on the chemical and spectral studies especially 2DNMR including 1H,1H COSY,1H,13C COSY and COLOC techniques,its structure has been established as a bisabolane derivative and showed as I.The absolute configuration was determined by CD data.
A new sesquiterpenoid compound named ligustilone was isolated from the roots of Ligusticum sinense Oliv.Based on the chemical and spectral studies especially 2DNMR including 1H,1H COSY,1H,13C COSY and COLOC techniques,its structure has been established as a bisabolane derivative and showed as I.The absolute configuration was determined by CD data.
1995, 6(5): 399-402
Abstract:
High performance liquid chromatography (HPLC)/electrospray mass spectrometry (ES MS) has been used to measure successfully the molecular weights of intact α and β chains of globin covaleutly modified with styrene oxide,having the molecular weight of xenobiotic moiety as 120 Da.The method also has revealed a variety of modified residues in the reacted hemoglobin after digestion with trypsin.
High performance liquid chromatography (HPLC)/electrospray mass spectrometry (ES MS) has been used to measure successfully the molecular weights of intact α and β chains of globin covaleutly modified with styrene oxide,having the molecular weight of xenobiotic moiety as 120 Da.The method also has revealed a variety of modified residues in the reacted hemoglobin after digestion with trypsin.
1995, 6(5): 403-406
Abstract:
The thermal decomposition of polyaniline (PAn) and poly-o-toluidine (POT) was studied by means of direct pyrolysis mass spectrometry (DPMS) and MS/MS.The results showed that both benzene-diamine and quinone-diimine units were produced,and the intensities of fragments corresponding to quinone-diimine units increased as the oxidation degrees increased.The mechanism of thermal decomposition of PAn and POT was given for the first time.
The thermal decomposition of polyaniline (PAn) and poly-o-toluidine (POT) was studied by means of direct pyrolysis mass spectrometry (DPMS) and MS/MS.The results showed that both benzene-diamine and quinone-diimine units were produced,and the intensities of fragments corresponding to quinone-diimine units increased as the oxidation degrees increased.The mechanism of thermal decomposition of PAn and POT was given for the first time.
1995, 6(5): 407-410
Abstract:
An efficient finite element method with a new type of trial function applied to Hartree-Fock-Stater calculations for molecular system is presented.The advantage of using new trial functions is that they are able to describe the cusplike behavior of molecular orbitals near location of atomic nuclei.The results calculated on the H2+ and H2 systems show that our approach is more practical and efficient than the traditional finite element method.
An efficient finite element method with a new type of trial function applied to Hartree-Fock-Stater calculations for molecular system is presented.The advantage of using new trial functions is that they are able to describe the cusplike behavior of molecular orbitals near location of atomic nuclei.The results calculated on the H2+ and H2 systems show that our approach is more practical and efficient than the traditional finite element method.
1995, 6(5): 411-414
Abstract:
In this letter ab initio electronic structure calculations are performed for extensive geometries of CS2.A newly written program is used to fit the computed energies into the Sorbie-Murrel function,whose contour plots are illustrated.
In this letter ab initio electronic structure calculations are performed for extensive geometries of CS2.A newly written program is used to fit the computed energies into the Sorbie-Murrel function,whose contour plots are illustrated.
1995, 6(5): 415-418
Abstract:
Cyclic voltammetric measurements were made on sodium dodecyl sulfate (SDS) in aqueous solutions using K4Fe (CN)5 as the electroactive probe and H2SO4 as the supporting electrolyte.Using extrapolation,we estimated the diffusion coefficient Dm,hydrodynamic radius Rm,aggregation number n,and the molecular weight of SDS micelles in aqueous solutions at various surfactant concentrations.The partition coefficients,KD,of the electroactive probe between micelle and water continuous phase were also estimated.
Cyclic voltammetric measurements were made on sodium dodecyl sulfate (SDS) in aqueous solutions using K4Fe (CN)5 as the electroactive probe and H2SO4 as the supporting electrolyte.Using extrapolation,we estimated the diffusion coefficient Dm,hydrodynamic radius Rm,aggregation number n,and the molecular weight of SDS micelles in aqueous solutions at various surfactant concentrations.The partition coefficients,KD,of the electroactive probe between micelle and water continuous phase were also estimated.
1995, 6(5): 419-420
Abstract:
A new solid polymer electrolyte has been prepared using NaClO4 and a comb-branch polymer with oligo (ethylene oxide) side chains.The thermal and ionic conductive properties of the electrolytes were investigated.The profile of conductivity at various temperatures follows the VTF plots.
A new solid polymer electrolyte has been prepared using NaClO4 and a comb-branch polymer with oligo (ethylene oxide) side chains.The thermal and ionic conductive properties of the electrolytes were investigated.The profile of conductivity at various temperatures follows the VTF plots.
1995, 6(5): 421-424
Abstract:
The direct electron transfer process of horse heart myoglobin,which was immobilized into a new type of cryo-hydrogel membrane ou a glassy carbon electrode surface,was studied and the characteristics of this cryo-hydrogel immobilized protein electrode were discussed.
The direct electron transfer process of horse heart myoglobin,which was immobilized into a new type of cryo-hydrogel membrane ou a glassy carbon electrode surface,was studied and the characteristics of this cryo-hydrogel immobilized protein electrode were discussed.
1995, 6(5): 425-428
Abstract:
Thin film electrodes of amorphous Ml-Ni (Ml=Mischmetal)alloy prepared by ion beam sputtering were investigated as cathodes for hydrogen evolution reaction in alkaline solution.The results show that the film cathodes of amorphous Ml-Ni alloy have good catalytic activity and excellent resistance to hydrogen embrittlement.
Thin film electrodes of amorphous Ml-Ni (Ml=Mischmetal)alloy prepared by ion beam sputtering were investigated as cathodes for hydrogen evolution reaction in alkaline solution.The results show that the film cathodes of amorphous Ml-Ni alloy have good catalytic activity and excellent resistance to hydrogen embrittlement.
1995, 6(5): 429-432
Abstract:
The influence of the dopant C60 on photoconductivity of zinc phthalocyanine (ZnPc) was examined.The results show that C60 doping can remarkably enhance the photoconductivity compared with the corresponding pure materials.The X-ray powder diffraction pattern and IR spectrum suggest that the enhancement of photoconductivity may be due to the polymorphic transformation and the change of molecular interaction in phthalocyanine composites,and a chargetransfer complex (CTC) of ZnPc with C60 may be formed.
The influence of the dopant C60 on photoconductivity of zinc phthalocyanine (ZnPc) was examined.The results show that C60 doping can remarkably enhance the photoconductivity compared with the corresponding pure materials.The X-ray powder diffraction pattern and IR spectrum suggest that the enhancement of photoconductivity may be due to the polymorphic transformation and the change of molecular interaction in phthalocyanine composites,and a chargetransfer complex (CTC) of ZnPc with C60 may be formed.
1995, 6(5): 433-436
Abstract:
The electron transfer between triethanolamine (TEOA) and methylviologen (MV2+) was photosensitized by water-soluble meeo-tetrakis (4-dimethylsulfonatopylanilino)porphyrins and meso-tetrakis (4-trimethylanilino) porphyrins excited in their triplet state by visible light in DMSO solution containing 20% V/V water at room temperature.The kinetic parameter A,photo-inductive time ti and initial reaction rate Vo are applied to measuring the photosensitivity of photosensitizers.
The electron transfer between triethanolamine (TEOA) and methylviologen (MV2+) was photosensitized by water-soluble meeo-tetrakis (4-dimethylsulfonatopylanilino)porphyrins and meso-tetrakis (4-trimethylanilino) porphyrins excited in their triplet state by visible light in DMSO solution containing 20% V/V water at room temperature.The kinetic parameter A,photo-inductive time ti and initial reaction rate Vo are applied to measuring the photosensitivity of photosensitizers.
1995, 6(5): 437-440
Abstract:
The stability constants of the binary complexes of Cu2+ with adenine and guanine as well as the ternary complexes of Cu (ATP) with the same ligands have been measured in aqueous solution spectrophotometrically and a strong stacking interaction between the heteroaromatic ring of the ligands and the purine moiety of ATP has been found.This stacking interaction may be one of the factors affecting the stability of the nucleic acid helices.
The stability constants of the binary complexes of Cu2+ with adenine and guanine as well as the ternary complexes of Cu (ATP) with the same ligands have been measured in aqueous solution spectrophotometrically and a strong stacking interaction between the heteroaromatic ring of the ligands and the purine moiety of ATP has been found.This stacking interaction may be one of the factors affecting the stability of the nucleic acid helices.
1995, 6(5): 441-442
Abstract:
ZrO2-supported Ru-Fe bimetallic clusters derived from Ru2 Fe (CO)12or RuFe2 (CO)12 displayed much higher activities in the hydrogenation of CO than that of mixed metal clusters or their monometallic clusters derived from Ru3 (CO)12 and Fe2(CO)9 and that of conventional catalysts prepared from RuCl3 and Fe(NO3)3.
ZrO2-supported Ru-Fe bimetallic clusters derived from Ru2 Fe (CO)12or RuFe2 (CO)12 displayed much higher activities in the hydrogenation of CO than that of mixed metal clusters or their monometallic clusters derived from Ru3 (CO)12 and Fe2(CO)9 and that of conventional catalysts prepared from RuCl3 and Fe(NO3)3.
1995, 6(5): 443-446
Abstract:
Titled catalysts applied to the selective oxidation of acrolein are characterized before and after the catalytic test by electron spin resonance,Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy.According to these results,we find that the active species of the catalysts is VO2+.
Titled catalysts applied to the selective oxidation of acrolein are characterized before and after the catalytic test by electron spin resonance,Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy.According to these results,we find that the active species of the catalysts is VO2+.
1995, 6(5): 447-448
Abstract:
Sealed-off carbon dioxide lasers encounter problem of dissociation of CO2,Which causes the output power to fall.Reformation of CO2 is therefore essential for long life CO2 lasers.Au/Fe2O3 and Au/NiFe2O4 are promising candidates for this application.
Sealed-off carbon dioxide lasers encounter problem of dissociation of CO2,Which causes the output power to fall.Reformation of CO2 is therefore essential for long life CO2 lasers.Au/Fe2O3 and Au/NiFe2O4 are promising candidates for this application.
1995, 6(5): 449-452
Abstract:
Emissions of europium(Ⅱ) and europium(Ⅲ) have been observed in SrMgF4:Eu and SrMgF4:Eu,Ce phosphors which are synthesized in Ar flow.It is notable that the intensity of the ESR peaks corresponding to Eu2+ is increased when cerium ion is incorporated which can be explained by electron transfer mechanism.
Emissions of europium(Ⅱ) and europium(Ⅲ) have been observed in SrMgF4:Eu and SrMgF4:Eu,Ce phosphors which are synthesized in Ar flow.It is notable that the intensity of the ESR peaks corresponding to Eu2+ is increased when cerium ion is incorporated which can be explained by electron transfer mechanism.
1995, 6(5): 453-454
Abstract:
A trivacant heteropolytungstate derivative P4W30Al4 (H2O)2O11330- has been synthesized from the lacunary precursor Na12[α-P2W15O56]·24H2O and characterized by IR.polarogram and 183W NMR spectrum.183W NMR of the title anion consists of eight lines with intensity ratio 1:2:2:2:2:2:2:2 as expected for the dimeric Dawson-typed anion with C2h symmetry.
A trivacant heteropolytungstate derivative P4W30Al4 (H2O)2O11330- has been synthesized from the lacunary precursor Na12[α-P2W15O56]·24H2O and characterized by IR.polarogram and 183W NMR spectrum.183W NMR of the title anion consists of eight lines with intensity ratio 1:2:2:2:2:2:2:2 as expected for the dimeric Dawson-typed anion with C2h symmetry.
