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1998 Volume 9 Issue 11
1998, 9(11): 979-982
Abstract:
The reaction of α-triazolyl-α, β-unsaturated ketones with phenyl hydrazine was studied. The result indicated that cyclization took place and new heterocyclic compounds of substituted 4,5-2H-pyrazoles were obtained, whose structures and conformation were characterized by 1H NMR, IR, MS, elemental analysis and X-ray diffraction.
The reaction of α-triazolyl-α, β-unsaturated ketones with phenyl hydrazine was studied. The result indicated that cyclization took place and new heterocyclic compounds of substituted 4,5-2H-pyrazoles were obtained, whose structures and conformation were characterized by 1H NMR, IR, MS, elemental analysis and X-ray diffraction.
1998, 9(11): 983-985
Abstract:
Lewis acid catalyzed cycloaddition reactions of N-arylideneaniline I with 2,3-dihydrofuran Ⅱ gave a pair of epimers dl-2, 3,3a, 4,5, 9b-hexahydro-4-arylfuro [3,2-c] quinolines Ⅲ and Ⅲ') and a few of their corresponding aromatized compounds Ⅳ.
Lewis acid catalyzed cycloaddition reactions of N-arylideneaniline I with 2,3-dihydrofuran Ⅱ gave a pair of epimers dl-2, 3,3a, 4,5, 9b-hexahydro-4-arylfuro [3,2-c] quinolines Ⅲ and Ⅲ') and a few of their corresponding aromatized compounds Ⅳ.
1998, 9(11): 987-988
Abstract:
A chiral building block, anti-l,3-diol 2,has been synthesized in 7 steps, starting from readily available and inexpensive D-(+)-xylose.
A chiral building block, anti-l,3-diol 2,has been synthesized in 7 steps, starting from readily available and inexpensive D-(+)-xylose.
1998, 9(11): 989-992
Abstract:
A series of stable semi-ketals were obtained via the reactions of 3',5'-0-(tetraisopropyldisiloxane-l, 3-diyl)-2'-ketouridine 1 with primary alcohols. In the addition reaction, only a single diastereomer was observed. The configuration of 3b was confirmed by X-ray diffraction.
A series of stable semi-ketals were obtained via the reactions of 3',5'-0-(tetraisopropyldisiloxane-l, 3-diyl)-2'-ketouridine 1 with primary alcohols. In the addition reaction, only a single diastereomer was observed. The configuration of 3b was confirmed by X-ray diffraction.
1998, 9(11): 993-996
Abstract:
A diester-calix [4]crown-4-ether bearing mono (azophenol) moiety shows a larger spectral change toward Ca2+ than other alkali and alkaline earth cations.
A diester-calix [4]crown-4-ether bearing mono (azophenol) moiety shows a larger spectral change toward Ca2+ than other alkali and alkaline earth cations.
1998, 9(11): 997-998
Abstract:
A series of new ω-azolylalkenes 3 were synthesized by N-alkylation of obromoalkenes 2 which were obtained by Witting reaction of o-hydroxyalkylphosphonium bromide with aromatic aldehydes and subsequent bromination. The structures of products were confirmed by 1HNMR, IR, MS and elemental analysis. The preliminary bioassay indicated that some of them had high fungicidal activities.
A series of new ω-azolylalkenes 3 were synthesized by N-alkylation of obromoalkenes 2 which were obtained by Witting reaction of o-hydroxyalkylphosphonium bromide with aromatic aldehydes and subsequent bromination. The structures of products were confirmed by 1HNMR, IR, MS and elemental analysis. The preliminary bioassay indicated that some of them had high fungicidal activities.
1998, 9(11): 999-1002
Abstract:
The stereoselective synthesis of (-)-slafrarninc has been achieved by utilizing the Sharplcss asymmetric epoxidation of divinylcarbinol (2) and the regio-selcctive dihydroxylation of compound 4 as the key steps.
The stereoselective synthesis of (-)-slafrarninc has been achieved by utilizing the Sharplcss asymmetric epoxidation of divinylcarbinol (2) and the regio-selcctive dihydroxylation of compound 4 as the key steps.
1998, 9(11): 1003-1004
Abstract:
We have synthesized two natural products, resveratrol I and isorhapotigcnin Ⅱ by 8 and 7 step reaction sequence, respectively. The synthetic products I and Ⅱ were characterized by IR, MS, 1H-NMR in comparison with the corresponding natural products.
We have synthesized two natural products, resveratrol I and isorhapotigcnin Ⅱ by 8 and 7 step reaction sequence, respectively. The synthetic products I and Ⅱ were characterized by IR, MS, 1H-NMR in comparison with the corresponding natural products.
1998, 9(11): 1005-1006
Abstract:
In order to explain the high activity of N-phosphoryl-α-amino acids, ab initio and MNDO calculations are performed to study the reaction pathway of the intermediate formation from N-dimethylphosphoryl-a-alanine (DMP-α-Ala) and the structures and energies involved in the reaction.
In order to explain the high activity of N-phosphoryl-α-amino acids, ab initio and MNDO calculations are performed to study the reaction pathway of the intermediate formation from N-dimethylphosphoryl-a-alanine (DMP-α-Ala) and the structures and energies involved in the reaction.
1998, 9(11): 1007-1008
Abstract:
The mechanism and kinetics for the decomposition of 3-hydroxy-3-methyl-2-butanone have been studied by using the ab initio RHF/3-21G method. The calculated activation barrier of the reaction is 249.6kJ/mol which is in reasonable agreement with the experimental data (222.2±3kJ/mol). The calculated results show that the decomposition is a concerted process with hydrogen transferring and bond breaking via a five-membered cyclic transition state. The thermal rate constants of the decomposition are obtained by calculating microcanonical probability fluxes through transition state1.
The mechanism and kinetics for the decomposition of 3-hydroxy-3-methyl-2-butanone have been studied by using the ab initio RHF/3-21G method. The calculated activation barrier of the reaction is 249.6kJ/mol which is in reasonable agreement with the experimental data (222.2±3kJ/mol). The calculated results show that the decomposition is a concerted process with hydrogen transferring and bond breaking via a five-membered cyclic transition state. The thermal rate constants of the decomposition are obtained by calculating microcanonical probability fluxes through transition state1.
1998, 9(11): 1009-1012
Abstract:
An ab initio computation of reorganization energy for the electron transfer reactions between metal atom-benzene and ion-benzene complexes is presented by using of both the George-Griffith-Marcus (GGM) method and Hessian matrix method. The results suggest that the coupling interactions between different vibrational modes are very important to caclculation the inner sphere reorganization energy for electron transfer reactions in gaseous phase.
An ab initio computation of reorganization energy for the electron transfer reactions between metal atom-benzene and ion-benzene complexes is presented by using of both the George-Griffith-Marcus (GGM) method and Hessian matrix method. The results suggest that the coupling interactions between different vibrational modes are very important to caclculation the inner sphere reorganization energy for electron transfer reactions in gaseous phase.
1998, 9(11): 1013-1015
Abstract:
A pair of dimeric stilbenes, gnetifolin M and gnetifolin N were isolated from the lianas of Gnetum montanum. All attempts to separate them by HPLC were unsuccessful. Their structures were elucidated by the spectroscopic analysis including 2D-NMR studies on the peracetate.
A pair of dimeric stilbenes, gnetifolin M and gnetifolin N were isolated from the lianas of Gnetum montanum. All attempts to separate them by HPLC were unsuccessful. Their structures were elucidated by the spectroscopic analysis including 2D-NMR studies on the peracetate.
1998, 9(11): 1017-1020
Abstract:
Two new baccatin Ⅲ type taxoids, 13-Cinnamoylbaccatin Ⅲ (1) and 7-xylosylbaccatin Ⅲ (2), have been isolated from the barks of Taxus yunnanensis. The structures were elucidated by spectral means.
Two new baccatin Ⅲ type taxoids, 13-Cinnamoylbaccatin Ⅲ (1) and 7-xylosylbaccatin Ⅲ (2), have been isolated from the barks of Taxus yunnanensis. The structures were elucidated by spectral means.
1998, 9(11): 1021-1024
Abstract:
Four new diterpenoids, baiyecrystals A-C and epi-baiyecrystal C,were isolated from I. leucophylla. Their structures were determined by means of spectral methods as 1-4.
Four new diterpenoids, baiyecrystals A-C and epi-baiyecrystal C,were isolated from I. leucophylla. Their structures were determined by means of spectral methods as 1-4.
1998, 9(11): 1025-1028
Abstract:
Three new diterpenoids, eriocalyxins C-E, were isolated from Isodon eriocalyx. Their structures were elucidated as 6β-hydroxy-15β-acetoxy-3α, 20-epoxy-16β, 17-epoxy-ent-kaur-1, 7-dione; la, 7β-dihydroxy-6β, 15β-diacetoxy-7, 20-epoxy-ent-kaur-16-ene; and 15β-acetoxy-l, 6-dioxo-6, 7-seco-ent-kaur-2, 16-dien-7, 20-olide by means of spectroscopic methods, including two-dimensional NMR techniques.
Three new diterpenoids, eriocalyxins C-E, were isolated from Isodon eriocalyx. Their structures were elucidated as 6β-hydroxy-15β-acetoxy-3α, 20-epoxy-16β, 17-epoxy-ent-kaur-1, 7-dione; la, 7β-dihydroxy-6β, 15β-diacetoxy-7, 20-epoxy-ent-kaur-16-ene; and 15β-acetoxy-l, 6-dioxo-6, 7-seco-ent-kaur-2, 16-dien-7, 20-olide by means of spectroscopic methods, including two-dimensional NMR techniques.
1998, 9(11): 1029-1032
Abstract:
Three new alkaloids, griffithclionc 1,griffiazanonc A 2 and griffiazanone B 3 were isolated from the rhizomes of Goniothalcimus griffithii Hook. F. et. Thorns. Their structures were elucidated by analysis the spectral data (IR, UV, MS, 1H and 13C NMR, HMBC, NOE experiment). The absolute configuration of griffithazanonc A 2 was determined by Mosher's methods.
Three new alkaloids, griffithclionc 1,griffiazanonc A 2 and griffiazanone B 3 were isolated from the rhizomes of Goniothalcimus griffithii Hook. F. et. Thorns. Their structures were elucidated by analysis the spectral data (IR, UV, MS, 1H and 13C NMR, HMBC, NOE experiment). The absolute configuration of griffithazanonc A 2 was determined by Mosher's methods.
1998, 9(11): 1033-1034
Abstract:
Stability and luminescence properties of Tb (Ⅲ) complexes with adrenaline have been studied. The Tb (Ⅲ) complexes with adrenaline are quite stable. The fluorescence spectra of the Tb (Ⅲ) complexes with adrenaline show the characteristic fluorescence bands of Tb (Ⅲ) ions which are attributed to energy transfer from ligands to Tb (Ⅲ) ions.
Stability and luminescence properties of Tb (Ⅲ) complexes with adrenaline have been studied. The Tb (Ⅲ) complexes with adrenaline are quite stable. The fluorescence spectra of the Tb (Ⅲ) complexes with adrenaline show the characteristic fluorescence bands of Tb (Ⅲ) ions which are attributed to energy transfer from ligands to Tb (Ⅲ) ions.
1998, 9(11): 1035-1038
Abstract:
Homogeneous liposome immunoassay for the determination of phenytoin was studied. Liposomes were prepared from cholesterol (CH) and phospholipids including dipalmitoyl phosphatidyl ethanolamine (DPPE) for conjugation with thiol-containing antibodies. Hemin chloride was entrapped in the liposome and antibody was modified by reaction with 3-(2-pyridyl-dithio) propionyl N-hydroxysuccinimidc ester (SPDP) to introduce thiol groups for efficient coupling. Antibody-coupled liposomes (immunoliposomes) were incubated with phenytoin and complement, and then with hemin substrate. The amount of hemin released from immunoliposomes, which increases with concentration increase of phenytoin, can be detected rapidly by determining the fluorescence with its substrate p-hydroxyphenyl propionic acid (HPPA) and hydrogen peroxide.
Homogeneous liposome immunoassay for the determination of phenytoin was studied. Liposomes were prepared from cholesterol (CH) and phospholipids including dipalmitoyl phosphatidyl ethanolamine (DPPE) for conjugation with thiol-containing antibodies. Hemin chloride was entrapped in the liposome and antibody was modified by reaction with 3-(2-pyridyl-dithio) propionyl N-hydroxysuccinimidc ester (SPDP) to introduce thiol groups for efficient coupling. Antibody-coupled liposomes (immunoliposomes) were incubated with phenytoin and complement, and then with hemin substrate. The amount of hemin released from immunoliposomes, which increases with concentration increase of phenytoin, can be detected rapidly by determining the fluorescence with its substrate p-hydroxyphenyl propionic acid (HPPA) and hydrogen peroxide.
1998, 9(11): 1039-1041
Abstract:
Multilayers of glucose oxidase (GOD)/N-ethyl-poly (4-vinyl) pyridine (EPVP) have been assembled on thiol self-assembled monolayers on gold electrode. Tliis electrode can be used as an amperometric enzyme electrode for glucosc. Fe (CN)63_/4_ incorporated in EPVP layer acts as the electron mediator, the linear range was 0.1 to 6mmol/L when the number of GOD layers was 5.
Multilayers of glucose oxidase (GOD)/N-ethyl-poly (4-vinyl) pyridine (EPVP) have been assembled on thiol self-assembled monolayers on gold electrode. Tliis electrode can be used as an amperometric enzyme electrode for glucosc. Fe (CN)63_/4_ incorporated in EPVP layer acts as the electron mediator, the linear range was 0.1 to 6mmol/L when the number of GOD layers was 5.
1998, 9(11): 1043-1044
Abstract:
Microemulsion electrokinetic chromatography (MEEKC) was developed for the separation of hydrophobic neutral compounds. The effects of core phase and co-surfactant on the separations were investigated. Under the selected condition, good resolutions were obtained for the test mixtures. The separation efficiencies were higher than 105 theoretical plates per metre.
Microemulsion electrokinetic chromatography (MEEKC) was developed for the separation of hydrophobic neutral compounds. The effects of core phase and co-surfactant on the separations were investigated. Under the selected condition, good resolutions were obtained for the test mixtures. The separation efficiencies were higher than 105 theoretical plates per metre.
1998, 9(11): 1045-1048
Abstract:
Monodisperse poly (chloromethylstyrene divinylbenzene) particles were prepared by a two-step swelling method. It was demonstrated that the packings have comparative advantages for biopolymer separation with high column efficiency, low interstitial volume and low back pressure to the packings prepared with suspension polymerization method. Using size exclusion chromatography and weak ion exchange chromatography as examples, it was shown that these packings could be modified chemically more easily than poly (styrene divinylbenzene) packings.
Monodisperse poly (chloromethylstyrene divinylbenzene) particles were prepared by a two-step swelling method. It was demonstrated that the packings have comparative advantages for biopolymer separation with high column efficiency, low interstitial volume and low back pressure to the packings prepared with suspension polymerization method. Using size exclusion chromatography and weak ion exchange chromatography as examples, it was shown that these packings could be modified chemically more easily than poly (styrene divinylbenzene) packings.
Relationship between the Conformation and Enzyme Activity of Commercial and Purified Glucose Oxidase
1998, 9(11): 1049-1050
Abstract:
Relationship between the conformation and enzyme activity of the commercial and purified GOD have been studied. Both enzyme activity and value of α/β of purified GOD in water solution and LB film were higher than that of commercial GOD.
Relationship between the conformation and enzyme activity of the commercial and purified GOD have been studied. Both enzyme activity and value of α/β of purified GOD in water solution and LB film were higher than that of commercial GOD.
1998, 9(11): 1051-1054
Abstract:
Inclusion of β-cyclodextrin (β-CD) with phenothiazine 1 and N-alkylpheno-thiazine derivatives (alkyl=ethyl 2, isobutyl 3 and isopentyl 4) in aqueous solution was studied by means of UV-vis spectroscopy. The association constant Ka values for the inclusion of β-CD with 1,2, 3 and 4 were determined to be 188, 214, 129 and 80 L/mol, respectively. It indicates that the stability of the inclusion complexes is dependent on the structure and the volume of the substituents in the guest compounds.
Inclusion of β-cyclodextrin (β-CD) with phenothiazine 1 and N-alkylpheno-thiazine derivatives (alkyl=ethyl 2, isobutyl 3 and isopentyl 4) in aqueous solution was studied by means of UV-vis spectroscopy. The association constant Ka values for the inclusion of β-CD with 1,2, 3 and 4 were determined to be 188, 214, 129 and 80 L/mol, respectively. It indicates that the stability of the inclusion complexes is dependent on the structure and the volume of the substituents in the guest compounds.
1998, 9(11): 1055-1058
Abstract:
Beginning from the formation of amorphous alloy film and its use of promise, this paper obtains the Ni-S amorphous alloy film by electroplating method using a bath containing Na2S2O3, and considers the deposition conditions in detail. The composition of Ni-S alloy film changes with the cathodic current density, Na2S2O3 content in the bath solution and bath pH, but the structure of the film is determined by the sulphur content in the deposit. X-ray diffraction (XRD) patterns show that films containing about 15-30% sulphur consist of amorphous alloy. In addition, the process of Ni-S alloy film deposition and the relation between the plating conditions and deposits were studied.
Beginning from the formation of amorphous alloy film and its use of promise, this paper obtains the Ni-S amorphous alloy film by electroplating method using a bath containing Na2S2O3, and considers the deposition conditions in detail. The composition of Ni-S alloy film changes with the cathodic current density, Na2S2O3 content in the bath solution and bath pH, but the structure of the film is determined by the sulphur content in the deposit. X-ray diffraction (XRD) patterns show that films containing about 15-30% sulphur consist of amorphous alloy. In addition, the process of Ni-S alloy film deposition and the relation between the plating conditions and deposits were studied.
1998, 9(11): 1059-1062
Abstract:
The interesting phenopmena of two aqueous phases coexisting in dilute aqueous solutions of sodium undecenoate-dodecyltrimethylammonium bromide mixture and sodium laurate-dodecyltrimethylammonium bromide mixture were investigated. Vesicles existing in both phases were shown by TEM images. The vesicles are dispersed in lower phase and flocculated in upper phase. Multilamellar structure of vesicles was found in the upper phase of sodium laurate-dodecyltrimethylammonium bromide system.
The interesting phenopmena of two aqueous phases coexisting in dilute aqueous solutions of sodium undecenoate-dodecyltrimethylammonium bromide mixture and sodium laurate-dodecyltrimethylammonium bromide mixture were investigated. Vesicles existing in both phases were shown by TEM images. The vesicles are dispersed in lower phase and flocculated in upper phase. Multilamellar structure of vesicles was found in the upper phase of sodium laurate-dodecyltrimethylammonium bromide system.
1998, 9(11): 1063-1066
Abstract:
Bond covalency, bond susceptibility and macroscopic linear susceptibility in NdCr1-x. xMxO3 (M=Mn, Fe, Co, 0.0 ≤ x ≤ 1.0) are investigated by complex chemical bond theory. The results indicate the bond covalencies are insensitive to the doping level. With the increasing doping level, the macroscopic linear susceptibilities increase for M=Mn, Fe, decrease for M=Co. The valence state of Cr can be strongly influenced by the properties of the doping ions.
Bond covalency, bond susceptibility and macroscopic linear susceptibility in NdCr1-x. xMxO3 (M=Mn, Fe, Co, 0.0 ≤ x ≤ 1.0) are investigated by complex chemical bond theory. The results indicate the bond covalencies are insensitive to the doping level. With the increasing doping level, the macroscopic linear susceptibilities increase for M=Mn, Fe, decrease for M=Co. The valence state of Cr can be strongly influenced by the properties of the doping ions.
1998, 9(11): 1067-1068
Abstract:
The complex of sodium perrhenate with ester derivative of calix [4] arene having the stoichiometric formula [NaL]ReO4·H20, was prepared. The X-ray structure analysis revealed that the sodium ion is coordinated to four ether and four carbonyl oxygen atoms giving a coordination number of eight with a tetragonal antiprism configuration. The complex cation [NaL]+ and anion ReO4- are linked by electrostatic attraction.
The complex of sodium perrhenate with ester derivative of calix [4] arene having the stoichiometric formula [NaL]ReO4·H20, was prepared. The X-ray structure analysis revealed that the sodium ion is coordinated to four ether and four carbonyl oxygen atoms giving a coordination number of eight with a tetragonal antiprism configuration. The complex cation [NaL]+ and anion ReO4- are linked by electrostatic attraction.
1998, 9(11): 1069-1072
Abstract:
Copper (Ⅱ) α-methacrylate reacts with triphenylphosphine to form mixed-valence copper (Ⅰ,Ⅱ) complex Cu4 (CH2=C(CH3)COO)6 (PPh3)4 (CH3OH)2 in methanol solution. The crystal and molecular structure of the complex has been determined by single crystal X-ray structural analysis. This material forms pale green crystals with triclinic symmetry, space group Pi, a=1.3567(2) nm, b=1.3946(3)nm, c=1.4569(3)nm, α=66.069(14)°,β=84.234(14)°, γ=69.975 (13)°, R=0.0536.
Copper (Ⅱ) α-methacrylate reacts with triphenylphosphine to form mixed-valence copper (Ⅰ,Ⅱ) complex Cu4 (CH2=C(CH3)COO)6 (PPh3)4 (CH3OH)2 in methanol solution. The crystal and molecular structure of the complex has been determined by single crystal X-ray structural analysis. This material forms pale green crystals with triclinic symmetry, space group Pi, a=1.3567(2) nm, b=1.3946(3)nm, c=1.4569(3)nm, α=66.069(14)°,β=84.234(14)°, γ=69.975 (13)°, R=0.0536.
