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1997 Volume 8 Issue 1
1997, 8(1): 1-4
Abstract:
A practical synthesis of trans-3,4-diol derivatives of substituted chromans via epoxidation with combined use of mangenese (Ⅲ) salen complex 3 and hydrogen peroxide has been developed.These diol derivatives are key intermediates for the synthesis of a series of biologically important chroman compounds.
A practical synthesis of trans-3,4-diol derivatives of substituted chromans via epoxidation with combined use of mangenese (Ⅲ) salen complex 3 and hydrogen peroxide has been developed.These diol derivatives are key intermediates for the synthesis of a series of biologically important chroman compounds.
1997, 8(1): 5-6
Abstract:
1H-Thiopyrano[3,4-b] quinolin-4(3H)-one 1,a new series of heterotricyclic ketone and their heterocycle fused compounds (2 and 3) were prepared by a simple procedure in good yields.
1H-Thiopyrano[3,4-b] quinolin-4(3H)-one 1,a new series of heterotricyclic ketone and their heterocycle fused compounds (2 and 3) were prepared by a simple procedure in good yields.
1997, 8(1): 7-8
Abstract:
The intramolecular reductive coupling reaction of 1,6-bis(substituted indolyl)hexane-1,6-dione using zero-valent titanium reagent as catalyst produces the novel photochromic 1,2-diheterocyclic cyclohexenes 2,together with unexpected compounds 3.
The intramolecular reductive coupling reaction of 1,6-bis(substituted indolyl)hexane-1,6-dione using zero-valent titanium reagent as catalyst produces the novel photochromic 1,2-diheterocyclic cyclohexenes 2,together with unexpected compounds 3.
1997, 8(1): 9-10
Abstract:
A series of new type of germasesquioxides.germatranes,and β-trichlorogermylpropionic acid derivatives containing α-amino group or α-aminophosphonyl group were synthesized by a convenient condensation reaction of β-trichlorogermyl propionyl chloride with α-amino acid esters or α-phosphonates in the presense of organic base.The structures of products were determined by 1HNMR.31PNMR,IR,MS,elemental analysis,and X-ray diffraction.
A series of new type of germasesquioxides.germatranes,and β-trichlorogermylpropionic acid derivatives containing α-amino group or α-aminophosphonyl group were synthesized by a convenient condensation reaction of β-trichlorogermyl propionyl chloride with α-amino acid esters or α-phosphonates in the presense of organic base.The structures of products were determined by 1HNMR.31PNMR,IR,MS,elemental analysis,and X-ray diffraction.
1997, 8(1): 11-12
Abstract:
The novel cyclic phosphate-phosphonates,cis/trans-2-phosphonobenzyloxy-4-aryl-5,5-dimethyl-1,3,2-dioxaphosphorinane 2-sulfides(selenides) (7a-f),were synthesized by a one-pot reaction using tris(diethylamino) phosphine activated by iodine as the phosphorylating and ring-closing reagent in good overall yields.The geometric stereoisomers were isolated and characterized.A cis-configuration and a chair preferred conformation of one isomer of 7b were established by X-ray diffraction analysis.
The novel cyclic phosphate-phosphonates,cis/trans-2-phosphonobenzyloxy-4-aryl-5,5-dimethyl-1,3,2-dioxaphosphorinane 2-sulfides(selenides) (7a-f),were synthesized by a one-pot reaction using tris(diethylamino) phosphine activated by iodine as the phosphorylating and ring-closing reagent in good overall yields.The geometric stereoisomers were isolated and characterized.A cis-configuration and a chair preferred conformation of one isomer of 7b were established by X-ray diffraction analysis.
1997, 8(1): 13-14
Abstract:
An efficient and stereoselective four step synthesis of (-)-Massoialactone (1) is described .The key step involves deoxygenation of one α,β-unsaturated carbonyl group in compound 5.
An efficient and stereoselective four step synthesis of (-)-Massoialactone (1) is described .The key step involves deoxygenation of one α,β-unsaturated carbonyl group in compound 5.
1997, 8(1): 15-16
Abstract:
An unexpected compound,hydroperoxide (4) formed from (3),the exo-cycloaddition product,which was synthesized through the Lewis acid catalyzed intramolecular Diels-Alder (IMDA) reaction.Its structure was confirmed by spectra and X-Ray diffraction analysis;An 1O2 oxidation mechanism was proposed.
An unexpected compound,hydroperoxide (4) formed from (3),the exo-cycloaddition product,which was synthesized through the Lewis acid catalyzed intramolecular Diels-Alder (IMDA) reaction.Its structure was confirmed by spectra and X-Ray diffraction analysis;An 1O2 oxidation mechanism was proposed.
1997, 8(1): 17-18
Abstract:
M.Stoll's total synthetic route for dl-muscone was improved. 2.15-Hexadecanedione was synthesized by PTC method.and converted into dehydromuscones through intramolecular aldol reaction by the mixture of zinc chloride and the Grinard reagent of isoamyl bromide used as condensing agent.Catalytic hydrogenation of dehydromuscones gave dl-muscone.
M.Stoll's total synthetic route for dl-muscone was improved. 2.15-Hexadecanedione was synthesized by PTC method.and converted into dehydromuscones through intramolecular aldol reaction by the mixture of zinc chloride and the Grinard reagent of isoamyl bromide used as condensing agent.Catalytic hydrogenation of dehydromuscones gave dl-muscone.
1997, 8(1): 19-20
Abstract:
(4R)-α-Terpineol,a natural product,was synthesized enantioselectively by an asymmetrical catalised Diels-Alder reaction from-1-phenylsulfonyl-3-buten-2-one with 2-methyl-1,3-butadiene.
(4R)-α-Terpineol,a natural product,was synthesized enantioselectively by an asymmetrical catalised Diels-Alder reaction from-1-phenylsulfonyl-3-buten-2-one with 2-methyl-1,3-butadiene.
1997, 8(1): 21-24
Abstract:
A novel one-pot synthesis of 4,5-bis(hydroxymethyl) imidazoles 2a-b,new ethers 3a-b and a new type of imidazolophane 4b by the bis-hydroxymethylation of imidazole or 2-methyl imidazole with formaldehyde and potassium hydroxide is reported.The structures of these compounds have been established by MS,1HNMR,IR and elemental analyses.
A novel one-pot synthesis of 4,5-bis(hydroxymethyl) imidazoles 2a-b,new ethers 3a-b and a new type of imidazolophane 4b by the bis-hydroxymethylation of imidazole or 2-methyl imidazole with formaldehyde and potassium hydroxide is reported.The structures of these compounds have been established by MS,1HNMR,IR and elemental analyses.
1997, 8(1): 25-26
Abstract:
Nor-ketoagarofuran (1),one of the furanoids isolated from agarowood oil,has been synthesized in a preparative scale in high yield from olefin 3 in 3 steps.Reaction of nor-ketoagarofuran (1) with CH3MgI afforded 4-hydroxydihydroagarofuran (2),another naturally occurring tetrahydrofuran derivative.
Nor-ketoagarofuran (1),one of the furanoids isolated from agarowood oil,has been synthesized in a preparative scale in high yield from olefin 3 in 3 steps.Reaction of nor-ketoagarofuran (1) with CH3MgI afforded 4-hydroxydihydroagarofuran (2),another naturally occurring tetrahydrofuran derivative.
1997, 8(1): 27-30
Abstract:
The stereocontrolled synthesis of 2,the structure proposed for villosol,was described.The synthetic work has shown that the proposed structure was incorrect.
The stereocontrolled synthesis of 2,the structure proposed for villosol,was described.The synthetic work has shown that the proposed structure was incorrect.
1997, 8(1): 31-34
Abstract:
The successful encapsulation of dysprosium(Dy) into fullerene cages by activating the Dy2O3 containing graphite rods in situ,"back-burning" carbon-arc evaporation with a high-yield of pyridine extraction technique is reported.
The successful encapsulation of dysprosium(Dy) into fullerene cages by activating the Dy2O3 containing graphite rods in situ,"back-burning" carbon-arc evaporation with a high-yield of pyridine extraction technique is reported.
1997, 8(1): 35-36
Abstract:
Two new amides,tataramide A (1) and tataramide B (2),were isolated from the roots of Acorus tatarinowii Schott.Their structures were determined by spectroscopic methods.
Two new amides,tataramide A (1) and tataramide B (2),were isolated from the roots of Acorus tatarinowii Schott.Their structures were determined by spectroscopic methods.
1997, 8(1): 37-38
Abstract:
Two new isopimarane diterpenes,tatarol (1) and tataroside (2) were isolated from the roots of Acorus tatarinowii Schott.Their structures were identified by spectral methods.
Two new isopimarane diterpenes,tatarol (1) and tataroside (2) were isolated from the roots of Acorus tatarinowii Schott.Their structures were identified by spectral methods.
1997, 8(1): 39-40
Abstract:
Tomentosin(1),a new C-glycosidic hydrolysable tannin,was isolated from the leaves of Rhodomyrtus tomentosa.Its structure was determined by chemical method and 1HNMR spectroscopic analysis.
Tomentosin(1),a new C-glycosidic hydrolysable tannin,was isolated from the leaves of Rhodomyrtus tomentosa.Its structure was determined by chemical method and 1HNMR spectroscopic analysis.
1997, 8(1): 41-42
Abstract:
From the aerial part of Hypericum japonicum Thunb.ex Murray,two new chromone glycosides,5,7-Dihydroxy-2-(1-methylpropyl) chromone-8-β-D-glucoside and 5,7-Dihydroxy-2-isopropylchromone-8-β-D-glucoside,were isolated and their structures were determined on basis of spectroscopic evidences.
From the aerial part of Hypericum japonicum Thunb.ex Murray,two new chromone glycosides,5,7-Dihydroxy-2-(1-methylpropyl) chromone-8-β-D-glucoside and 5,7-Dihydroxy-2-isopropylchromone-8-β-D-glucoside,were isolated and their structures were determined on basis of spectroscopic evidences.
1997, 8(1): 43-46
Abstract:
Two new flavonol glycosides,artabotryside A (1),artabotryside B (2),and three known flavonoids taxifolin (3),glucoluteolin (4) and apigenin-7-O-apiosyl (1→2) glucoside(5) were isolated from the leaves of Artabotrys hexapetalus (Annonaceae).The structures of 1 and 2 were established as quercetin-3-O-α-L-rhamnopyranosyl (1→2)-α-L-arabinofuranoside(1) and kaempferol-3-O-α-L-rhamnopyranosyl (1→2)-α-L-arabinofurano-side (2),on the bases of spectral analysis.
Two new flavonol glycosides,artabotryside A (1),artabotryside B (2),and three known flavonoids taxifolin (3),glucoluteolin (4) and apigenin-7-O-apiosyl (1→2) glucoside(5) were isolated from the leaves of Artabotrys hexapetalus (Annonaceae).The structures of 1 and 2 were established as quercetin-3-O-α-L-rhamnopyranosyl (1→2)-α-L-arabinofuranoside(1) and kaempferol-3-O-α-L-rhamnopyranosyl (1→2)-α-L-arabinofurano-side (2),on the bases of spectral analysis.
1997, 8(1): 47-48
Abstract:
The microbiological transformation of a natural taxoid,10-deacetylbaccatin Ⅲ into its C-7 epimer,10-deacetylbaccatin V with Microsphaeropsis onychiuri,a fungus isolated from the inner bark of Taxus yunnanensis is described.
The microbiological transformation of a natural taxoid,10-deacetylbaccatin Ⅲ into its C-7 epimer,10-deacetylbaccatin V with Microsphaeropsis onychiuri,a fungus isolated from the inner bark of Taxus yunnanensis is described.
1997, 8(1): 49-52
Abstract:
λ-DNA Hind Ⅲ was denatured by HCl,renatured by NaOH,and digested by DNase I sequentially.The produced mixture was separated with Sephadex G200 column,and the chromatograph showed a very weak peak of one component resistant to the digestion of DNase I.The results of AFM studies on this component indicated that an unusual form of DNA was present,with the height 13 times that of double-stranded DNA.By comparison with known results,it is suggested that this is a multi-stranded DNA other than simple supercoils.
λ-DNA Hind Ⅲ was denatured by HCl,renatured by NaOH,and digested by DNase I sequentially.The produced mixture was separated with Sephadex G200 column,and the chromatograph showed a very weak peak of one component resistant to the digestion of DNase I.The results of AFM studies on this component indicated that an unusual form of DNA was present,with the height 13 times that of double-stranded DNA.By comparison with known results,it is suggested that this is a multi-stranded DNA other than simple supercoils.
1997, 8(1): 53-56
Abstract:
In the presence of histidine.N-(O,O-diisopropyl) phosphoryl serine could catalyze the cleavage of RNA in aqueous solution at neutral pH.The results were detected by sub-marine agarose gel electrophoresis and capillary zone electrophoresis.It was found that at high cpncentration histidine could cleave the RNA slightly.While the participation of DIPP-Ser could significantly accelerate the cleavage reaction.N-phosphodipeptide-N-(O.O-diisopropyl) phosphoryl Ser-His are proposed to be involved in the mechanism.
In the presence of histidine.N-(O,O-diisopropyl) phosphoryl serine could catalyze the cleavage of RNA in aqueous solution at neutral pH.The results were detected by sub-marine agarose gel electrophoresis and capillary zone electrophoresis.It was found that at high cpncentration histidine could cleave the RNA slightly.While the participation of DIPP-Ser could significantly accelerate the cleavage reaction.N-phosphodipeptide-N-(O.O-diisopropyl) phosphoryl Ser-His are proposed to be involved in the mechanism.
1997, 8(1): 57-58
Abstract:
The binding of bromo-pyrogallol red (BPR) to proteins is accompanied by the enhancement of Rayleigh light scattering at 332nm.and based on this.a new quantitative protein assay method is put forward.
The binding of bromo-pyrogallol red (BPR) to proteins is accompanied by the enhancement of Rayleigh light scattering at 332nm.and based on this.a new quantitative protein assay method is put forward.
1997, 8(1): 59-60
Abstract:
The ion mobilities of selected amines were measured by IMS.The minimum detection limits and linear ranges of selected amines were detected.
The ion mobilities of selected amines were measured by IMS.The minimum detection limits and linear ranges of selected amines were detected.
1997, 8(1): 61-64
Abstract:
Adsorptive enhancements of several inorganic salts on copper(Ⅱ) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode.Increases in peak current of Cu(Ⅱ) were observed in alkaline phosphate or carbonate media owing to adsorption.Silicate can also enhance the peak current of Cu(Ⅱ).The enhancing power of phosphate,carbonate,and silicate is 33,26,and 8.9 times,respectively.
Adsorptive enhancements of several inorganic salts on copper(Ⅱ) were studied by adsorptive stripping voltammetry with a hanging mercury drop electrode.Increases in peak current of Cu(Ⅱ) were observed in alkaline phosphate or carbonate media owing to adsorption.Silicate can also enhance the peak current of Cu(Ⅱ).The enhancing power of phosphate,carbonate,and silicate is 33,26,and 8.9 times,respectively.
1997, 8(1): 65-66
Abstract:
A new rapid method for the analysis of chromate ion in water by using high performance capillary electrophoresis is described.The detection limit is 1.0 μg/ml by using 100 m mol/1 Tris-HCl buffer containing 2 m mol/l 1,6-hexanediamine which was used as an electroosmosis modifier to improve the separation and detection sensitivity.
A new rapid method for the analysis of chromate ion in water by using high performance capillary electrophoresis is described.The detection limit is 1.0 μg/ml by using 100 m mol/1 Tris-HCl buffer containing 2 m mol/l 1,6-hexanediamine which was used as an electroosmosis modifier to improve the separation and detection sensitivity.
1997, 8(1): 67-70
Abstract:
Based on the different hydrophobicities of the intermediates of proteins,the various conformational intermediates of the refolding of α-amylase originally denatured with 8.0 mol/L urea solution were separated with high performance hydrophobic interaction chromatography (HPHIC).Compared to the separation of the same intermediates with weak anion exchange chromatography and size-exclusion chromatography,the result obtained with HPHIC is the best.It would be expected that HPHIC may be a strongly potential tool to separate intermediates of some proteins which cannot be,or cannot completely be refolded by HPHIC.
Based on the different hydrophobicities of the intermediates of proteins,the various conformational intermediates of the refolding of α-amylase originally denatured with 8.0 mol/L urea solution were separated with high performance hydrophobic interaction chromatography (HPHIC).Compared to the separation of the same intermediates with weak anion exchange chromatography and size-exclusion chromatography,the result obtained with HPHIC is the best.It would be expected that HPHIC may be a strongly potential tool to separate intermediates of some proteins which cannot be,or cannot completely be refolded by HPHIC.
1997, 8(1): 71-72
Abstract:
Ab initio UHF/6-31G** method has been employed to study the mechanism of the thermal isomerization from 1,2-butadiene to 1,3-butadiene,The energies were corrected at MP2//6-31G**+ZPE(zero-point energy) level.The results indicate that it is a stepwise reaction via a radical intermediate .The calculated activation barriers are 65.01 and 64.16 kcal./mol.,respectively.
Ab initio UHF/6-31G** method has been employed to study the mechanism of the thermal isomerization from 1,2-butadiene to 1,3-butadiene,The energies were corrected at MP2//6-31G**+ZPE(zero-point energy) level.The results indicate that it is a stepwise reaction via a radical intermediate .The calculated activation barriers are 65.01 and 64.16 kcal./mol.,respectively.
1997, 8(1): 73-74
Abstract:
The effects of the nature of salts,salt concentration,pH value,degree of hydrolysis as well as surfactant on molecular size of HPAM were studied.It is found that [η] of HPAM changes with all the above variables,and the molecular weight of HPAM can be obtained through [η] measurement at a specific salts environment in which the [η] is independent of above factors.
The effects of the nature of salts,salt concentration,pH value,degree of hydrolysis as well as surfactant on molecular size of HPAM were studied.It is found that [η] of HPAM changes with all the above variables,and the molecular weight of HPAM can be obtained through [η] measurement at a specific salts environment in which the [η] is independent of above factors.
1997, 8(1): 75-78
Abstract:
The donor-acceptor complex HEC-TCNQ (HEC=9-hydroxyethylcarbazole;TCNQ=tetracyanoquinodimethane) has been synthesized.Under the illumination of Ar+ laser,the photoinduced charge transfer salt HEC+TCNQ- can be formed with a conductivity of at least one order of magnitude larger than that of HEC-TCNQ.
The donor-acceptor complex HEC-TCNQ (HEC=9-hydroxyethylcarbazole;TCNQ=tetracyanoquinodimethane) has been synthesized.Under the illumination of Ar+ laser,the photoinduced charge transfer salt HEC+TCNQ- can be formed with a conductivity of at least one order of magnitude larger than that of HEC-TCNQ.
1997, 8(1): 79-80
Abstract:
Double-layer organic electroluminescent devices have been constructed.A new fluorescent dye,9,10-bis(phenylethynyl) anthracence,was chosen as the dopant which was molecularly dispersed in the polymer film,and green light was observed from the device with luminance of 130cd/m2 at 17V.
Double-layer organic electroluminescent devices have been constructed.A new fluorescent dye,9,10-bis(phenylethynyl) anthracence,was chosen as the dopant which was molecularly dispersed in the polymer film,and green light was observed from the device with luminance of 130cd/m2 at 17V.
1997, 8(1): 81-82
Abstract:
Seven new boronic acid adducts of technetium(Ⅲ) tris(dioxime) (BATO) were prepared and the biodistribution in mice of 99mTc labelled BATOs were determined.The uptake of 1.62% ID in mice heart at 2 min after injection of 99mTcCl(MeCDO)3BMe indicates high myocardial extraction of this BATO.99mTcCl(MeCDO)3BMe shows promise as a myocardial perfusion imaging agent.
Seven new boronic acid adducts of technetium(Ⅲ) tris(dioxime) (BATO) were prepared and the biodistribution in mice of 99mTc labelled BATOs were determined.The uptake of 1.62% ID in mice heart at 2 min after injection of 99mTcCl(MeCDO)3BMe indicates high myocardial extraction of this BATO.99mTcCl(MeCDO)3BMe shows promise as a myocardial perfusion imaging agent.
1997, 8(1): 83-86
Abstract:
Sm2O3-LaF3 and BaF2 promoted Sm2O3-LaF3 catalysts shown good catalytic performance for the Oxidative Dehydrogenation of Ethane(ODE).XRD and XPS characterizations of the catalysts show the structure defects,which may be produced by the partial exchange of anions and cations,enhance the electron donating ability and increase the surface adsorbed oxygen concentration,thus should be favorable to improve the catalytic activity.However,the higher concentration of surface adsorbed oxygen is unfavorable for the ethene selectivity.
Sm2O3-LaF3 and BaF2 promoted Sm2O3-LaF3 catalysts shown good catalytic performance for the Oxidative Dehydrogenation of Ethane(ODE).XRD and XPS characterizations of the catalysts show the structure defects,which may be produced by the partial exchange of anions and cations,enhance the electron donating ability and increase the surface adsorbed oxygen concentration,thus should be favorable to improve the catalytic activity.However,the higher concentration of surface adsorbed oxygen is unfavorable for the ethene selectivity.
1997, 8(1): 87-90
Abstract:
Yoon's equation which predicted point of zero charge of complex oxide should predict the zero point of net charge (ZPNC) of mixture of variable and permanent charge rather than the point of zero charge (PZC) of the variable charge component.The calculated values with modified Yoon's equation agreed with the experimental values.
Yoon's equation which predicted point of zero charge of complex oxide should predict the zero point of net charge (ZPNC) of mixture of variable and permanent charge rather than the point of zero charge (PZC) of the variable charge component.The calculated values with modified Yoon's equation agreed with the experimental values.
1997, 8(1): 91-94
Abstract:
The atomic weight of samarium was redetermined as Ar(Sm)=150.3661(2).Application of substitute calibration using the true isotopic ratio of Eu151/153 results in Ar(Sm)=150.3740(10).A summary is given including the results for other five rare earth elements.
The atomic weight of samarium was redetermined as Ar(Sm)=150.3661(2).Application of substitute calibration using the true isotopic ratio of Eu151/153 results in Ar(Sm)=150.3740(10).A summary is given including the results for other five rare earth elements.
