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1998 Volume 9 Issue 6
1998, 9(6): 509-512
Abstract:
U.V. irradiation of N, N-dimethylaniline (DMA) in the presence of 7,7-dichloronorcarane (DCN) in acetonitrile solution produces N-methylaniline, 4,4'-methylenebis-(N,N-dimethyIaniline), N-(4'-N',N'-dimethylaminobenzyl)-N-methylaniline and 7-chloronorcarane as the major products. A photoinduced electron transfer mechanism is proposed.
U.V. irradiation of N, N-dimethylaniline (DMA) in the presence of 7,7-dichloronorcarane (DCN) in acetonitrile solution produces N-methylaniline, 4,4'-methylenebis-(N,N-dimethyIaniline), N-(4'-N',N'-dimethylaminobenzyl)-N-methylaniline and 7-chloronorcarane as the major products. A photoinduced electron transfer mechanism is proposed.
1998, 9(6): 513-514
Abstract:
Stereospecific (trans) and regioselective nucleophilic opening of the title epoxide (Ⅰ) by different amines at the alumina surface are described.
Stereospecific (trans) and regioselective nucleophilic opening of the title epoxide (Ⅰ) by different amines at the alumina surface are described.
1998, 9(6): 515-517
Abstract:
A diazafulleroid derivative with adjacent 5-6 junctions has been synthesized by the regioselective addition of 1,2-di(azidomethyl) benzene to [60]fullerene. Reaction of [60]fullerene with 1,4-di(azidomethyl) benzene in refluxing chlorobenzene gave a copolymer.
A diazafulleroid derivative with adjacent 5-6 junctions has been synthesized by the regioselective addition of 1,2-di(azidomethyl) benzene to [60]fullerene. Reaction of [60]fullerene with 1,4-di(azidomethyl) benzene in refluxing chlorobenzene gave a copolymer.
1998, 9(6): 519-520
Abstract:
A new synthesis of 1-(ω-haloalkyl)-imidazole has been developed. The synthesis involves a Hoffmann-type elimination of the 2-cyanoethyl group from imidazolium salts obtained by the reaction of α,ω-dihalide with 1-(2-cyanoethyl)-imidazole.
A new synthesis of 1-(ω-haloalkyl)-imidazole has been developed. The synthesis involves a Hoffmann-type elimination of the 2-cyanoethyl group from imidazolium salts obtained by the reaction of α,ω-dihalide with 1-(2-cyanoethyl)-imidazole.
1998, 9(6): 521-522
Abstract:
Microwave irradiation can accelerate the rate of the synthetic reaction of α,β-unsaturated ketones by using KF-Al203 as catalyst. The rate enhancement of the reaction is 360-860 fold.
Microwave irradiation can accelerate the rate of the synthetic reaction of α,β-unsaturated ketones by using KF-Al203 as catalyst. The rate enhancement of the reaction is 360-860 fold.
1998, 9(6): 523-526
Abstract:
The cleavage and formation of the disulfide bond of 2,5-dimercapto-l,3,4-thiadiazole (DMcT) were examined in an aqueous solution of pH value from 0 to 14 with and without polyaniline (PAn). The redox reaction of DMcT was accelerated by PAn in acidic condition. The cell using this anodic material was set-up and characterized in aqueous electrolyte.
The cleavage and formation of the disulfide bond of 2,5-dimercapto-l,3,4-thiadiazole (DMcT) were examined in an aqueous solution of pH value from 0 to 14 with and without polyaniline (PAn). The redox reaction of DMcT was accelerated by PAn in acidic condition. The cell using this anodic material was set-up and characterized in aqueous electrolyte.
1998, 9(6): 527-528
Abstract:
Four 1,2,3,4-tetrahydro-β-carboline amino acid esters with a heterocycle at the C-l position were used as chiral ligands in the enantioselective addition reactions. The different positions of the heteroatoms gave different effects, and medium but opposite enantioselectivity was recorded.
Four 1,2,3,4-tetrahydro-β-carboline amino acid esters with a heterocycle at the C-l position were used as chiral ligands in the enantioselective addition reactions. The different positions of the heteroatoms gave different effects, and medium but opposite enantioselectivity was recorded.
1998, 9(6): 529-531
Abstract:
We synthesized a series of hydrazones, a novel type of nitrogen-containing prostaglandins, from different aromatic hydrazines and variant 2-substituted amino-3-hydroxy bicyclo [3.2.0]hept-6-ones Ⅳ.
We synthesized a series of hydrazones, a novel type of nitrogen-containing prostaglandins, from different aromatic hydrazines and variant 2-substituted amino-3-hydroxy bicyclo [3.2.0]hept-6-ones Ⅳ.
1998, 9(6): 533-536
Abstract:
the acetate of a novel phenolic glycoside, 1-0-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyloxy-3-hydroxy-5-methylbenzene, anacardoside, from the fruits of Semecarpus anacardium，and its diastereomer were first synthesized using Koenigs-Knorr method from D-glucose through six steps with total yields 33% and 16% respectively.
the acetate of a novel phenolic glycoside, 1-0-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyloxy-3-hydroxy-5-methylbenzene, anacardoside, from the fruits of Semecarpus anacardium，and its diastereomer were first synthesized using Koenigs-Knorr method from D-glucose through six steps with total yields 33% and 16% respectively.
1998, 9(6): 537-538
Abstract:
A new isoflavone glucoside, 3'-methoxy-5'-hydroxy-isoflavone-7-0-β-D-glucoside, was isolated from the roots of Astragalus membranaceus and its structure was elucidated by spectroscopic data.
A new isoflavone glucoside, 3'-methoxy-5'-hydroxy-isoflavone-7-0-β-D-glucoside, was isolated from the roots of Astragalus membranaceus and its structure was elucidated by spectroscopic data.
1998, 9(6): 539-540
Abstract:
A new antifungal antibiotics, WA, was isolated from the secondary metabolites of soil fungus strain 38，and its structure was elucidated as 4-(2-hydroxy-3-butynoxy)benzoic acid by means of the spectral data (1H-and 13C-NMR, DEPT, 1H-1H COSY, 1H-13C COSY, HMBC).
A new antifungal antibiotics, WA, was isolated from the secondary metabolites of soil fungus strain 38，and its structure was elucidated as 4-(2-hydroxy-3-butynoxy)benzoic acid by means of the spectral data (1H-and 13C-NMR, DEPT, 1H-1H COSY, 1H-13C COSY, HMBC).
1998, 9(6): 541-543
Abstract:
Eucaglobulin 1,a new complex of gallotannin and monoterpene, was isolated from the leaves of Eucalyptus globulus. Its structure was determined by spectral methods.
Eucaglobulin 1,a new complex of gallotannin and monoterpene, was isolated from the leaves of Eucalyptus globulus. Its structure was determined by spectral methods.
1998, 9(6): 545-547
Abstract:
A new bisabolane sesquiterpene was isolated from Cremanthodium discoideum. The structure was elucidated by spectroscopic methods including the 2D-NMR technique.
A new bisabolane sesquiterpene was isolated from Cremanthodium discoideum. The structure was elucidated by spectroscopic methods including the 2D-NMR technique.
1998, 9(6): 549-552
Abstract:
The biliary metabolites of orally administered icariin in rats were investigated. Two metabolites B-l and B-2 were isolated and identified as icaritin 3-0-α-L-rhamnopyranosyl-7-0-β-D-glucopyranuronoside and icariside Ⅱ，respectively, on the basis of chemical and spectroscopic evidences.
The biliary metabolites of orally administered icariin in rats were investigated. Two metabolites B-l and B-2 were isolated and identified as icaritin 3-0-α-L-rhamnopyranosyl-7-0-β-D-glucopyranuronoside and icariside Ⅱ，respectively, on the basis of chemical and spectroscopic evidences.
1998, 9(6): 553-556
Abstract:
The chemical ionization mass spectra of ten different glucosinolates isolated from rape seed have been studied. More intense diagnostic ions were identified than in the electron impact mass spectra. The method is suitable for the structure analysis of mixture of glucosinolates.
The chemical ionization mass spectra of ten different glucosinolates isolated from rape seed have been studied. More intense diagnostic ions were identified than in the electron impact mass spectra. The method is suitable for the structure analysis of mixture of glucosinolates.
1998, 9(6): 557-560
Abstract:
This paper reports a polarographic catalytic wave of lysozyme (LE) in the presence of KI03. The mechanism of the catalytic wave was discussed. It is illustrated by the catalytic wave of LE that, besides the Brdicka current, there exists a new kind of catalytic wave of protein.
This paper reports a polarographic catalytic wave of lysozyme (LE) in the presence of KI03. The mechanism of the catalytic wave was discussed. It is illustrated by the catalytic wave of LE that, besides the Brdicka current, there exists a new kind of catalytic wave of protein.
1998, 9(6): 561-563
Abstract:
A simple method was developed to quantify DNA fragments such as PCR (polymerase chain reaction) products by capillary electrophoresis. Restraint fragments with different lengths were employed as internal standards in the study, which makes it possible for the evaluation of the quantity of PCR product in a single run.
A simple method was developed to quantify DNA fragments such as PCR (polymerase chain reaction) products by capillary electrophoresis. Restraint fragments with different lengths were employed as internal standards in the study, which makes it possible for the evaluation of the quantity of PCR product in a single run.
1998, 9(6): 565-568
Abstract:
Cyclodextrin-modified CZE was applied to the chiral separation of two basic drugs, i.e., esmolol and terazosin. Selector screening and concentration optimization experiments were performed. Resolution 3.1 for esmolol, 1.2 for terazosin were achieved when using 60 mmol/L γ-CD and 60 mmol/L DM-β-CD, respectively, in 50 mmol/L pH 2.5 sodium phosphate buffer.
Cyclodextrin-modified CZE was applied to the chiral separation of two basic drugs, i.e., esmolol and terazosin. Selector screening and concentration optimization experiments were performed. Resolution 3.1 for esmolol, 1.2 for terazosin were achieved when using 60 mmol/L γ-CD and 60 mmol/L DM-β-CD, respectively, in 50 mmol/L pH 2.5 sodium phosphate buffer.
1998, 9(6): 569-571
Abstract:
A novel, simple and convenient method for the determination of hydroxyl radicals is established. Hydroxyl radicals produced by Fenton reaction is trapped by spin trap reagent phenyl-t-butyl nitrone (PBN), and the free radical adduct of PBN can be detected by single sweep oscillopolarography, with its second order derivative cathodic wave at -0.52V vs SCE. The optimum experimental conditions for the determination is discussed, and the scavenging effects of some compounds on OH was also studied.
A novel, simple and convenient method for the determination of hydroxyl radicals is established. Hydroxyl radicals produced by Fenton reaction is trapped by spin trap reagent phenyl-t-butyl nitrone (PBN), and the free radical adduct of PBN can be detected by single sweep oscillopolarography, with its second order derivative cathodic wave at -0.52V vs SCE. The optimum experimental conditions for the determination is discussed, and the scavenging effects of some compounds on OH was also studied.
1998, 9(6): 573-575
Abstract:
The mixed LB film of mono crown ether substituted phthalocyanine (CPc) and potassium picrate (PiK) were prepared by adding potassium picrate in subphase. The π-A isotherms show that the addition of PiK in subphase increases the orientation angles of phthalocyanine in monolayers. The absorption spectra revealed that the monolayer can be transferred to substrates easily. X-ray diffraction results show that the mixed film possesses the same thickness as that of pure phthalocyanine film.
The mixed LB film of mono crown ether substituted phthalocyanine (CPc) and potassium picrate (PiK) were prepared by adding potassium picrate in subphase. The π-A isotherms show that the addition of PiK in subphase increases the orientation angles of phthalocyanine in monolayers. The absorption spectra revealed that the monolayer can be transferred to substrates easily. X-ray diffraction results show that the mixed film possesses the same thickness as that of pure phthalocyanine film.
1998, 9(6): 577-578
Abstract:
Neodymium phosphonate [Nd(P204)3] combined by di(n-butyl) magnesium [Mg(n-Bu)2] with hexamethylphosphoramide (HMPA) was first found to be an effective catalyst. The results of infrared spectrum and elemental analysis showed that the copolymers containing carbonyl group were produced.
Neodymium phosphonate [Nd(P204)3] combined by di(n-butyl) magnesium [Mg(n-Bu)2] with hexamethylphosphoramide (HMPA) was first found to be an effective catalyst. The results of infrared spectrum and elemental analysis showed that the copolymers containing carbonyl group were produced.
1998, 9(6): 579-581
Abstract:
Molybdenum nitride powder with 115m2g-1 of Sg has been prepared by a temperature programmed reaction of MoO3 in H2/N2 mixture. It exhibited high catalytic activity in CO oxidation at low temperatures. DTA in airflow showed that the crystal phase of Mo2N was maintained under 500℃. The suitable operation temperature is below 500℃ in CO oxidation.
Molybdenum nitride powder with 115m2g-1 of Sg has been prepared by a temperature programmed reaction of MoO3 in H2/N2 mixture. It exhibited high catalytic activity in CO oxidation at low temperatures. DTA in airflow showed that the crystal phase of Mo2N was maintained under 500℃. The suitable operation temperature is below 500℃ in CO oxidation.
1998, 9(6): 583-586
Abstract:
Ab initio calculations based on density functional theory have been used to study the decompsition of N2O on MgO. The reaction is predicted to occur on 03c and O4c atoms, but not on 05c atoms, with an activation barrier of 25-27 kcal/mol, in agreement with the experimental value of 35 kcal/mol. Natural bond orbital analysis shows that the reaction leaves O ad-atoms on those surface O anions to form a peroxide-like "022-" species. The O-O bond stretching frequency is predicted to be in the range from 820 cm-1 to 825 cm-1.
Ab initio calculations based on density functional theory have been used to study the decompsition of N2O on MgO. The reaction is predicted to occur on 03c and O4c atoms, but not on 05c atoms, with an activation barrier of 25-27 kcal/mol, in agreement with the experimental value of 35 kcal/mol. Natural bond orbital analysis shows that the reaction leaves O ad-atoms on those surface O anions to form a peroxide-like "022-" species. The O-O bond stretching frequency is predicted to be in the range from 820 cm-1 to 825 cm-1.
1998, 9(6): 587-590
Abstract:
The miscibility, crystallization behavior and morphological structure of PHB/PMA blends have been studied by the differential scanning calorimeter (DSC) and polarized optical microscopy (POM). The chemical repeat units of the two components of the blend are isomers. The results indicate that PHB and PMA are miscible in the melt. The addition of PMA into PHB results in a depression in the spherulite growth rate of PHB. With increasing PMA content in the blends, the texture of PHB spherulite becomes more open.
The miscibility, crystallization behavior and morphological structure of PHB/PMA blends have been studied by the differential scanning calorimeter (DSC) and polarized optical microscopy (POM). The chemical repeat units of the two components of the blend are isomers. The results indicate that PHB and PMA are miscible in the melt. The addition of PMA into PHB results in a depression in the spherulite growth rate of PHB. With increasing PMA content in the blends, the texture of PHB spherulite becomes more open.
1998, 9(6): 591-593
Abstract:
Dicyclopentadiene was polymerized by reaction injection molding (RIM) using a catalyst system based on molybdenum (Ⅴ) chloride and anhydrous aluminum chloride and triethylaluminum. The effect of the reaction temperature on the polymer network and the type of the polymerization were discussed.
Dicyclopentadiene was polymerized by reaction injection molding (RIM) using a catalyst system based on molybdenum (Ⅴ) chloride and anhydrous aluminum chloride and triethylaluminum. The effect of the reaction temperature on the polymer network and the type of the polymerization were discussed.
1998, 9(6): 595-597
Abstract:
The vinylidene-bridged cluster μ3-FcCHCFeCo2(CO)9 2 was prepared by the expansion reaction of ferrocenyl-acetylene dicobalt complex μ-FcCCHCo2(CO)6 1. Benzylideneacetone-tricarbonyliron [(BDA)Fe(CO)3] was used as the source of Fe(CO)3. The molecular structure of the cluster 2 was determined by x-ray structural analysis.
The vinylidene-bridged cluster μ3-FcCHCFeCo2(CO)9 2 was prepared by the expansion reaction of ferrocenyl-acetylene dicobalt complex μ-FcCCHCo2(CO)6 1. Benzylideneacetone-tricarbonyliron [(BDA)Fe(CO)3] was used as the source of Fe(CO)3. The molecular structure of the cluster 2 was determined by x-ray structural analysis.
1998, 9(6): 599-602
Abstract:
The crystal structure of the title ligand and its copper(Ⅱ) complex was determined by single crystal X-ray diffraction, The electrochemical properties and the third-order nonlinear optical response of the ligand and its copper (Ⅱ) complex were also studied.
The crystal structure of the title ligand and its copper(Ⅱ) complex was determined by single crystal X-ray diffraction, The electrochemical properties and the third-order nonlinear optical response of the ligand and its copper (Ⅱ) complex were also studied.
