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1991 Volume 2 Issue 5
1991, 2(5): 345-346
Abstract:
Enantiomerically pure syn-4,5-dihydroxy carboxylic acid lactones were prepared by microbial reduction of acyl lactones with resting cell of Aspergillus niger.
Enantiomerically pure syn-4,5-dihydroxy carboxylic acid lactones were prepared by microbial reduction of acyl lactones with resting cell of Aspergillus niger.
1991, 2(5): 347-348
Abstract:
Perfluoroalkylbenzo crown ethers were readily prepared from the reaction of benzo crown ethers with sodium perfluoroalkanesulfinates in the presence of an oxidizing agent such as Ce(SO4)2 or Mn(OAc)3·2H2O in good yields through a radical process.
Perfluoroalkylbenzo crown ethers were readily prepared from the reaction of benzo crown ethers with sodium perfluoroalkanesulfinates in the presence of an oxidizing agent such as Ce(SO4)2 or Mn(OAc)3·2H2O in good yields through a radical process.
1991, 2(5): 349-350
Abstract:
A series of substituted chiral benzhydrols were synthesized by the reaction of aromatic aldehydes with chiral intermediates formed from chiral titanates and arylmagnesium halides.
A series of substituted chiral benzhydrols were synthesized by the reaction of aromatic aldehydes with chiral intermediates formed from chiral titanates and arylmagnesium halides.
1991, 2(5): 351-352
Abstract:
Reductive coupling of aromatic nitriles 1 by titanium tetrachloride/zinc provides an efficient general synthesis of 1,2-arylethanones.
Reductive coupling of aromatic nitriles 1 by titanium tetrachloride/zinc provides an efficient general synthesis of 1,2-arylethanones.
1991, 2(5): 353-356
Abstract:
α-Oxo ketene dithioacetals 2 via 1,2-nucleophilie addition by methallyl magnesium chloride afforded corresponding alcohols (3). Treated with water or methanol and catalyzed by Lewis acid, the alcohols 3 were converted regiospecifically to substituted phenols 5'or related phenol methyl ethers 5 respectively. This reaction is a novel approach to the synthesis of phenols and their derivatives starting from non-aromatic precursors.
α-Oxo ketene dithioacetals 2 via 1,2-nucleophilie addition by methallyl magnesium chloride afforded corresponding alcohols (3). Treated with water or methanol and catalyzed by Lewis acid, the alcohols 3 were converted regiospecifically to substituted phenols 5'or related phenol methyl ethers 5 respectively. This reaction is a novel approach to the synthesis of phenols and their derivatives starting from non-aromatic precursors.
1991, 2(5): 357-358
Abstract:
A simple method for synthesis of benoxazole crown ether cyanine dyes is described.
A simple method for synthesis of benoxazole crown ether cyanine dyes is described.
1991, 2(5): 359-360
Abstract:
9-Chlorofluorene reacted with aromatic aldehydes and ketones in the presence of phase transfer catalyst, giving the Darzens conden-sation epoxy products.
9-Chlorofluorene reacted with aromatic aldehydes and ketones in the presence of phase transfer catalyst, giving the Darzens conden-sation epoxy products.
1991, 2(5): 361-362
Abstract:
Treatment of denudatine 1 with 10% HCl soln. at 45-50℃ for 3 days leads to a pair of epimers 4A and 4B, Structures of 4A and 4B have been elucidated on the basis of chemical and spectral methods.
Treatment of denudatine 1 with 10% HCl soln. at 45-50℃ for 3 days leads to a pair of epimers 4A and 4B, Structures of 4A and 4B have been elucidated on the basis of chemical and spectral methods.
1991, 2(5): 363-364
Abstract:
The reactions of denudatine 1 and diacetyldenudatine 2 with NBS-50% HOAc soln. afforded 4 and 6, respectively, in high yields.Treatment of 6 with (Ac)2CO-Pyr. gives 7. The structures of 3,6 and 7 were deduced on the basis of spectral and chemical methods.
The reactions of denudatine 1 and diacetyldenudatine 2 with NBS-50% HOAc soln. afforded 4 and 6, respectively, in high yields.Treatment of 6 with (Ac)2CO-Pyr. gives 7. The structures of 3,6 and 7 were deduced on the basis of spectral and chemical methods.
1991, 2(5): 365-368
Abstract:
The modified Hofmann degradation of koumine(1) has proved abortive. The struture and stereochemistry of the main product(3) were deduced by spectral methods and confirmed by X-ray diffration analysis. From the roots of Gelsemium elegans, dihydrokounine was first isolated as a natural product.
The modified Hofmann degradation of koumine(1) has proved abortive. The struture and stereochemistry of the main product(3) were deduced by spectral methods and confirmed by X-ray diffration analysis. From the roots of Gelsemium elegans, dihydrokounine was first isolated as a natural product.
1991, 2(5): 369-370
Abstract:
Two new alkaloids, maistemonine and oxymaistemonine were isolated from the roots of Stemona mairei collected from Yunnan Province, southwest of China. Their structures were elucidated by 2D-NMR techniques including 1H-1H COSY, 13C-1H-COSY, NOESY and other spectral analyses.
Two new alkaloids, maistemonine and oxymaistemonine were isolated from the roots of Stemona mairei collected from Yunnan Province, southwest of China. Their structures were elucidated by 2D-NMR techniques including 1H-1H COSY, 13C-1H-COSY, NOESY and other spectral analyses.
1991, 2(5): 371-372
Abstract:
A nco-clcrodane diterpcne, teuponin, was isolated from the aerial parts of Teucrium japonicum. Its structure was established as (12S)-19-nor-neo-clcroda-15α-hydroxy-4,13-diene-16,15;18,6β;20,12-triolide by spcctroscopic means. The absolute configuration was determined by X-ray diffraction analysis and CD spectrum.
A nco-clcrodane diterpcne, teuponin, was isolated from the aerial parts of Teucrium japonicum. Its structure was established as (12S)-19-nor-neo-clcroda-15α-hydroxy-4,13-diene-16,15;18,6β;20,12-triolide by spcctroscopic means. The absolute configuration was determined by X-ray diffraction analysis and CD spectrum.
1991, 2(5): 373-374
Abstract:
Two new compounds, ergostan-3.24-diol(4) and 2-hydroxy-lappaol B(8) along with twelve known compounds have been isolated fron the aerial parts of Sanssurea gossypiphora D.Don. Their structures have been elucidated by spectral analysis and chealcal aethods.
Two new compounds, ergostan-3.24-diol(4) and 2-hydroxy-lappaol B(8) along with twelve known compounds have been isolated fron the aerial parts of Sanssurea gossypiphora D.Don. Their structures have been elucidated by spectral analysis and chealcal aethods.
1991, 2(5): 375-376
Abstract:
Two new compounds have been isolated from methanol extract of roots of Pulsatilla chinensis(Bunge) Hegel. Their structures were established as 3-oxo-23-hydroxy-lup-20(29)-en-28-oic acid (Ⅱ) and 3-0-α-L-arabinopyranosyl-3β, 23-dihydroxy-lup-20(29)-en-28-oic acid (Ⅲ).
Two new compounds have been isolated from methanol extract of roots of Pulsatilla chinensis(Bunge) Hegel. Their structures were established as 3-oxo-23-hydroxy-lup-20(29)-en-28-oic acid (Ⅱ) and 3-0-α-L-arabinopyranosyl-3β, 23-dihydroxy-lup-20(29)-en-28-oic acid (Ⅲ).
1991, 2(5): 377-380
Abstract:
A new diterpene glucoside with an ent-kaurene skeleton was isolated from Isodon parvifolia(Butalin)Hara. Its structure (1) was established by spectrbscopic and chemical methods.
A new diterpene glucoside with an ent-kaurene skeleton was isolated from Isodon parvifolia(Butalin)Hara. Its structure (1) was established by spectrbscopic and chemical methods.
1991, 2(5): 381-382
Abstract:
In this paper the absorption spectra of Nd-SXO-CPC complex by 4f electron tran-sitions have been studied by zero-order and fourth-order derivative spectrophotometry. The molar absorptivity is 2.6×103 1.mol-1·cm-1 at 585 nm, the fourth-order derivative molar absorptivity is 1.4×104 1.mol-1·cm-1 at 584.5(-) and 587(+) nm. They are 300 times and 1600 times greater than those of the chloride, respectively.
In this paper the absorption spectra of Nd-SXO-CPC complex by 4f electron tran-sitions have been studied by zero-order and fourth-order derivative spectrophotometry. The molar absorptivity is 2.6×103 1.mol-1·cm-1 at 585 nm, the fourth-order derivative molar absorptivity is 1.4×104 1.mol-1·cm-1 at 584.5(-) and 587(+) nm. They are 300 times and 1600 times greater than those of the chloride, respectively.
1991, 2(5): 383-386
Abstract:
A new way for the synthesis of human interferon-αA monoclonal antibody (IFN-αA-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling efficiency and specific activity of IFN-αA-McAb can be obtained by activated diol-silica gel with activating agent. After purification using this packing material in HPAFC, the specific activity of recombinant human interferon-αA (rIFN-αA) rose up to 1.03×107IU/mg protein and the purification efficiency is appoximately 100 times.
A new way for the synthesis of human interferon-αA monoclonal antibody (IFN-αA-McAb) bound to silica gel packing material in high-performance affinity chromatography (HPAFC) has been developed. The high coupling efficiency and specific activity of IFN-αA-McAb can be obtained by activated diol-silica gel with activating agent. After purification using this packing material in HPAFC, the specific activity of recombinant human interferon-αA (rIFN-αA) rose up to 1.03×107IU/mg protein and the purification efficiency is appoximately 100 times.
1991, 2(5): 387-390
Abstract:
To investigate the aroma components characteristic of roasted green tea and fresh tea leaves the aroma concentrate was obtained by distillation and then extraction[1,2]. The aroma concentrate was treated under various experimental conditions. 70 and 52 aroma components were identified in roasted green tea and fresh tea leaves respectively.
To investigate the aroma components characteristic of roasted green tea and fresh tea leaves the aroma concentrate was obtained by distillation and then extraction[1,2]. The aroma concentrate was treated under various experimental conditions. 70 and 52 aroma components were identified in roasted green tea and fresh tea leaves respectively.
1991, 2(5): 391-392
Abstract:
A new method of assessing ginseng and screening its bioactive constituents by fuzzy pattern recognition has been proposed.
A new method of assessing ginseng and screening its bioactive constituents by fuzzy pattern recognition has been proposed.
1991, 2(5): 393-396
Abstract:
Glycerides are first separated to classes of triglycerides(TGs), diglycerides(DGs) and monoglycerides(MGs) by normal phase HPLC on silica gel column. Individual triglyceride separation is then achieved by non-aqueous reversed phase(NARP) HPLC on C18 column with UV detection at 215nm.
Glycerides are first separated to classes of triglycerides(TGs), diglycerides(DGs) and monoglycerides(MGs) by normal phase HPLC on silica gel column. Individual triglyceride separation is then achieved by non-aqueous reversed phase(NARP) HPLC on C18 column with UV detection at 215nm.
1991, 2(5): 397-398
Abstract:
The 2E spectra and substituent effects and target gas pressure dependence of the 2E spectra of 7 biphenyl derivatives were discussed. The electron-donating groups favour the molecular ions, but the electron withdrawing groups favour the fragaent ions produced by losing the substituents from molecular ions. The variation of target gas pressure affects the TIC,sample ion current,and the ratio of sample ion current to TIC sharply.However it has no effect on the fragmentation pattern.
The 2E spectra and substituent effects and target gas pressure dependence of the 2E spectra of 7 biphenyl derivatives were discussed. The electron-donating groups favour the molecular ions, but the electron withdrawing groups favour the fragaent ions produced by losing the substituents from molecular ions. The variation of target gas pressure affects the TIC,sample ion current,and the ratio of sample ion current to TIC sharply.However it has no effect on the fragmentation pattern.
1991, 2(5): 399-400
Abstract:
A ligand-field calculation has been performed on laser crystal LiNdP4O12 with C2v point group. The parameters of ligand field of this crystal is obtained and discussed. The calculated Stark sublevels are in good agreement with the enperimental values within 6.7 cm-1.
A ligand-field calculation has been performed on laser crystal LiNdP4O12 with C2v point group. The parameters of ligand field of this crystal is obtained and discussed. The calculated Stark sublevels are in good agreement with the enperimental values within 6.7 cm-1.
1991, 2(5): 401-402
Abstract:
The kinetics of the reaction of [Ni(PnAO)-6H]° with formaldehyde was studied in H2O-CH3OH solution under neutral condition and a complicated mechanism with three steps including competitive, consecutive and reverse reactions was proposed.
The kinetics of the reaction of [Ni(PnAO)-6H]° with formaldehyde was studied in H2O-CH3OH solution under neutral condition and a complicated mechanism with three steps including competitive, consecutive and reverse reactions was proposed.
1991, 2(5): 403-404
Abstract:
The electronic structure and bonding nature of adsorbing bonding complexes which consist of Amphoteric Collector-I and Mg2+, Ca2+, MgPO4-, CaPO4-, CaCO3, as well aa MgCO3, are studied using quantum chemistry CNDO/2, It is predicted that magnesium salts are more liable to form adsorbing chelates with Amphoteric Collector-I than calcium salts, and all results coincide with that obtained in flotation
The electronic structure and bonding nature of adsorbing bonding complexes which consist of Amphoteric Collector-I and Mg2+, Ca2+, MgPO4-, CaPO4-, CaCO3, as well aa MgCO3, are studied using quantum chemistry CNDO/2, It is predicted that magnesium salts are more liable to form adsorbing chelates with Amphoteric Collector-I than calcium salts, and all results coincide with that obtained in flotation
1991, 2(5): 405-406
Abstract:
This paper establishes a new model for calculation of the standard entropies of solid binary oxides as follows:S298θ=27.07×Φ1+1.120×Φ2+n1×k×Φ3-22.19 e.u (R=0.9960) We have invesigated 103 binary oxides. and found good agreemenl between estimated and experimental entropies.
This paper establishes a new model for calculation of the standard entropies of solid binary oxides as follows:S298θ=27.07×Φ1+1.120×Φ2+n1×k×Φ3-22.19 e.u (R=0.9960) We have invesigated 103 binary oxides. and found good agreemenl between estimated and experimental entropies.
1991, 2(5): 407-410
Abstract:
Five samples of the indium material were examined for the isotopic abundance, and no variation was found. The isotopic ratio R191/193 was precisely measured by thermal ionization mass spectrometry, yielding a new value of the atomic weight of indium, which after correc-tion for the vaporization effect is 114.8185±0.0002.
Five samples of the indium material were examined for the isotopic abundance, and no variation was found. The isotopic ratio R191/193 was precisely measured by thermal ionization mass spectrometry, yielding a new value of the atomic weight of indium, which after correc-tion for the vaporization effect is 114.8185±0.0002.
1991, 2(5): 411-414
Abstract:
The preparation method of H4Mo8O26-polyaniline film modified electrode and its voltammetric behaviour are described. The modified electrode has high electrocatalytic activity on chlorate ions.
The preparation method of H4Mo8O26-polyaniline film modified electrode and its voltammetric behaviour are described. The modified electrode has high electrocatalytic activity on chlorate ions.
1991, 2(5): 415-418
Abstract:
The effect of substituting silver for barium on the structure and superconducting properties of YBa2Cu3O7-y has been studied. The structure of the silver-doping system (YBa2-xAgxCu3O7-y) with x<0.3 is orthorhombic. For x>0.3, YBCO, Y2BaCuO5 phase and metallic silver ro-exist in the system. The superconducting transition temperature Tc(R=0) decrease with increasing silver content. However, the critic current density Jc is found to be enhanced from 56.6 A/cm2 to 195 A/cm2
The effect of substituting silver for barium on the structure and superconducting properties of YBa2Cu3O7-y has been studied. The structure of the silver-doping system (YBa2-xAgxCu3O7-y) with x<0.3 is orthorhombic. For x>0.3, YBCO, Y2BaCuO5 phase and metallic silver ro-exist in the system. The superconducting transition temperature Tc(R=0) decrease with increasing silver content. However, the critic current density Jc is found to be enhanced from 56.6 A/cm2 to 195 A/cm2
1991, 2(5): 419-422
Abstract:
A three-component enzyme system that catalyzes in vivo the oxidation of CH4 to CH3OH has been purified with high specific activity from an unusual type I methanotroph through the use of stabilizing reagents.
A three-component enzyme system that catalyzes in vivo the oxidation of CH4 to CH3OH has been purified with high specific activity from an unusual type I methanotroph through the use of stabilizing reagents.
