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2001 Volume 12 Issue 4
2001, 12(4): 283-286
Abstract:
CO2 adducts of L-(+)-asparaginic acid and some polyhydroxylated alkaloids was studied by 1HNMR and 13CNMR in this paper.
CO2 adducts of L-(+)-asparaginic acid and some polyhydroxylated alkaloids was studied by 1HNMR and 13CNMR in this paper.
Dehalogenation of Aryl Halides Catalyzed by MontK10 Immobilized PVP-Pd-Sn Catalyst in Aqueous System
2001, 12(4): 287-290
Abstract:
A series of PVP-Pd-Sn/MontK10 catalysts were prepared by immobilization of PVP [poly (N-vinyl-2-pyrrolidone)] supported bimetallic catalyst using MontK10 as carrier. This catalyst has good catalytic activity for hydrogen transfer dehalogenation of aryl halides. The catalytic reaction was carried out in aqueous system in the presence of phase transfer catalyst and sodium formate as hydrogen source. The catalyst with loading Pd 0.19wt% and molar ratio of Pd/Sn 8:1 gives the highest activity and good stability. This catalyst is more reducible with NaBH4. It is also found that the catalyst is easily separated from the reaction system.
A series of PVP-Pd-Sn/MontK10 catalysts were prepared by immobilization of PVP [poly (N-vinyl-2-pyrrolidone)] supported bimetallic catalyst using MontK10 as carrier. This catalyst has good catalytic activity for hydrogen transfer dehalogenation of aryl halides. The catalytic reaction was carried out in aqueous system in the presence of phase transfer catalyst and sodium formate as hydrogen source. The catalyst with loading Pd 0.19wt% and molar ratio of Pd/Sn 8:1 gives the highest activity and good stability. This catalyst is more reducible with NaBH4. It is also found that the catalyst is easily separated from the reaction system.
2001, 12(4): 291-292
Abstract:
Baker's Yeast mediated reduction of optically active diketone has been described.
Baker's Yeast mediated reduction of optically active diketone has been described.
2001, 12(4): 293-296
Abstract:
1,4-Addition reaction of Grignard's reagent to 5-methoxy-2 (5H)-furanone 1 was accomplished, which provided a new possible route for synthesizing β-alkyl-γ-alkyloxy-γ-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.
1,4-Addition reaction of Grignard's reagent to 5-methoxy-2 (5H)-furanone 1 was accomplished, which provided a new possible route for synthesizing β-alkyl-γ-alkyloxy-γ-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.
2001, 12(4): 297-300
Abstract:
An efficient synthetic route has developed to the antitumor compound salvicine via 9 steps from ferruginol. The key reaction is the rearrangement of the angular methyl group of compound 7 to 4,5-seco-5,10,-friedo-abieta diterpene 8.
An efficient synthetic route has developed to the antitumor compound salvicine via 9 steps from ferruginol. The key reaction is the rearrangement of the angular methyl group of compound 7 to 4,5-seco-5,10,-friedo-abieta diterpene 8.
2001, 12(4): 301-304
Abstract:
Some known and new hexaaryloxyphosphazene N3P3 (O-C6H4-R)6] (R=H, CH3, OCH3, C(CH3)3, CHO, F, C6H5COOR, etc) were readily obtained with ca. 70% isolated yield in refluxing acetonitrile in the presence of anhydrous potassium phosphate. All compounds were characterized by means of elemental analysis,1H-NMR,31P-NMR spectroscopy.
Some known and new hexaaryloxyphosphazene N3P3 (O-C6H4-R)6] (R=H, CH3, OCH3, C(CH3)3, CHO, F, C6H5COOR, etc) were readily obtained with ca. 70% isolated yield in refluxing acetonitrile in the presence of anhydrous potassium phosphate. All compounds were characterized by means of elemental analysis,1H-NMR,31P-NMR spectroscopy.
2001, 12(4): 305-306
Abstract:
The enzymatic resolution of racemic methyl 3-phenylglycidate was investigated. It was found that the hydrolysis rate of (2S, 3R)-enantiomer was faster than that of (2R, 3S)-enantiomer by a new lipase. At optimal condition 96% of (2R, 3S)-methyl phenylglycidate with ee of 100% was recovered from the racemic mixture.
The enzymatic resolution of racemic methyl 3-phenylglycidate was investigated. It was found that the hydrolysis rate of (2S, 3R)-enantiomer was faster than that of (2R, 3S)-enantiomer by a new lipase. At optimal condition 96% of (2R, 3S)-methyl phenylglycidate with ee of 100% was recovered from the racemic mixture.
2001, 12(4): 307-308
Abstract:
A series of aromatic imines were reduced to corresponding amines in excellent yields by 2-phenyl-N, N-dimethylbenzimidazoline (PDMBI) photochemically in the presence of magnesium perchloride (Mg(ClO4)2). A Mg2+ mediated photoinduced electron transfer mechanism was proposed.
A series of aromatic imines were reduced to corresponding amines in excellent yields by 2-phenyl-N, N-dimethylbenzimidazoline (PDMBI) photochemically in the presence of magnesium perchloride (Mg(ClO4)2). A Mg2+ mediated photoinduced electron transfer mechanism was proposed.
2001, 12(4): 309-312
Abstract:
The photoisomerization of provitamin D3 is carried out in silica gel-hexane matrix, ethanol and hexane. The results show that in silica gel-hexane matrix and ethanol, the desired product of prevtamin D3 and vitamin D3 can be obtained in high yield, while the undesirable byproducts are greatly limited.
The photoisomerization of provitamin D3 is carried out in silica gel-hexane matrix, ethanol and hexane. The results show that in silica gel-hexane matrix and ethanol, the desired product of prevtamin D3 and vitamin D3 can be obtained in high yield, while the undesirable byproducts are greatly limited.
2001, 12(4): 313-316
Abstract:
The oligouridylates formation with N-(O,O-diisopropyl)-phosphoryl alanine in the presence of poly(β-(N7-adeninyl)ethyl methacrylate) was studied. An increased yield by the presence of the polymeric nucleic acid analog was confirmed by anion exchange column HPLC, C18 reverse phase HPLC, and turbo ionspray MS.
The oligouridylates formation with N-(O,O-diisopropyl)-phosphoryl alanine in the presence of poly(β-(N7-adeninyl)ethyl methacrylate) was studied. An increased yield by the presence of the polymeric nucleic acid analog was confirmed by anion exchange column HPLC, C18 reverse phase HPLC, and turbo ionspray MS.
2001, 12(4): 317-320
Abstract:
Inclusion compound of retinoic acid with β-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry (DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-guest.
Inclusion compound of retinoic acid with β-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry (DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-guest.
2001, 12(4): 321-324
Abstract:
The rapid synthesis of 3-bromocarbazole-N-acetic acid was performed using microwave irradiation. Under the optimal conditions the yield was 85.6%. The crystal structure showed that the carboxylic groups form bifurcated hydrogen bonds and the hydroxyl oxygen atoms serve as proton donors and also acceptor. Each carboxylic group was involved in four hydrogen bonds. The packing of crystal was dominated by links of these hydrogen bonds.
The rapid synthesis of 3-bromocarbazole-N-acetic acid was performed using microwave irradiation. Under the optimal conditions the yield was 85.6%. The crystal structure showed that the carboxylic groups form bifurcated hydrogen bonds and the hydroxyl oxygen atoms serve as proton donors and also acceptor. Each carboxylic group was involved in four hydrogen bonds. The packing of crystal was dominated by links of these hydrogen bonds.
2001, 12(4): 325-326
Abstract:
Soluble reactive copoly (aryl ether ketone ketone) was synthesized from the condensation of 2,2',3,3',6,6'-hexaphenyl-4,4'-diphenol, 2,2-p-hydroxyphenyl-iso-propane, and 1-methyl-cyclohex-1-ene-4,5-diyl-bis (4-fluorophenyl methanone). FT-IR, DSC and TGA were used to characterize the novel polymer.
Soluble reactive copoly (aryl ether ketone ketone) was synthesized from the condensation of 2,2',3,3',6,6'-hexaphenyl-4,4'-diphenol, 2,2-p-hydroxyphenyl-iso-propane, and 1-methyl-cyclohex-1-ene-4,5-diyl-bis (4-fluorophenyl methanone). FT-IR, DSC and TGA were used to characterize the novel polymer.
2001, 12(4): 327-330
Abstract:
Two aminooligosaccharides, isovalertatins D03 (1) and D23 (2), were isolated from the culture filtrate of Streptomyces luteogriseus. Their structures were reinvestigated and revised by spectroscopic evidences including ESI multistage mass spectrometry and 2-dimensional NMR techniques.
Two aminooligosaccharides, isovalertatins D03 (1) and D23 (2), were isolated from the culture filtrate of Streptomyces luteogriseus. Their structures were reinvestigated and revised by spectroscopic evidences including ESI multistage mass spectrometry and 2-dimensional NMR techniques.
2001, 12(4): 331-332
Abstract:
Saikosaponin v-2 (1), was isolated from the roots of the title plant and the structure was identified on the basis of spectral analysis. Saikosaponin v-2 is a new compound, which was identified as 3β,16α,23,28-tetrahydroxy-olean-11,13 (18)-dien-30-oic acid-3-O-β-D-glucopyrano-syl-(1→2) glucopyranosyl-(1→3)-β-D-fucopyranosyl-30-O-xylitol ester.
Saikosaponin v-2 (1), was isolated from the roots of the title plant and the structure was identified on the basis of spectral analysis. Saikosaponin v-2 is a new compound, which was identified as 3β,16α,23,28-tetrahydroxy-olean-11,13 (18)-dien-30-oic acid-3-O-β-D-glucopyrano-syl-(1→2) glucopyranosyl-(1→3)-β-D-fucopyranosyl-30-O-xylitol ester.
2001, 12(4): 333-334
Abstract:
Two new compounds, melanochromone and 2-ethoxyl-2-(4-hydroxyphenyl) ethanol, were isolated from the whole plants of Melanosoiadum pimpinelloideum H. Boiss. The known compounds isolated were 1-(4-hydroxyphenyl)-1,2-ethanediol, tymine, cimifugin, umtatin, bergenin, daucosterol and stigmasterol. Their structures were determined on the basis of spectral data.
Two new compounds, melanochromone and 2-ethoxyl-2-(4-hydroxyphenyl) ethanol, were isolated from the whole plants of Melanosoiadum pimpinelloideum H. Boiss. The known compounds isolated were 1-(4-hydroxyphenyl)-1,2-ethanediol, tymine, cimifugin, umtatin, bergenin, daucosterol and stigmasterol. Their structures were determined on the basis of spectral data.
2001, 12(4): 335-336
Abstract:
A new p-terphenyl derivative 1 was isolated from the fruiting bodies of Boletopsis grisea. Its structure was established as 2, 3-diacetoxy-4', 4'', 5, 6-tetrahydroxy-p-terphenyl by spectroscopic and chemical means.
A new p-terphenyl derivative 1 was isolated from the fruiting bodies of Boletopsis grisea. Its structure was established as 2, 3-diacetoxy-4', 4'', 5, 6-tetrahydroxy-p-terphenyl by spectroscopic and chemical means.
2001, 12(4): 337-338
Abstract:
A new quinolizidine alkaloid, 3-(4-hydroxyphenyl)-4-(3-methoxy-4-hydroxyphenyl)-3, 4-dehydroquinolizidine (1), was isolated from the ethanol extract of the whole plants of Boehmeria siamensis Craib. Its structure was elucidated on the analysis of 1D NMR and 2D NMR spectrum.
A new quinolizidine alkaloid, 3-(4-hydroxyphenyl)-4-(3-methoxy-4-hydroxyphenyl)-3, 4-dehydroquinolizidine (1), was isolated from the ethanol extract of the whole plants of Boehmeria siamensis Craib. Its structure was elucidated on the analysis of 1D NMR and 2D NMR spectrum.
2001, 12(4): 339-342
Abstract:
Two new diterpenoid quinones, coleon S and T were isolated from the chloroform extract of the leaves of Coleus forskohlii, and based on spectroscopic data, their structures were identified as 1,4-phenathrenedione-4b,5,6,8a,9,10-hexahydro-3,9b,10a-trihydroxy-4b,7,8-rimethyl-2-(2-ethoxypropyl) (1) and 1,4-phenathrenedione-2,3,4b,5,6, 8a,9,10-octahydro-3,9β,10α-tri-hydroxy-4b,7,8-trimethyl-2-propylene(2), respectively.
Two new diterpenoid quinones, coleon S and T were isolated from the chloroform extract of the leaves of Coleus forskohlii, and based on spectroscopic data, their structures were identified as 1,4-phenathrenedione-4b,5,6,8a,9,10-hexahydro-3,9b,10a-trihydroxy-4b,7,8-rimethyl-2-(2-ethoxypropyl) (1) and 1,4-phenathrenedione-2,3,4b,5,6, 8a,9,10-octahydro-3,9β,10α-tri-hydroxy-4b,7,8-trimethyl-2-propylene(2), respectively.
2001, 12(4): 343-344
Abstract:
A new monoterpene glucoside, (2E,6Z)-2,6-dimethyl-8-β-D-glucosyloxy-2,6-octadien-oic acid, was isolated from the leaves of Betula platyphylla Suk. The structure was established by spectroscopic data.
A new monoterpene glucoside, (2E,6Z)-2,6-dimethyl-8-β-D-glucosyloxy-2,6-octadien-oic acid, was isolated from the leaves of Betula platyphylla Suk. The structure was established by spectroscopic data.
2001, 12(4): 345-346
Abstract:
A new triterpenoid, 3β, 4β, 23-trihydroxy-24, 30-dinorolean-12, 20 (29)-dien-28-oic acid, together with five known compounds, 2α, 3β, 23-trihydroxy-12-oleanen-28-oic acid-b-D-glucopyranosyl ester, palbinone, 2-hydroxy-benzoic acid, vanillic acid, syringic acid, were isolated from the roots of Paeonia delavayi Franch. Their structures were characterized by spectral analysis.
A new triterpenoid, 3β, 4β, 23-trihydroxy-24, 30-dinorolean-12, 20 (29)-dien-28-oic acid, together with five known compounds, 2α, 3β, 23-trihydroxy-12-oleanen-28-oic acid-b-D-glucopyranosyl ester, palbinone, 2-hydroxy-benzoic acid, vanillic acid, syringic acid, were isolated from the roots of Paeonia delavayi Franch. Their structures were characterized by spectral analysis.
2001, 12(4): 347-350
Abstract:
DFT/6-311+g** level calculations are performed to study the electron transfer bond-breaking reaction of CH3-X. The calculated values are in good agreement with the experimental results or the empirical model. Through analyzing the change of the energy and the charge density along the reaction path, the bond-breaking in ET reaction for CH3X is investigated.
DFT/6-311+g** level calculations are performed to study the electron transfer bond-breaking reaction of CH3-X. The calculated values are in good agreement with the experimental results or the empirical model. Through analyzing the change of the energy and the charge density along the reaction path, the bond-breaking in ET reaction for CH3X is investigated.
2001, 12(4): 351-352
Abstract:
The effect of cosolvent cyclohexane, chloroform, and acetonitrile on the keto-enol tautomeric equilibrium of ethyl acetoacetate in supercritical CO2 was studied by UV-Vis spectroscopy over the pressure range from 76 to 110 bar at 308.15 K. It was found that the equilibrium constant decreases with increasing polarity of the cosolvents.
The effect of cosolvent cyclohexane, chloroform, and acetonitrile on the keto-enol tautomeric equilibrium of ethyl acetoacetate in supercritical CO2 was studied by UV-Vis spectroscopy over the pressure range from 76 to 110 bar at 308.15 K. It was found that the equilibrium constant decreases with increasing polarity of the cosolvents.
2001, 12(4): 353-354
Abstract:
13C spin-lattice relaxtion times for polystyrene nanolatex particles have been investigated. It was found that the dramatic increase at 80℃ annealing temperature is well below the Tg temperature of bulk polystyrene, the increase of relaxation time of aromatic carbons is larger than that of for aliphatic carbons at transition annealing temperature.
13C spin-lattice relaxtion times for polystyrene nanolatex particles have been investigated. It was found that the dramatic increase at 80℃ annealing temperature is well below the Tg temperature of bulk polystyrene, the increase of relaxation time of aromatic carbons is larger than that of for aliphatic carbons at transition annealing temperature.
2001, 12(4): 355-356
Abstract:
Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions, enantiomeric propranolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3, v/v) as mobile phase on Lichrospher-100-DIOL column.
Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions, enantiomeric propranolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3, v/v) as mobile phase on Lichrospher-100-DIOL column.
2001, 12(4): 357-358
Abstract:
Enantiomer of n-pyrrolidinyl phenylpropanol was studied by capillary electrophoresis using β-cyclodextrin polymer as chiral selector. We determined the enantiomeric excess value of n-pyrrolidinyl phenylpropanol with RSD 0.48%.
Enantiomer of n-pyrrolidinyl phenylpropanol was studied by capillary electrophoresis using β-cyclodextrin polymer as chiral selector. We determined the enantiomeric excess value of n-pyrrolidinyl phenylpropanol with RSD 0.48%.
2001, 12(4): 359-362
Abstract:
The adsorbent crosslinked chitosan-β-cyclodextrin (β-CD) was prepared by the reaction of glutaraldehyde with chitosan and β-cyclodextrin. This type of adsorbent has high adsorption capacity for unconjugated bilirubin. The adsorption capacity was related to the β-CD content of the adsorbent; phosphate buffer concentration; temperature; pH value; ionic strength and the adsorbent beads. The results indicated that the chitosan-β-CD was a good adsorbent for unconjugated bilirubin with high capacity.
The adsorbent crosslinked chitosan-β-cyclodextrin (β-CD) was prepared by the reaction of glutaraldehyde with chitosan and β-cyclodextrin. This type of adsorbent has high adsorption capacity for unconjugated bilirubin. The adsorption capacity was related to the β-CD content of the adsorbent; phosphate buffer concentration; temperature; pH value; ionic strength and the adsorbent beads. The results indicated that the chitosan-β-CD was a good adsorbent for unconjugated bilirubin with high capacity.
2001, 12(4): 363-364
Abstract:
A capillary electrophoresis method for the separation and quantification of reduced glutathione (GSH) and oxidized glutathione (GSSG) was developed. A baseline separation was achieved within five minutes. The effects of time and the concentrations of hydrogen peroxide (H2O2) on the oxidation of GSH were investigated.
A capillary electrophoresis method for the separation and quantification of reduced glutathione (GSH) and oxidized glutathione (GSSG) was developed. A baseline separation was achieved within five minutes. The effects of time and the concentrations of hydrogen peroxide (H2O2) on the oxidation of GSH were investigated.
2001, 12(4): 365-368
Abstract:
Cellulose carbamates (CC) were synthesized with microcrystalline cellulose as raw materials. The Fourier transform infrared spectra of CC with different nitrogen content were recorded. The accurate results of the nitrogen content for CC can be obtained by using the deconvolution method when the nitrogen content is less than 3.5%. The relationship between the nitrogen content and the absorption intensity ratio of the corresponding separated absorption peaks in FTIR spectra has been expressed by an equation precisely.
Cellulose carbamates (CC) were synthesized with microcrystalline cellulose as raw materials. The Fourier transform infrared spectra of CC with different nitrogen content were recorded. The accurate results of the nitrogen content for CC can be obtained by using the deconvolution method when the nitrogen content is less than 3.5%. The relationship between the nitrogen content and the absorption intensity ratio of the corresponding separated absorption peaks in FTIR spectra has been expressed by an equation precisely.
2001, 12(4): 369-372
Abstract:
In this paper, the fluorescence spectra of model compounds of light-emitting alternating copolymers, M (TPA-PPV) and M (TPA-PAV) (Scheme 1) were studied and the effect of KNO3 on the interaction between model compounds and ionic micelle-water interface was also investigated. It is found that (I) The fluorescence changes of M (TPA-PPV) are related to the state of CTAB and SDS solution. (Ⅱ) Aggregated state can be formed in M (TPA-PAV) solution at low concentration of CTAB. (Ⅲ) Higher concentration of KNO3 may affect the interaction between model compounds and ionic micelle-water interface.
In this paper, the fluorescence spectra of model compounds of light-emitting alternating copolymers, M (TPA-PPV) and M (TPA-PAV) (Scheme 1) were studied and the effect of KNO3 on the interaction between model compounds and ionic micelle-water interface was also investigated. It is found that (I) The fluorescence changes of M (TPA-PPV) are related to the state of CTAB and SDS solution. (Ⅱ) Aggregated state can be formed in M (TPA-PAV) solution at low concentration of CTAB. (Ⅲ) Higher concentration of KNO3 may affect the interaction between model compounds and ionic micelle-water interface.
2001, 12(4): 373-376
Abstract:
A new organo-directed titanium phosphate,[NH3CH2CH2NH3]·[TiO(HPO4)2], was synthesized by the solvothermal method and its structure was determined by single crystal X-ray diffraction. The structure consists of 1-D zigzag chains built up from trans-corner-sharing titanium oxo octahedra running along the b axis, with fused Ti2P three-membered rings being attached to the-Ti-O-Ti-O-backbone.
A new organo-directed titanium phosphate,[NH3CH2CH2NH3]·[TiO(HPO4)2], was synthesized by the solvothermal method and its structure was determined by single crystal X-ray diffraction. The structure consists of 1-D zigzag chains built up from trans-corner-sharing titanium oxo octahedra running along the b axis, with fused Ti2P three-membered rings being attached to the-Ti-O-Ti-O-backbone.
2001, 12(4): 373-376
Abstract:
A new organo-directed titanium phosphate,[NH3CH2CH2NH3]·[TiO(HPO4)2], was synthesized by the solvothermal method and its structure was determined by single crystal X-ray diffraction. The structure consists of 1-D zigzag chains built up from trans-corner-sharing titanium oxo octahedra running along the b axis, with fused Ti2P three-membered rings being attached to the-Ti-O-Ti-O-backbone.
A new organo-directed titanium phosphate,[NH3CH2CH2NH3]·[TiO(HPO4)2], was synthesized by the solvothermal method and its structure was determined by single crystal X-ray diffraction. The structure consists of 1-D zigzag chains built up from trans-corner-sharing titanium oxo octahedra running along the b axis, with fused Ti2P three-membered rings being attached to the-Ti-O-Ti-O-backbone.
