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2000 Volume 11 Issue 3
2000, 11(3): 189-190
Abstract:
The sulfinatodehalogenation reaction of α,α-difluorobenzyl halides,ArCF2X (Ar=C6F5,C6H5; X=Br,I),with sodium dithionite took place readily in aqueous acetonitrile under mild conditions,giving the corresponding sodium sulfinate. The 1:1 adducts were obtained when alkenes were added to the reaction system in some cases.
The sulfinatodehalogenation reaction of α,α-difluorobenzyl halides,ArCF2X (Ar=C6F5,C6H5; X=Br,I),with sodium dithionite took place readily in aqueous acetonitrile under mild conditions,giving the corresponding sodium sulfinate. The 1:1 adducts were obtained when alkenes were added to the reaction system in some cases.
2000, 11(3): 191-194
Abstract:
Tetrahydrofuran ring can be opened with acyl chlorides or anhydrides catalyzed by gallium triiodides to afford iodo esters under mild conditions in good yields.
Tetrahydrofuran ring can be opened with acyl chlorides or anhydrides catalyzed by gallium triiodides to afford iodo esters under mild conditions in good yields.
2000, 11(3): 195-198
Abstract:
Active metal bismuth is produced in situ via Sm/BiCl3 system in aqueous media. Promoted by this active species,β-aminoesters and α-selenoesters are synthesized via reaction of α-bromoesters with 1-(a-aminoalkyl) benzotriazole and diselenides in moderate to good yields.
Active metal bismuth is produced in situ via Sm/BiCl3 system in aqueous media. Promoted by this active species,β-aminoesters and α-selenoesters are synthesized via reaction of α-bromoesters with 1-(a-aminoalkyl) benzotriazole and diselenides in moderate to good yields.
2000, 11(3): 199-202
Abstract:
An α-4(20)-epoxy-5α-hydroxytaxinine B 1,when treated with diethylaluminum chloride,underwent reactions involving intramolecular substitution along with deacetylation or addition leading to new rings. Two novel 1-deoxy compounds 2 and 3 were isolated and fully characterized.
An α-4(20)-epoxy-5α-hydroxytaxinine B 1,when treated with diethylaluminum chloride,underwent reactions involving intramolecular substitution along with deacetylation or addition leading to new rings. Two novel 1-deoxy compounds 2 and 3 were isolated and fully characterized.
2000, 11(3): 203-206
Abstract:
Some 1-imino-3,3-disubstituted-1,3-dihydro isobenzofuran and 2-(1,1-disubstituted hydroxymethyl) benzamide derivatives have been obtained by the aminolysis of phthalide in the presence of triethylamine/aluminum chloride. 1-Benzylimino-3,3-disubstituted-1,3-dihydro isobenzofuran can be peroxidized to the corresponding hydroperoxides on exposure to the air for a long period. The structure was characterized by single crystal X-ray diffraction and the possible mechanism was suggested.
Some 1-imino-3,3-disubstituted-1,3-dihydro isobenzofuran and 2-(1,1-disubstituted hydroxymethyl) benzamide derivatives have been obtained by the aminolysis of phthalide in the presence of triethylamine/aluminum chloride. 1-Benzylimino-3,3-disubstituted-1,3-dihydro isobenzofuran can be peroxidized to the corresponding hydroperoxides on exposure to the air for a long period. The structure was characterized by single crystal X-ray diffraction and the possible mechanism was suggested.
2000, 11(3): 207-208
Abstract:
One simple and versatile method is established for the synthesis of DNA recognition molecules-polyamides containing alternating N-methylpyrrole and N-methylimidazole without necessitating NH2- group protection.
One simple and versatile method is established for the synthesis of DNA recognition molecules-polyamides containing alternating N-methylpyrrole and N-methylimidazole without necessitating NH2- group protection.
2000, 11(3): 209-211
Abstract:
An improved procedure for the preparation of chiral NAD(P)H model,(SS)-1-benzyl-3-(p-tolylsulfinyl)-1,4-dihydropyridine,with satisfactary chemical yield and excellent enantiopurity is reported.
An improved procedure for the preparation of chiral NAD(P)H model,(SS)-1-benzyl-3-(p-tolylsulfinyl)-1,4-dihydropyridine,with satisfactary chemical yield and excellent enantiopurity is reported.
2000, 11(3): 213-216
Abstract:
The first stereoselective total synthesis of oplopandiol acetate 1,a potent antimyco-bacterial polyyne isolated from Oplopanax horridus,is presented. And its absolute configuration is confirmed to be (11S,16S).
The first stereoselective total synthesis of oplopandiol acetate 1,a potent antimyco-bacterial polyyne isolated from Oplopanax horridus,is presented. And its absolute configuration is confirmed to be (11S,16S).
2000, 11(3): 217-218
Abstract:
We have developed an alternative route to synthesize the natural product,isorhapotogenin. The synthetic product was characterized by IR and 1H-NMR in comparison with the corresponding natural product.
We have developed an alternative route to synthesize the natural product,isorhapotogenin. The synthetic product was characterized by IR and 1H-NMR in comparison with the corresponding natural product.
2000, 11(3): 219-222
Abstract:
DFT/BLYP method is used to theoretically investigate the electron transfer (ET) reactions between M (Li,Na,Mg)-C6H6 and M+-C6H6 complexes in the gas phase. The geometry optimization of the precursor complexes and the transition state in the process of ET reaction was performed at 6-31G basis set level. The activation energy,the coupling matrix element and the rate constant of the ET reaction are calculated at semi-quantitative level.
DFT/BLYP method is used to theoretically investigate the electron transfer (ET) reactions between M (Li,Na,Mg)-C6H6 and M+-C6H6 complexes in the gas phase. The geometry optimization of the precursor complexes and the transition state in the process of ET reaction was performed at 6-31G basis set level. The activation energy,the coupling matrix element and the rate constant of the ET reaction are calculated at semi-quantitative level.
2000, 11(3): 223-224
Abstract:
The methoxycarbonylations of cyclohexene and 1-decene with CO2 can take place under ambient conditions by catalysis of[Co]([Co]=Co(acac)2,Co(OAc)2,CoCl2) in the presence of ultraviolet irradiation.
The methoxycarbonylations of cyclohexene and 1-decene with CO2 can take place under ambient conditions by catalysis of[Co]([Co]=Co(acac)2,Co(OAc)2,CoCl2) in the presence of ultraviolet irradiation.
2000, 11(3): 225-228
Abstract:
Two novel poly-oxygen bipyridine alkaloids,speranculatines A (1) and B (2) have been isolated from Speranskia tuberculata. Their structures were elucidated by spectroscopic methods including 2D NMR techniques and X-ray crystallographic analysis.
Two novel poly-oxygen bipyridine alkaloids,speranculatines A (1) and B (2) have been isolated from Speranskia tuberculata. Their structures were elucidated by spectroscopic methods including 2D NMR techniques and X-ray crystallographic analysis.
2000, 11(3): 229-230
Abstract:
A new abietane quinone diterpenoid was isolated,together with horminone,16-acetoxy-7-0-acetylhorminone,β-sitosterol,stigmasterol,ursolic acid and palmitic acid from the leaves of Rabdosia Serra (MAXIM) Hara. The new compound was elucidated as 16-acetoxy-7α-ethoxyroyleanone.
A new abietane quinone diterpenoid was isolated,together with horminone,16-acetoxy-7-0-acetylhorminone,β-sitosterol,stigmasterol,ursolic acid and palmitic acid from the leaves of Rabdosia Serra (MAXIM) Hara. The new compound was elucidated as 16-acetoxy-7α-ethoxyroyleanone.
2000, 11(3): 231-234
Abstract:
Two new iridoid glucosides,serratoside A and serratoside B,were isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Their structures were elucidated by spectral and chemical methods.
Two new iridoid glucosides,serratoside A and serratoside B,were isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Their structures were elucidated by spectral and chemical methods.
2000, 11(3): 235-238
Abstract:
A new taxane diterpenoid with a rearranged 5/7/6-membered ring system was isolated from the seeds of the Chinese yew,Taxus yunnanensis. Its structure was established as 9α-acetoxy-5α-cinnamoyl-11(15→1)-abeotaxa-4(20),11-diene-10β,13α,15-triol on the basis of spectroscopic analysis. Its relative stereochemistry is proposed from the results of a NOESY experment.
A new taxane diterpenoid with a rearranged 5/7/6-membered ring system was isolated from the seeds of the Chinese yew,Taxus yunnanensis. Its structure was established as 9α-acetoxy-5α-cinnamoyl-11(15→1)-abeotaxa-4(20),11-diene-10β,13α,15-triol on the basis of spectroscopic analysis. Its relative stereochemistry is proposed from the results of a NOESY experment.
2000, 11(3): 239-242
Abstract:
Muricatenol 1,a new acetogenin,has been isolated from the seeds of Annona muricata L.. Compound 1 is a C37 acetogenin without any THF rings,with four hydroxyls and one double bond in the long aliphatic chain. The hydroxyls of 1 are located at C-4,C-10,C-18 and C-19,respectively. The vicinal diol at C-18/C-19 is threo-configuration,and the double bond at C-14/C-15 is cis-configuration.
Muricatenol 1,a new acetogenin,has been isolated from the seeds of Annona muricata L.. Compound 1 is a C37 acetogenin without any THF rings,with four hydroxyls and one double bond in the long aliphatic chain. The hydroxyls of 1 are located at C-4,C-10,C-18 and C-19,respectively. The vicinal diol at C-18/C-19 is threo-configuration,and the double bond at C-14/C-15 is cis-configuration.
2000, 11(3): 243-246
Abstract:
The thermal property of the polymerization of brain tubulin was studied by a high-sensitivity differential scanning calorimeter. The phenomenon that heat flows increased and decreased consistently and obviously was observed. This phenomenon was called heat flow oscillation. It was probably correlated to the dynamic instability of microtubules. The effect of cisplatin on it was reported,too.
The thermal property of the polymerization of brain tubulin was studied by a high-sensitivity differential scanning calorimeter. The phenomenon that heat flows increased and decreased consistently and obviously was observed. This phenomenon was called heat flow oscillation. It was probably correlated to the dynamic instability of microtubules. The effect of cisplatin on it was reported,too.
2000, 11(3): 247-250
Abstract:
The binding of nicotine to bovine serum albumin (BSA) was studied by UV absorption,fluorescence,and 1H NMR methods. With the addition of nicotine,the absorption band of BSA at about 210 nm decreased gradually,moved to longer wavelengths,and narrowed. BSA fluorescence of tryptophan residue was quenched by nicotine. The 1H NMR peaks of nicotine moved to downfield by the addition of BSA. The experimental results showed that nicotine was capable of binding with BSA to form a 1:1 complex. BSA's high selectivity for nicotine binding suggests a unique role for this protein in the detoxification and/or transport of nicotine.
The binding of nicotine to bovine serum albumin (BSA) was studied by UV absorption,fluorescence,and 1H NMR methods. With the addition of nicotine,the absorption band of BSA at about 210 nm decreased gradually,moved to longer wavelengths,and narrowed. BSA fluorescence of tryptophan residue was quenched by nicotine. The 1H NMR peaks of nicotine moved to downfield by the addition of BSA. The experimental results showed that nicotine was capable of binding with BSA to form a 1:1 complex. BSA's high selectivity for nicotine binding suggests a unique role for this protein in the detoxification and/or transport of nicotine.
2000, 11(3): 251-254
Abstract:
The resonance light-scattering (RLS) of human serum albumin (HSA) and bovine serum albumin (BSA) is reported for the first time,and applied to study photochemical reaction of HSA and BSA. The fact of photocrosslinking self-association effect in HSA and BSA solutions is identified by the enhancement of RLS. The fluorescence quenching at about 350 nm and 700 nm proves that tryptophan (Trp) residues are one of the photochemical activity sites in HSA and BSA molecules. The Rayleigh scattering (RS) spectra of HSA and BSA that were neglected in fluorescence spectra before are found at about 296 nm,592 nm and 888 nm for the first time,and are of adventageous to studying the aggregation of HSA or BSA. The possible photochemical reaction mechanism is also proposed.
The resonance light-scattering (RLS) of human serum albumin (HSA) and bovine serum albumin (BSA) is reported for the first time,and applied to study photochemical reaction of HSA and BSA. The fact of photocrosslinking self-association effect in HSA and BSA solutions is identified by the enhancement of RLS. The fluorescence quenching at about 350 nm and 700 nm proves that tryptophan (Trp) residues are one of the photochemical activity sites in HSA and BSA molecules. The Rayleigh scattering (RS) spectra of HSA and BSA that were neglected in fluorescence spectra before are found at about 296 nm,592 nm and 888 nm for the first time,and are of adventageous to studying the aggregation of HSA or BSA. The possible photochemical reaction mechanism is also proposed.
2000, 11(3): 255-258
Abstract:
In acid medium,sparfloxacin is oxidized by nitrous acid,then reacts with hydrobromic acid to form a new fluorescence substance,which can emit the strong fluorescence,which is 151 fold more than that of sparfloxacin itself. By this,a new sensitive method for the determination of sparfloxacin in human urine by derivative-synchronous fluorescence is presented with good results.
In acid medium,sparfloxacin is oxidized by nitrous acid,then reacts with hydrobromic acid to form a new fluorescence substance,which can emit the strong fluorescence,which is 151 fold more than that of sparfloxacin itself. By this,a new sensitive method for the determination of sparfloxacin in human urine by derivative-synchronous fluorescence is presented with good results.
2000, 11(3): 259-260
Abstract:
NMR studies of some chiral 3-acyclcamphor were conducted. A complete assignment was given to 3-(4-pyridyl)carbonylcamphor by the 2D NMR technology. Assignments were also given to other β-diketones. The results showed that those 3-acylcamphors exist in the enol forms,while 2-benzoyl menthone exists in diketon form.
NMR studies of some chiral 3-acyclcamphor were conducted. A complete assignment was given to 3-(4-pyridyl)carbonylcamphor by the 2D NMR technology. Assignments were also given to other β-diketones. The results showed that those 3-acylcamphors exist in the enol forms,while 2-benzoyl menthone exists in diketon form.
2000, 11(3): 261-262
Abstract:
The transient absorption spectra of 1-naphthylacetic acid in tetrahydrofuran have been obtained by laser flash photolysis technique. The transient species bands are at 509.535 and 553 nm. These peak intensities increase in the maximum values at 10.4 μs.
The transient absorption spectra of 1-naphthylacetic acid in tetrahydrofuran have been obtained by laser flash photolysis technique. The transient species bands are at 509.535 and 553 nm. These peak intensities increase in the maximum values at 10.4 μs.
2000, 11(3): 263-264
Abstract:
Speciation of Pr(Ⅲ) in human blood plasma has been investigated by computer simulation. The speciation and distribution of Pr(Ⅲ) has been obtained. It has been found that most of Pr(Ⅲ) is bound to phosphate and to form precipitate. The results obtained are in accord with experimental observations.
Speciation of Pr(Ⅲ) in human blood plasma has been investigated by computer simulation. The speciation and distribution of Pr(Ⅲ) has been obtained. It has been found that most of Pr(Ⅲ) is bound to phosphate and to form precipitate. The results obtained are in accord with experimental observations.
2000, 11(3): 265-266
Abstract:
Heptakis(2,6-di-O-pentyl-3-O-allyl)-β-cyclodextrin as an excellent gas chromato-graphic stationary phase separating phenol and cresol isomers is described.
Heptakis(2,6-di-O-pentyl-3-O-allyl)-β-cyclodextrin as an excellent gas chromato-graphic stationary phase separating phenol and cresol isomers is described.
2000, 11(3): 267-270
Abstract:
The PET-CO2- film was prepared and the lipase was assembled on the surface of the PET-CO2- substrate. The structure at the surface and activity of lipase/PET monolayer were studied by ATR-FTIR and AFM,and other methods.
The PET-CO2- film was prepared and the lipase was assembled on the surface of the PET-CO2- substrate. The structure at the surface and activity of lipase/PET monolayer were studied by ATR-FTIR and AFM,and other methods.
2000, 11(3): 271-274
Abstract:
An investigation of the structural conversion in microemulsion system of sodium dodecylsulfonate-butanol-heptane-water was carried out by cyclic voltammetry and conductivity techniques.
An investigation of the structural conversion in microemulsion system of sodium dodecylsulfonate-butanol-heptane-water was carried out by cyclic voltammetry and conductivity techniques.
2000, 11(3): 275-278
Abstract:
High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorption and reaction of CO on the Mo(100)-c(2×2)N surface. CO directly adsorbed on the N atoms from the c(2×2) layer to form isocyanate (NCO) surface species was found in addition to CO adsorbed on the molybdenum atoms at 120 K,indicating that both Mo and N atoms of the Mo(100)-c(2×2)-N surface are of high reactivities for CO adsorption.
High resolution electron energy loss spectroscopy (HREELS) has been used to investigate the adsorption and reaction of CO on the Mo(100)-c(2×2)N surface. CO directly adsorbed on the N atoms from the c(2×2) layer to form isocyanate (NCO) surface species was found in addition to CO adsorbed on the molybdenum atoms at 120 K,indicating that both Mo and N atoms of the Mo(100)-c(2×2)-N surface are of high reactivities for CO adsorption.
2000, 11(3): 279-282
Abstract:
This paper presents a computer model using thermodynamic relationships and mass balance to investigate the speciation of aluminum in acidic natural water equilibria with mineral kaolinite. Factors affecting the distribution are discussed. Compared with the case of equilibria with gibbsite, some unique characteristics are discovered. The model is verified by analyzing practical water samples. Effect of errors in thermodynamic data on calculation is evaluated by the Monte Carlo simulation.
This paper presents a computer model using thermodynamic relationships and mass balance to investigate the speciation of aluminum in acidic natural water equilibria with mineral kaolinite. Factors affecting the distribution are discussed. Compared with the case of equilibria with gibbsite, some unique characteristics are discovered. The model is verified by analyzing practical water samples. Effect of errors in thermodynamic data on calculation is evaluated by the Monte Carlo simulation.
