1996 Volume 7 Issue 11

Chemisorbed dimethylammonium chlorochromate as selective oxidants for primary and second aryAlcohols
Gui Sheng ZHANG , Qi Zeng SHI , Mi Feng CHEN , Kun CAI
1996, 7(11): 973-974
[Abstract](151) [FullText HTML] [PDF 94KB](0)
Abstract:
Two new reagents.dimethylammonium chlorochromate adsorbed on alumina and silica gel are described as convenient reagents for efficient oxidation of a variety of primary and secondary alcohols.Tliese two reagents are very stable and can be safely used for the oxidation of alcohols containing double bond.
Efficient and Convenient Procedures forthe Formation and cleavage of steroid acetals catalysed by montmorillonite aite K 10
Tong Shuang LI , Sheng Hui LI , Ji Tat LI , Hui Zhang LI , Xiu Xiang WU
1996, 7(11): 975-978
[Abstract](154) [FullText HTML] [PDF 188KB](0)
Abstract:
Acetalization of steroid ketones and cleavage of the acetals have been carried out in excellent yield under catalysis of montmorillonite K 10.
Studies of artificial Hydrolytic metalloenzymes The catalytic carboxyester hydrolysis by novel nucleophile containing phenolic pendant macrocyclic polyamines
Wan Dong CHEN , Xiang Chen YIN , Shou Rong ZHU , Hua Kuan LIN , Fu Ping KOU , Chun Chen LIN , Mei Rong LIN , Yun Ti CHEN
1996, 7(11): 979-980
[Abstract](152) [FullText HTML] [PDF 113KB](0)
Abstract:
Zinc(Ⅱ)complexes of new macrocyclic tetraamines(cyclam derivatives)having a strategically appended phenolate group,have been examined as catalyst for the hydrolysis of 4-nitrophenyl acetate(NA).It was proven that coordinated phenolate can serve as a good nucleophile that efficiently catalyze 4-nitrophenyl acetate(NA)hydrolysis.
KBH4/BiCl3--A new and facile reduction system for the Conversion of Aromatic Nitro Compounds to Primary Amines
Shi Feng PAN , Ping Da REN , Ting Wei DONG
1996, 7(11): 981-983
[Abstract](160) [FullText HTML] [PDF 107KB](0)
Abstract:
Various aromatic nitro compounds could be selectively and rapidly reduced to the corresponding amines in excellent yields by potassium borohydride-bismuth chloride/ethanol-water,a new and facile reductive system.
Synthesis and Biological Evaluation of Substituted 3'-N-Benzoyl Taxol Analogs
Qin YUE , Qi-Cheng FANG , Xiao Tian UANG
1996, 7(11): 984-986
[Abstract](159) [FullText HTML] [PDF 150KB](0)
Abstract:
A series of substituted 3'-N-benzoyl taxol analogs [7a~i] were synthesized by Schotten-Baumann acylation of the key intermediate,13-O-[(2'R,3'S)-3'-phenylisoserinoyl] baccatin Ⅲ[6].Evaluation of the newly prepared derivatives for cytotoxicity against KB cell line revealed that electron-donating groups at the para position(such as-CH3,-OCH3,etc.)have positive effect on activity,while electron-attracting groups(such as-NO2,-Br,etc.)have negative effect.Sterically hindered substituents at the ortho position could dramatically reduce the activity.But none of the analogs had higher cytotoxicity than taxol.
Synthesis and Antitumor Activity of New Derivatives of Podophyllotoxin
Yan Guang WANG , Jian Lin PAN , Yao Zu CHEN
1996, 7(11): 987-988
[Abstract](169) [FullText HTML] [PDF 88KB](0)
Abstract:
A series of analogues of etoposide(VP-16),the C-4 alkylamino-substituted 4'-demethyl-epipodophyllotoxins,have been synthesized and studied for their activity to inhibit L1210 and KB cells in vitro.Most new compounds are as active or more active than VP-16 in their inhibition of both L1210 and KB cells.
Synthesis of 2-Methylenesuccinimides Modified by Germatranes
Zhong Biao ZHANG , Ru Yu CHEN
1996, 7(11): 989-990
[Abstract](157) [FullText HTML] [PDF 84KB](0)
Abstract:
A series of 2-methylenesuccinimides modified by germatranes were synthesized by two methods.The structures of products were confirmed by 1HNMR.IR,elemental analysis,and X-ray diffraction.
Synthesis of the Precursor of Tetrasaccharide from Laminin
Xiao Xiang ZHU , Ping Yu DING , Meng Shen CAI
1996, 7(11): 991-992
[Abstract](156) [FullText HTML] [PDF 83KB](0)
Abstract:
Synthesis of the protected tetrasaccharide 11 is reported as the key intermediate of tetrasaccharide from laminin that is an important glycoprotein on the basement membrane.
Synthesis of F-alkylated MDP Analogs
Ming Zhu ZRANG , Jie Cheng XU
1996, 7(11): 993-994
[Abstract](151) [FullText HTML] [PDF 87KB](0)
Abstract:
Four F-alkylated muramyl dipeptides were synthesized by an efficient coupling reagent,Benzotriazol-1-yloxy-bis(pyrrolidino)carbonium hexafluoro-phosphate(BBC)[1].
RING ENLARGEMENT OF SECURININE
Jian Wei ZHANG , Xiao Tian LIANG , Li Yu GUO
1996, 7(11): 995-996
[Abstract](169) [FullText HTML] [PDF 74KB](1)
Abstract:
Treatment of N-cyanomethylsecurinine bromide with NaH in tetrahydrofuran gave ring enlargement products with [3,2] rearrangement
The Stereochemistry of the Migrating Groups in the Pyrolysis of Stable Steroidal Ozonides
Jiong YANG , Tong Shuang LI , Yu Lin LI
1996, 7(11): 997-998
[Abstract](162) [FullText HTML] [PDF 104KB](0)
Abstract:
Diacholest-13(17)-ene ozonides(1a and lb)and 4,4-dimethyldiacholest-13(17)-ene ozonides(2a and 2b)underwent pyrolysis to afford the coressponding 17-oxo-13,14;13,17-disecodiacholestano-13,14-lactones(3a and 3b)and 4,4-dimethyl-17-oxo-13,14;13,17-disecodiacholestano-13,14-lactones(4a and 4b),respectively.The stereochemistry of the migrating groups was proven to be conserved by comparison with the Baeyer-Villiger oxidation of the corresponding 13,17-secodiacholesta-13,17-diones(5)and 4,4-dimethyl-13,17secodiacholesta-13,17-diones(6).
An AM1 Study on the Mechanism of Uridine Phospborolysis
Shan Rong ZHAO , Qin Mi WANG , Kai Xian CHEN , Suo-Bao RONG , Ru-Yun JI
1996, 7(11): 999-1002
[Abstract](158) [FullText HTML] [PDF 177KB](0)
Abstract:
We have used quantum chemical method to study the transition states of undine phosphorolysis reaction under the neutral condition.Comparing the activation energies of different reaction modes,we conclude that uridine phosphorolysis takes place mainly according to a concerted mechanism.The computational results are consistent with some critical experimental facts.
The Fallacy of Using Chiral Shift Reagents to Differentiate d,l and meso Isomers
Jian Wei ZHANG , Ji Yu GUO , Xiao Tian LIANG , Mu Jian LU
1996, 7(11): 1003-1004
[Abstract](164) [FullText HTML] [PDF 105KB](0)
Abstract:
A d,l mixture(R-R and S-S)can be resolved into the d and the I enantiomers.while the meso isomer(R-S,identical with S-R)cannot be physically separated.This fact has occasionally been "extrapolated" to differentiate d,I and meso isomers with a chiral shift reagent,where the meso isomer is presumed not to show any signal "doubling" during the(usually)downfield shift.This assumption has been shown to be incorrect by the behavior of a meso molecule which does give signal "doubling".
Two New Triterpenoid Saponins from Aster Lingulatus
Bin HU , Yu SHAO , Guo Wei QIN , Chi Tang HO , Chee Kok CHIN , Robert T. Rosen
1996, 7(11): 1005-1008
[Abstract](158) [FullText HTML] [PDF 195KB](0)
Abstract:
Two new saponins named asterlingulatosides A and B were isolated from the whole plants of Aster lingulatus.Their structures were elucidated by spectral and chemical evidence as 3-O-β-D-glucopyranosyl-3β,16α-dihydroxyolean-12-en-28-oic acid-28-O-α-L-arabinopyranoside and 3-O-β-D-glucopyranosyl-3β,16α-dihydroxyolean-12-en-28-oic acid-28-O-α-L-rhamnopy-ranosyl-(1→2)-α-L-arabinopyranoside respectively.They showed inhibitory activity on DNA synthesis of human leukemia HL-60 cells.
Chemistry and Pharmacological Activity of Peptidoglycan from Lycium Barbaruml
Chun Jiu ZHAO , Yun Qing HE , Rong Zi LI , Guo Hui CUI
1996, 7(11): 1009-1010
[Abstract](167) [FullText HTML] [PDF 97KB](1)
Abstract:
Two homogeneous new peptidoglycans were obtained from Lycium barbarum L.They were found to be effective ingredients capable of resisting lipid peroxidation.The components and linkages of the two homogeneous polysaccharides were studied by means of complete acid hydrolysis,periodate oxidation,Smith degradation,enzyme hydrolysis,IR,GC and amino acid analysis.Homogeneous polysaccharide LBPC2 was found to be a β(1→4)(1→6)peptidoglycan with MW of 1.2×104,composed of Xyl,Rha,Man in a molar ratio of 8.8:2.3:1;LBP4,was found to be a α(1→4)(1→6)peptidoglycan with MW of 1.0×104,composed of glucans.
New Constituents from Hypericum Japonicum
Qing Li WU , Sheng Ping WANG , Yong Hong LIAO , Li Wei WANG , Yu Xiu FENG , Jun Shan YANG , Pei Gen XIAO , Shao Liana HONG
1996, 7(11): 1011-1012
[Abstract](151) [FullText HTML] [PDF 109KB](0)
Abstract:
Two new glycosides 1,5-dihydroxyxathanone-6-o-β-D-glucoside and flavanonol-taxifolin-3,7-o-α-L-dirbamnoside.were isolated from the aerial parts of Hypericum japonicum Thunb.ex Murray.The chemical structures were determined by spectroscopic methods and chemical evidences
The Structure of Sophoridine N-oxide from Inner Mongolian Sophora Alopecuroides L
Wen ZHANG , Ri Gen MO , Hui Zhen XU
1996, 7(11): 1013-1015
[Abstract](179) [FullText HTML] [PDF 104KB](1)
Abstract:
Sophoridine N-oxide(A)was isolated from the seeds of Inner Mongolian Sophora alopecuroides L.Its structure was characterized.Deoxygenation of A gave sophoridine whereas N-oxidation of sophoridine gave two N-oxides,The stereochemical features of the two isomers were given by analysis of its 1H-and 13C-NMR spectra.
A Simple New Method for the Fabrication of Carbon Paste Microelectrode and its Characterization
Jian Jun SUN , Hui Qun FANG , Hong Yuan CHEN
1996, 7(11): 1016-1018
[Abstract](153) [FullText HTML] [PDF 121KB](0)
Abstract:
A procedure for preparing carbon paste microeletrodes is described.This procedure is based on incorporation of carbon paste into the microholes at the tips of chemically etched microdisk electrodes.The electrodes combine the advantages of microdisk electrodes and carbon paste electrodes.Sigmoidal-shape voltammograms were observed and steady-state currents were quickly achieved on these electrodes.
Study on a New Type of All-Solid-StateReference Electrode
Chao Lun HUANG , Ju Jie REN , Da Feng XU
1996, 7(11): 1019-1022
[Abstract](160) [FullText HTML] [PDF 154KB](0)
Abstract:
A new type of all-solid-state Ag/AgCl reference electrode was constructed by using urea-formaldehyde resin as the frame material and KCl powder as the active component.The properties of the electrode were studied in detail.The electrode exhibited excellent characteristics and could be applied to the electrochemical measurements in syrupy,colloidal and higher temperature solutions as a reference electrode.
Flow-injection Chemiluminescence Sensor for the Determination of Free Chlorine in Tap Water
Shu Na LIU , Wei QIN , Zhu Jun ZHANG
1996, 7(11): 1023-1026
[Abstract](152) [FullText HTML] [PDF 137KB](0)
Abstract:
A novel chemiluminescence.Cl sensor combined with flow-injection analysis has been developed for determining free chlorine in tap water.The analytical reagent luminol was immobilized on an anion exchange resin column.While a volume of the sodium hydroxide passed the column,luminol was eluted from the resin in alkaline aqueous solution and then mixed with the sample stream to react and produce Cl.The Cl emission intensity was correlated with the standard C10- concentration in the range of 1×10-3 to 4×10-5 g ml-1,and the detection limit was 8×10-9g ml-1 C10-.Interfering metal ions present in water were effectively separated by a pre-column cation exchanger.A complete analysis,including sampling and washing,could be performed in 1 min with a relative standard deviation of less than 5%.The sensor was stable for over 200 times and has been applied successfully to the determination of C10- in tap water.
Reversed-Phase High-Performance Liquid Chromatographic Determination of Drugs of Abuse
Chen MA , Hong Jin DUAN , Yan Qing XU , Tong Hui ZHOU
1996, 7(11): 1027-1028
[Abstract](157) [FullText HTML] [PDF 92KB](0)
Abstract:
A high-performance liquid chromatographic method using uv detection for the determination of 10 drugs of abuse is described.The method is simple and sensitive.The linear ranges are 20~100 ng/ml with relative standard deviations of 0.7~2.6%(n=7)and detection limits of 5~10ng/ml.
A Study on the Reaction Mechanism of Bromocresol Green with Bovine Serum Albumin
Ken Zhu , Ke An LI , Shen Yang TONG
1996, 7(11): 1029-1032
[Abstract](158) [FullText HTML] [PDF 189KB](2)
Abstract:
The protein assay with bromocresol green(BCG)method is commonly used because of its convenience,but it is not well understood on a molecular level.In this paper,the study on the reaction between BCG and bovine serum albumin(BSA)is reported.The binding numbers and the binding constants are given at different pH by using three methods with relevant comparison.It was proved that there were three sorts of binding sites of BSA to react with BCG and BCG transformed into its basic form in the presence of BSA.
Capillary Electrophoretic Separation of Monosialogangliosides by using cyclodectrin and borax as selectors
Wen CHANG , Zhao Lou YU , Gui Yun XU , Yi CHEN
1996, 7(11): 1033-1034
[Abstract](156) [FullText HTML] [PDF 96KB](0)
Abstract:
The CE separation of monosialoganglioads(MSGLS)is generally difficult owing to their mixed micelle formation.The addition of high concentration of borax to the buffer containing α-Cyclodextrin allowed for improvement of selectivity of separation.Under the optimum conditions,several forms of MSGLS were successfully separated and the commercial standard GMl gave two peaks,suggesting that the standard may contain two different types of species.
Diethyl Tartrate on Polystyrene Bead as Chiral Stationary Phase in Liquid Chromatography
Qing Yan LIU , Xiao Jun WU , Ji Gan HE , Guo Quan LIU
1996, 7(11): 1035-1036
[Abstract](162) [FullText HTML] [PDF 98KB](0)
Abstract:
L-(+)-diethyl tartrate was bound to hydroxymethyl polystyrene bead as a chiral stationary phase in high-performance liquid chromatography(HPLC)for the resolution of pharmaceutically racemic compounds,such as D,L-amygdalic acid,D,L-brufen,and D,L-phenylephrine in an isocratic elution mode.
Investigation of HNO3 Chemincally Oxidized Porous Silicon
Feng YIN , Xue Ping LI , Zhen Zong ZHANG , Tie Feng CHEN , Xu Rui XIAO
1996, 7(11): 1037-1038
[Abstract](178) [FullText HTML] [PDF 144KB](2)
Abstract:
The stability of the photoluminescence(PL)from porous silicon(PS)has evidently improved by HNO3 chemical oxidation.The PL intensity and peak wavelength of PS were changed with the increase of HNO3 concentration and oxidation time.Being different from other oxidized ways,the PS oxidized by HNO3 remains sensitive to adsorbates.PTIR spectroscopic data suggest that these phenomena are attributed to the presence of HSi(SiaO3-a)(a≤3)layer on PS surface.
Synthesis and Characterization of Thermotropic Liquid Crystalline Complexes Containing Ferrocenyl Group
Zhan Mei LIU , Wei LIAN , Hai Xia SHI , Tong NIU , Xi Shan LIA
1996, 7(11): 1039-1040
[Abstract](160) [FullText HTML] [PDF 92KB](0)
Abstract:
Four ferrocenyl long-chain alkyl β-diketonato zinc(Ⅱ)complexes with a general formula ZnL2(L=C5H5FeC5H4COCHCOCnH2n+1.n=6-9)were synthesized.These complexes were characterized by elementary analysis,IR.1HNMR MS、polarizing microscopy with a heating stage and DSC.It was found that the complexes have thermotropic liquid crystalline properties.The type of the heteronuclear liquid crystalline metal complexes have not been reported so far.
Studies on Porphyrin and Phthalocyanine Monolayers by Means of Compression-Recompression Isotherms and BAM
Hai Shui WANG , Wei LI , Shi Quan XI
1996, 7(11): 1041-1042
[Abstract](133) [FullText HTML] [PDF 95KB](0)
Abstract:
Monolayers of porphyrin and phthalocyanine at the air-water interface were studied by means of film balance and Brewster angle microscopy(BAM).Results showed that the final point of compression isotherm and that of recompression isotherm were coincident or not coincident depending on the target pressures.Results were discussed in terms of the morphology of monolayers observed by BAM.
Ab Initio Study on the Reaction of La++CH4→La+-CH2+H2
Rong Shun ZHU , Shu Shan DAI
1996, 7(11): 1043-1046
[Abstract](148) [FullText HTML] [PDF 186KB](0)
Abstract:
Ab initio study on the reaction of the ground state(a3F)and excited state(a1D)of La+ with methane has been performed.Reaction channel on the singlet and triplet potential energy surface(PES)has been examined and the reaction mechanism are discussed.Comparisons between singlet and triplet PESs show that the excited state(a1D)of La+ is more reactive than its ground state(a3F)due to the spin quantum number conservation with the more stable insertion intermediate for excited state(1D),which is in good agreement with the experiment.
Investigation of Deuterium Isotope Effects in the Carbon Dioxide Reforming of Methaneto Syngas over Rhodium Catalysts
Hai You WANG , Chak Tong AU
1996, 7(11): 1047-1050
[Abstract](162) [FullText HTML] [PDF 185KB](0)
Abstract:
Deuterium isotope effects in the CO2-reforming of methane to syngas were first investigated over SiO2-supported rhodium catalysts.Normal deuterium isotope effect was more noticeable on the methane conversion reaction than on the CO formation reaction,while there was no such effect on the CO2 conversion reaction.It can be concluded that the dissociation of the C-H bond in methane is a key step and some CO is formed by the reverse water-gas shift reaction.
The Evolution of IR Spectra of H2 Adsorbed on ZrO2 with Changing Temperature(298-723K)
Wen LI , Yuan Qi YIN , Rui Ling HOU , Pei Ju NHENG
1996, 7(11): 1051-1053
[Abstract](145) [FullText HTML] [PDF 121KB](0)
Abstract:
I.r.bands at 1559.0,1441.0,1378.9,1360.3,1031.1,981.4 and 947.3 cm-1 due to various types of dissociative adsorption of H2 over ZrO2 with changing temperature were observed by in situ FT-IR spectroscopy.
Synthesis and Electrical Properties of Some Carbonium-Metal-(DMIT)2 Complexes
Shu Qing SUN , Pei Ji WU , Dao Ben ZHU
1996, 7(11): 1054-1056
[Abstract](154) [FullText HTML] [PDF 133KB](0)
Abstract:
Several precursors of organic conductors based on metal-(dmit)2 anion complex with carbonium as counter cations were first synthesized.Some of them exhibit greatly increased conductivities upon iodine doping.
Room-Temperature Synthesis of Fe-containing Mesoporous Silica
Zhong Yong YUAN , Tie Hong CHEN , Jing Zhong WANG , He Xuan LI
1996, 7(11): 1057-1058
[Abstract](131) [FullText HTML] [PDF 80KB](0)
Abstract:
A Fe-containing mesoporous silica has been synthesized at room temperature using alkylamine as templating surfactant;XRD,IR,ESR and 29Si MAS NMR spectra provided evidence of the presence of framework and non-framework iron(Ⅲ)in Fe-HMS material.
Characterization of Oxygen Species on MgO(100) Surface by XPS andSRPES
Jian Wen DA , Shi Kong SHEN
1996, 7(11): 1059-1060
[Abstract](163) [FullText HTML] [PDF 108KB](0)
Abstract:
The present work reported the results of the characterization of the surface oxygen species on single crystal MgO(100)using surface sensitive analyzing methods ARXPS(angular resolved X-ray photoelectron spectroscopy)and SRPES(synchrotron radiation photoelectron spectroscopy).
Study on the Methods Of Adsorbent Enriching-SFE Desorbing and Off-line GC-MS-DS Determination of Trace Organic Pollutants from Coal Smoke
Zhao Jie CUI , Lian Chun GAO , Chun Yang ZhANG , Shu Ren WANG
1996, 7(11): 1061-1064
[Abstract](163) [FullText HTML] [PDF 261KB](0)
Abstract:
The optimum conditions of supercritical fluid extraction(SFE)desorping the organic pollutants adsorbed and enriched by the adsorbent Porapak P and the effects of the conditions on the efficiencies of SFE desorping organic pollutants are studied emphatically.Different kinds of organic adsorbents and modifiers were tested.The recoveries of SFE are compared with Soxhlet extraction.The recoveries between 93.1% and 109.3% are obtained for 25 kinds of compounds at 35 MPa,100℃ and 9.0 ml SF-CO2,and their relative standard deviations(RSD)are in the range of 0.6-12.6 percent.
periodic TableClassification Method Using Three Parameters"ZI/ZT/Pn"for Organic Compounds
Xin Ming LI
1996, 7(11): 1065-1066
[Abstract](144) [FullText HTML] [PDF 120KB](0)
Abstract:
In this paper,the "periodic table" (PT)classification method(PTCM)using three parameters "Z1/ZT/Pn" for organic compounds has been presented.About 460 classes of compounds have been classified by PTCM.
Address:Zhongguancun North First Street 2,100190 Beijing, PR China Tel: +86-010-82449177-888
Powered By info@rhhz.net