1999 Volume 10 Issue 12

Alkylation of Phenol with Methanol over Basic X Zeolites
Jun XU , Al Zhen YAN , Qin Hua XU
1999, 10(12): 983-986
[Abstract](160) [FullText HTML] [PDF 145KB](0)
Abstract:
The alkylation of phenol with methanol was studied and a high selectivity for Oalkylation was attained over alkali-metal cation-exchanged X zeolites. The transformation of primary products of the title reaction was also studied over CsX zeolite. On the basis of experimental results, a reaction scheme on CsX zeolite was suggested
Reductive Cleavage of the Se-Se Bond by the Sm-CdCl2-HMPA System:A New One-Pot Method for the Synthesis of Selenoesters
Xiao Liang XU , Ping LU , Yong Min ZHANG
1999, 10(12): 983-986
[Abstract](151) [FullText HTML] [PDF 56KB](0)
Abstract:
Treatment with Sm-CdCl2-HMPA system, dibenzyl and diphenyl diselenides react with acyl halides and acid anhydrides in one-pot to give corresponding selenoesters in good yields under mild and neutral conditions.
Alkylations of Resorcarenes and Calix[4]pyrroles in Phase Transfer Catalytic Systems
Chao Guo YAN , Jing SUN
1999, 10(12): 987-988
[Abstract](168) [FullText HTML] [PDF 86KB](0)
Abstract:
Resorcarens la-b (R'=Ph, p-MeOC6H4) Were fully alkylated with alkyl iodides or bromides in TEBA/KOH/DMF solid-liquid PTC process with 63-82% yields. whereas the three calix[4]pyrroles 3a-b (2R=2Me, (CH2)4(CH2)5) were alkylated with alkyl iodides in TBAB/50%NaOH/CH2Cl2 liquid-liquid PTC system with lower yields (10-38%).
Novel Reaction of Nitrosonium(NO+) with Hantzsch Dihydropyridines
Wang CHEN , Mei Zhong JIN , Zhong li LIU , Long Min WU
1999, 10(12): 989-990
[Abstract](180) [FullText HTML] [PDF 167KB](1)
Abstract:
The oxidation on 1,4-substituted Hantzsch 1,4-dihydropyridines with nitrosonium tetrafluorohorate (NO+BF4-) in acetonitrile gave Hantzsch pyridines in good yields. In some cases the dealkylation occurred. The evidences to draw the mechanism were presented.
Synthesis and Characterization of New Schiff Base and Polyoxa-aza Cryptands and Their Rare Earth Cryptates with [1+1] Condensation and Reduction Methods
Zhen MA , Ru Dong YANG , Lan YAN
1999, 10(12): 991-994
[Abstract](169) [FullText HTML] [PDF 191KB](0)
Abstract:
The Schiff base cryptand and its cryptates were synthesized with the methods of [1+1] condensation of trialdehyde and tris(2-aminoethyl)amine and obtained in 60-65%, 5-25% and 70-80% yields respectively with or without some rare earth elements as templates. The polyoxa-aza cryptand was produced in 72% and 60-70% yields with reduction of Schiff base and its cryptates respectively.
Synthesis of 6,8,9,12-Tetrahydroxylated Dihydroagarofuran Sesquiterpenoid from α-Santonin
Wu Jiong XIA , Liang Dong SUN , Yong Qiang TU
1999, 10(12): 995-998
[Abstract](168) [FullText HTML] [PDF 133KB](0)
Abstract:
The tittle compound has been synthesized successfully through the efficient and selective functional transformation of α-santonin This procedure is the first successful approach developed for synthesis of the dihydroagarofuran kind of sesquiterpenoids from the eduesmanolide sesquiterpenoid α-santonin.
Synthesis and Antitumor Activity of 4β-(1,2,3-Triazol-1-yl) podophyllotoxins
Chang Nian CAO , Yu Yin CHEN , Yan Guang WANG , Yao Zu CHEN
1999, 10(12): 999-1002
[Abstract](170) [FullText HTML] [PDF 107KB](0)
Abstract:
Three 4β-(1,2,3-triazol-l-y1) podophyllotoxins 2~4 have been synthesized and tested for their antitumor activity in vitro. The compound 3 was found to be much more cytotoxic than the clinically used etoposide (VP-16) against L1210 cells.
Synthesis of Cholesterol Derivative with Amino Acid as Hydrophilic Group and the Vesicles Prepared Therefrom
Zi Chen LI , Wei JIN , Fu Mian LI
1999, 10(12): 1003-1006
[Abstract](163) [FullText HTML] [PDF 273KB](0)
Abstract:
Three single chain amphiphilic cholesterol derivatives with amino acid as hydrophilic groups,Ⅰ, Ⅱ and Ⅲ, were synthesized. When they were hydrated in water, they can all form lamellae structures as evidenced by DSC measurement. The lamellae states of Ⅱ and Ⅲ can be converted to vesicles upon ultrasonication of the diluted aqueous solutions. The vesicles showed very slow release rate of the encapsulated water-soluble dyes, indicating that they are stable and belong to the least permeable vesicles.
Synthesis of Macrocyclic Arsinous Acid Esters
Xin You CHEN , Ying Qin YANG , Wen Tian TAO
1999, 10(12): 1007-1012
[Abstract](174) [FullText HTML] [PDF 86KB](0)
Abstract:
The reactions of the bis (dimethylamino) alkylarsine with diols lead to the formations of macrocyclic arsinous acid esters. The synthesis of title compounds was described and their structures were characterized by elemental analysis, IR, 1HNMR, and MS.
Synthesis and Characterization of Reactive Poly(Aryl Ether Ketone Ketone) Containing Cyclohexene Ring
Ying Nan XUAN , Xi Gao JIAN , Zhi Yong XU
1999, 10(12): 1013-1014
[Abstract](158) [FullText HTML] [PDF 72KB](0)
Abstract:
A novel heterocyclic poly (aryl ether ketone ketone) (PPEKK) containing cyclohexene ring was prepared from 1-methyl-cyclohex-l-ene-4,5-diyl-bis(4-chlorophenyl methanone) and 4-(4-hydroxyphenyl)(2H) phthalazin-l-one. The polymer was characterized by FTIR, 1HNMR, DSC, TG and X-ray analysis
Synthesis and Effect of Cation Binding on Photophysical Properties of 1,8-Anthraceno-18-Crown-5
Hua JIANG , Hui Jun XU , Pei Jie XIA , Qing Fu ZHOU
1999, 10(12): 1015-1018
[Abstract](180) [FullText HTML] [PDF 137KB](0)
Abstract:
A new type of anthracene crown ether 1,8-anthraceno-l8-crown-5 has been synthesized and the photophysical properties upon complexation with alkali and alkaline-earth metal cations were investigated.The fluorescence quantum yield and lifetime are appreciably enhanced, and the stability constant Ks were determined by fluorometric titration. It was found that the magnitude of Ks is controlled by the size and charge density of the complexed cations.
Synthesis and Study of Two-Photon Induced Fluorescence of Novel Dyes
Li Zhu WU , Xin Jing TANG , Min Hua JIANG , Chen Ho TUNG
1999, 10(12): 1019-1022
[Abstract](176) [FullText HTML] [PDF 132KB](0)
Abstract:
The synthesis and upconverted fluorescent properties of three novel organic compounds with the structure:donor/bridge/acceptor are reported. The dyes show strong upconverted fluorescence.
Two New Diterpenoid Glucosides from Clerodendrum serratum
Hui YANG , Jia WANG , Ai Jun HOU , Zhong Wen LIN , Han Dong SUN
1999, 10(12): 1023-1026
[Abstract](176) [FullText HTML] [PDF 133KB](0)
Abstract:
Two new diterpenoid glucosides,cleroserroside A and cleroserroside B, were isolated from the aerial parts of Clerodendrum serratum var. amplexifolium Moldenke. Their structures were characterized by spectral and chemical methods.
A Minor New Diterpenoid Alkaloids from the Roots of Delphinium Souliei Franch
Lan HE , Yuan Jiang PAN , Bo Gang LI , Yao Zu CHEN
1999, 10(12): 1027-1028
[Abstract](168) [FullText HTML] [PDF 71KB](0)
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A minor new diterpenoid alkaloid, soulidine, was isolated from the roots of Delphinium Souliei Franch, its structure was established on the basis of spectral evidences.
A Novel Sesquiterpenoid from Coleus xanthanthus
Shuang Xi ME , Chao Ming LI , Hui Lan ZHENG , Qi Tai ZHENG , Yang LU , Han Dong SUN
1999, 10(12): 1029-1030
[Abstract](175) [FullText HTML] [PDF 84KB](0)
Abstract:
Phytochemical re-investigation of Coleus xanthanthus led to the isolation and identification of a novel sesquiterpenoid 1, named as 4,5,11-trimethyl-8,9-seco-1(10),7(11)-eremophiladien-8,12-o1id-9-oic acid. The structure of 1 was elucidated by modern spectroscopic methods, especially by X-ray diffraction.
Three New Triterpenoid Saponins from the Seeds of Aesculus chinensis
Xiu Wei YANG , Jing ZHAO , Yu Xin CUI
1999, 10(12): 1031-1034
[Abstract](177) [FullText HTML] [PDF 156KB](0)
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Three new triterpenoid saponins, escins IVg (1), IVh (2) and VIb (3) were isolated from the seeds of Aesculus chinensis along with two known saponins, escin Ⅲa (4) and desacylescin I (5). Their structures were elucidated by spectroscopic analysis and chemical hydrolysis.
A New Triterpenoid Saponin from Anemone tomentosa
Xun LIAO , Shu Lin PENG , Bo Gang LI , Yao Zu CHEN , Li Sheng DING
1999, 10(12): 1035-1036
[Abstract](174) [FullText HTML] [PDF 84KB](0)
Abstract:
A new triterpenoid saponin, tomentoside (5), together with prosapogenin CP 4 (1), huzhangoside B (2), C (3) and D (4) was isolated from the ethanolic extract ofAnemone tomentosa. Its structure was established by spectroscopic and chemical evidence.
Two New Cyclic Peptides from Psammosilene tunicoides
Zhong Tao DING , You Chu WANG , Jun ZHOU , Ning Hua TAN , Hou Ming WU
1999, 10(12): 1037-1040
[Abstract](170) [FullText HTML] [PDF 141KB](0)
Abstract:
From Psammosilene tunicoides W. C. Wu et C. Y. Wu, two cyclic octapeptides (named psammosilenins A and B) were isolated. Their structures were determined as cyclo(-Pro1-Phe1-Pro2-Phe2-Phe2-Ala-Pro3-Leu-) and cyclo(-Pro1-Gly-Phe1-Val-Pro2-Phe2-Thr-Ile-) by spectroscopic methods.
UV-visible Absorption Studies of Tetrachloro-p-benzoquinone and Tertiary Amines Charge Transfer Complexes in Trichloromethane
Fang GAO , Yong Yuan YANG
1999, 10(12): 1041-1044
[Abstract](170) [FullText HTML] [PDF 111KB](0)
Abstract:
The spectophotometry of charge transfer (CT) complexes of tetrachloro-p-benzoquinone (TCB) with tertiary amine [triethylamine (TEA), triphylamine (TPA), N,N-dimethylphenylamine (DMPA), N-ethylcarbazole (ECZ)] have been studied in dichloromethane in L1V-visible region. The CT complexes parameter, molar ratio of reactants in complex, molar extinction coefficient εCT, equilibrium constant KCT, free energy 0G and dissociation energy of the CT complex excited state E, have also been estimated and discussed.
Spectroscopic Study of the Interaction between New Fluorescent Dyes with Nucleic Acids
Xue Mei WANG , Lin Tao CAI
1999, 10(12): 1045-1048
[Abstract](170) [FullText HTML] [PDF 239KB](0)
Abstract:
A series of new dansylamide derivatives have been synthesized and the specific binding affinity of such fluorophores to nucleic acids has been investigated by using absorption, circular dichroism (CD), fluorescence and atomic force microscopy (AFM) The results indicate that the positive charge of the ligand and the π-π stacking between the dansyl part of the ligand and the DNA base pair may play an important role when binding to polynucleotides.
XPS Study of the Oxygen on A2BO4-type Compounds-A New Discovery of O1S Peaks
Zhi MA , Yong Ning QIN , Xiao Zhou QI , Fei HE
1999, 10(12): 1049-1050
[Abstract](271) [FullText HTML] [PDF 78KB](0)
Abstract:
By means of XPS, a new O1s peak which reflects the lattice oxygen on A2BO4-type compounds is discovered, suggesting that the lattice oxygen might have two energy states on this type of material.
Standard Enthalpy of Formation of Monoclinic Ammonium Paratungstate
Shi Jun LIU , Qi Yuan CHEN , Ping Min ZHANG
1999, 10(12): 1051-1052
[Abstract](215) [FullText HTML] [PDF 81KB](1)
Abstract:
The enthalpy of reaction for the decomposition of monoclinic ammonium paratungstate, (NH4)10H2W12O424H2O(s), was measured using a HT-1000 calorimeter. From the experimental results, the standard enthalpy of formation of ammonium paratungstate at 298.15 K is obtained.
Hartree-Fock and Density Functional Theory Studies on the Molecular Recognition of the Cyclodextrin
Lei LIU , Xiao Song LI , Qing Xiang GUO , You Cheng LIU
1999, 10(12): 1053-1056
[Abstract](171) [FullText HTML] [PDF 207KB](0)
Abstract:
This study involves initial Hartree-Fock and Density Functional theory calculations on the molecular recognition of the cyclodextrins. The α-cyclodextrin-acetophenone complexation system was investigated with PM3, HF/3-21G* and B3LYP/3-21G* methods. The results indicated that the inclusion orientation in which the acetyl group of the acetophenone points towards the secondary hydroxyls of the α-cyclodextrin was preferable in energy. The steric effect was supposed as the physical reason of such a behavior. Hence, the simple rule the anti-parallel arrangement of the dipoles of the host and guest molecules in the cyclodextrin complexation is not generally applicable.
A Study on Adsorption of Electrogenerated Cystine Precipitate onto An Electrode using Electrochemical Quartz Crystal Impedance System
You Yu ZHANG , Qing Ji XIE , Yang Hui GUO , Xiang Jun WANG , Shou Zhuo YAO
1999, 10(12): 1057-1060
[Abstract](171) [FullText HTML] [PDF 231KB](0)
Abstract:
An electrochemical quartz crystal impedance system has been applied to monitor generation of precipitate and adsorption of the precipitate onto Au electrode during electrochmical oxidation and Fe(CN)63-/Fe(CN)64- electrochemical catalytic oxidation of L-cysteine in phosphate aqueous buffer (pH 7.4). Significant decreases in the resonant frequency and increases in the motional resistance and the static capacitance were found during the precipitate adsorption, and the frequency shift found in solution was ca. 2 times that in air. Similar responses of quartz crystal impedance and a white precipitate were obtained during redox titration of L-cysteine solution using K3Fe(CN)6 solution. FT-IR analysis indicated that the white precipitate is cystine. The electrode collection efficiency of the electrogenerated cystine was estimated.
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