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1.
E. F. Dankova V. A. Bakulev Yu. Yu. Morzherin 《Chemistry of Heterocyclic Compounds》1992,28(8):931-936
The reaction of malonothioamides with benzene-sulfonyl azide and 2-azido-3-ethylbenzthiazolium tetrafluoroborate gave amides of 2-diazothiomalonic acid, which underwent cyclization to a mixture of 5-N-R-amino-1,2,3-thiadiazole-4-carbothioamides and 5-amino-1,2,3-thiadiazole-4-N-R-carbothioamides. The ratio of the isomeric thiadiazoles formed in this reaction is the same as in the reactions of 2-diazo-2-cyanoacetamides, 5-amino-1,2,3-thiadiazole- and 5-mercapto-1,2,3-triazole-4-carboxamides with P4S10 and of 5-amino-1, 2,3-thiadiazole-4-carbonitriles with H2S; it is characteristic of the influence of substituents on the reactivity of -diazothioacetamides. It was found that the cyclization of the diazo compounds is accelerated when electron-acceptor substituents are attached to the nitrogen atom of the carbothioamide group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1106–1112, August, 1992. 相似文献
2.
Rong ZHENG Chang Jin ZHU Yi LIU Dong WANG 《中国化学快报》2006,17(4):434-436
A pair of derivatives of tetrameric N-methylpyrrole polyamide were synthesized in order to develop a new method for the study of interaction of the polyamide derivatives with DNA. Indole acetic acid and nicotinic acid were introduced to the polyamide in the synthesized compound, which showed an expected red shift in the UV spectrum. These compounds may function as a potential tool in the detection of the polyamide binding to DNA. 相似文献
3.
StructureofPotassiumofUndecatungstomononickelosilicateQuLun-Yu;MaRong-Hua;ChenYa-Guang(DepartmentofChemistry,NortheastNormalU... 相似文献
4.
LUO Su Zhang Feng-chun SUN Chang-jiang LIU Cheng-bai ZHUANG Jiang-xing ZHANG Jin 《高等学校化学研究》2004,20(3)
The DNA of P3 promoter region of IGF-Ⅱ gene was obtained by means of PCR technique. The examination of DNA polymorphism by restriction endonuclease BstE Ⅱ and the examination of AFP by bioluminescence immunoassay technique were carried out. The results have a significant difference(P<0.005). But the positive rate of AFP is higher than that of DNA polymorphism. The experimental result shows that the change of the DNA polymorphism of IGF-Ⅱis not the only carcinogenic factor. The suggested unite examination is the best method for the diagnosis of the primary hepatocellular carcinoma. 相似文献
5.
LUO Su ** ZHANG Feng-chun SUN Chang-jiang LIU Cheng-bai ZHUANG Jiang-xing ZHANG Jin . Medical college Beihua University Jilin P. R. China . Collgege of Life Science Jilin University Changchun P. R. China . Affiliated Hospital of Nantorg Medical College Nantong Medical College Nantong P. R. China . Zhangzhou Institute for Drug Control Zhangzhou P. R. China 《高等学校化学研究》2004,20(3):314-316
IntroductionTheinnatecharacterofthesolidcarcinomaistheresultthatcellgrowthgetsoutofcontrol.Itsbasicreasonconsistsintheabnormalityofthetumorgene .SomeonethinksthatthegeneofIGF Ⅱisoneofthecancergenesofthe primaryhepatocellularcarcino ma[1] ,andalsothinkstheoverexpressionofthegeneofIGF Ⅱtakesplaceintheearlierperiodofthepri maryhepatocellularcarcinoma ,whichmaybetheear lierdiagnosticnormofprimaryhepatocellularcarcino ma .ThefurtherresearcheshavedemonstratedthattheactivationofIGF Ⅱ genepromo… 相似文献
6.
类胡萝卜素是一类奇特的色素,由高等植物和微生物光化学合成,作为防止单线氧通过光敏反应产生危害的必要基团,类胡萝卜素最近受到了关注。类胡萝卜素联于富勒烯上,既可大大增加在可见光区域光诱导电子转移的有效吸收断面,又可抑制富勒烯敏化单线氧的危害能力。合成了类胡萝卜素的相关化合物,报道的某些反应条件先进且简洁。 相似文献
7.
The kinetics of transformation of 1,3,4,7-tetramethylisoindole(1)to 1,3,4,7-tetramethyl-1H-isoindole(2)in water or in deuterium oxide at various pH or pD at 25℃ were measuredspectrophotometricalty.The results indicated that the transformation of 1 to 2 could be promotedby acid and base.From the solvent isotope effects and the fact that the 1-position of isoindole nucleusis electron-rich,the mechanism of this transformation is suggested. 相似文献
8.
In the present investigation,the non-volatile constituents of Danguei (Tang-Kuei) roots of Gansu origin [Angelica sinensis (Oliv.) Diels] were analyzed and thirty seven organic constituin s were also identified,fifteen of which have not been recorded in literature before,including a new optically active compound named as Angelicide and an antibiotie,Brereldin A.By plasma emission spectrometry,thirteen minor elements were also detecled 相似文献
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10.
Yu. A. Andrianov L. G. Sedova V. L. Shirokii V. A. Knizhnikov 《Russian Chemical Bulletin》1993,42(11):1902-1905
The decomposition of alkylcyclopentadienyl nitrosyl -complexes of nickel, (C5H4R)(NO)Ni (R=H, Et,i-Pr, CH2Ph), under the action of electron impact has been studied. The nature of the nitrosyl ligand has been shown to be the factor determining the main fragmentation pathway which involves the abstraction of an NO molecule. The effect of the nature of the ligand on the ability of the molecular ion (C5H4R)LNi+ (L=C5H4R, C5H5, C3H5, NO) to rearrange with hydrogen atom migration from one ligand to another has been considered. The structure of the alkyl group R determines a competing fragmentation pathway involving cleavage of the -C-C bond with respect to the cyclopentadienyl ring in the substituent.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1985–1988, November, 1993. 相似文献
11.
《合成化学》2004,(Z1)
Gossypol was obtained as an yellow platelike crystal with m.p. 210-214o . In CDCl3 there were three tautomers of gossypol: I aldehyde, II lactol,III ketal , in equilibrium .Their total H 1 NMR spectra were assigned by means of 1D and 2D NMR techniques including 1H-1H cosy , DEPT , HMQC (1H Detected Heteronuclear Multiple Quantum Coherence) and HMBC (1H Detected Heteronuclear Multiple Bond Connectivity) experiments . This paper first reported that we took use of the 2D NMR t… 相似文献
12.
S. G. Pukhovskaya Yu. B. Ivanova Dao The Nam A. S. Vashurin 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2014,88(10):1670-1676
Spectrophotometric titration is used to study the basic properties of a series of porphyrins with a continuously increasing degree of macrocycle deformation resulting from the introduction of strong electron-withdrawing substituents: 2,3,7,8,12,13,17,18-octaethylporphyrin (I), 5-nitro-2,3,7,8,12,13,17,18-octaethylporphyrin (II), 5,15-dinitro-2,3,7,8,12,13,17,18-octaethylporphyrin (III), 5,10,15-trinitro-2,3,7,8,12,13,17,18-octaethylporphyrin (IV), and 5,10,15,20-tetranitro-2,3,7,8,12,13,17,18-octaethylporphyrin (V). It is found that the values of logK b (total basicity constants) obtained for the investigated compounds consistently diminish with an increase in the number of meso-substituents: 11.85 (I) > 10.45 (II) > 10.31 (III) > 10.23 (IV) > 9.56 (V). It is shown that two opposing factors, the steric and electronic effects of the substituents, change the basic properties of the above series of compounds. 相似文献
13.
《European Polymer Journal》1986,22(10):769-773
Effects of the concentrations and ratio of reacting components and of temperature on the kinetics of reaction of N-propionyllactam (I) with potassium salt of lactam (KL) were studied for derivatives of ϵ-caprolactam, 8-octanelactam and 12-dodecanelactam. For ϵ-caprolactam, the initial rates of propagation, acylation of open-chain amide groups and condensation of growth centres were estimated. At the ratio of the starting components [I]0/[KL]0 = 0.5-3, the participation of the polymerization reaction is constant, amounting to ca 45% of the overall consumption of 1. The condensation reaction is 14–36% of the total consumption of I; its initial rate passes through a maximum at [I]0/[KL]0 = 2. With increasing permittivity of the medium, the total rate of consumption of I increases; in two media with the same bulk permittivity, however, the rates may differ by as much as one order of magnitude. 相似文献
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15.
R. G. Savchenko Ya. R. Urazaeva S. A. Kostyleva V. N. Odinokov 《Russian Journal of Organic Chemistry》2013,49(4):610-613
Ozonolysis of ω-anhydro-20-hydroxyecdysone diacetonide gave a mixture of 24- and 25-oxo derivatives, and only the first of these (23-carbaldehyde) reacted with malonic acid according to Knoevenagel to give 14α-hydroxy-2β,3β: 20,22-bis(isopropylidenedioxy)-6-oxo-27-nor-5β-cholesta-7,24-dien-26-oic acid. The oxidation of 23-carbaldehyde with ozone, followed by treatment with diazomethane, afforded 20-hydroxy-25,26,27-trinorecdysone-23-carboxylic acid methyl ester diacetonide. 相似文献
16.
Construction of the Skeleton of Phthalascidin, Mechanism of the Formation of the Key Tricyclic Lactam Intermediate 总被引:1,自引:0,他引:1
Zhan Zhu LIU Ye WANG Shi Zhi CHEN* Institute of Materia Medica Chinese Academy of Medical Sciences& Peking Union Medical College Beijing 《中国化学快报》2002,13(8)
Phthalascidin is a structurally simplified version of Et-743, which is a potent anti-tumor marine natural product isolated from Ecteinascidia turbinata. Its antiproliferative activity is greater than that of the agents taxol, camptothecin, adriamycin, mitomycin C, cisplatin, bleomycin, and etoposide by 1-3 orders of magnitude. An elegant synthesis of Et-743 and phthalascidin has been reported by E. J. Corey and co-workers1,2. As part of our continuing program, we have also engaged in dev… 相似文献
17.
Numerous studies postulated the possible modes of anthelmintic activity by targeting alternate or extended regions of colchicine binding domain of helminth β-tubulin. We present three interaction zones (zones vide −1 to −3) in the colchicine binding domain of Haemonchus contortus (a helminth) β-tubulin homology model and developed zone-wise structure-based pharmacophore models coupled with molecular docking technique to unveil the binding hypotheses. The resulted ten structure-based hypotheses were then refined to essential three point pharmacophore features that captured recurring and crucial non-covalent receptor contacts and proposed three characteristics necessary for optimal zone-2 binding: a conserved pair of H bond acceptor (HBA to form H bond with Asn226 residue) and an aliphatic moiety of molecule separated by 3.75 ± 0.44 Å. Further, an aliphatic or a heterocyclic group distant (11.75 ± 1.14 Å) to the conserved aliphatic site formed the third feature component in the zone-2 specific anthelmintic pharmacophore model. Alternatively, an additional HBA can be substituted as a third component to establish H bonding with Asn204. We discern that selective zone-2 anthelmintics can be designed effectively by closely adapting the pharmacophore feature patterns and its geometrical constraints. 相似文献
18.
Eight of new 5-oxo[1] benzopyrano [2,3-b] pyridines as the analogues of tetracycline, were designed and synthesized, and their affinity to the hydroxyapatite-the inorganic composition of bone were tested. 相似文献
19.
Russian Chemical Bulletin - Dehydrogenation of cyclohexane on crystalline α-Cr2O3 proceeds according to a sextet-type mechanism. This conclusion agrees with the structural principles of... 相似文献
20.
Ching‐Wan Lam 《Journal of mathematical chemistry》2000,27(1-2):23-25
Henze and Blair [2] have successfully derived algorithms for enumerating the number of constitutional isomers of aliphatic
compounds using alkyl radicals; however, the algorithms cannot be extended to enumerate constitutional isomers of cyclic compounds.
Similarly, Read [4] has advocated the use of alkyl biradicals to enumerate constitutional isomers of aliphatic compounds,
but not cyclic compounds. Apparently, the use of alkyl biradicals in the enumeration of constitutional isomers of cyclic compounds
has been neglected. In this communication, an algorithm using alkyl biradicals to enumerate the number of constitutional isomers
of cyclic compounds, namely alkylcyclopropanes, is described.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献