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质谱技术研究儿茶素及儿茶素-锗多聚体特性 总被引:8,自引:0,他引:8
采用HPLC-ESI-Q-TOF和MALD I-TOF质谱技术分析儿茶素组成与结构,发现儿茶素中的表没食子儿茶素没食子酸酯(EGCG)具有多聚体特性。有机化学法合成EGCG-Ge4 化合物,并经HPLC进一步分离纯化。红外光谱和质谱技术分析并证实EGCG不仅能形成多聚体,而且还能络合金属锗(包括其他金属离子),成为EGCG-Ge4 和EGCG-Ge4 多聚体。EGCG-Ge4 抑制肺癌细胞生长速率明显高于EGCG,其提高幅度约为30%~40%左右。 相似文献
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Three new 8-hydroxyquinoline derivatives, i.e. 5-[(4-styryl-benzylidene)-amino]-quinolin-8-ol (1), 5-[(4-bromo-2-fluoro-benzylidene)-amino]-quinoline-8-ol (2) and 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol (3), and their metallic complexes were synthesized and identified by ultraviolet-visible (UV-Vis), 1H nuclear magnetic resonance (1H NMR), Fourier transform infrared spectrometer (FTIR), mass spectrometry (MS) spectra and elemental analyses. Their fluorescence
properties were studied by photoluminescence, which indicated that the luminescence wavelength of 5-and 2-substitued-8-hydroxyquinoline
derivatives shifted to red in comparison with that of 8-hydroxyquinoline. Meanwhile, the fluorescence lifetime of 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol
and its zinc complex showed long lifetime in benzene solution.
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Translated from Chinese Journal of Organic Chemistry, 2007, 27(3): 402–408 [译自: 有机化学] 相似文献
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We report on the bulk and surface properties of dispersions consisting of nonstoichiometric polyelectrolyte complex (PEC) nanoparticles. PEC nanoparticles were prepared by mixing poly(l-lysine) (PLL) or poly(diallyldimethylammonium chloride) (PDADMAC) with poly(maleic acid-co-alpha-methylstyrene) (PMA-MS) or poly(maleic acid-co-propylene) (PMA-P). The monomolar mixing ratio was n-/n+ = 0.6, and the concentration ranged from 1 to 6 mmol/L. Subsequent centrifugation enabled the separation of the excess polycation, resulting in a stable coacervate phase further used in the experiments. The bulk phase parameters turbidity and hydrodynamic radius (R(h)) of the PEC nanoparticles showed a linear dependence on the total polymer content independently of the mixed polyelectrolytes. This can be interpreted by the increased collision probability of the polyelectrolyte chains when the overlap concentration is approached or exceeded. Different morphologies of the cationic PEC nanoparticles, which were solution-cast onto Si supports, were obtained by atomic force microscopy (AFM). The combinations of PLL/PMA-MS and PDADMAC/PMA-MS revealed more or less hemispherical particle shapes, whereas that of PLL/PMA-P revealed an elongated needlelike particle shape. Circular dichroism and attenuated total reflection Fourier transform infrared (ATR-FTIR) measurements proved the alpha-helical conformation for the PEC PLL/PMA-P and the random coil conformation for the PEC PLL/PMA-MS. We conclude that stiff alpha-helical PLL induces anisotropic elongated PEC nanoparticles, whereas randomly coiled PLL forms isotropic spherical PEC nanoparticles. 相似文献
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The reactions of 1,1-disubstituted ethenes with 2,4-pentanedione in the presence of manganese(III) acetate and atmospheric oxygen yielded 4-acetyl-6,6-diaryl-3-methyl-1,2-dioxan-3-ols. The latter gave 4-(2-hydroperoxy-2,2-diarylemyl)-3,5-dimethylpyrazoles by the reaction with hydrazines in methanol-acetic acid (1:1 v/v) at 50° in 15-77% yields, or 4-(2-hydroxy-2,2-diarylethyl)-3,5-dimethylpyrazoles by the reaction with hydrazines in methanol in 2-78% yields. The acid-catalyzed reaction of 4-(2-hydroperoxy-2,2-diarylethyl)-3,5-dimethylpyrazoles yielded 4-(aroylmethyl)-3,5-dimethylpyrazoles (15-55%) and 4-(2,2-diarylethenyl)-3,5-dimethylpyrazoles (9-29%). 相似文献
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Yan Ouyang Wei Zhang Yue Ma Na Xu Dai-Zheng Liao Kazuyoshi Yoshimura Shi-Ping Yan 《Structural chemistry》2007,18(6):891-898
Two new tetranuclear complexes of macrocyclic oxamide [Cd(CuL)3](NO3)2·2.5H2O 1, [Mn(CuL)3(OH)2](ClO4)2·Mn(H2O)6·4.5H2O 2 (L = 1,4,8,11-tatraazacyclotradecanne-2,3-dione) have been synthesized, structurally characterized and preliminary investigated
by magnetic studies. The structures of the title complexes consist of a tetranuclear units MCu3 (M = Cd, Mn), the packing diagram shows two-dimensional and three-dimensional system through intermolecular weak interactions.
The temperature-dependent magnetic susceptibilities of complex 2 were analyzed by an approximate treatment leading to J = −33 cm−1, gCu = 2.10, gMn = 1.95 indicating antiferromagnetic exchange between Cu(II) and Mn(II) ions. 相似文献
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采用弱碱性阴离子交换树脂HJ-30对发酵液中1,6-二磷酸果糖的分离进行了研究。详细地研究了树脂的吸附和脱附性能。实验结果表明,HJ-30树脂对FDP的吸附量达0.28gFDP/g湿树脂,以0.05mol/LNaCl洗脱光机磷和1mol/LNaCl洗脱1,6-二磷酸果糖,产品的收率和纯度分别为92%和99.4%。 相似文献