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181.
Ping He 《Journal of fluorine chemistry》2005,126(5):825-830
The reactions of fluoroalkanesulfonyl azides 1 with different indole derivatives have been studied in detail. Treatment of 1 with equimolar amount of 1,3-dimethylindole 3 in 1,4-dioxane at room temperature afforded 2-(1,3-dimethyl-1,3-dihydro-indolinylidene) fluoroalkanesulfonylimines 5 in moderate to good yields. However, under the same reaction conditions, in the case of 1 with 1,2-dimethylindole 4, the corresponding 2-fluoroalkanesulfonyl (1,2-dimethyl-1H-indol-3-yl)-amide 6 was obtained in moderate yields. In addition, the reactions of 1 and indole 7 gave different products under different conditions. Possible mechanisms of these reactions were proposed. 相似文献
182.
183.
阳、阴、非离子表面活性剂胶束对酯碱性水解的影响 总被引:13,自引:0,他引:13
应用紫外分光光度法和热动力学方法研究了芳香酸酯和正脂肪酸酯在表面活性剂DTAB、TTAB、CTAB、SDS、Brij35、TritonX-100胶束中的碱性水解反应。阳、阴、非离子表面活性剂胶束对酯的碱性水解均有禁阻作用。讨论了胶束对酯碱性水解禁阻作用的原因。 相似文献
184.
Recycling Chiral Organocatalyst (4S)-Phenoxy-(S)-proline for Direct Asymmetric Aldol Reaction in Ionic Liquid (bmim)PF6 总被引:1,自引:0,他引:1
Room temperature ionic liquid (bmim)PF6 was evaluated for recycling an organocatalyst (4S)-phenoxy-(S)-proline for direct asymmetric aldol reactions. The desired aldol products were obtained with good yields up to 93.2% and enantioselectivities up to 88.5%, and isolation of the products by simple extraction allowed recycling the ionic liquid containing the immobilized catalyst in subsequent reactions without significant decrease of yields and enantioselectivities. 相似文献
185.
The electrophoretic behavior of a sphere in a non-Newtonian fluid is investigated theoretically by analyzing the phenomenon that occurs in a spherical cavity under the condition of a weak applied electrical field. Non-Newtonian behavior in the liquid phase may be due to, for example, the addition of polymer to a colloidal dispersion to improve its stability. It may also arise from the increase in the volume fraction of the dispersed phase such as the slurry used in chemical mechanical polishing. A Carreau model is adopted to characterize the shear-thinning behavior of the liquid phase. We show that the difference between the mobility of the particle based on the present model and that based on the corresponding Newtonian fluid increases with the decrease in the thickness of a double layer. The shear-thinning nature of the liquid phase has the effect of increasing the mobility. 相似文献
186.
Yangke Wanyan Xixi Xu Kehang Liu Huidan Zhang Junai Zhen Rong Zhang Jumei Wen Ping Liu Yuqing Chen 《Molecules (Basel, Switzerland)》2020,25(23)
Inhibition of the glycolytic pathway is a critical strategy in anticancer therapy because of the role of aerobic glycolysis in cancer cells. The glycolytic inhibitor 2-Deoxy-d-glucose (2-DG) has shown potential in combination with other anticancer agents. Buforin IIb is an effective antimicrobial peptide (AMP) with broad-spectrum anticancer activity and selectivity. The efficacy of combination treatment with 2-DG and buforin IIb in prostate cancer remains unknown. Here, we tested the efficacy of buforin IIb as a mitochondria-targeting AMP in the androgen-independent human prostate cancer cell line DU145. Combining 2-DG with buforin IIb had a synergistic toxic effect on DU145 cells and mouse xenograft tumors. Combination treatment with 2-DG and buforin IIb caused stronger proliferation inhibition, greater G1 cell cycle arrest, and higher apoptosis than either treatment alone. Combination treatment dramatically decreased L-lactate production and intracellular ATP levels, indicating severe inhibition of glycolysis and ATP production. Flow cytometry and confocal laser scanning microscopy results indicate that 2-DG may increase buforin IIb uptake by DU145 cells, thereby increasing the mitochondria-targeting capacity of buforin IIb. This may partly explain the effect of combination treatment on enhancing buforin IIb-induced apoptosis. Consistently, 2-DG increased mitochondrial dysfunction and upregulated Bax/Bcl-2, promoting cytochrome c release to initiate procaspase 3 cleavage induced by buforin IIb. These results suggest that 2-DG sensitizes prostate cancer DU145 cells to buforin IIb. Moreover, combination treatment caused minimal hemolysis and cytotoxicity to normal WPMY-1 cells. Collectively, the current study demonstrates that dual targeting of glycolysis and mitochondria by 2-DG and buforin IIb may be an effective anticancer strategy for the treatment of some advanced prostate cancer. 相似文献
187.
The behavior of double proton transfer occurring in a representative glycinamide-formic acid complex has been investigated at the B3LYP/6-311 + + G( * *) level of theory. Thermodynamic and, especially, kinetic parameters, such as tautomeric energy, equilibrium constant, and barrier heights have been discussed, respectively. The relevant quantities involved in the double proton transfer process, such as geometrical changes, interaction energies, and intrinsic reaction coordinate calculations have also been studied. Computational results show that the participation of a formic acid molecule favors the proceeding of the proton transfer for glycinamide compared with that without mediate-assisted case. The double proton transfer process proceeds with a concerted mechanism rather than a stepwise one since no ion-pair complexes have been located during the proton transfer process. The calculated barrier heights are 11.48 and 0.85 kcal/mol for the forward and reverse directions, respectively. However, both of them have been reduced by 2.95 and 2.61 kcal/mol to 8.53 and -1.76 kcal/mol if further inclusion of zero-point vibrational energy corrections, where the negative barrier height implies that the reverse reaction should proceed with barrierless spontaneously, analogous to that occurring between glycinamide and formamide. Furthermore, solvent effects on the thermodynamic and kinetic processes have also been predicted qualitatively employing the isodensity surface polarized continuum model within the framework of the self-consistent reaction field theory. Additionally, the oxidation process for the double H-bonded glycinamide-formic acid complex has also been investigated. Contrary to that neutral form possessing a pair of two parallel intermolecular H bonds, only a single H bond with a comparable strength has been found in its ionized form. The vertical and adiabatic ionization potentials for the neutral complex have been determined to be about 9.40 and 8.69 eV, respectively, where ionization is mainly localized on the glycinamide fragment. Like that ionized glycinamide-formamide complex, the proton transfer in the ionized complex is characterized by a single-well potential, implying that the proton initially attached to amide N4 in the glycinamide fragment cannot be transferred to carbonyl O13 in the formic acid fragment at the geometry of the optimized complex. 相似文献
188.
Six new 4″-benzyloxyimino-4″-deoxyavermectin Bla derivatives were synthesized from avermectin Bla by the selective protection of C-5-hydroxy group,oxidation of C-4″-hydroxy group,and deprotection followed by reaction with O-substituted hydroxylamine hydrochlorides.Their structures were confirmed by IR,~1H NMR,~(13)C NMR and MS.Insecticidal activities of the derivatives against Phopalosiphum pseudobrassicae,Spodoptera exigua and Pluteua xylosteua were evaluated. 相似文献
189.
Wei Ge ZHANG Ying Hua JIN Ping QI Kai BAO Jin Guang LIN Nai Li WANG Xin Shen YAO 《中国化学快报》2006,17(1):9-11
Erythromycin has been extensively used in the treatment of bacterial infections for over 50 years1. In addition to the antimicrobial effect, the quite unique antiinflammatory activity of the erythromycin derivatives has attracted much attention as new the… 相似文献
190.