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81.
Cancer cell metabolism is characterized by an enhanced uptake and utilization of glucose, a phenomenon known as the Warburg effect. The persistent activation of aerobic glycolysis in cancer cells can be linked to activation of oncogenes or loss of tumor suppressors, thereby fundamentally advancing cancer progression. In this respect, inhibition of glycolytic capacity may contribute to an anticancer effect on malignant cells. Understanding the mechanisms of aerobic glycolysis may present a new basis for cancer treatment. Accordingly, interrupting lactate fermentation and/or other cancer-promoting metabolic sites may provide a promising strategy to halt tumor development. In this review, we will discuss dysregulated and reprogrammed cancer metabolism followed by clinical relevance of the metabolic enzymes, such as hexokinase, phosphofructokinase, pyruvate kinase M2, lactate dehydrogenase, pyruvate dehydrogenase kinase and glutaminase. The proper intervention of these metabolic sites may provide a therapeutic advantage that can help overcome resistance to chemotherapy or radiotherapy. 相似文献
82.
Mi-Yeon Jang Xiao-Ping Song Mathy Froeyen Philippe Marlière Eveline Lescrinier Jef Rozenski Piet Herdewijn 《Chemistry & biology》2013,20(3):416-423
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83.
Jaeyoung Ko Janggyoo Choi Soo Kyung Bae Jinwoong Kim Kee Dong Yoon 《Journal of separation science》2013,36(24):3860-3865
A rapid and efficient high‐performance counter‐current chromatography (HPCCC) method was developed to separate five oligostilbenes from the roots of Vitis amurensis. An n‐hexane/ethyl acetate/methanol/water system (4:8:4:10, v/v/v/v) was selected as an optimal two‐phase solvent system of which the upper phase was used as the stationary phase and the lower phase was used as the mobile one. Partition coefficient values for the target compounds under these optimized conditions were 0.28 ( 1 , ampleosin A), 7.12 ( 2 , (+)‐g‐viniferin), 2.26 ( 3 , vitisin A), 5.38 ( 4 , wilsonol C), and 11.23 ( 5 , vitisin B). Flow‐rate gradient HPCCC (4 mL/min in 0–70 min, 8 mL/min in 70–250 min) was applied to isolate the target compounds in as high purity as possible within the shortest possible run time. Under these conditions, ampelopsin A (12.1 mg), (+)‐g‐viniferin (10.4 mg), vitisin A (2.8 mg), wilsonol C (3.2 mg), and vitisin B (37 mg) were isolated with >95% purity from 150 mg of enriched oligostilbene extract. Although the KD of the last eluted compound, vitisin B (KD = 11.23), was relatively large, it was eluted in 115–145 min using the two‐phase solvent system. This study shows that HPCCC is an efficient tool for the isolation and purification of natural products. 相似文献
84.
Cl3CCONH2/PPh3 was a versatile reagent to convert carboxylic acids into their corresponding acid chlorides. This intermediate was clearly confirmed by spectroscopic methods (IR, 1H, 13C NMR). This one-pot reaction of in situ acid chloride generated with various alcohols successfully furnished the corresponding esters in moderate to excellent yields. 相似文献
85.
Gold nanospheres modified with bifunctional molecules have been separated and characterized by using agarose gel electrophoresis as well as optical spectroscopy and electron microscopy. The electrophoretic mobility of a gold nanosphere capped with 11‐mercaptoundecanoic acid (MUA) has been found to depend on the number of MUA molecules per gold nanosphere, indicating that it increases with the surface charge of the nanoparticle. The extinction spectrum of gold nanospheres capped with MUA at an MUA molecules per gold nanosphere value of 1000 and connected via 1,6‐hexanedithiol (HDT) decreases by 33% in magnitude and shifts to the red as largely as 22 nm with the increase of the molar ratio of HDT to MUA (RHM). Gold nanospheres capped with MUA and connected via HDT have been separated successfully using gel electrophoresis and characterized by measuring reflectance spectra of discrete electrophoretic bands directly in the gel and by monitoring transmission electron microscope images of gold nanoparticles collected from the discrete bands. Electrophoretic mobility has been found to decrease substantially with the increment of HDT to MUA, indicating that the size of aggregated gold nanoparticles increases with the concentration of HDT. 相似文献
86.
Jun Hyup Lee Ihwa Jang Sook Hee Hwang Seung Jun Lee Seung Hoo Yoo 《Liquid crystals》2013,40(8):973-981
New discotic nematic liquid crystals have been prepared through intermolecular hydrogen bonding between the core of 1,3,5-trihydroxybenzene (phloroglucinol, PG) or 1,3,5-tris(4-hydroxyphenyl)benzene (THPB) and the peripheral molecules of stilbazole derivatives. The various nematic phases formed by new hydrogen bonding building blocks were investigated by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. The first discotic complexes of PG and trans-4-alkoxy-4′-stilbazoles exhibited nematic columnar (NC) and hexagonal columnar phases depending on the length of alkyl chains, which were considered as the basic discotic structure. Several structural variations on the building blocks were attempted to examine their effects on the liquid crystalline properties of discotic complexes. The nematic lateral phase (NL) with enhanced intercolumnar order was observed for the complexes of PG and trans-4-cyanoalkoxy-4′ stilbazoles due probably to the strong dipole interactions between cyano groups at the end of alkoxy chains. By introducing the nonlinear structure in three arms of supramolecular discotic mesogen, a discotic nematic phase (ND) was observed for the complex of THPB and trans-4-octyloxy-4 -stilbazole. The single hydrogen bonding between phenol and pyridine moieties in this study provides a simple and effective method for preparing the rarely found discotic nematic liquid crystals. 相似文献
87.
Woo-Kyung Jang Jumi Yun Hyung-Il Kim Young-Seak Lee 《Colloid and polymer science》2013,291(5):1095-1103
The more sensitive and rapid ammonia gas sensors were prepared with nanocomposites of polypyrrole (PPy) and graphitic materials such as graphite, graphite oxide (GO), and reduced graphene oxide (RGO). Pyrrole was polymerized uniformly on the surface of graphitic materials by in situ polymerization method. The structures of nanocomposites were studied by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy indicating the well-exfoliated GO and RGO in PPy matrix with favorable interfacial interaction. PPy/RGO nanocomposite showed the highly improved response in detecting ammonia gas mainly due to the effective electron charge transfer between PPy and ammonia and the efficient transfer of electrical resistance variation by the uniformly dispersed conductive RGO in PPy. PPy/RGO nanocomposite gas sensor also showed the excellent reproducibility in ammonia sensing behavior during the recovery process at lower temperature of 373 K. 相似文献
88.
Sun Hye Hwang Jongmin Roh Prof. Dr. Jyongsik Jang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(39):13120-13126
Enhanced harvesting of visible light is vital to the development of highly efficient dye‐sensitized solar cells (DSSCs). Nanosilver‐decorated TiO2 nanofibers (Ag@TiO2 NFs) were synthesized by depositing chemically reduced Ag ions onto the surface of electrospun TiO2 nanofibers (TiO2 NFs). The prepared Ag@TiO2 NFs were coated with SiO2 (SiO2@Ag@TiO2 NFs) by using PVP as coupling agent for protecting corrosion of Ag nanoparticle by I?/${{\rm I}{{- \hfill \atop 3\hfill}}}$ solution. The fabricated SiO2@Ag@TiO2 NFs demonstrated a synergistic effect of light scattering and surface plasmons, leading to an enhanced light absorption. Moreover, an anode consisting of SiO2@Ag@TiO2 NFs incorporating TiO2 nanoparticles (NPs) increased light harvesting without substantially sacrificing dye attachment. The power conversion efficiency increased from 6.8 to 8.7 % for a thick film (10 μm), that is, 28 %. These results suggest that SiO2@Ag@TiO2 NFs are promising materials for enhanced light absorption in dye‐sensitized solar cells. 相似文献
89.
The mixed moments for the Askey–Wilson polynomials are found using a bootstrapping method and connection coefficients. A similar bootstrapping idea on generating functions gives a new Askey–Wilson generating function. Modified generating functions of orthogonal polynomials are shown to generate polynomials satisfying recurrences of known degree greater than three. An important special case of this hierarchy is a polynomial which satisfies a four term recurrence, and its combinatorics is studied. 相似文献
90.
An efficient and simple protocol for the Meyer–Schuster rearrangement of propargyl alcohols into α,β-unsaturated carbonyl compounds has been developed using catalytic amounts of p-toluenesulfonic acid in 1,2-dichloroethane. 相似文献