Epithelial-to-Mesenchymal Transition Is Not a Major Modulating Factor in the Cytotoxic Response to Natural Products in Cancer Cell Lines

Numerous natural products exhibit antiproliferative activity against cancer cells by modulating various biological pathways. In this study, we investigated the potential use of eight natural compounds (apigenin, curcumin, epigallocatechin gallate, fisetin, forskolin, procyanidin B2, resveratrol, urolithin A) and two repurposed agents (fulvestrant and metformin) as chemotherapy enhancers and mesenchymal-to-epithelial (MET) inducers of cancer cells. Screening of these compounds in various colon, breast, and pancreatic cancer cell lines revealed anti-cancer activity for all compounds, with curcumin being the most effective among these in all cell lines. Although some of the natural products were able to induce MET in some cancer cell lines, the MET induction was not related to increased synergy with either 5-FU, irinotecan, gemcitabine, or gefitinib. When synergy was observed, for example with curcumin and irinotecan, this was unrelated to MET induction, as assessed by changes in E-cadherin and vimentin expression. Our results show that MET induction is compound and cell line specific, and that MET is not necessarily related to enhanced chemosensitivity.     

Structural and magnetic studies on mono- and polynuclear chromium ascorbate complexes

Polynuclear chromium ascorbate complexes were isolated and physicochemically analyzed in a comparative manner with their mononuclear analog (1). Characterization by elemental analysis, electronic, vibrational, ¹³C-n.m.r and mass spectroscopies, and variable temperature magnetic susceptibility studies, allowed structural proposals for the binuclear, [Cr₂(μ-OH)₂(H₂O)(C₆H₇O₆)₃(OH)] · 4H₂O (2), and trinuclear, [Cr₃(μ-O)₃(H₂O)₆(C₆H₇O₆)₃] · 4 H₂O (3) complexes. The pseudo-octahedral Cr^III centers were suggested to be connected through hydroxo bridges in (2) and in (3) by oxo bridges forming a hexocyclic ring. An erratum to this article is available at .     

Scalable total synthesis of (-)-berkelic acid by using a protecting-group-free strategy

Supply chain: the polycyclic core of (-)-berkelic acid (1) was constructed in just one step from very simple starting materials. The total synthesis of 1 involves a seven-step linear sequence. Protection/deprotection steps were avoided and all but the last step were performed on a gram scale. This synthesis could solve the supply problem associated with the exhaustion of the natural source.     

Synthesis and characterization of an acrylate polymer containing chlorine-1,3-dioxalane groups in side chains

Poly[2-（4-chlorophenyl）-1,3-dioxolan-4-yl]methyl acrylate,poly（CPhDMA）,was synthesized with radical polymerization process using 2,2′-azobisisobutyronitrile as radical initiator in 1,4-dioxane at 60℃.The structure of poly（CPhDMA） was confirmed by means of UV-Vis,FT-IR,¹H-NMR,and ¹³C-NMR spectral techniques.The molecular weight distribution values of the polymer were determined with gel permeation chromatography（GPC）.The number-average molecular weight（M_n）,weight-average molecular weight（M_W） and polydispersity index（PDI） values of poly（CPhDMA） were determined to be 10300,21600 and 2.097,respectively.The thermal degradation kinetics of the polymer was investigated by using TG/DTG-DTA and DSC analyses at different heating rates in dynamic nitrogen atmosphere.The apparent activation energy values obtained by Flynn-Wall-Ozawa and Friedman methods were found to be 91.68 and 85.23 kJ mol^-1,respectively,for thermal decomposition of poly（CPhDMA）.Also,the thermal degradation activation energy value of poly（CPhDMA） was calculated by using the Kissinger method based on the DTG,DTA and DSC data.Then the mechanism function of it was determined by master plots method.Finally,electrical and optical properties of poly（CPhDMA） were determined by four-point probe and UV-Vis techniques,respectively.     

The reaction of N-tosyl imines with heteroaromatic compounds: a new access to triheteroarylmethanes

Useful triheteroarylmethanes were prepared by the double Friedel-Crafts reaction of a wide variety of aromatic N-tosyl imines with furan, thiophene, and pyrrole in the presence of Cu(OTf)₂ and Montmorillonite K-10 clay catalysts.     

Cation Additive Enabled Rechargeable LiOH-Based Lithium–Oxygen Batteries

Lithium–oxygen (Li–O₂) batteries have attracted extensive research interest due to their high energy density. Other than Li₂O₂ (a typical discharge product in Li–O₂ batteries), LiOH has proved to be electrochemically active as an alternative product. Here we report a simple strategy to achieve a reversible LiOH-based Li–O₂ battery by using a cation additive, sodium ions, to the lithium electrolyte. Without redox mediators in the cell, LiOH is detected as the sole discharge product and it charges at a low charge potential of 3.4 V. A solution-based reaction route is proposed, showing that the competing solvation environment of the catalyst and Li⁺ leads to LiOH precipitation at the cathode. It is critical to tune the cell chemistry of Li–O₂ batteries by designing a simple system to promote LiOH formation/decomposition.