Design and Synthesis of (2-oxo-1,2-Dihydroquinolin-4-yl)-1,2,3-triazole Derivatives via Click Reaction: Potential Apoptotic Antiproliferative Agents

A mild and versatile method based on Cu-catalyzed [2+3] cycloaddition (Huisgen-Meldal-Sharpless reaction) was developed to tether 3,3’-((4-(prop-2-yn-1-yloxy)phenyl)methylene)bis(4-hydroxyquinolin-2(1H)-ones) with 4-azido-2-quinolones in good yields. This methodology allowed attaching three quinolone molecules via a triazole linker with the proposed mechanism. The products are interesting precursors for their anti-proliferative activity. Compound 8g was the most active one, achieving IC50 = 1.2 ± 0.2 µM and 1.4 ± 0.2 µM against MCF-7 and Panc-1 cell lines, respectively. Moreover, cell cycle analysis of cells MCF-7 treated with 8g showed cell cycle arrest at the G2/M phase (supported by Caspase-3,8,9, Cytochrome C, BAX, and Bcl-2 studies). Additionally, significant pro-apoptotic activity is indicated by annexin V-FITC staining.

Gravitational tests of electroweak relaxation

We consider a scenario in which the electroweak scale is stabilized via the relaxion mechanism during inflation, focussing on the case in which the back-reaction potential is generated by the confinement of new strongly interacting vector-like fermions. If the reheating temperature is sufficiently high to cause the deconfinement of the new strong interactions, the back-reaction barrier then disappears and the Universe undergoes a second relaxation phase. This phase stops when the temperature drops sufficiently for the back-reaction to form again. We identify the regions of parameter space in which the second relaxation phase does not spoil the successful stabilization of the electroweak scale. In addition, the generation of the back-reaction potential that ends the second relaxation phase can be associated to a strong first order phase transition. We then study when such transition can generate a gravitational wave signal in the range of detectability of future interferometer experiments.

Experimental and Theoretical Study on the Transformation Behavior of Bisphenol S by Radicals Driven Persulfate Oxidation

An in-depth study on the degradation of bisphenol S (BPS) by both single-walled carbon nanotubes and heat activated persulfate (PS) was investigated in detail. The factors like materials dosage, initial substrate concentration, initial pH and water matrix on removal of BPS were evaluated and 10 µM BPS could be completely removed in 90 min under the optimal conditions of [BPS]0: [PS]0 = 1: 100, T = 25 ℃, pH0 = 7.0, [N-SWCNTs] = 20 mg·L− 1. Fast removal of BPS was also obtained when reaction temperature reached 65 ℃ without catalyst. There were 15 intermediates identified in total; and hydroxylation, sulfate addition, carboxylation, the cleavage of S − C bond and polymerization were considered as the main transformation pathways of BPS in both two systems based on LC-MS analysis. The proportion discrepancy of •OH and SO4•− involved in two systems led to different distribution and abundance of observed products. The results of transition state calculation further confirmed the reaction potential of hydroxylation, hydrogen atom abstraction and sulfate addition, and the minimum reaction barriers were 22.20, 25.06 and 13.85 kJ/mol, respectively. The present work firstly reveals the overall transformation behavior of BPS in radicals-triggered PS system by combining experimental and theoretical study.

The Alcohol Catalytic Mechanism for Schiff Base 1,3-Proton Transfer

In order to explore the catalytic effect of alcohols on the 1,3-proton transfer of 1,1-diphenyl-N-(1-phenylethylidene) methylamine, the reaction potential energy surface was systematically studied at the theoretical level of ωB97-MV / def2-QZVPP // PBE0(D3BJ) / 6-31G**. The results show that the catalytic mechanism of benzyl alcohol can be divided into the acid channel and basic channel, in which the acid channel is the dominant one. In the first step, benzyl alcohol protonated the nitrogen atom of imine to form imine cation and benzyl alcohol anion, and the newly formed benzyl alcohol anion preferentially combined with the proton on C1; in the second step, benzyl alcohol continued to protonize the C3 atom, and the newly formed benzyl alcohol anion combined with the hydrogen on nitrogen, thus completing the whole proton migration process. By means of wave function analysis, it is proved that the stronger the hydrogen bond (O–H···N) is, the lower the free energy barrier is. When alcohols with lower pKa values are used as catalysts, the reaction barrier will be lower.

Synthesis and X-ray crystallographic analysis of free base and hexafluorophosphate salts of 3,4-dihydroisoquinolines from the Bischler–Napieralski reaction

Free base and hexafluorophosphate salts of 3,4-dihydroisoquinolines from the Bischler–Napieralski reaction: potential supramolecular modulation. Centrosymmetric/enantiomorphic crystals.