Synthesis,Antibacterial, and Antioxidant Evaluation of Novel Series of Condensed Thiazoloquinazoline with Pyrido,Pyrano, and Benzol Moieties as Five- and Six-Membered Heterocycle Derivatives

A novel synthesis of thiazolo[2,3-b]quinazolines 4(a–e), pyrido[2′,3′:4,5]thiazolo[2,3-b]quinazolines {5(a–e), 6(a–e), and 7(a–e)}, pyrano[2′,3′:4,5]thiazolo[2,3-b]quinazolines 8(a–e), and benzo[4,5]thiazolo[2,3-b]quinazoloine9(a–e) derivatives starting from 2-(Bis-methylsulfanyl-methylene)-5,5-dimethyl-cyclohexane-1,3-dione 2 as efficient α,α dioxoketen dithioacetal is reported and the synthetic approaches of these types of compounds will provide an innovative molecular framework to the designing of new active heterocyclic compounds. In our study, we also present optimization of the synthetic method along with a biological evaluation of these newly synthesized compounds as antioxidants and antibacterial agents against the bacterial strains, like S. aureus, E. coli, and P. aeruginosa. Among all the evaluated compounds, it was found that some showed significant antioxidant activity at 10 μg/mL while the others exhibited better antibacterial activity at 100 μg/mL. The results of this study showed that compound 6(c) possessed remarkable antibacterial activity, whereas compound 9(c) exhibited the highest efficacy as an antioxidant. The structures of the new synthetic compounds were elucidated by elemental analysis, IR, ¹H-NMR, and ¹³C-NMR.     

Multiplicity studies and effective energy in ALICE at the LHC

In this work we explore the possibility to perform “effective energy” studies in very high energy collisions at the CERN large hadron collider (LHC). In particular, we focus on the possibility to measure in pp collisions the average charged multiplicity as a function of the effective energy with the ALICE experiment, using its capability to measure the energy of the leading baryons with the zero degree calorimeters. Analyses of this kind have been done at lower centre-of-mass energies and have shown that, once the appropriate kinematic variables are chosen, particle production is characterized by universal properties: no matter the nature of the interacting particles, the final states have identical features. Assuming that this universality picture can be extended to ion–ion collisions, as suggested by recent results from RHIC experiments, a novel approach based on the scaling hypothesis for limiting fragmentation has been used to derive the expected charged event multiplicity in AA interactions at LHC. This leads to scenarios where the multiplicity is significantly lower compared to most of the predictions from the models currently used to describe high energy AA collisions. A mean charged multiplicity of about 1000–2000 per rapidity unit (at η∼0) is expected for the most central Pb–Pb collisions at . In memory of A. Smirnitskiy     

The Formation of Imidazolium Salt Intimate (Contact) Ion Pairs in Solution

1‐n‐Butyl‐2,3‐dimethylimidazolium (BMMI) ionic liquids (ILs) associated with different anions undergo H/D exchange preferentially at 2‐Me group of the imidazolium in deuterated solvents. This process is mainly related to the existence of ion pairs rather than the anion basicity. The H/D exchange occurs in solvents (CDCl₃ and MeCN for instance) in which intimate contact ion pairs are present and the anion possesses a labile H in its structure, such as hydrogen carbonate and prolinate. In D₂O, separated ion pairs are formed and the H/D exchange does not occur. A plausible catalytic cycle is that the IL behaves as a neutral base in the course of all H/D exchange processes. NMR experiments, density functional calculations, and molecular dynamics simulations corroborate these hypotheses.     

Performance studies of a full-length prototype for the CASTOR forward calorimeter at the CMS experiment

The Time-Of-Flight detector (TOF) of the ALICE experiment at the CERN LHC is based on Multi-gap Resistive Plate Chambers (MRPCs). The TOF detector consists of 152928 readout channels covering a total area of 141 m². In this paper the results of the calibration with cosmic-ray data collected during 2009 are presented.     

Novel inorganic frameworks constructed from double-four-ring (D4R) units: computational design,structures, and lattice energies of silicate,aluminophosphate, and gallophosphate candidates

The design of new and interesting inorganic frameworks is an ongoing challenge in materials sciences. New structures containing double-four-ring (D4R) units have recently received particular attention. The present work focuses on the computational design of new three-dimensional frameworks made of D4R units exclusively. In a first step, our simulations explore the possible ways to assemble predefined D4R units in 3D space using a sophisticated cascade of simulated annealing/minimizations steps (autoassembly of secondary building units method). While the existing zeotype topologies were successfully generated, new topologies were predicted including very open frameworks containing new types of cages. In a second step, lattice energy minimizations were performed to estimate the viability of these hypothetical frameworks as silicate, aluminophosphaste, and gallophosphate candidates. When comparing the hypothetical structures to existing compounds, our results raise the challenging question of the appropriate chemical composition that should be aimed at for a given framework topology of interest.     

Base-promoted in situ generation of methyl acrylate from dimethyl 3, 3'-dithiodipropionate. Application To N-alkylation of heterocycles

In basic medium, dimethyl 3,3'-dithiopropionate generates methyl acrylate, which serves in situ as a source of propionate moiety. This property was applied to the alkylation of indoles and other nitrogen heterocycles leading to a series of 3-(heteroaryl-substituted) propionates. A mechanistic rationale for the generation of acrylate is presented along with supportive experimental data.     

Optical activity induced by a velocity gradient in a monatomic gas

In a pair of atoms in collision, the polarizability of the system depends on the relative velocity. The mechanism introduced here implies the time dependence of the effective field acting on the partners. The linear term of the expansion with respect to the velocity suggests the existence of an optical activity for a monatomic fluid submitted to a non-uniform flow.     

The synthesis of a leukotriene with SRS-like activity

The synthesis and biological characteristics of an SRS-like leukotriene are described.     

Photochemical rearrangement of oxaziridines and nitrones in the hexahydroindole series: a convenient synthetic route to 1-azabicyclo[5.2.0]nonan-2-ones as novel RGD mimetics

[reaction: see text] Photolysis of oxaziridines a or nitrones b provides a convenient synthetic route to fused bicyclic lactams c adequately substituted on both cycles A and B as scaffolds for mimicking conformationally constrained beta-turn peptides as in the tripeptide RGD signaling motif of fibronectin.