Predictive ADMET study of rhodanine-3-acetic acid chalcone derivatives

Considered one of the chronic diseases in a global state of emergency, diabetes mellitus (DM) may cover an area of 629 million people affected by 2045. The main route of hyperglycemia in the human body is associated with the action of the enzyme aldose reductase on glucose molecules, resulting in the accumulation of sorbitol in blood and tissue cells. Thus, the present study is a high-throughput virtual screening (HTS) of the various molecular datasets available online, as well as an investigation of the pharmacokinetic properties of absorption, distribution, metabolism, excretion, and toxicity (ADMET) and enzyme inhibition aldose reductase from a series of derivatives of rhodanine-3-acetic acid chalcones (D1-8). Four derivatives (D1-4) showed greater oral bioavailability, as they are anions of low relative polarity, showing better viability to interact with the aldose reductase target with a low toxic response to the host.     

Characterization of dislocation interactions in olivine using electron tomography

We have investigated by electron tomography, in a transmission electronic microscope, the interactions between dislocations in olivine single crystals and polycrystals deformed in axial compression at T < 1000 °C (T < 0.5T_m). Dislocations are mostly of the [0?0?1] type, except in the polycrystal where [1?0?0] and [0?0?1] dislocations have been activated. A few 〈1?0?1〉 junctions have been found and characterized. Many collinear interactions have been identified either involving direct interactions between crossing dislocations of opposite Burgers vectors or indirect interactions between dislocations gliding in parallel planes and sessile dislocation loops. We suggest that collinear interaction, already identified as the primary source of strain hardening in FCC metals, is the main dislocation interaction mechanism in olivine deformed at temperatures below 1000 °C.     

Revisiting Aromaticity and Chemical Bonding of Fluorinated Benzene Derivatives

The electron delocalization of benzene (C₆H₆) and hexafluorobenzene (C₆F₆) was analyzed in terms of the induced magnetic field, nucleus-independent chemical shift (NICS), and ring current strength (RCS). The computed out-of-plane component of the induced magnetic field at a distance (r) greater than or equal to 1.0 Å above the ring center correlates well (R²>0.99) with the RCS value. According to these criteria, fluorination has two effects on the C₆ skeleton; concomitantly, the resonant effects diminish the π electron delocalization and the inductive effects decrease the charge density at the ring center and therefore reduce the magnitude of the paratropic current generated in this region. The equilibrium between both effects decreases aromaticity in the fluorinated benzene derivatives. These results can be extrapolated to determine the aromaticity of any derivative within the series of fluorinated benzene derivatives (C₆H_(6−n)F_n, where n=1–5).     

Diblock Polyelectrolytic Copolymers Containing Cationic Iron and Cobalt Sandwich Complexes: Living ROMP Synthesis and Redox Properties

Diblock metallopolymer polyelectrolytes containing the two redox‐robust cationic sandwich units [CoCp′Cp]⁺ and [FeCp′(η⁶‐C₆Me₆)]⁺ (Cp = η⁵‐C₅H₅; Cp′ = η⁵‐C₅H₄‐) as hexafluorophosphate ([PF₆]⁻) salts are synthesized by ring‐opening metathesis polymerization using Grubbs' third generation catalyst. Their electrochemical properties show full chemical and electrochemical reversibilities allowing fine determination of the copolymer molecular weight using Bard–Anson's electrochemical method by cyclic voltammetry.

     

Convergence analysis of a DDFV scheme for a system describing miscible fluid flows in porous media

In this article, we prove the convergence of a discrete duality finite volume scheme for a system of partial differential equations describing miscible displacement in porous media. This system is made of two coupled equations: an anisotropic diffusion equation on the pressure and a convection‐diffusion‐dispersion equation on the concentration. We first establish some a priori estimates satisfied by the sequences of approximate solutions. Then, it yields the compactness of these sequences. Passing to the limit in the numerical scheme, we finally obtain that the limit of the sequence of approximate solutions is a weak solution to the problem under study. © 2014 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 31: 723–760, 2015     

Initial guess of the solution of dynamic optimization of chemical processes

Numerical methods and software packages for solving dynamic optimization or optimal control problems require a suitable initial estimation of the solution. This paper focuses on problems that arise in chemical processes described by complex dynamics. We present a very simple method, based on Pontryagin’s Minimum Principle, to obtain an initial guess for the solution. Our method presents numerous advantages: it is very easy to programme, it allows a wide range of problems to be addressed, the computation time is very short, the initial guess is very close to the solution and is attracted to a global minimum.     

Effect of the structure of the diamine backbone of P-N-N-P ligands in iron(II) complexes on catalytic activity in the transfer hydrogenation of acetophenone

The asymmetric transfer hydrogenation of aromatic ketones can be efficiently accomplished using catalysts that are based on platinum group metals which are more toxic and less abundant than iron. For that reason the discovery of iron based catalysts for the use in this transformation is important. To address this issue, we synthesized a new series of iron(II)-based precatalysts trans-[Fe(Br)(CO)(PPh(2)CH(2)CH═NCHRCHRN═CHCH(2)PPh(2))]BPh(4) (5a-5d) containing P-N-N-P ligands with the diamines (R,R)-1,2-diaminocyclohexane (a), (R,R)-1,2-diphenyl-1,2-diaminoethane (b), (R,R)-1,2-di(4-methoxyphenyl)-1,2-diaminoethane (c), and ethylenediamine (d) incorporated in the backbone using a convenient one-pot synthesis using readily available starting materials. All of the complexes, when activated with a base, show a very high activity in the transfer hydrogenation catalysis of acetophenone, using 2-propanol as a reducing agent under mild conditions. A comparison of the TOF of complexes 5a-5d show that the catalytic activity of complexes increase as the size of the substituents in the backbone of ligands increases (d < a < b = c).