In vitro, in vivo and in silico antiplasmodial profiling of the aqueous extract of Hibiscus asper HOOK F. Leaf (Malvaceae).

Ethnopharmacological Relevance: Plasmodium resistance to antimalarial drugs raises the urgent need to seek for alternative treatments. Aqueous extract of Hibiscus asper leaves is currently used in malaria management but remains less documented.

Aim Of The Study: The study aims to evaluate antimalarial effects of the aqueous extract of Hibiscus asper.

Deciphering the influence of Pd and Pd oxidation states on non-standard chemical bonds within bis(jN-heterocyclic carbene) complexes: insights from DFT.

Bis-N-heterocyclic carbene ligands (bis(NHC)) have introduced a new approach to designing homogeneous and heterogeneous catalysts, demonstrating the versatility of ligand concepts in catalysis. This study presents a computational analysis of palladium (+ii and +iv) complexes containing either a normally (bis(nNHC)) or an abnormally (bis(aNHC)) bound CH-bridged bis-N-heterocyclic carbene ligand; in addition, ancillary ligands are permuted from chlorides (X = Cl) to bromides (X = Br). Density functional theory at the B3PW91/6-31G(d)/Lanl2DZ level in the gas phase was used to investigate the electronic structure and bonding properties of bis(NHC)PdX and bis(NHC)PdX for bis(NHC) palladium(ii) dihalide and palladium(iv) tetrachloride complexes, respectively.

Exploring the Mechanism of the Intramolecular Diels-Alder Reaction of (2,4,6)-2(allyloxy)cycloocta-2,4,6-trien-1-one Using Bonding Evolution Theory.

In the present work, the bond breaking/forming events along the intramolecular Diels-Alder (IMDA) reaction of (2,4,6)-2(allyloxy)cycloocta-2,4,6-trien-1-one have been revealed within bonding evolution theory (BET) at the density functional theory level, using the M05-2X functional with the cc-pVTZ basis set. Prior to achieving this task, the energy profiles and stationary points at the potential energy surface (PES) have been characterized. The analysis of the results finds that this rearrangement can proceed along three alternative reaction pathways (a-c).

Mononuclear half-sandwich nd metallo drug complexes based on bidentate N∩N dendritic scaffolds: DFT (B3LYP; BP86 and B3PW91) examination.

Through an use of three functionals (B3PW91, B3LYP and BP86) associated to a generic basis set LanL2DZ for transition metals (as well as halogen atoms) and 6-311+G (d,p) for others atoms, an examination of the bonding properties of a series of mononuclear half-sandwich nd transition metal (anticancer) complexes based on N∩N dendritic scaffolds (L) has been done. Collectively, complexes studied have adopted the piano-stool environment. An examination of the performance of each functional has shown that for the most reliable geometrical analysis of Metal-Nitrogen and Metal-Halogen bonds, the B3LYP and B3PW91 functionalities are suitable respectively.

Topological investigation of the reaction mechanism of glycerol carbonate decomposition by bond evolution theory.

The reaction mechanisms of the decomposition of glycerol carbonate have been investigated at the density functional theory level within the bond evolution theory. The four reaction pathways yield to 3-hydroxypropanal (TS1), glycidol (TS2a and TS2b), and 4-methylene-1,3-dioxolan-2-one (TS3). The study reveals non-concerted processes with the same number (four) of structural stability domains for each reaction pathway.

Decoding the reaction mechanism of the cyclocondensation of ethyl acetate2-oxo-2-(4-oxo-4H-pyrido [1.2-a] pyrimidin-3-yl) polyazaheterocycle and ethylenediamine using bond evolution theory.

We investigated the flow of electron density along the cyclocondensation reaction between ethyl acetate 2-oxo-2-(4-oxo-4H-pyrido[1.2-a]pyrimidin-3-yl) polyazaheterocycle (1) and ethylenediamine (2) at the ωB97XD/6-311++G(d,p)computational method within of bond evolution theory (BET). The exploration of potential energy surface shows that this reaction has three channels (1-3) with the formation of product 3 via channel-2 (the most favorable one) as the main product and this is in good agreement with experimental observations.

Unraveling the sequence of electron flow along the cyclocondensation reaction between ciprofloxacin and thiosemicarbazide through the bonding evolution theory.

We have theoretically conducted a comprehensive investigation on the cyclocondensation reaction between ciprofloxacin and thiosemicarbazide at the MN15/6-311++G(d,p) level of approximation. In order to revisit and understand the sequence of electronic flow rearrangement, as described in terms of electron pair distribution, within the framework of Bonding Evolution Theory (BET) approach as provided by the application of Thom's elementary Catastrophe Theory (CT) to the changes, along the intrinsic reaction coordinate, of the gradient vector field of the electron localization function (ELF). This reaction has two channels (a and b) and each one takes place via three steps.

Exploring The Sequence of Electron Density Along The Chemical Reactions Between Carbonyl Oxides And Ammonia/Water Using Bond Evolution Theory.

The molecular mechanism of the reactions between four carbonyl oxides and ammonia/water are investigated using the M06-2X functional together with 6-311++G(d,p) basis set. The analysis of activation and reaction enthalpy shows that the exothermicity of each process increased with the substitution of electron donating substituents (methyl and ethenyl). Along each reaction pathway, two new chemical bonds C-N/C-O and O-H are expected to form.

Deciphering the Curly Arrow Representation and Electron Flow for the 1,3-Dipolar Rearrangement between Acetonitrile Oxide and (1,2,4)-2-Cyano-7-oxabicyclo[2.2.1]hept-5-en-2-yl Acetate Derivatives.

This study is focused on describing the molecular mechanism beyond the molecular picture provided by the evolution of molecular orbitals, valence bond structures along the reaction progress, or conceptual density functional theory. Using bonding evolution theory (BET) analysis, we have deciphered the mechanism of the 1,3-dipolar rearrangement between acetonitrile oxide and (1,2,4)-2-cyano-7-oxabicyclo[2.2.

Density Functional Theory Investigation of the Binding of ThioTEPA to Purine Bases: Thermodynamics and Bond Evolution Theory Analysis.

Density functional theory with the ωB97X-D exchange-correlation functional together with implicit as well as explicit solvation is used to describe the reactions of the adenine and guanine purine bases on ,',″-triethylenethiophosphoramide (thioTEPA), an alkylating agent used as an anticancer drug. This reaction is decomposed into (i) a nucleophilic addition and (ii) a proton "migration" that is mediated by the solvent molecules. The calculations reveal that the first step is rate determining and that the presence of an explicit water molecule to mediate the proton migration has a negligible role on the kinetics of the first step, so that the focus is set on the first step of the reaction.

Intramolecular [3 + 2] Cycloaddition Reactions of Unsaturated Nitrile Oxides. A Study from the Perspective of Bond Evolution Theory (BET).

The reaction mechanism of the [3 + 2] intramolecular cycloaddition of 3,3-dimethyl-2-(prop-2-en-1-yloxy) and (prop-2-en-1-ylsulfanyl) nitrile oxides is analyzed using different DFT functionals with the 6-311++G(d,p) basis set. The activation and the reaction energies for the cis and trans pathways are evaluated at the DFT, MP2, and CCSD(T) levels of theory as well as their Gibbs free energy counterparts. It is shown that the trans regioisomers are both thermodynamic and kinetic compounds, in agreement with experimental outcomes.