A comparative computational study on molecular structure, NBO analysis, multiple interactions, chemical reactivity and first hyperpolarisability of imatinib mesylate polymorphs using DFT and QTAIM approach

DFT study on the structural and chemical properties of Janus kinase inhibitor drug Baricitinib

Baricitinib is a small molecule used to treat moderate to severe rheumatoid arthritis (RA) in adults. It is an inhibitor of Janus kinase 1 and 2 (JAK1 and JAK2). It has also been repurposed as a potential treatment for Covid 19. The current study has been carried out to understand the structural and chemical properties of this molecule. The molecule is optimized by using density functional theory (DFT) method. The DFT calculations are performed using Gaussian 09 W software package. The bond lengths and bond angles between atoms in the molecules are investigated. The intramolecular interaction within the molecule is identified using the natural bond orbital (NBO) study. The atom in molecule (AIM) study is performed using Multiwfn software. All the calculations are performed at B3LYP /6311G++ (d, p) level of theory. The molecular parameters, such as first-order hyperpolarizability, HOMO-LUMO energy gap, global electrophilicity index, dipole moment, chemical potential, hardness, ionization energy and electron affinity are determined from the calculation. The molecular docking analysis of Baricitinib is also carried out against different target proteins such as 6VSB, 6W9C and 6LU7.

Van der Waals enhanced interfacial interaction in cellulose/zinc oxide nanocomposite coupled by graphitic carbon nitride

In-depth understanding of interfacial property is the key to guiding the synthesis of biomass composites with desired performance. However, the exploration is of great challenge due to limitations of experimental techniques in locating hydrogen, requiring large/good crystals and detecting a weak interaction like van der Waals (vdW). Herein, we experimentally and computationally investigated the composite cellulose/zinc oxide/g-C₃N₄. Hydrothermal synthesis afforded cellulose/ZnO, and then fabricated the ternary composite by adding g-C₃N₄ under ultrasonic condition. Three components are found to co-exist in the composite, and the ZnO nanoparticle is attaching to cellulose and coupling with g-C₃N₄. These experimental findings were corroborated by relativistic DFT calculations. The interfacial coupling is elaborated as contributions of dative bonds, hydrogen bonds and vdW interaction. The vdW is increased by a factor of 4.23 in the ZnO/g-C₃N₄ interface. This improves electron-hole separation and offers prospective application of the composite in photocatalysis, antibacteria and gas sensing.

Insights into co-amorphous systems in therapeutic drug delivery

Co-amorphous (CAM) systems are promising drug-delivery systems in the arena of therapeutic drug delivery, addressing the poor aqueous solubility of drugs by enhancing solubility and thereby improving the oral bioavailability and therapeutic effect of the drug. A CAM system is a single-phase homogeneous blend of two or more low molecular weight molecules that can be drug–drug or drug–co-former, stabilized via intermolecular interactions, adding the benefit of thermodynamic stability. This review covers the fundamentals of CAM systems and recent advances in formulation development. In particular, we strive to address the theoretical, molecular, technical and biopharmaceutical aspects, advantages over polymeric amorphous solid dispersions, mechanisms of stabilization of amorphous forms, insights into unexplored in silico tools in excipient selection and regulatory viewpoints.

Inverse Trans Influence in Low-Valence Actinide-Group 10 Metal Complexes of Phosphinoaryl Oxides: A Theoretical Study via Tuning Metals and Donor Ligands

The recognition and in-depth understanding of inverse trans influence (ITI) have successfully guided the synthesis of novel actinide complexes and enriched actinide chemistry. Those complexes, however, are mainly limited to the involvement of high-valence actinide and/or metal-ligand multiple bonds. Examples containing both low oxidation state actinide and metal-metal single bond remain rare. Herein, more than 20 actinide-transition metal (An-TM) complexes of phosphinoaryl oxide ligands have been designed in accordance with several experimentally known analogs, by changing the metal atoms (An = Th, Pa, U, Np, and Pu; and TM = Ni, Pd, and Pt), actinide oxidation states (IV and III) and metal-metal axial donor ligands (X = Me₃SiO, F, Cl, Br, and I). The relativistic density functional theory study of structural (trans-An-X and cis-An-O toward An-TM), bonding (topological electron/energy density), and electronic properties reveals the order of the ITI stabilizing actinide-metal bond. Computed electron affinity (EA) values, related to the electrochemical reduction, linearly correlate with experimentally measured reduction potentials. Although the same ITI order for the ligand donors was shown as in a previous study, the correlation between electrochemical reduction and the ITI was found to be weak when the actinide atoms were changed. For most complexes, the reduction is primarily of an actinide-based mechanism with minor participation of transition metal and phosphinoaryl oxide, whereas that of thorium-nickel complexes is different.