Vibrational assignments, spectroscopic investigation (FT-IR and FT-Raman), NBO, MEP, HOMO‒LUMO analysis and intermolecular hydrogen bonding interactions of 7-fluoroisatin, 7-bromoisatin and 1-methylisatin ‒ A comparative study

Targeting necroptosis in MCF-7 breast cancer cells: In Silico insights into 8,12-dimethoxysanguinarine from Eomecon Chionantha through molecular docking, dynamics, DFT, and MEP studies

Breast cancer remains a significant challenge in oncology, highlighting the need for alternative therapeutic strategies that target necroptosis to overcome resistance to conventional therapies. Recent investigations into natural compounds have identified 8,12-dimethoxysanguinarine (SG-A) from Eomecon chionantha as a potential necroptosis inducer. This study presents the first computational exploration of SG-A interactions with key necroptotic proteins-RIPK1, RIPK3, and MLKL-through molecular docking, molecular dynamics (MD), density functional theory (DFT), and molecular electrostatic potential (MEP) analyses. Molecular docking revealed that SG-A exhibited a stronger affinity for MLKL (-9.40 kcal/mol) compared to the co-crystallized ligand (-6.29 kcal/mol), while its affinity for RIPK1 (-6.37 kcal/mol) and RIPK3 (-7.01 kcal/mol) was lower. MD simulations further demonstrated the stability of SG-A within the MLKL site, with RMSD values stabilizing between 1.4 and 3.3 Å over 300 ns, indicating a consistent interaction pattern. RMSF analysis indicated the preservation of protein backbone flexibility, with average fluctuations under 1.7 Å. The radius of gyration (Rg) results indicated a consistent value of ~15.3 Å across systems, confirming the role of SG-A in maintaining protein integrity. Notably, SG-A maintains two critical H-bonds within the active site of MLKL, reinforcing the stability of the interaction. Principal component analysis (PCA) indicated a significant reduction in MLKL's conformational space upon SG-A binding, implying enhanced stabilization. Dynamic cross-correlation map (DCCM) analysis further revealed that SG-A induced highly correlated motions, reducing internal fluctuations within MLKL compared to the co-crystallized ligand. MM-PBSA revealed the enhanced binding efficacy of SG-A, with a significant binding free energy of -31.03 ± 0.16 kcal/mol against MLKL, surpassing that of the control (23.96 ± 0.11 kcal/mol). In addition, the individual residue contribution analysis highlighted key interactions, with ARG149 showing a significant contribution (-176.24 kcal/mol) in the MLKL-SG-A complex. DFT and MEP studies corroborated these findings, revealing that the electronic structure of SG-A is conducive to stable binding interactions, characterized by a narrow band gap (~0.16 units) and distinct electrostatic potential favourable for necroptosis induction. In conclusion, SG-A has emerged as a compelling inducer of necroptosis for breast cancer therapy, warranting further experimental validation to fully realize its therapeutic potential.

Quantum chemical determination of molecular geometries and spectral investigation of 4-ethoxy-2, 3-difluoro benzamide

The present work reports the application of density functional theory (DFT) at B3LYP with various basis sets which provide the relationship between the structural and spectral properties of 4-ethoxy-2, 3-difluoro benzamide (4EDFB). A Complete vibrational analysis has been performed at the density functional theory (DFT) method with various basis sets in the ground state. The results of vibrational wave numbers are in good agreement with the experimental spectra (Infrared and Raman). Energy gap of the molecule is evaluated using frontier molecular orbital energies (HOMO-LUMO). The frontier energy gap value reveals the chemical reactivity and intermolecular charge transfer occur within the molecule. Global chemical descriptors provide the local and global softness and local reactivity parameters used to identify the nucleophilic and electrophilic behavior of a specific site within the compound. The dimer structure is performed to evaluate the intermolecular hydrogen bond (O-H-O). The title molecule is capable of receiving second harmonic generation (SHG) is due to high value of hyperpolarizability indicates the NLO activity of the molecule. Apart from NLO entities, aromaticity and the molecular electrostatic potential surface (MEP) explain the hydrogen bonding and provide the reactive behavior of the molecule. The Mulliken population analysis leads to redistribution of electron density in the ring.

Bioactive and luminescent indole and isatin based gold(i) derivatives

Combination of bioactive indole and isatin derivatives with Au(i) affords highly cytotoxic metallic species even for cisplatin resistant leukemia cells (Jurkat-shBak).

In vitro leishmanicidal activity and theoretical insights into biological action of ruthenium(II) organometallic complexes containing anti-inflammatories

Leishmaniasis, a neglected tropical disease caused by protozoans of the genus Leishmania, kills around 20-30 thousand people in Africa, Asia, and Latin America annually and, despite its potential lethality, it can be treated and eventually cured. However, the current treatments are limited owing to severe side effects and resistance development by some Leishmania. These factors make it urgent to develop new leishmanicidal drugs. In the present study, three ruthenium(II) organometallic complexes containing as ligands the commercially available anti-inflammatories diclofenac (dic), ibuprofen (ibu), and naproxen (nap) were synthesized, characterized, and subjected to in vitro leishmanicidal activity. The in vitro cytotoxicity assays against Leishmania (L.) amazonensis and Leishmania (L.) infantum promastigotes have shown that complexes [RuCl(dic)(η⁶-p-cymene)] (1) and [RuCl(nap)(η⁶-p-cymene)] (3) were active against both Leishmania species. Complex [RuCl(ibu)(η⁶-p-cymene)] (2) has exhibited no activity. The IC₅₀ values for the two active complexes were respectively 7.42 and 23.55 μM, for L. (L.) amazonensis, and 8.57 and 42.25 μM, for L. (L.) infantum. Based on the toxicological results and computational analysis, we proposed a correlation between the complexes and their activity. Our results suggest both complexation to ruthenium(II) and ligands structure are key elements to leishmanicidal activity.

RAFT Polymerization of Styrene and Maleimide in the Presence of Fluoroalcohol: Hydrogen Bonding Effects with Classical Alternating Copolymerization as Reference

The impacts of hydrogen bonding on polymerization behavior has been of interest for a long time; however, universality and in-depth understanding are still lacking. For the first time, the effect of hydrogen bonding on the classical alternating-type copolymerization of styrene and maleimide was explored. N-phenylmaleimide (N-PMI)/styrene was chosen as a model monomer pair in the presence of hydrogen bonding donor solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), which interacted with N-PMI via hydrogen bonding. Reversible addition-fragmentation chain transfer polymerization (RAFT) technique was used to guarantee the "living" polymerization and thus the homogeneity of chain compositions. In comparison with the polymerization in nonhydrogen bonding donor solvent (toluene), the copolymerization in HFIP exhibited a high rate and a slight deviation from alternating copolymerization tendency. The reactivity ratios of N-PMI and St were revealed to be 0.078 and 0.068, respectively, while the reactivity ratios in toluene were 0.026 and 0.050. These interesting results were reasonably explained by using computer simulations, wherein the steric repulsion and electron induction by the hydrogen bonding between HFIP and NPMI were revealed. This work first elucidated the hydrogen bonding interaction in the classical alternating-type copolymerization, which will enrich the research on hydrogen bonding-induced polymerizations.

Vibrational analysis and chemical activity of paracetamol–oxalic acid cocrystal based on monomer and dimer calculations: DFT and AIM approach

Hydrogen bonding network present in monomer and dimer + 2OXA models of cocrystal.