Red-shifted optical absorption induced by donor-acceptor-donor π-extended dibenzalacetone derivatives.

Chalcones demonstrate significant absorption in the near ultraviolet-visible spectrum, making them valuable for applications such as solar cells, light-emitting diodes, and nonlinear optics. This study investigates four dibenzalacetone derivatives (DBAd), DBA, DBC, DEP, and DMA, examining the impact of electron-donating and electron-withdrawing groups and conjugation elongation on their electronic structure in solvents of varying polarities. Using the Polarizable Continuum Model (PCM) and time-dependent density functional theory (TD-DFT), we characterized the excited states of these compounds.

description of the adsorption of cell signaling pathway proteins ovalbumin, glutathione, LC3, TLR4, ASC PYCARD, PI3K and NF-Kβ on 7.0 nm gold nanoparticles: obtaining their Lennard-Jones-like potentials through docking and molecular mechanics.

The impact of vaccination on the world's population is difficult to calculate. For developing different types of vaccines, adjuvants are substances added to vaccines to increase the magnitude and durability of the immune response and the effectiveness of the vaccine. This work explores the potential use of spherical gold nanoparticles (AuNPs) as adjuvants.

Losartan as an ACE inhibitor: a description of the mechanism of action through quantum biochemistry.

Losartan (LST) is a potent and selective angiotensin II (Ang II) type 1 (AT1) receptor antagonist widely used in the treatment of hypertension. The formation of Ang II is catalyzed by the angiotensin I-converting enzyme (ACE) through proteolytic cleavage of angiotensin I (Ang I), which is involved in the control of blood pressure. Despite the vast literature on the relationship of losartan with the renin-angiotensin system (RAS), the actions of losartan on the sACE enzyme are so far poorly understood.

Antitumor Potential of the Isoflavonoids (+)- and (-)-2,3,9-Trimethoxypterocarpan: Mechanism-of-Action Studies.

Synthetically derived samples of (+)-(6a,11a)-2,3,9-trimethoxypterocarpan [(+)-] and its enantiomer [(-)-], both of which are examples of naturally occurring isoflavonoids, were evaluated, together with the corresponding racemate, as cytotoxic agents against the HL-60, HCT-116, OVCAR-8, and SF-295 tumor cell lines. As a result it was established that compound (+)- was particularly active with OVCAR-8 cells being the most sensitive and responding in a dose-dependent manner. A study of cell viability and drug-induced morphological changes revealed the compound causes cell death through a mechanism characteristic of apoptosis.

Nanoencapsulation of benznidazole in calcium carbonate increases its selectivity to Trypanosoma cruzi.

Chagas disease is a public health problem, affecting about 7 million people worldwide. Benznidazole (BZN) is the main treatment option, but it has limited effectiveness and can cause severe adverse effects. Drug delivery through nanoparticles has attracted the interest of the scientific community aiming to improve therapeutic options.

Two Binding Geometries for Risperidone in Dopamine D3 Receptors: Insights on the Fast-Off Mechanism through Docking, Quantum Biochemistry, and Molecular Dynamics Simulations.

Risperidone is an atypical antipsychotic used in the treatment of schizophrenia and of symptoms of irritability associated with autism spectrum disorder (ASD). Its main action mechanism is the blockade of D2-like receptors acting over positive and negative symptoms of schizophrenia with small risk of extrapyramidal symptoms (EPS) at doses corresponding to low/moderate D2 occupancy. Such a decrease in the side effect incidence can be associated with its fast unbinding from D2 receptors in the nigrostriatal region allowing the recovery of dopamine signaling pathways.

A quantum biochemistry investigation of willardiine partial agonism in AMPA receptors.

We employ quantum biochemistry methods based on the Density Functional Theory (DFT) approach to unveil the detailed binding energy features of willardiines co-crystallized with the AMPA receptor. Our computational results demonstrate that the total binding energies of fluorine-willardiine (FW), hydrogen-willardiine (HW), bromine-willardiine (BrW) and iodine-willardiine (IW) to the iGluR2 ligand-pocket correlate with the agonist binding energies, whose experimental sequential data match our computational counterpart, excluding the HW case. We find that the main contributions to the total willardiine-iGluR2 binding energy are due to the amino acid residues in decreasing order Glu705 > Arg485 > Ser654 > Tyr450 > T655.

Antipsychotic haloperidol binding to the human dopamine D3 receptor: beyond docking through QM/MM refinement toward the design of improved schizophrenia medicines.

As the dopamine D3R receptor is a promising target for schizophrenia treatment, an improved understanding of the binding of existing antipsychotics to this receptor is crucial for the development of new potent and more selective therapeutic agents. In this work, we have used X-ray cocrystallization data of the antagonist eticlopride bound to D3R as a template to predict, through docking essays, the placement of the typical antipsychotic drug haloperidol at the D3R receptor binding site. Afterward, classical and quantum mechanics/molecular mechanics (QM/MM) computations were employed to improve the quality of the docking calculations, with the QM part of the simulations being accomplished by using the density functional theory (DFT) formalism.

Optical absorption of the antitrypanocidal drug benznidazole in water.

UV-vis optical absorption spectra of the antitrypanocidal drug benznidazole solvated in water were measured for various concentrations. The spectra show a prominent peak around 3.80 eV, while deconvolution of the UV-vis optical absorption spectra revealed six bands centered at 3.

Explaining statin inhibition effectiveness of HMG-CoA reductase by quantum biochemistry computations.

By taking advantage of the crystallographic data of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) complexed with statins, a quantum biochemistry study based on the density functional theory is performed to estimate the interaction energy for each statin when one considers binding pockets of different sizes. Assuming a correlation between statin potency and the strength of the total HMGR-statin binding energy, clinical data as well as IC(50) values of these cholesterol-lowering drugs are successfully explained only after stabilization of the calculated total binding energy for a larger size of the ligand-interacting HGMR region, one with a radius of at least 12.0 Å.