Unraveling the role of chitosan in enhancing the photodegradation of ciprofloxacin by using chitosan-titanates composites: Experimental and in-silico approach.

A hybrid composite (inorganic-organic) based on chitosan-functionalized hydrogen titanate nanotubes (TiCH) was synthesized by the hydrothermal method assisted by microwave, during 5h at 150 °C. The in-silico analysis determined the possible chitosan chemical adsorption models after calculating the Gibbs energies of their HOMO-LUMO orbitals. The TGA analysis confirmed the stability and helped to obtain the real functionalization degrees for the 3TiCH (2.

The peptide bond rupture mechanism in the serine proteases: an study based on sequential scale models.

Given the importance of serine proteases for biochemical processes, we have studied the peptide bond rupture mechanism using three sequential scale models as representations of the KLK5 enzyme (a protein overexpressed in ovarian cancer). The first model contains the basic functional groups of the residues that conform to the catalytic triad present in serine proteases; the second model contains some additional residues and, finally, the last representation includes all atoms of the KLK5 protein together with 10.000 explicit water molecules.

Synthesis of bis-furyl-pyrrolo[3,4-]pyridin-5-ones Ugi-Zhu reaction and activity assays against human SARS-CoV-2 and studies on its main proteins.

An Ugi-Zhu three-component reaction (UZ-3CR) coupled in one pot manner to a cascade process (-acylation/aza Diels-Alder cycloaddition/decarboxylation/dehydration) was performed to synthesize a series of bis-furyl-pyrrolo[3,4-]pyridin-5-ones in 45 to 82% overall yields using ytterbium triflate as a catalyst, toluene as a solvent, and microwaves as a heat source. The synthesized molecules were evaluated against human SARS-CoV-2 through a time-of-addition approach, finding that compound 1e, at a concentration of 10.0 μM, exhibited a significant reduction at the initial infection stages, thus showing prophylactic potential.

Grammatical evolution-based design of SARS-CoV-2 main protease inhibitors.

A series of SARS-CoV-2 main protease (SARS-CoV-2-M) inhibitors were modeled using evolutive grammar algorithms. We have generated an automated program that finds the best candidate to inhibit the main protease, M, of SARS-CoV-2. The candidates were constructed based on a pharmacophore model of the above-mentioned target; relevant moieties of such molecules were modified using data-basis sets with similar chemical behavior to the reference moieties.

Binding Analysis of Functionalized Multimode Optical-Fiber Sandwich-like Structure with Organic Polymer and Its Sensing Application for Humidity and Breath Monitoring.

In recent years, the chemical modification of optical fibers (OFs) has facilitated the manufacture of sensors because OFs can identify several analytes present in aqueous solutions or gas phases. Nevertheless, it is imperative better to understand the chemical interactions in this molecular system to generate low-cost and efficient sensors. This work presents a theoretical and experimental study of organic polymeric functionalized OF structures and proposes a cost-effective alternative to monitor breathing and humidity.