Unexpected discovery: "A new 3,3'-bipyrazolo[3,4-]pyridine scaffold and its comprehensive analysis".

In this study, a novel 3,3'-bipyrazolo [3,4-]pyridine-type structure was synthesized from 5-acetylamino-3-methyl-1-phenylpyrazole using the Vilsmeier-Haack reaction as a key step. The spectroscopic properties and structural elucidation of the compound were determined with the use of FT-IR, HRMS, H NMR, and C NMR. Likewise, the theoretical analysis of the IR and NMR spectra allowed peaks to be assigned and a solid correlation was demonstrated between the experimental and theoretical results.

Role of Triplet States in the Photolysis of Proteogenic Amino Acids.

This investigation delves into the UV photodissociation of pivotal amino acids (Alanine, Glycine, Leucine, Proline, and Serine) at 213 nm, providing insights into triplet-state deactivation pathways. Utilizing a comprehensive approach involving time-dependent density functional calculations (TD-DFT), multi-configurational methods, and ab-initio molecular dynamics (AIMD) simulations, we scrutinize the excited electronic states (T , T , and S ) subsequent to 213 nm excitation. Our findings demonstrate that α-carbonyl C-C bond-breaking in triplet states exhibits markedly lower barriers than in singlet states (below 5.

Elucidating the N-N and C-N Bond-breaking Mechanism in the Photoinduced Formation of Nitrile Imine.

In this study, we revealed the significance of chemical bonding for the photochemically induced mechanism of 2-phenyl tetrazole derivatives generating nitrile imines. The correlated electron localization function shows that the formation of imine nitrile involves two key bond events: (i) the heterolytic C-N breakage taking place in the T state and (ii) the homolytic N-N rupture occurring in the T excited state. In particular, a cation-radical specie results from the C-N cleavage, whereas the N-N rupture creates a biradical resonant form of imine nitrile.

Phenolic Profile and Cholinesterase Inhibitory Properties of Three Chilean Altiplano Plants: (Benth.) Kuntze [Lamiaceae], Ruiz & Pav. var. hirsuta (Meyen) Cabrera, and (Kunth) [Asteraceae].

This research aimed to identify the phenolic profile and composition of the aerial parts of three native species used in traditional medicine in the Andean Altiplano of northern Chile: (Benth.) Kuntze [Lamiaceae] (commonly known as Muña-Muña), Ruiz & Pav. var.

Design, synthesis, theoretical study, antioxidant, and anticholinesterase activities of new pyrazolo-fused phenanthrolines.

Pyrazole-fused phenanthroline compounds were obtained through several synthetic routes. NMR, HRMS, and IR techniques were used to characterize and confirm the chemical structures. Crystal structures were obtained from compounds 3a, 5b, 5j, 5k, and 5n and analyzed using X-ray diffraction.

Tetrahydroquinoline-Isoxazole/Isoxazoline Hybrid Compounds as Potential Cholinesterases Inhibitors: Synthesis, Enzyme Inhibition Assays, and Molecular Modeling Studies.

A series of 44 hybrid compounds that included in their structure tetrahydroquinoline (THQ) and isoxazole/isoxazoline moieties were synthesized through the 1,3-dipolar cycloaddition reaction (1,3-DC) from the corresponding -allyl/propargyl THQs, previously obtained via cationic Povarov reaction. In vitro cholinergic enzymes inhibition potential of all compounds was tested. Enzyme inhibition assays showed that some hybrids exhibited significant potency to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE).

Efficient synthesis and antioxidant activity of novel -propargyl tetrahydroquinoline derivatives through the cationic Povarov reaction.

New N-propargyl tetrahydroquinolines have been synthesized efficiently through the cationic Povarov reaction (a domino Mannich/Friedel-Crafts reaction), catalyzed by Indium (III) chloride (InCl), from the corresponding -propargylanilines preformed, formaldehyde and -vinylformamide, with good to moderate yields. All tetrahydroquinoline derivatives obtained were evaluated as free radical scavengers. Results showed that compound presents a potent antioxidant effect compared with ascorbic acid, used as a reference compound.

Preparation of Hydrogel/Silver Nanohybrids Mediated by Tunable-Size Silver Nanoparticles for Potential Antibacterial Applications.

In this study, a versatile synthesis of silver nanoparticles of well-defined size by using hydrogels as a template and stabilizer of nanoparticle size is reported. The prepared hydrogels are based on polyvinyl alcohol and maleic acid as crosslinker agents. Three hydrogels with the same nature were synthesized, however, the crosslinking degree was varied.

Rational Development of a Novel Hydrogel as a pH-Sensitive Controlled Release System for Nifedipine.

This work depicts the rational development (in-silico design, synthesis, characterization and in-vitro evaluation) of polyvinyl alcohol hydrogels (PVAH) cross-linked with maleic acid (MA) and linked to γ-cyclodextrin molecules (γ-CDPVAHMA) as systems for the controlled and sustained release of nifedipine (NFD). Through computational studies, the structural blocks (PVA chain + dicarboxylic acid + γ-CD) of 20 different hydrogels were evaluated to test their interaction energies (Δ) with NFD. According to the Δ obtained, the hydrogel cross-linked with maleic acid was selected.

Catalytic Divergent [3+3]- and [3+2]-Cycloaddition by Discrimination Between Diazo Compounds.

Highly selective divergent cycloaddition reactions of enoldiazo compounds and α-diazocarboximides catalyzed by copper(I) or dirhodium(II) have been developed. With tetrakis(acetonitrile)copper(I) tetrafluoroborate as the catalyst epoxypyrrolo[1,2-a]azepine derivatives were prepared in good yields and excellent diastereoselectivities through the first reported [3+3]-cycloaddition of a carbonyl ylide. Use of Rh (pfb) or Rh (esp) directs the reactants to regioselective [3+2]-cycloaddition generating cyclopenta[2,3]pyrrolo[2,1-b]oxazoles with good yields and excellent diastereoselectivities.