Alzheimer's disease (AD) is a neurodegenerative disease that affects the majority of people worldwide. To date, there is no cure for the disease, so new therapeutic targets need to be identified and studied. Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are the main targets of drugs for the treatment of AD. To study the inhibition of enzymes associated with this disease and identify new inhibitors, a newly synthesized series comprised 37 molecules of (2-hydroxy-N-phenylbenzamide) derivatives. Our work focuses on the use of molecular modeling methods based on molecular docking, QSAR and ADME property estimation.

The discussion of molecular docking results is based on a number of parameters. Analysis of these obtained results showed that the ligands L18, L17 and L6 have a high inhibitory effect in the case of the enzyme AChE, while the ligands L6', L30' and L4' have a high inhibitory effect in the case of the enzyme BuChE. . In addition, the calculation of ADME properties proved that these ligands follow the rules: Lipinski, Veber and Egan, this allowed us to select them as being probably the best inhibitors.

Then, a QSAR model was developed to explain and predict the inhibitory activity of a series of 33 compounds using targeted and relevant descriptors. This model has been validated by two methods: internal and external.

According to certain theories, aldehydes play a significant role as precursor species in the creation of new atmospheric particles. In the current study, we first optimized the structure of the title compound by using the B3LYP 631-G (d, p) basic set. This compound's electrostatic potential, electrophilicity (

The Chemical-bioprospecting is a conceptual, and methodological, tool of singular importance for the evaluation of biodiversity as a sustainable source of metabolites with high added value. In this communication it is reported the strategy of chemical-prospecting, in sustainable and scalable conditions, of Cuban biodiversity, specifically the edaphic fauna and the diplopoda group (Rhinocrycidae-Rhinocricus duvernoyi Karsh 1881), orienting the process towards the isolation of NEE and NEF from defensive secretions. The existence of 5 chemotypes in populations of endemic Cuban millipedes belonging to the species Rhinocricus duvernoyi Karsh 1881 was determined: Yumurí-02 Valley - Isle of Youth (two components, 31/33 and 68/66 % respectively); Alamar-Banao localities (5-9 components with concentrational variations); La Palma (1 component, 100 %); La Coca (mixture of aliphatic hydrocarbons), and Yumurí-01 Valley - Mayarí (quinone, > 80 %). Several novel components were isolated and characterized for this genus (Rhinocricus) and this endemic species of the Cuban archipelago: 1-methyl-2-methoxy-p-quinone, 2-(3,4-dimethoxy-phenyl)-ethylene-1-amine and 4-hydroxy-5-methoxybenzaldehyde (vanillin), as well as polysubstituted phenolic derivatives, which increase the repugnatorial action of these defensive secretions. The work reports a structural-chromatographic database containing the components of defensive secretions and their fragmentation pathways (GC-MS) for geographic populations of the millipede Rhinocricus duvernoyi Karsh inhabiting the western zone of the Cuban archipelago. Its mapping revealed the existence of a singular compositional heterogeneity (5-7 components of aromatic, benzoquinonic and hydrocarbon nature with specific substitution patterns) in the western zone of the Cuban archipelago, allowing the analysis of some ecological and evolutionary considerations for this species and its eco-geographical variations. The cytotoxic, microbiocidal and fungicidal capacity against Gram (-) and Gram (+) pathogenic microorganisms was evaluated, observing a potent biocidal effect, which supported the protocols for the preparation of therapeutic formulations. An eco-sustainable synthetic process of the 1-methyl-2-methoxy-p-quinone derivative with microbiocidal and fungicidal activity was designed, using a non-conventional procedure.

The Ugi-Azide MCR (UA) is one of the most efficient methods for the synthesis of 1,5-disubstituted-1H-tetrazoles (1,5-DS-T). Complex drug-like scaffolds incoporating tetrazoles have demostrated a wide range of therapeutic benefits such as anti-inflammatory, antiviral, antibiotics, anti-ulcer, anxiety and anti-hypertensive agents, attributable to their mimetic cis amide of peptide bonds enhance metabolic stability, selectivity and other beneficial physicochemical properties, in addition to their applications in bioimaging, photoimaging and coordination chemistry, Herein we present the ultrasound-assisted sustainable synthesis of six novel 1,5 DS-T under solvent-free conditions.

pyrido[2,3-d]pyrimidine ring structure is one of the most interesting heterocycles in drug design, these later witch containing this moiety have various pharmacological activities such as antitumor, antipyretic, antihypertensive, antifungal, antibacterial, and anti-inflammatory activities. More specifically pyrido[2,3-d]pyrimidines were considered as inhibitors of dihydrofolate reductases (DHFR), tyrosine kinases and adenosine kinase. Moreover, the synthesis of these fused heterocyclic compounds provides an interesting challenge in medicinal chemistry.
In this work, we present a simple and efficient synthesis of pyrido[2,3-d]pyrimidines via multicomponent reaction under solvent-free conditions.

1,6-diamino-2-oxo-1,2-dihydropyridine-3,5-dicarbonitrile, prepared by the reaction of cyanoacetohydrazide with arylmethylene malononitriles, react with ninhydrin to give correspondingWith the formation of derivatives of dihydroindeno[1,2-e]pyrido[1,2-b][1,2,4]triazines. The reaction with glyoxal proceeds under mild conditions with the formation of 1,2,4-triazolo[1,5-a]pyridine.

The cross-conjugated dienones containing the 1,5-diaryl-3-oxo-1,4-pentadienyl pharmacophore have diverse biological activities. These sometimes called monocarbonyl analogs of curcumin (MACs) have especially pronounced biological activity when containing electron-withdrawing group at the ortho position of the benzene ring. Their biological activity most likely stems from selective Michael reaction with thiols. It has been reported in the literature that in vitro certain MACs (in particular, EF24) react as electrophiles with glutathione and form bis adducts. Five MACs were prepared ((2Е,5Е)-2,5-bis(2-bromobenzylidene)cyclopentanone, (2BrCP), (2E,6E)-2,6-bis(2-bromo-benzylidene)cyclohexanone (2BrCX), 4-tert-butyl-(2E,6E)-2,6-bis(2-bromobenzylidene)cyclohexanone (4tB2BrCX), (3E,5E)-3,5-bis(2-bromobenzylidene)-4-piperidone, (2Br4PIP), and (3Е,5Е)-3,5-bis(2-fluoro-benzylidene)-4-piperidone, EF24), purified and characterized by spectroscopic means. The relative reactivity of these MACs towards 2-(dimethylamino)ethanethiol was assessed via previously developed UV-Vis spectroscopic method and compared to EF24, which reacts readily in solution with thiols such as glutathione and cysteamine. All of the bis(2-bromobenzylidene) MACs, react slower with 2-(dimethylamino)thiol in 80:20 (v/v) acetonitrile/water compared to EF24. The relative reactivity of the analogs with 2-(dimethylamino)ethanethiol was EF24 > 2Br4PIP > 2BrCX > 4tB2BrCX ≈ 2BrCP.

The conversion of semicarbazones to 1,2,4-triazolidin-3-ones and vice versa (ring-chain isomerism) was studied by the DFT B3LYP/6-311++G(d,p) method. The thermodynamic and kinetic characteristics of this reaction were calculated and discussed.

Environmental pollution is one of the main concerns of contemporary research.

The content of all metal ions when it exceeds the acceptable threshold becomes toxic.

Particular attention is paid to the recognition of toxic metal ions, as these cause serious damage to human health and the environment.

Over the past decades, several small molecule-based fluorescence chemosensors have been developed.

There is a wide range of strongly electronegative fluorescent hetero-aromatics (nitrogen, oxygen, etc.). Additionally, pyridine ring molecules are used as nonlinear optical materials, electrical materials, and chelating agents in metal-ligand chemistry.

In the present work, we report the synthesis of chemosensors containing the pyrinidic moiety as a fluorophore unit, therefore, we studied their influence on the detection of toxic cations, including chromium, iron, cobalt, nickel, and copper in acetonitrile/water (1:1) mixtures given the importance of developing water-soluble probes for metal detection in biological and environmental systems.

The increase on the investigation of different self-assembled architectures derived from thiosemicarbazone ligands are interesting due to the different metallosupramolecular architectures with several applications that can be obtained. The potentially tetradentate organic bisthiosemicarbazone ligand H₂L possesses two flexibles bidentate [NS] domains separated by a short and rigid spacer, which could stabilize several metal ions and thus different metallosupramolecular architectures. H₂L has been prepared by a condensation reaction between two equivalents of N-ethylhydrazinecarbothioamide and one equivalent of 1,1',1''-(benzene-1,3,5-triyl)tris(ethan-1-one), and was fully studies by using several techniques, including X-ray diffraction.