Wnt/β-catenin signalling: function, biological mechanisms, and therapeutic opportunities

The Wnt/β-catenin pathway comprises a family of proteins that play critical roles in embryonic development and adult tissue homeostasis. The deregulation of Wnt/β-catenin signalling often leads to various serious diseases, including cancer and non-cancer diseases. Although many articles have reviewed Wnt/β-catenin from various aspects, a systematic review encompassing the origin, composition, function, and clinical trials of the Wnt/β-catenin signalling pathway in tumour and diseases is lacking. In this article, we comprehensively review the Wnt/β-catenin pathway from the above five aspects in combination with the latest research. Finally, we propose challenges and opportunities for the development of small-molecular compounds targeting the Wnt signalling pathway in disease treatment.

Neutral Mo6Q8-clusters with terminal phosphane ligands – a route to water soluble molecular units of Chevrel phases

Despite the numerous works on Chevrel phases, their building blocks – molecular compounds containing {Mo6Q8} cluster core, are hardly presented in literature. Here we present rare examples of phosphane molybdenum...

MOLECULAR MODELING, REACTIVITY PARAMETERS AND SPECTROCHEMIC STUDIES OF ε-CAPROLACTAM AND o-PHENANTROLINE

In this work, molecular models were obtained, and the reactivity parameters of ε-caprolactam and ophenanthroline were calculated to evaluate the interaction in the formation of complex molecular compounds. It was observed that the main electron donor atoms, in the formation of the metal-ligand bond, are centered mainly on the oxygen and nitrogen atoms, respectively, which are sterically more favorable in these species. Conductance measurements in an aqueous solution were obtained to observe the electrolytic behavior of these compounds. Infrared spectra were also recorded to characterize vibrational transitions in identifying these species when present in complex systems. Molecular spectra of absorption in the UV-visible region were recorded to evaluate the spectrochemical properties of these individual ligands and further verify their influence on the formation of complex molecular systems. The parameters evaluated include the molar absorptivity ε, integrated absorption coefficient, oscillator force, and transition dipole moment. It was observed that the ε parameter indicates molecular transitions in the 190 – 300 nm region and the near-infrared, and the oscillator strength is typical of molecules used as dyes and sensitizers for optical light-emitting systems or light-to-electricity converters.

New Copper Bromide Organic-Inorganic Hybrid Molecular Compounds with Anionic Inorganic Core and Cationic Organic Ligands

Here, organic-inorganic hybrid molecular compounds based on copper(I) bromide have been synthesized by slow-diffusion method. The inorganic modules of these two structures are Cu2Br42− anion, and the inorganic modules are coordinated to cationic organic ligands via Cu-N coordinative bonds. Both of these compounds are luminescent, emitting green emissions under UV excitation.

Compensatory Phenolic Induction Dynamics in Aspen After Aphid Infestation

Condensed tannins (CTs) are polyphenolics and part of the total phenolic (TP) pool that shape resistance in aspen (Populus tremula). CTs negatively associate with pathogens, but their resistance properties against herbivores are less understood. Piercing, sucking arthropods, such as aphids, share similar defence pathways with pathogens suggesting that CTs could also shape resistance to aphids, potentially together with other phenolics. Being highly variable it can further be questioned whether CT-shaped resistance is better described by constitutive levels, by the induced response potential, or by both. Here, aspen genotypes were propagated and selected to represent a range of inherent abilities to produce and store foliar CTs; the plantlets were then exposed to Chaitophorus aphid infestation and to mechanical (leaf rupture) damage, and the relative abundance of constitutive and induced CTs was related to aphid fitness parameters. As expected, aphid fecundity was negatively related to CT-concentrations of the aphid infested plants although more consistently related to TPs. While TPs increased in response to damage, CT induction was generally low and it even dropped below constitutive levels in more CT-rich genotypes, suggesting that constitutive CTs are more relevant measurements of resistance compared to induced CT-levels. Relating CT and TP dynamics with phenolic low molecular compounds further suggested that catechin (the building block of CTs) increased in response to aphid damage in amounts that correlated negatively with CT-induction and positively with constitutive CT-levels and aphid fecundity. Our study portrays dynamic phenolic responses to two kinds of damage detailed for major phenylpropanoid classes and suggests that the ability of a genotype to produce and store CTs may be a measurement of resistance, caused by other, more reactive, phenolic compounds such as catechin. Rupture damage however appeared to induce catechin levels oppositely supporting that CTs may respond differently to different kinds of damage.

Vibrational Properties of CO Adsorbed on Au Single Atom Catalysts on TiO2(101), ZrO2(101), CeO2(111), and LaFeO3(001) Surfaces: A DFT Study

The nature and local environment of Au single atoms supported and stabilized on four different oxides is studied by means of DFT + U calculations using CO as probe molecule and its stretching frequency, ωe, as a fingerprint of the site where the Au atom is bound. Four oxides are considered, anatase TiO2, tetragonal ZrO2, cubic CeO2, and a perovskite LaFeO3. In this latter case a recently reported experimental study has detected a stretching mode for CO adsorbed on Au1/LaFeO3 of 2215 cm−1, with a large blue shift, ∆ω(CO) = 72 cm−1 with respect to free CO. In order to identify the Au adsorption site that can give rise to this large blue-shift we have considered five cases: (a) Au replacing a lattice cation, (Au)subM; (b) Au replacing a lattice O anion, (Au)subO; (c) Au adsorbed on the surface, (Au)ads; (d) Au bound to an extra O atom on the surface, (AuO)ads, or (e) Au bound to two extra O atoms on the surface, (AuO2)ads. It turns out that the correct reproduction of ∆ω for CO adsorbed on positively charged gold, Auδ+, is challenging for DFT. Therefore, we have performed a comparative study of Auδ+-CO molecular compounds for which ωe(CO) is known experimentally using various kinds of DFT functionals and accurate CCSD and CCSD(T) quantum chemistry methods. Also based on this comparison we propose a tentative assignment for the observed frequency of CO adsorbed on Au1/LaFeO3 single atom catalyst. Graphic Abstract

In-Silico Investigation on Chloroquine Derivatives: A Potential Anti-COVID-19 Main Protease

SARS-CoV-2 (Covid 19) continues to be a great threat to lives globally as it causes illnesses such as the common cold, severe acute respiratory syndrome and spreads easily among people. In this work, thirteen molecular compounds were studied via quantum chemical calculations, molecular docking, and dynamic simulation, and ADMET (absorption, distribution, metabolism, excretion, and toxicity). The obtained descriptors (Log P, HBA, HBD, and molecular weight) showed that the studied compounds have the ability to act as a drug. Thus, it was detected that all the studied selected compounds possess a better tendency to inhibit main coronavirus protease; however, compound C1 has a higher tendency to inhibit main coronavirus protease than the other compounds, including the standard (Chloroquine). ADMET properties of compound C1 proved that the predicted ADMET level was better than the ADMET properties of the referenced drug.

Theoretical Evaluation of Potential Anti-Alanine Dehydrogenase Activities of Acetamide Derivatives

Tuberculosis is an airborne communicable syndrome, which has been observed to be among the top ten (10) causes of death worldwide. This work studied eleven molecular compounds via quantum chemical calculations, molecular docking method, and ADMET (absorption, distribution, metabolism, excretion, and toxicity). The selected obtained descriptors (Log P, HBA, HBD, and molecular weight) showed that the studied compounds have the ability to act drug-like. Compound D inhibited far better than the other studied ligands as well as the standard. ADMET properties of compound D proved that the predicted ADMET level was closer to the ADMET properties of the referenced drug (Isoniazid).

Reductive Catalytic Fractionation of Lignocellulosic Biomass: A New Promising Method of its Integrated Processing

The review discusses the results of recent studies in the promising field of integrated processing of lignocellulosic biomass – the reductive catalytic fractionation (RCF). The effect of catalysts, cocatalysts, solvents, hydrogen sources and features of lignocellulosic feedstock on the selectivity of monomeric products formation from lignin is considered. RCF processes are performed mostly with the heterogeneous catalysts, which allow implementing the reductive depolymerization of lignin to obtain low-molecular compounds and preserve carbohydrate components of biomass. Among the studied catalysts based on platinum group metals and transition metals, the highest activity is observed for the catalysts containing Pd, Pt, Ru and Ni. Features of the metal also affect the composition of the resulting products. Thus, ruthenium catalysts make it possible to obtain 4-propylguaiacol as the main product, while Ni and Pd – 4-propanolguaiacol. Mo-containing catalysts, owing to their lower hydrogenating activity, can be used to obtain monolignols or their etherified derivatives with the preservation of carbohydrate components of lignocellulosic biomass. However, most efficient in RCF processes are the bifunctional catalysts, which have both the acidic and metallic active sites. Acidic sites promote the cleavage of the ether β-O-4 bonds, whereas metallic sites – the reduction of the formed intermediate compounds. An important aspect of choosing the appropriate catalysts for RCF process is the possibility of their repeated application. The use of a ferromagnetic catalyst or a catalyst basket allows separating the catalyst from the products.

VDB Analysis for Zeolites LTA Structures

A distinct number used to characterize a molecular graph's chemical structure and significant chemical properties is a topological index. Quite a number of Vertex degree-based (VDB) indices have been introduced to investigate the structure of molecular compounds. Zeolites are a widely used family of aluminosilicates that have applications in chemistry, medicine, and commercial production due to their advantageous chemical properties. To aid in their creation, computer simulations have found millions of possible specific structures for zeolites. However, only a small percentage of these structures have been created. To aid in this discovery process, we extend the literature by computing the analytical expressions of VDB indices, VDB entropy measures, and VDB irregularity indices.