Search

Mai Zhang,1 Yan Li,1,2 Chunli Han,3 Shiying Chu,1 Peng Yu,1 Wenbo Cheng1,2 1Mass Spectrometry Application Center, Tianjin Guoke Medical Technology Development Co., Ltd, Tianjin, People’s Republic of China; 2Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences (CAS), Suzhou, People’s Republic of China; 3Mass Spectrometry Application Center, Shandong CAS Intelligent Manufacturing Medical Device Technology Co., Ltd, Zaozhuang, People’s Republic of ChinaCorrespondence: Wenbo Cheng, Email chengwb@sibet.ac.cnBackground: Inhibition of amyloid β protein fragment (Aβ) aggregation is considered to be one of the most effective strategies for the treatment of Alzheimer’s disease. (-)-Epigallocatechin-3-gallate (EGCG) has been found to be effective in this regard; however, owing to its low bioavailability, nanodelivery is recommended for practical applications. Compared to chemical reduction methods, biosynthesis avoids possible biotoxicity and cumbersome preparation processes.Materials and Methods: The interaction between EGCG and Aβ 42 was simulated by molecular docking, and green tea-conjugated gold nanoparticles (GT-Au NPs) and EGCG-Au NPs were synthesized using EGCG-enriched green tea and EGCG solutions, respectively. Surface active molecules of the particles were identified and analyzed using various liquid chromatography-tandem triple quadrupole mass spectrometry methods. ThT fluorescence assay, circular dichroism, and TEM were used to investigate the effect of synthesized particles on the inhibition of Aβ 42 aggregation.Results: EGCG as well as apigenin, quercetin, baicalin, and glutathione were identified as capping ligands stabilized on the surface of GT-Au NPs. They more or less inhibited Aβ 42 aggregation or promoted fibril disaggregation, with EGCG being the most effective, which bound to Aβ 42 through hydrogen bonding, hydrophobic interactions, etc. resulting in 39.86% and 88.50% inhibition of aggregation and disaggregation effects, respectively. EGCG-Au NPs were not as effective as free EGCG, whereas multiple thiols and polyphenols in green tea accelerated and optimized heavy metal detoxification. The synthesized GT-Au NPs conferred the efficacy of diverse ligands to the particles, with inhibition of aggregation and disaggregation effects of 54.69% and 88.75%, respectively, while increasing the yield, enhancing water solubility, and decreasing cost.Conclusion: Biosynthesis of nanoparticles using green tea is a promising simple and economical drug-carrying approach to confer multiple pharmacophore molecules to Au NPs. This could be used to design new drug candidates to treat Alzheimer’s disease.Keywords: gold nanoparticles, green synthesis, (-)-epigallocatechin-3-gallate, liquid chromatography tandem triple quadrupole mass spectrometry, amyloid β protein, green tea

Using the results of virtual ligand screening (VLS) of a representative set of 66834 commercially available drug-like ligands and 8400 di- and tripeptides in the central cavity of Transthyretin (TTR) amyloid fibrils, it has been shown that despite the great chemical diversity, among commercially available drug-like organic compounds and ultrashort peptides (USPs), only 7 USPs are able to bind in the central cavity of TTR amyloid fibrils, thus preventing the growth of amyloid fibrils. The results of VLS also show that the relaxation of ligand steric strains in the obtained complexes not only significantly improves docking scores but also radically (>50%) changes the main result of VLS, the molecular composition of 1% of the best ligands. Thus, the relaxation of steric strains after VLS can more than double the effectiveness of VLS in the development of new drugs. [ABSTRACT FROM AUTHOR]

MDA-9/Syntenin, a key scaffolding protein and a molecular hub involved in a diverse range of cell signaling responses, has proved to be a challenging target for the design and discovery of small molecule probes. In this paper, we report on the design and synthesis of small molecule ligands of this key protein. Genetic algorithm-based computational design and the five–eight step synthesis of three molecules led to ligands with affinities in the range of 1–3 µM, a 20–60-fold improvement over literature reports. The design and synthesis strategies, coupled with the structure-dependent gain or loss in affinity, afford the deduction of principles that should guide the design of advanced probes of MDA-9/Syntenin. [ABSTRACT FROM AUTHOR]

Cancer remains one of the leading diseases of mortality worldwide. Janus kinases 2/3 (JAK2/3) have been considered a drug target for the development of drugs to treat different types of cancer. JAK2/3 play a critical role in innate immunity, inflammation, and hematopoiesis by mediating the signaling of numerous cytokines, growth factors, and interferons. The current focus is to develop new selective inhibitors for each JAK type. In this review, the current strategies of computer-aided studies, and biological evaluations against JAK2/3 are addressed. We found that the new synthesized JAK2/3 inhibitors are prone to containing heterocyclic aromatic rings such as pyrimidine, pyridine, and pyrazolo [3,4-d]pyrimidine. Moreover, inhibitors of natural origin derived from plant extracts and insects have shown suitable inhibitory capacities. Computer-assisted studies have shown the important features of inhibitors for JAK2/3 binding. Biological evaluations showed that the inhibition of the JAK receptor affects its related signaling pathway. Although the reviewed compounds showed good inhibitory capacity in vitro and in vivo, more in-depth studies are needed to advance toward full approval of cancer treatments in humans. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells can be effective immunotherapeutic anti-cancer agents due to their ability to selectively target and kill tumor cells. This activity is modulated by the interaction of NK cell receptors with inhibitory ligands on the surface of target cells. NK cell inhibitory ligands can be upregulated on tumor cell surfaces in response to interferon-gamma (IFN-γ), a cytokine which is produced by activated NK cells. We hypothesized that the resistance of tumor cells to NK cell killing could be overcome by expression of the parainfluenza virus 5 (PIV5) V protein, which has known roles in blocking IFN-γ signaling. This was tested with human PM21-NK cells produced through a previously developed particle-based method which yields superior NK cells for immunotherapeutic applications. Infection of human SK-N-SH neuroblastoma cells with PIV5 blocked IFN-γ-mediated upregulation of three NK cell inhibitory ligands and enhanced in vitro killing of these tumor cells by PM21-NK cells. SK-N-SH cells transduced to constitutively express the V protein alone were resistant to IFN-γ-mediated increases in cell surface expression of NK cell inhibitory ligands. Real-time in vitro cell viability assays demonstrated that V protein expression in SK-N-SH cells was sufficient to increase PM21-NK cell-mediated killing. Toward a potential therapeutic application, transient lentiviral delivery of the V gene also enhanced PM21-NK cell killing in vitro. Our results provide the foundation for novel therapeutic applications of V protein expression in combination with ex vivo NK cell therapy to effectively increase the killing of tumor cells. [ABSTRACT FROM AUTHOR]

Cytosolic Glycerol-3-phosphate dehydrogenase 1 (GPD1, EC 1.1.1.8) plays a pivotal role in regulating the Embden-Meyerhof glucose glycolysis pathway (E-M pathway), as well as in conditions such as Huntington's disease, cancer, and its potential role as a specific marker for Dormant Glioma Stem Cells. In this study, we conducted virtual screening using the ZINC database (http://zinc.docking.org/) and the GPD1 structure to identify potential GPD1 modulators. The investigation involved screening active candidate ligands using ADMET (Absorption, Distribution, Metabolism, Excretion, Toxicity) parameters, combined with molecular docking, pose analysis, and interaction analysis based on Lipinski and Veber criteria. Subsequently, the top 10 ligands were subjected to 200 ns all-atom molecular dynamics (M.D.) simulations, and binding free energies were calculated. The findings revealed that specific residues, namely TRP14, PRO94, LYS120, ASN151, THR264, ASP260, and GLN298, played a crucial role in ensuring system stability. Furthermore, through a comprehensive analysis involving molecular docking, molecular M.D., and DeLA-Drug, we identified 10 promising small molecules. These molecules represent potential lead compounds for developing effective therapeutics targeting GPD1-associated diseases, thereby contributing to a deeper understanding of GPD1-associated mechanisms. This study's significance lies in identifying key residues associated with GPD1 and discovering valuable small molecules, providing a foundation for further research and development. [ABSTRACT FROM AUTHOR]

This multifaceted landscape of long-acting gels in diverse medical fields, aims to enhance therapeutic outcomes through localized treatment and controlled drug release. The objective involves advancements spanning cancer treatment, immunotherapy, diabetes management, neuroendocrine disorders, ophthalmic applications, contraception, HIV/AIDS treatment, chronic diseases, wound care, and antimicrobial treatments. It explores the potential of long-acting gels to offer sustained and extended drug release, targeted therapy, and innovative administration routes while addressing limitations such as scalability challenges and regulatory hurdles. Future directions focus on personalized therapies, biodegradability, combination therapies, interdisciplinary innovation, regulatory considerations, and patient-centric development. This comprehensive review highlights the pivotal role of long-acting gels in transforming therapeutic approaches and improving patient outcomes across various medical conditions. [ABSTRACT FROM AUTHOR]

Due to the rapid growth in the number of patients with diabetes in a complicated epidemiological picture, the question of the possibility of exposure of a substance to several targets becomes more important. It is noted that the most common infectious diseases in patients with diabetes mellitus are infections of the respiratory and urinary tract, skin and soft tissues, diabetic foot ulcers, otitis media and periodontal infections. Antimicrobial agents can have both direct and indirect hypoglycemic effects. Quinazolinones belonging to the group of heterocyclic derivatives exhibit a wide range of pharmacological activity. The use of the PASS program for the purpose of computer prediction of pharmacological activity showed a high probability of the hypoglycemic effect of new derivatives. The obtained results motivated the authors to search for the relationship between antimicrobial action and hypoglycemic effect within the general direction of studying the multi-targeting of drug ligands. Analysis of the literature data, as well as own studies of new quinazolinone derivative pharmacological activity make it possible to divide all ligands into functional groups that cause additional binding to the target molecule. The quinazolinone fragment, characterized by the uniqueness of its structure, can be reasonably attributed to multi-target ligands. The triazole cycle and the sulfonamide group can also purposefully bind to the target molecule. A carbamide residue, a fragment of sulfonylurea and an acetamide group, depending on the structure of the substance they are part of, can function both as a specific ligand and as a functional group involved in the stabilization of the intermediate transition state. The results obtained by the authors, as well as other researchers, allow us to formulate an assumption about the relationship between the mechanisms of antimicrobial and hyperglycemic activity.

Calix[n]arenes offer ideal chemical functionality through the polyphenolic lower rim to construct nano-sized coordination clusters with lanthanide (Ln) metal ions (e.g., Nd III10 , Gd III8). However, the number of metal centers they can accommodate is still limited compared to that achievable with smaller ligands (e.g., Gd III140 , Gd III104). Here, we exploit a combination of the "anion template strategy" and "templating ligands" to synthesise three highly symmetric (D3h, trigonal planar) Ln III18 (Ln = La, Nd, and Gd) systems, representing the largest calix[n]arene-based coordination clusters yet. The Ln III18 fragment is templated by a chloride anion located at the center of the cluster, wherefrom twelve μ3-OH− ligands bind 'internally' to the eighteen LnIII ions. 'Externally' the metallic skeleton is connected by p-tert-butylcalix[8]arene, oxo, chloro and carbonate ligands. The crystal packing in the lattice reveals large cylindrical channels of ∼26 Å in diameter, whose pore volume corresponds to ∼50% of the unit cell volume (using a 1.2 Å spherical probe radius). Magnetic measurements reveal the predominance of weak antiferromagnetic exchange in the Gd analog. Heat capacity data of Gd III18 reveal a high magnetic entropy with −ΔSm = 23.7 J K−1 kg−1, indicating potential for engineering magnetic refrigerant materials with calix[8]arenes. [ABSTRACT FROM AUTHOR]

PNP pincers represent some of the most well-studied ligand systems in coordination chemistry owing to their high thermal and chemical stability, and the predictable metal coordination geometries of associated metal complexes. Examples of first-row transition metal complexes bearing acridine-based PNP pincer ligands are extremely rare. This study reports the preparation and structural authentication of acridine-based copper(I) PNP complexes, which reveal the profound effects that the steric bulk of methylene-tethered P-substituents has on metal centre coordination number and geometry. The capacity of these systems to mediate copper-catalysed alkyne hydroboration and the borylation of aryl halides is also investigated. [ABSTRACT FROM AUTHOR]

In this work, the reaction between the drug gatifloxacin (as a ligand) with Ru(III) ions was investigated and the resulting complex was structurally and morphologically characterized. The structural properties of the complex were assessed using elemental analyses, molar conductance, thermogravimetry, UV-Vis, and IR spectroscopies, where the morphological characteristics were evaluated using SEM-EDX and XRD methods. The analyses suggested that two ligand molecules were coordinated to the Ru(III) ion via the nitrogen atoms of piperazine rings. The complex was formulated as [Ru(L)2(Cl)2]Cl, where the Ru(III) ion has a six-coordinate mode, and the coordination sphere is complemented by chlorine atoms. The interaction of the ligand with the Ru(III) ions leads to the product having an organized smooth plate-like structure with a main diameter of 39.42 nm. The RuO2 oxide in the nanoscale range was generated by the thermal decomposition of the [Ru(L)2(Cl)2]Cl complex at 600 oC for 3 hours. SEM micrographs indicated that the RuO2 material possesses uniform and organized microstructures with many internal cavities enabling it to be used as a catalyst for the heterogeneous degradation of dyes and organic pollutants. [ABSTRACT FROM AUTHOR]

A series of four novel heteroleptic Cu(I) complexes, bearing bis(1H-indazol-1-yl)methane analogues as N,N ligands and DPEPhos as the P,P ligand, were synthesised in high yields under mild conditions and characterised by spectroscopic and spectrometric techniques. In addition, the position of the carboxymethyl substituent in the complexes and its effect on the electrochemical and photophysical behaviour was evaluated. As expected, the homoleptic copper (I) complexes with the N,N ligands showed air instability. In contrast, the obtained heteroleptic complexes were air- and water-stable in solid and solution. All complexes displayed green-yellow luminescence in CH2Cl2 at room temperature due to ligand-centred (LC) phosphorescence in the case of the Cu(I) complex with an unsubstituted N,N ligand and metal-to-ligand charge transfer (MLCT) phosphorescence for the carboxymethyl-substituted complexes. Interestingly, proper substitution of the bis(1H-indazol-1-yl)methane ligand enabled the achievement of a remarkable luminescent yield (2.5%) in solution, showcasing the great potential of this novel class of copper(I) complexes for potential applications in luminescent devices and/or photocatalysis. [ABSTRACT FROM AUTHOR]