Uracil derivatives as HIV-1 capsid protein inhibitors: design, in silico, in vitro and cytotoxicity studies

Targeting Blood-Stage Malaria: Design, Synthesis, Characterization, In Vitro, and In Silico Evaluation of Pyrrolidinodiazenyl Chalcones

Malaria is a pervasive and deadly threat to the global population, and the resources available to treat this disease are limited. There is widespread clinical resistance to the most commonly prescribed antimalarial drugs. To address this issue, we synthesized a range of 4'-pyrrolidinodiazenyl chalcones using a covalent bitherapy approach to study their potential antimalarial properties. We examined the structure-activity relationships of these compounds, which could explain their antimalarial activities. The in vitro blood stage antimalarial activity of the compounds was evaluated against the mixed-blood stage culture (ring, trophozoites and schizonts) of Plasmodium falciparum 3D7, and the 50% inhibitory concentrations (IC50s) ranged from 3.3 to 22.2 μg/mL after 48 h of exposure. Compounds 11, 19, and 22 displayed pronounced IC50 values of 7.6 μg/mL, 6.4 μg/mL, and 3.3 μg/mL, respectively. The in vitro cytotoxicity of the active compounds was evaluated on human-derived Mo7e cells and murine-derived BA/F3 cells. Compounds 11 and 19 were found to be noncytotoxic (> 40 μg/mL), whereas compound 22 displayed cytotoxicity at higher concentrations. Moreover, these compounds exerted negligible hemolytic effects on human RBCs at their active concentrations. Molecular docking of these compounds revealed good hydrophobic and hydrogen bonding interactions with the binding sites of Plasmodium falciparum-dihydrofolate reductase, providing a rationale for their antimalarial activity, which is consistent with the in vitro results.

Applications of catalytic systems containing DNA nucleobases (adenine, cytosine, guanine, and thymine) in organic reactions

In recent years, nucleobases have attracted special attention because of their abundant resources and multiple interaction sites, which enable them to interact with and functionalize other molecules. This review focuses on the catalytic activities of each of the four main nucleobases found in deoxyribonucleic acid (DNA) in various organic reactions. Based on the studies, most of the nucleobases act as heterogeneous catalytic systems. The authors hope their assessment will help chemists and biochemists to propose new procedures for utilizing nucleobases as catalysts in various organic synthetic transformations. The review covers the corresponding literature published till the end of August 2023.

Development of a Divergent Synthesis Strategy for 5-Sulfonyl-Substituted Uracil Derivatives

An efficient, diversity-orientated synthesis of 5-sulfone-substituted uracils was established. The use of protecting groups to synthesize sulfones from N-heterocycles was avoided. Various heterocycles were synthesized for the first time from favorable, easily accessible starting materials. Diversity-orientated syntheses are important for the medicinal chemistry of virostatics and chemotherapeutics. This approach provides a broad substrate tolerance and excellent yields of up to 98%.

Pharmacophore-based 3D-QSAR modeling, virtual screening, docking, molecular dynamics and biological evaluation studies for identification of potential inhibitors of alpha-glucosidase

CONTEXT

Alpha-glucosidase enzyme is considered an important therapeutic target for controlling hyperglycemia associated with type 2 diabetes. Novel scaffolds identified as potential alpha-glucosidase inhibitors from the Maybridge library utilizing pharmacophore modeling, molecular docking and biological evaluation are reported in this manuscript.

METHOD

A total of 51 xanthone series scaffolds previously reported as alpha-glucosidase inhibitors were collected and used as training and test sets. These sets were employed to develop and validate a pharmacophore-based 3D-QSAR model with statistically meaningful results using Schrodinger software. The model showed a high F value (F, 80.1) at five component partial least square factors, a high cross-validation coefficient (Q2, 0.66) and a good correlation coefficient (R2, 0.95). Pearson correlation coefficient (r) of 0.8400 indicated a greater degree of confidence in the model. Subsequently, virtual screening was performed with PHASE module of Schrodinger software using the above model to identify novel alpha-glucosidase inhibitors, and mapped compounds were evaluated for their interactions with the protein. The X-ray co-crystallised structure of the alpha-glucosidase protein in complex with acarbose (PDB Code: 5NN8) was used for molecular docking analysis using GLIDE module and a total of eight compounds were further selected for biological evaluation. Molecular dynamics analysis using GROMACS software was performed in the active site of alpha-glucosidase protein to gain insights into binding mechanism of the four active compounds which were finally found to exhibit inhibitory activity in the biological assay.

Elucidation of 7,8-dihydroxy flavone in complexing with the oxidative stress-inducing enzymes, its impact on radical quenching and DNA damage: an in silico and in vitro approach

Oxidative stress (OS) has been attributed to the progression of various disorders, including cancer, diabetes, and cardiovascular diseases. Several antioxidant compounds and free radical quenchers have been shown to mitigate oxidative stress. However, large-scale randomized controlled trials of such compounds on chronic disease aversion have yielded paradoxical and disappointing results due to the constrained cognizance of their oxidative mechanisms and therapeutic targets. The current study sought to identify the potential therapeutic targets of 7,8-Dihydroxyflavone (7,8-DHF) by analyzing its interactions with the enzymes implicated in oxidative stress and also to explore its radicle quenching potential and prophylactic impact on the H2O2-induced DNA damage. Through the in silco approach, we investigated the antioxidant potential of 7,8-DHF by evaluating its interactions with the human oxidative stress-inducing enzymes such as myeloperoxidase (MPO), NADPH oxidase (NOX), nitric oxide synthase (NOS), and xanthine oxidase (XO) and a comparative analysis of those interactions with known antioxidants (Ascorbic acid, Melatonin, Tocopherol) used as controls. The best-scoring complex was adopted for the simulation analysis in investigating protein-ligand conformational dynamics. The in vitro radicle quenching potential was evaluated by performing a spectrum of antioxidant assays, and radical quenching was observed in a dose-dependent fashion with IC50 values of < 60 µM/mL. Further, we probed its anti-hemolytic potential and prophylactic impact in avian erythrocytes subjected to H2O2-induced hemolysis and DNA damage by implementing hemolysis and comet assays. The protective effect was more pronounced at higher concentrations of the drug.Communicated by Ramaswamy H. Sarma.