Adamantane-derived scaffolds targeting the sigma-2 receptor; an in vitro and in silico study

Recent Advances in the Development of Sigma Receptor (Radio)Ligands and Their Application in Tumors

Cancer ranks among the top triumvirate leading causes of human deaths worldwide. The pathological mechanisms are notably intricate, demonstrating proliferative and metastatic capabilities, which complicate therapeutic interventions. The sigma-1 receptor (σ1R) plays a crucial role in tumor survival and migration, while the sigma-2 receptor (σ2R) is intimately associated with tumor proliferation. This review encapsulated the investigation concerning σ1R and σ2R in neoplasms and rigorously summarized the ligands and radio-ligands development and their tumor applications, such as antitumor cell proliferation and PET/SPECT imaging in tumors. A comprehensive classification discussion was undertaken regarding the chemical structures and emphasized the possibility of dual/multitargeted ligands. Ultimately, we discussed the effects of chiral structures and the pharmacological characteristics of ligands on affinity and pharmacokinetic features in vivo, particularly concerning radiopharmaceuticals. This review functions as a beneficial resource, fostering ligand deployment and stimulating the generation of innovative ideas for developing innovative radiopharmaceuticals.

Improving the thermostability of ulvan lyase from polysaccharide lyase family 25 based on multiple computational rational design strategies

A rational design strategy to improve the thermal stability of enzymes is essential for advancing industrial applications. This study proposes a computer-aided rational design strategy combining deep learning and multiple energy function methods to enhance the thermal stability of ulvan lyase. ColabFold was employed for structure prediction. FoldX, Rosetta, and Schrödinger used to screen mutants for thermal stability. Three single-point mutants, A117V, K145L, and A237V, exhibited significantly enhanced enzyme thermal stability. Further combination of mutations revealed synergistic effects, with the most prominent double mutant A117V/A237V showing a half-life of 31.11 min, extending by 8.91 and 13.95 min compared to A117V and A237V, respectively. It also showed a 10 °C increase in Tm and retained 5.12-fold residual activity after 30 min of incubation at 40 °C compared to those of wild type, respectively. Molecular dynamics simulations revealed that the A117V/A237V reduced the flexibility of the loop regions and increased the intramolecular hydrogen bonds. Additionally, the A237V exhibited an optimal pH of 10.0, while the double mutants A117V/A237V and K145L/A237V showed a shift to pH 9.0, compared to pH 8.0 for the wild type. This study demonstrates that computer-aided rational design as a promising strategy to improve the thermostability of ulvan lyase.

Identification of potential SPHK1 inhibitors based on structural optimization by molecular simulation

Sphingosine Kinase 1 (SPHK1), observed to be overexpressed in an array of human malignancies, plays a pivotal role in modulating essential cellular activities throughout the process of tumor formation. Consequently, SPHK1 represents a promising therapeutic target, offering novel approaches to tumor treatment. Here, the structure-activity relationship was researched by using CoMFA and CoMSIA models. Both CoMFA (q2=0.621; n = 10; r2=0.992) and CoMSIA (q2=0.585; n = 7; r2=0.967) demonstrated satisfactory predictive capabilities. The structure-activity relationship of the compounds was analyzed by the counter maps of various fields. Further on, the compounds were interfaced with SPHK1 using the Surfex-Dock method to elucidate their interactive characteristics. Findings reveal that the binding is predominantly reliant on van der Waals, carbon-hydrogen bonds and hydrophobic interactions. Furthermore, the potential activities and ADME/T properties of six novel compounds were predicted utilizing 3D-QSAR models and online tools. The newly designed compounds were validated to have better activities and suitable ADME/T properties. In addition, molecular dynamics (MD) simulation further revealed that key residues, such as Ala339, Ala170, Ala115, Asp81, Gly342, Phe288 Ser164, Phe188, Ile170, etc. This study offers a roadmap to the discovery and design of innovative SPHK1 inhibitors.

Nascent pharmacological advancement in adamantane derivatives

The adamantane moiety has attracted significant attention since its discovery in 1933 due to its remarkable structural, chemical, and medicinal properties. This molecule has a notable impact in the therapeutic field because of its "add-on" lipophilicity to any pharmacophoric moieties. As in the case of molecular hybridization, in which one pharmacophore is attached to another one(s) with a probability of increasing the biological activity, adding an adamantane unit improves the absorption distribution, metabolism and excretion properties of the resultant hybrid molecule. This review summarizes various reports highlighting the biological activities of adamantane-based synthetic compounds and their structure-activity relationship study. The information presented in this review may open up possible dimensions for adamantane-based drug development and discovery in the pharmaceutical industry after proper structural modifications.

Anti-Diabetic Activity of Bioactive Compound Extracted from Spondias mangifera Fruit: In-Vitro and Molecular Docking Approaches

Spondias mangifera is a drupaceous fruit popular for its flavour and health advantages. There is little scientific knowledge about S. mangifera, despite its widespread usage in traditional medicine, in the North-Eastern region of India. Inhibiting the key carbohydrate hydrolysing enzymes is one of the strategies for managing diabetes. Therefore, this study studied the antioxidant and anti-diabetic properties of different fraction S. mangifera fruit extract (SMFFs) from Indian geographical origin by in vitro experimental assays and silico docking simulation studies. The ADMET prediction for active substances was also investigated using the AdmetSAR database. Based on the binding affinity/molecular interactions between phytocompounds and target enzymes, in silico investigations were done to confirm the in vitro enzymatic inhibitory capability. β-sitosterol in EtOH-F was analysed using RP-HPLC with RP-C18 column as stationary phase and photo diode array detector. The percentage of β-sitosterol was found to be 1.21% ± 0.17% of total weight of extract (w/w). S. mangifera fruit ethanolic extract had a significant inhibitory concentration of 50% against free radicals produced by ABTS (89.71 ± 2.73%) and lipid peroxidation assay (88.26 ± 2.17%) tests. Similarly, the in vitro antidiabetic test findings indicated that S. mangifera inhibited alpha-amylase (73.42 ± 2.01%) and alpha-glucosidase (79.23 ± 1.98%) enzymes dose-dependently. The maximum glycosylated Hb percentage inhibitory activity shown in the ethanolic fraction was (83.97 ± 2.88%) at 500 µg/mL. The glucose uptake of the ethanolic fraction by the yeast cell showed significant (p < 0.05) at 500 µg/mL when compared with metformin (91.37 ± 1.59%), whereas the other fraction did not show the uptake of glucose by the yeast cell at the same concentration. In the docking study, the main phytoconstituents of S. mangifera fruit, such as oleanolic acid, beta-sitosterol, and beta amyrin, show strong affinity for pancreatic α-amylase. These results imply that S. mangifera has α-amylase and α-glucosidase inhibitory properties and may be used as antidiabetic with antioxidant characteristics.