Novel synthesis of isoindoline/isoindoline-1,3-dione derivatives under solventless conditions and evaluation with the human D2 receptor

Benzofurans as Acetylcholinesterase Inhibitors for Treating Alzheimer's Disease: Synthesis, in vitro Testing, and in silico Analysis

Alzheimer's disease (AD) is a neurodegenerative disorder and the leading cause of dementia worldwide. It is characterized by a progressive decline in cholinergic neurotransmission. During the development of AD, acetylcholinesterase (AChE) binds to β-amyloid peptides to form amyloid fibrils, which aggregate into plaque deposits. Meanwhile, tau proteins are hyperphosphorylated, forming neurofibrillary tangles (NFTs) that aggregate into inclusions. These complexes are cytotoxic for the brain, causing impairment of memory, attention, and cognition. AChE inhibitors are the main treatment for AD, but their effect is only palliative. This study aimed to design and synthesize novel benzofuran derivatives and evaluate their inhibition of AChE in vitro and in silico. Results: The seven synthesized benzofuran derivatives inhibited AChE in vitro. Benzofurans hydroxy ester 4, amino ester 5, and amido ester (±)-7 had the lowest inhibition constant (Ki) values and displayed good affinity for EeAChE in molecular docking. Six derivatives showed competitive inhibition, while the best compound (5: Ki=36.53 μM) exhibited uncompetitive inhibition. The amino, hydroxyl, amide, and ester groups of the ligands favored interaction with the enzyme by hydrogen bonds. Conclusion: Three benzofurans were promising AChE inhibitors with excellent Ki values. In future research on their their application to AD, 5 will be considered as the base structure.

In silico identification of a biarylamine acting as agonist at human β3 adrenoceptors and exerting BRL37344-like effects on mouse metabolism

Human β3-adrenoceptor (β3AR) agonists were considered potential agents for the treatment of metabolic disorders. However, compounds tested as β3AR ligands have shown marked differences in pharmacological profile in rodent and human species, although these compounds remain attractive as they were successfully repurposed for the therapy of urinary incontinence. In this work, some biarylamine compounds were designed and tested in silico as potential β3AR agonists on 3-D models of mouse or human β3ARs. Based on the theoretical results, we identified, synthesized and tested a biarylamine compound (polibegron). In CHO-K1 cells expressing the human β3AR, polibegron and the β3AR agonist BRL 37344 were partial agonists for stimulating cAMP accumulation (50 and 57% of the response to isoproterenol, respectively). The potency of polibegron was 1.71- and 4.5-fold higher than that of isoproterenol and BRL37344, respectively. These results indicate that polibegron acts as a potent, but partial, agonist at human β3ARs. In C57BL/6N mice with obesity induced by a high-fat diet, similar effects of the equimolar intraperitoneal administration of polibegron and BRL37344 were observed on weight, visceral fat and plasma levels of glucose, cholesterol and triglycerides. Similarities and differences between species related to ligand-receptor interactions can be useful for drug designing.

Crystal structure, DFT calculations and evaluation of 2-(2-(3,4-dimethoxyphenyl)ethyl)isoindoline-1,3-dione as AChE inhibitor

Dioxoisoindolines have been included as a pharmacophore group in diverse drug-like molecules with a wide range of biological activity. Various reports have shown that phthalimide derivatives are potent inhibitors of AChE, a key enzyme involved in the deterioration of the cholinergic system during the development of Alzheimer's disease. In the present study, 2-(2-(3,4-dimethoxyphenyl)ethyl)isoindoline-1,3-dione was synthesized, crystallized and evaluated as an AChE inhibitor. The geometric structure of the crystal and the theoretical compound (from molecular modeling) were analyzed and compared, finding a close correlation. The formation of the C6-H6···O19 interaction could be responsible for the non-negligible out of phenyl plane deviation of the C19 methoxy group, the O3 from the carbonyl group lead to C16-H16···O3i intermolecular interactions to furnish C(9) and C(14) infinite chains within the (- 4 0 9) and (- 3 1 1) families of planes. Finally, the biological experiments reveal that the isoindoline-1,3-dione exerts a good competitive inhibition on AChE (Ki = 0.33-0.93 mM; 95% confidence interval) and has very low acute toxicity (LD50 > 1600 mg/kg) compared to the AChE inhibitors currently approved for clinical use.