Structure-based design of new N-benzyl-piperidine derivatives as multitarget-directed AChE/BuChE inhibitors for Alzheimer's disease.

The pathogenic complexity of Alzheimer's disease (AD) demands the development of multitarget-directed agents aiming at improving actual pharmacotherapy. Based on the cholinergic hypothesis and considering the well-established role of butyrylcholinesterase (BuChE) in advanced stages of AD, the chemical structure of the acetylcholinesterase (AChE) inhibitor drug donepezil (1) was rationally modified for the design of new N-benzyl-piperidine derivatives (4a-d) as potential multitarget-direct AChE and BuChE inhibitors. The designed analogues were further studied through the integration of in silico and in vitro methods. ADMET predictions showed that 4a-d are anticipated to be orally bioavailable, able to cross the blood-brain barrier and be retained in the brain, and to have low toxicity. Computational docking and molecular dynamics indicated the formation of favorable complexes between 4a-d and both cholinesterases. Derivative 4a presented the lowest binding free energy estimation due to interaction with key residues from both target enzymes (-36.69 ± 4.47 and -32.23 ± 3.99 kcal/mol with AChE and BuChE, respectively). The in vitro enzymatic assay demonstrated that 4a was the most potent inhibitor of AChE (IC50 2.08 ± 0.16 µM) and BuChE (IC50 7.41 ± 0.44 µM), corroborating the in silico results and highlighting 4a as a novel multitarget-directed AChE/BuChE inhibitor.

Cinnamoyl-N-Acylhydrazone-Donepezil Hybrids: Synthesis and Evaluation of Novel Multifunctional Ligands Against Neurodegenerative Diseases.

A new series of ten multifunctional Cinnamoyl-N-acylhydrazone-donepezil hybrids was synthesized and evaluated as multifunctional ligands against neurodegenerative diseases. The molecular hybridization approach was based on the combination of 1-benzyl-4-piperidine fragment from the anti-Alzheimer AChE inhibitor donepezil (1) and the cinnamoyl subunit from curcumin (2), a natural product with remarkable antioxidant, neuroprotective and anti-inflammatory properties, using a N-acylhydrazone fragment as a spacer subunit. Compounds 4a and 4d showed moderate inhibitory activity towards AChE with IC50 values of 13.04 and 9.1 µM, respectively. In addition, compound 4a and 4d showed a similar predicted binding mode to that observed for donepezil in the molecular docking studies. On the other hand, compounds 4a and 4c exhibited significant radical scavenging activity, showing the best effects on the DPPH test and also exhibited a significant protective neuronal cell viability exposed to t-BuOOH and against 6-OHDA insult to prevent the oxidative stress in Parkinson's disease. Similarly, compound 4c was capable to prevent the ROS formation, with indirect antioxidant activity increasing intracellular GSH levels and the ability to counteract the neurotoxicity induced by both OAß1-42 and 3-NP. In addition, ADMET in silico prediction indicated that both compounds 4a and 4c did not show relevant toxic effects. Due to their above-mentioned biological properties, compounds 4a and 4c could be explored as lead compounds in search of more effective and low toxic small molecules with multiple neuroprotective effects for neurodegenerative diseases.

The Design of Multi-target Drugs to Treat Cardiovascular Diseases: Two (or more) Birds on One Stone.

Cardiovascular diseases (CVDs) comprise a group of diseases and disorders of the heart and blood vessels, which together are the number one cause of death worldwide, being associated with multiple genetic and modifiable risk factors, and that may directly arise from different etiologies. For a long time, the search for cardiovascular drugs was based on the old paradigm "one compound - one target", aiming to obtain a highly potent and selective molecule with only one desired molecular target. Although historically successful in the last decades, this approach ignores the multiple causes and the multifactorial nature of CVDs. Thus, over time, treatment strategies for cardiovascular diseases have changed, and, currently, pharmacological therapies for CVD are mainly based on the association of two or more drugs to control symptoms and reduce cardiovascular death. In this context, the development of multitarget drugs, i.e., compounds having the ability to act simultaneously at multiple sites, is an attractive and relevant strategy that can be even more advantageous to achieve predictable pharmacokinetic and pharmacodynamics correlations as well as better patient compliance. In this review, we aim to highlight the efforts and rational pharmacological bases for the design of some promising multitargeted compounds to treat important cardiovascular diseases like heart failure, atherosclerosis, acute myocardial infarction, pulmonary arterial hypertension, and arrhythmia.

The long and winding road of designing phosphodiesterase inhibitors for the treatment of heart failure.

Cyclic nucleotide phosphodiesterases (PDEs) are a superfamily of enzymes known to play a critical role in the indirect regulation of several intracellular metabolism pathways through the selective hydrolysis of the phosphodiester bonds of specific second messenger substrates such as cAMP (3',5'-cyclic adenosine monophosphate) and cGMP (3',5'-cyclic guanosine monophosphate), influencing the hypertrophy, contractility, apoptosis and fibroses in the cardiovascular system. The expression and/or activity of multiple PDEs is altered during heart failure (HF), which leads to changes in levels of cyclic nucleotides and function of cardiac muscle. Within the cardiovascular system, PDEs 1-5, 8 and 9 are expressed and are interesting targets for the HF treatment. In this comprehensive review we will present a briefly description of the biochemical importance of each cardiovascular related PDE to the HF, and cover almost all the "long and winding road" of designing and discovering ligands, hits, lead compounds, clinical candidates and drugs as PDE inhibitors in the last decade.