Synthesis and biological evaluation of 2-phenoxyacetamide analogues, a novel class of potent and selective monoamine oxidase inhibitors

Synthesis, characterization, molecular docking and molecular dynamics simulations of novel 2,5-disubstituted-1,3,4-thiadiazole derivatives as potential cholinesterase/monoamine oxidase dual inhibitors for Alzheimer's disease

Designing multi-targeted drugs (MTD) for Alzheimer's disease (AD) is now one of the priorities for medicinal chemists, as the disease has a complicated not fully understood pathological nature and the approved mono-targeted drugs only alleviate the symptoms. In this study, the synthesis, spectral analyses and in vitro inhibition activity against cholinesterase (ChE) and monoamine oxidase (MAO) enzymes of a novel series of N-[5-(adamantan-1-yl)-1,3,4-thiadiazol-2-yl]-2-(4-un/substituted) cyclic secondary amino-acetamide/propanamide derivatives were done. Generally, derivatives were more selective against acetylcholinesterase (AChE) and h-MAO-B than butyrylcholinesterase (BChE) and h-MAO-A, respectively. Derivatives 4a, 4b, 3a, 3d and 3b ordered from the most potent to the least displayed significant inhibition against AChE. Also, derivatives 4a, 4b and 3a still maintained their significant inhibition against h-MAO-B in the same potency order, making them dual inhibitors and MTD candidates for AD. Binding interactions with several crucial amino acid residues for activity and selectivity as well as the stability of the most active derivatives-enzyme complex were confirmed utilizing molecular docking and molecular dynamic simulation studies.Communicated by Ramaswamy H. Sarma.

Synthesis of aryloxyacetamides from arylboronic acids and 2-bromoacetonitrile promoted by alkaline solutions of hydrogen peroxide

A novel and metal catalyst-free synthesis of aryloxyacetamides from the corresponding arylboronic acids and 2-bromoacetonitrile promoted by alkaline solutions of hydrogen peroxide has been developed involving an oxidation-reduction of eco-friendly H₂O₂ with simultaneous reaction ipso-hydroxylation of arylboronic acid and hydration of the nitrile. This protocol is compatible with sensitive substituents attached to the arylboronic acid and provides desired products in moderate to good yields in pure water.

2-Phenoxyacetamide derivatives as SARS-CoV-2 main protease inhibitor: In silico studies

2-Phenoxyacetamide group has been identified as one of markers in the discovery and development of SARS-CoV-2 antiviral agent through its main protease (M^pro) inhibition pathway. This study aims to study a series of 2-phenoxyacetamide derivatives using in silico method toward SARS-CoV-2 M^pro as the protein target. The study was initiated by employing structure-based pharmacophore to virtually screen and to select the ligands, which have the best fit score (hits) along with the common pharmacophore features being matched. The result shows that from the 11 ligands designed, four ligands are selected as the hits by demonstrating fit score in the range of 56.20 to 65.53 to the pharmacophore model, employing hydrogen bond acceptor (HBA) and hydrophobic (H) as the common features. The hits were then docked into the binding site of the M^pro to see the binding mode of the corresponding hits as well as its affinity. The docking results free energy of binding (ΔG_bind) of the hits are in agreement with the pharmacophore fit score, in the range of −6.83 to −7.20 kcal/ mol. To gain the information of the hits as a potential drug to be developed, the in silico study was further proceed by predicting the mutagenic potency, toxicity and pharmacokinetic profiles. Based on the efficiency percentage, all hits meet the criteria as drug candidates by showing 84–88% leading to a conclusion that 2-phenoxyacetamide derivatives are beneficial to be marked as the lead compound for SARS-CoV-2 M^pro inhibitor.

Novel approaches to the discovery of selective human monoamine oxidase-B inhibitors: is there room for improvement?

Introduction: Selective monoamine oxidase-B (MAO-B) inhibitors are currently used as coadjuvants for the treatment of early motor symptoms in Parkinson's disease. They can, based on their chemical structure and mechanism of inhibition, be categorized into reversible and irreversible agents. Areas covered: This review provides a comprehensive update on the development state of selective MAO-B inhibitors describing the results, structures, structure-activity relationships (SARs) and Medicinal chemistry strategies as well as the related shortcomings over the past five years. Expert opinion: Researchers have explored and implemented new and old chemical scaffolds achieving high inhibitory potencies and isoform selectivity. Most of them were characterized and proposed as multitarget agents able to act at different levels (including AChE inhibition, H3R or A_2AR antagonism, antioxidant and chelating properties, Aβ_1-42 aggregation reduction) in the network of aetiologies of neurodegenerative disorders. These results can also be used to avoid 'cheese-reaction' effects and the occurrence of serotonergic syndrome in patients.