Thiadiazolodiazepine analogues as a new class of neuromuscular blocking agents: Synthesis, biological evaluation and molecular modeling study

Ensemble-Based Virtual Screening Led to the Discovery of Novel Lead Molecules as Potential NMBAs

Neuromuscular blocking agents (NMBAs) are routinely used during anesthesia to relax skeletal muscle. Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels; NMBAs can induce muscle paralysis by preventing the neurotransmitter acetylcholine (ACh) from binding to nAChRs situated on the postsynaptic membranes. Despite widespread efforts, it is still a great challenge to find new NMBAs since the introduction of cisatracurium in 1995. In this work, an effective ensemble-based virtual screening method, including molecular property filters, 3D pharmacophore model, and molecular docking, was applied to discover potential NMBAs from the ZINC15 database. The results showed that screened hit compounds had better docking scores than the reference compound d-tubocurarine. In order to further investigate the binding modes between the hit compounds and nAChRs at simulated physiological conditions, the molecular dynamics simulation was performed. Deep analysis of the simulation results revealed that ZINC257459695 can stably bind to nAChRs' active sites and interact with the key residue Asp165. The binding free energies were also calculated for the obtained hits using the MM/GBSA method. In silico ADMET calculations were performed to assess the pharmacokinetic properties of hit compounds in the human body. Overall, the identified ZINC257459695 may be a promising lead compound for developing new NMBAs as an adjunct to general anesthesia, necessitating further investigations.

Novel GABAA Agonist Entities: Pharmacological Investigation and Molecular Modeling Study of Thiazolo- and Thiadiazolo-[3,2-a][1,3]diazepine Analogs

Thiazolo- and thiadiazolo-[3,2-a][1,3]diazepines and their patented derivatives, tested with diverse CNS pharmacological activities, constitute an important class of compounds for new drug development. Therefore, research efforts were continued to design, synthesize, and evaluate compounds for their ultra-short, short-acting hypnotic, anticonvulsant, and neuromuscular blocking activities. The present review provides a summary of the work accomplished by these heterocycles and their biological evaluation.

1,3-Diazepine: A privileged scaffold in medicinal chemistry

Privileged structures have been widely used as effective templates for drug discovery. While benzo-1,4-diazepine constitutes the first historical example of such a structure, the 1,3 analogue is just as rich in terms of applications in medicinal chemistry. The 1,3-diazepine moiety is present in numerous biological active compounds including natural products, and is used to design compounds displaying a large range of biological activities. It is present in the clinically used anticancer compound pentostatin, in several recent FDA approved β-lactamase inhibitors (e.g., avibactam) and also in coformycin, a natural product known as a ring-expanded purine analogue displaying antiviral and anticancer activities. Several other 1,3-diazepine containing compounds have entered into clinical trials. This heterocyclic structure has been and is still widely used in medicinal chemistry to design enzyme inhibitors, GPCR ligands, and so forth. This review endeavours to highlight the main use of the 1,3-diazepine scaffold and its derivatives, and their applications in medicinal chemistry, drug design, and therapy. We will focus more particularly on the development of enzyme inhibitors incorporating this scaffold, with a strong emphasis on the molecular interactions involved in the inhibition mechanism.

Synthesis, antimicrobial, anti-biofilm evaluation, and molecular modelling study of new chalcone linked amines derivatives

A series of amide chalcones conjugated with different secondary amines were synthesised and characterised by different spectroscopic techniques 1H NMR, 13C NMR, and ESI-MS. They were screened for in vitro antibacterial activity. Compounds 36, 37, 38, 42, and 44 are the most active among the synthesised series exhibiting MIC value of 2.0-10.0 µg/ml against different bacterial strains. Compound 36 was equipotent to the standard drug Ampicillin displaying MBC value of 2.0 µg/ml against the bacterial strain Staphylococcus aureus. The products were screened for anti-biofilm activity. Compounds 36, 37, and 38 exhibited promising anti-biofilm activity with IC50 value ranges from 2.4 to 8.6 µg. Molecular modelling was performed suggesting parameters of signalling anti-biofilm mechanism. AspB327 HisB340 (arene-arene interaction) and IleB328 amino acid residues seemed of higher importance to inhibit c-di-GMP. Hydrophobicity may be crucial for activity. ADME calculations suggested that compounds 36, 37, and 38 could be used as good orally absorbed anti-biofilm agents.