Novel imidazobenzazepine derivatives as dual H1/5-HT2A antagonists for the treatment of sleep disorders

Discovery of new chemotypes of dual 5-HT2A/D2 receptor antagonists with a strategy of drug design methodologies

Aim: Through the application of structure- and ligand-based methods, the authors aimed to create an integrative approach to developing a computational protocol for the rational drug design of potent dual 5-HT_2A/D₂ receptor antagonists without off-target activities on H₁ receptors. Materials & methods: Molecular dynamics and virtual docking methods were used to identify key interactions of the structurally diverse antagonists in the binding sites of the studied targets, and to generate their bioactive conformations for further 3D-quantitative structure-activity relationship modeling. Results & conclusion: Toward the goal of finding multi-potent drugs with a more effective and safer profile, the obtained results led to the design of a new set of dual antagonists and opened a new perspective on the therapy for complex brain diseases.

In silico identification of novel 5-HT2A antagonists supported with ligand- and target-based drug design methodologies

A wide range of neuropsychological disorders is caused by serotonin 5-HT_2A receptor (5-HT_2AR) malfunction. Therefore, this receptor had been frequently used as target in CNS drug research. To design novel potent 5-HT_2AR antagonists, we have combined ligand-based and target-based approaches. This study was performed on wide range of structurally diverse antagonists that were divided into three different clusters: clozapine, ziprasidone, and ChEMBL240876 derivatives. By performing the 50 ns long molecular dynamic simulations with each cluster representative in complex with 5-HT_2A receptor, we have obtained virtually bioactive conformations of the ligands and three different antagonist-bound, inactive, conformations of the 5-HT_2AR. These three 5-HT_2AR conformations were further used for docking studies and generation of the bioactive conformations of the data set ligands in each cluster. Subsequently, selected conformers were used for 3D-Quantitative Structure Activity Relationship (3D-QSAR) modelling and pharmacophore analysis. The reliability and predictive power of the created model was assessed using an external test set compounds and showed reasonable external predictability. Statistically significant variables were used to define the most important structural features required for 5-HT_2A antagonistic activity. Conclusions obtained from performed ligand-based (3D-QSAR) and target-based (molecular docking and molecular dynamics) methods were compiled and used as guidelines for rational drug design of novel 5-HT_2AR antagonists.Communicated by Ramaswamy H. Sarma.

Reactions of [2-(Bromomethyl)phenyl](4-chlorophenyl)methanone: A New Synthesis of [1,3]Thiazolo[3,2-b][2,4]benzodiazepine, Benzimidazo[1,2-b][2,4]benzodiazepine and Benzimidazo[1,2-b][2]benzazepine Derivatives

A new approach to the development of a number of azolo-condensed azepines and diazepines has been proposed. The method for the synthesis of [1,3]thiazolo[3,2-b][2,4]benzodiazepine, benzimidazo[1,2-b][2,4]benzodiazepineandbenzimidazo[1,2-b][2]benzazepinederivatives involves the reaction of [2-(bromomethyl)phenyl](4-chlorophenyl)methanonewith5-methyl-1,3-thiazol-2-amine, 1H-benzimidazol-2-amineand1,2-dimethyl-1H-benzimidazole. The formation of the quaternary salt of the initial diazole has been done under mild conditions in MeCN. The following intramolecular condensation has been realized by heating 2-amino azolium salts in AcOH or in Et3N as in the case of 2-methyl azolium salt. The structures of these cyclic compounds have been confirmed by mass spectrometry measurements, elemental analysis and NMR spectra.