Identification of Promising Biofilm Inhibitory and Cytotoxic Quinazolin‐4‐one Derivatives: Synthesis, Evaluation, Molecular Docking and ADMET Studies

Design and synthesis of new quinazolinone derivatives: investigation of antimicrobial and biofilm inhibition effects

New quinazolin-4-ones 9-32 were synthesized in an attempt to overcome the life-threatening antibiotic resistance phenomenon. The antimicrobial screening revealed that compounds 9, 15, 16, 18, 19, 20 and 29 are the most broad spectrum antimicrobial agents in this study with safe profile on human cell lines. Additionally, compounds 19 and 20 inhibited biofilm formation in Pseudomonas aeruginosa, which is regulated by quorum sensing system, at sub-minimum inhibitory concentrations (sub-MICs) with IC50 values 3.55 and 6.86 µM, respectively. By assessing other pseudomonal virulence factors suppression, it was found that compound 20 decreased cell surface hydrophobicity compromising bacterial cells adhesion, while both compounds 19 and 20 curtailed the exopolysaccharide production which constitutes the major component of the matrix binding biofilm components together. Also, at sub-MICs Pseudomonas cells twitching motility was impeded by compounds 19 and 20, a trait which augments the cells pathogenicity and invasion potential. Molecular docking study was performed to further evaluate the binding mode of candidates 19 and 20 as inhibitors of P. aeruginosa quorum sensing transcriptional regulator PqsR. The achieved results demonstrate that both compounds bear promising potential for discovering new anti-biofilm and quorum quenching agents against Pseudomonas aeruginosa without triggering resistance mechanisms as the normal bacterial life cycle is not disturbed.

Unraveling the access to the regioselective synthesis of highly functionalized pyranopyrazoles using an ionic liquid catalyst

An efficient and green strategy for the regioselective synthesis of highly functionalized pyranopyrazole via one-pot condensation of 3-methyl-1-phenyl-5-pyrazolone or EAA and hydrazine hydrate, substituted aromatic aldehydes with NMSM [(E)-N-Methyl-1-(methylthio)-2-nitro-ethenamine] in the existence of IL [(EMIM)Ac] as catalyst with solvent-free condition (SFC) is described. This domino protocol produces biologically substantial heterocycles through Knoevenagel condensation proceeded by Michael addition and O-cyclization with an eradication of methanethiol group, which create the one stereo-center and creation of "C-C, C-N, C-O, C=C, C=N, bonds." The final product is produced by exceptionally easy filtering after the reaction mass was triturated with ethanol. The strategy's noteworthy features include the use of biodegradable IL catalyst, excellent to exceptional yield with rapid reaction times, applicability to a wide range of substrate, clear reaction profile, and straightforward workup process.

Synthesis, cytotoxicity and antioxidant activity of new 1,3-dimethyl-8-(chromon-3-yl)-xanthine derivatives containing 2,6-di-tert-butylphenol fragments

New xanthine analogs of isoflavone were synthesized and exhibited promising anticancer and antioxidant activities.

Synthesis of heterocyclic analogs of isoflavone and homoisoflavone based on 3-formylchromone

The review is focused on recent developments of chemistry of synthetic analogs of natural compounds, isoflavone and homoisoflavone. The possible synthetic strategies to access heterocyclic analogs of these compounds starting from readily available 3-formylchromone and its derivatives (3-cyanochromone, 2-amino-3-formylchromone) and products of its condensation with simplest C- and N-nucleophiles are discussed. The structural features of the reaction products that depend on the nature of the reaction medium, structure of the starting compounds, and reagent ratio are considered. Particular attention is given to the application of the modern strategies of organic synthesis, namely green chemistry approaches, click reactions, domino reactions, etc. Examples of compounds of this group most promising for clinical application due to wide and pronounced pharmacological effects are given.