Solvent-free microwave-assisted synthesis and biological evaluation of aurones and flavanones based on 2,2-dimethylchroman-4-one

Chromanone-A Prerogative Therapeutic Scaffold: An Overview

Chromanone or Chroman-4-one is the most important and interesting heterobicyclic compound and acts as a building block in medicinal chemistry for isolation, designing and synthesis of novel lead compounds. Structurally, absence of a double bond in chromanone between C-2 and C-3 shows a minor difference from chromone but exhibits significant variations in biological activities. In the present review, various studies published on synthesis, pharmacological evaluation on chroman-4-one analogues are addressed to signify the importance of chromanone as a versatile scaffold exhibiting a wide range of pharmacological activities. But, due to poor yield in the case of chemical synthesis and expensive isolation procedure from natural compounds, more studies are required to provide the most effective and cost-effective methods to synthesize novel chromanone analogs to give leads to chemistry community. Considering the versatility of chromanone, this review is designed to impart comprehensive, critical and authoritative information about chromanone template in drug designing and development.

Aurone derivatives as promising antibacterial agents against resistant Gram-positive pathogens

A set of variously substituted aurones was synthesized and evaluated against Methicillin-Resistant S. aureus (MRSA) and P. aeruginosa. Several analogues were found active against MRSA, but no effect was recorded against P. aeruginosa. Compounds 27, 30 and 33 showed low cytotoxicity, and were tested against a full range of bacterial (Gram-positive and Gram-negative) and fungal species, including resistant strains. These aurones displayed a selective inhibition of Gram-positive bacteria with excellent Therapeutic Index values, while showing no significant action on several Gram-negative strains, H. pylori and V. alginolyticus being the only susceptible strains among the Gram-negative bacteria tested. A permeabilization assay showed that the antibacterial activity of at least some of the aurones could be linked to alterations of the bacterial membrane. Overall, this study endorses the use of the aurone scaffold for the development of new potent and selective antibacterial agents.

Design, synthesis and evaluation of novel 2,2-dimethyl-2,3-dihydroquinolin-4(1H)-one based chalcones as cytotoxic agents

We designed and synthesised a series of novel chalcones, incorporating the heterocyclic framework of 2,2-dimethyl-2,3-dihydro-4(1H)-quinolinone, which was prepared via Sonogashira coupling of a substituted orthoaniline under aqueous conditions using Pd catalysis followed by acid-mediated cyclisation. The compounds were screened against the NCI-N87 and DLD-1 cancer cell lines, with most compounds showing low micromolar cytotoxic activity.