Quinolinedione nucleus as a novel scaffold for A1 and A2A adenosine receptor antagonists

Exploration of chalcones and related heterocycle compounds as ligands of adenosine receptors: therapeutics development

Adenosine receptors (ARs) are ubiquitously distributed throughout the mammalian body where they are involved in an extensive list of physiological and pathological processes that scientists have only begun to decipher. Resultantly, AR agonists and antagonists have been the focus of multiple drug design and development programmes within the past few decades. Considered to be a privileged scaffold in medicinal chemistry, the chalcone framework has attracted a substantial amount of interest in this regard. Due to the potential liabilities associated with its structure, however, it has become necessary to explore other potentially promising compounds, such as heterocycles, which have successfully been obtained from chalcone precursors in the past. This review aims to summarise the emerging therapeutic importance of adenosine receptors and their ligands, especially in the central nervous system (CNS), while highlighting chalcone and heterocyclic derivatives as promising AR ligand lead compounds.

Synthesis and adenosine receptors binding affinities of a series of 3-arylcoumarins

OBJECTIVES

In the present communication, we report the synthesis, pharmacological evaluation, theoretical evaluation of absorption, distribution, metabolism and excretion properties and structure-activity relationship study of a selected series of 3-arylcoumarins (compounds 1-9). Adenosine receptors (ARs) binding activity and selectivity of the synthesized compounds 1-9 were evaluated in this study. Different substituents were introduced in both benzene rings of the evaluated scaffold, at positions 6 and 3' or 4' of the moiety. The lack of data on the 3-arylcoumarin scaffold encouraged us to explore the ARs' binding activity of a selected series of derivatives.

METHODS

A new series of coumarins (compounds 1-9) were synthesized and evaluated by radioligand binding studies towards ARs.

KEY FINDINGS

Analysing the experimental data, it can be observed that neither the simple 3-arylcoumarin nor the 4'-nitro derivatives presented detectable binding affinity for the evaluated receptors, although most of the other substituted derivatives have good binding affinity profiles, especially against the hA1 /hA3 or only hA3 AR.

CONCLUSIONS

The most remarkable derivative is compound 2, presenting the best affinity for hA3 AR (Ki  = 2680 nM) and significant selectivity for this subtype.