Background: Adenosine is a purine, with an adenine group and a ribose sugar, formed
endogenously by ATP catabolism both intracellularly and extracellularly. Among the medicinal features
of adenosine and its receptors (A1, A2A, A2B and A3), anticancer activity has been an intense field
of research. The anticancer potential of adenosine receptor ligands has been brought to the forefront of
research and evidenced in innumerous research articles and patents.
Objective: The present review focuses on the patent literature from 2002 onwards (2002-May 2017).
Methods: Patents were searched and downloaded from the open access patent data bases and are available
Results: A significant number of patents (65) have been published on adenosine receptor ligands
claiming anticancer activity, or presenting new methods of preparation or treatment thereof, from
2002-2017 (May). From these, 35 were published highlighting the promising attributes of compounds/
methods to fight cancer. Most of the compounds act as adenosine A3 receptor agonists, while
others act as antagonists for the other adenosine receptor subtypes. The signaling events triggered by
activation of adenosine A3 receptor or by blockade of adenosine A1, A2A and A2B receptors can reverse
an environment from being pro-cancer to an anti-cancer in the body.
Conclusion: The promising anticancer effects mediated by adenosine receptor ligands put them in the
forefront as new drug candidates. The present compilation can be worthy to medicinal chemists, pharmacologists,
biochemists and other researchers focusing on the putative anticancer activity of adenosine