8362
As a result , novel ligands exhibiting excellent potency ( K ( i ) on A ( 3 ) AR < 20 nM ) and selectivity profiles ( above 100 - fold within the adenosine receptors family ) are reported .
 adenosine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 adenosine