6416
Interest is increasing in developing fluorescent ligands for characterization of adenosine receptors ( ARs ) , which hold a promise of usefulness in the drug discovery process .
 Chemical: adenosine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: adenosine