15634
Synthesis and biological evaluation of purine 2 ' - fluoro - 2 ' - deoxyriboside ProTides as anti - influenza virus agents .
 purine 2 ' - fluoro - 2 ' - deoxyriboside
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 purine 2 ' - fluoro - 2 ' - deoxyriboside