15637
Whereas the parent nucleosides were devoid of antiviral activity in two different cellular assays , the 5 ' - O - naphthyl ( methoxy - L - alaninyl ) ProTide derivatives of 6 - O - methyl - 2 ' - fluoro - 2 ' - deoxyguanosine , 6 - O - ethyl - 2 ' - fluoro - 2 ' - deoxyguanosine , and 2 ' - deoxy - 2 ' - fluoro - 6 - chloroguanosine , and the 5 ' - O - naphthyl ( ethoxy - L - alaninyl ) ProTide of 6 - O - ethyl - 2 ' - fluoro - 2 ' - deoxyguanosine displayed antiviral EC ( 99 ) values of ~ 12 mu M .
 nucleosides, 5 ' - O - naphthyl ( methoxy - L - alaninyl ), 6 - O - methyl - 2 ' - fluoro - 2 ' - deoxyguanosine, 6 - O - ethyl - 2 ' - fluoro - 2 ' - deoxyguanosine, 2 ' - deoxy - 2 ' - fluoro - 6 - chloroguanosine, 5 ' - O - naphthyl ( ethoxy - L - alaninyl ), 6 - O - ethyl - 2 ' - fluoro - 2 ' - deoxyguanosine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 nucleosides, 5 ' - O - naphthyl ( methoxy - L - alaninyl ), 6 - O - methyl - 2 ' - fluoro - 2 ' - deoxyguanosine, 6 - O - ethyl - 2 ' - fluoro - 2 ' - deoxyguanosine, 2 ' - deoxy - 2 ' - fluoro - 6 - chloroguanosine, 5 ' - O - naphthyl ( ethoxy - L - alaninyl ), 6 - O - ethyl - 2 ' - fluoro - 2 ' - deoxyguanosine