22106
The corresponding 2 ' - deoxy - 2 ' , 2 ' - difluororibonucleoside 5 ' - O - triphosphates were found to be good substrates for bacterial DNA polymerases , but are inhibitors of human polymerase alpha .
 Chemical: 2 ' - deoxy - 2 ' , 2 ' - difluororibonucleoside 5 ' - O - triphosphates
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: 2 ' - deoxy - 2 ' , 2 ' - difluororibonucleoside 5 ' - O - triphosphates